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Publication
Journal: Endocrinology
April/28/2015
Abstract
In this study, we evaluated the role of <em>WNT</em>16 in regulating bone size, an important determinant of bone strength. Mice with targeted disruption of the Wnt16 gene exhibited a 24% reduction in tibia cross-sectional area at <em>12</em> weeks of age compared with that of littermate wild-type (WT) mice. Histomorphometric studies revealed that the periosteal bone formation rate and mineral apposition rate were reduced (P < .05) by 55% and 32%, respectively, in Wnt16 knockout (KO) vs WT mice at <em>12</em> weeks of age. In contrast, the periosteal tartrate resistant acid phosphatase-labeled surface was increased by 20% in the KO mice. Because mechanical strain is an important physiological regulator of periosteal bone formation (BF), we determined whether mechanical loading-induced periosteal BF is compromised in Wnt16 KO mice. Application of 4800-μe strain to the right tibia using a 4-point bending loading method for 2 weeks (2-Hz frequency, 36 cycles per day, 6 days/wk) produced a significant increase in cross-sectional area (11% above that of the unloaded left tibia, P < .05, n = 6) in the WT but not in the KO mice (-0.2% change). Histomorphometric analyses revealed increases in the periosteal bone formation rate and mineral apposition rate in the loaded bones of WT but not KO mice. Wnt16 KO mice showed significant (20%-70%) reductions in the expression levels of markers of canonical (β-catenin and Axin2) but not noncanonical (Nfatc1 and Tnnt2) <em>WNT</em> signaling in the periosteum at 5 weeks of age. Our findings suggest that <em>WNT</em>16 acting via canonical <em>WNT</em> signaling regulates mechanical strain-induced periosteal BF and bone size.
Publication
Journal: Clinical Cancer Research
December/17/2014
Abstract
OBJECTIVE
To determine the pharmacokinetics (PK), maximum tolerated dose (MTD), safety, and antitumor activity of an oral formulation of rigosertib, a dual phosphoinositide 3-kinase (PI3K) and polo-like kinase 1 (Plk1) pathway inhibitor, in patients with advanced solid malignancies.
METHODS
Patients with advanced solid malignancies received rigosertib twice daily continuously in 21-day cycles. Doses were escalated until intolerable grade ≥2 toxicities, at which point the previous dose level was expanded to define the MTD. All patients were assessed for safety, PK, and response. Urinary PK were performed at the MTD. Archival tumors were assessed for potential molecular biomarkers with multiplex mutation testing. A subset of squamous cell carcinomas (SCC) underwent exome sequencing.
RESULTS
Forty-eight patients received a median of 2 cycles of therapy at 5 dose levels. Rigosertib exposure increased with escalating doses. Dose-limiting toxicities were hematuria and dysuria. The most common grade ≥2 drug-related toxicities involved urothelial irritation. The MTD is 560 mg twice daily. Activity was seen in head and neck SCCs (1 complete response, 1 partial response) and stable disease for ≥<em>12</em> weeks was observed in 8 additional patients. Tumors experiencing ≥partial response had PI3K pathway activation, inactivated p53, and unique variants in ROBO3 and FAT1, two genes interacting with the <em>Wnt</em>/β-catenin pathway.
CONCLUSIONS
The recommended phase II dose of oral rigosertib is 560 mg twice daily given continuously. Urinary toxicity is the dose-limiting and most common toxicity. Alterations in PI3K, p53, and Wnt/β-catenin pathway signaling should be investigated as potential biomarkers of response in future trials.
Publication
Journal: Calcified Tissue International
June/2/2010
Abstract
Glucocorticoids exert both anabolic and catabolic effects on bone. Previously, we reported that endogenous glucocorticoids control mesenchymal lineage commitment and osteoblastogenesis through regulation of Wnt signaling in osteoblasts. Here, we investigated the effects of glucocorticoids on Wnt expression in mature osteoblasts. Mature osteoblasts and their immature progenitors were separately isolated from Col2.3-GFP transgenic mice in which mature osteoblasts are identifiable through GFP expression. mRNA levels of WntWntWntWntWntWnt-fold higher in osteoblasts compared to their progenitors (P < 0.05). Expression of WntWntWnt inhibitors sFRP-1 and DKK-1 two- to threefold (P < 0.05). We conclude that the contrasting anabolic and catabolic effects of glucocorticoids on bone are, at least in part, mediated through the regulation of Wnt expression and its inhibitors in mature osteoblasts.
Publication
Journal: Molecular Cancer Research
October/5/2017
Abstract
The microphthalmia family (MITF, TFEB, TFE3, and TFEC) of transcription factors is emerging as global regulators of cancer cell survival and energy metabolism, both through the promotion of lysosomal genes as well as newly characterized targets, such as oxidative metabolism and the oxidative stress response. In addition, MiT/TFE factors can regulate lysosomal signaling, which includes the mTORC1 and <em>Wnt</em>/β-catenin pathways, which are both substantial contributors to oncogenic signaling. This review describes recent discoveries in MiT/TFE research and how they impact multiple cancer subtypes. Furthermore, the literature relating to TFE-fusion proteins in cancers and the potential mechanisms through which these genomic rearrangements promote tumorigenesis is reviewed. Likewise, the emerging function of the Folliculin (FLCN) tumor suppressor in negatively regulating the MiT/TFE family and how loss of this pathway promotes cancer is examined. Recent reports are also presented that relate to the role of MiT/TFE-driven lysosomal biogenesis in sustaining cancer cell metabolism and signaling in nutrient-limiting conditions. Finally, a discussion is provided on the future directions and unanswered questions in the field. In summary, the research surrounding the MiT/TFE family indicates that these transcription factors are promising therapeutic targets and biomarkers for cancers that thrive in stressful niches. Mol Cancer Res; 15(<em>12</em>); 1637-43. ©2017 AACR.
Publication
Journal: Journal of the American Society of Nephrology : JASN
September/22/2010
Abstract
Significant variation in the course of autosomal dominant polycystic kidney disease ( ADPKD) within families suggests the presence of effect modifiers. Recent studies of the variation within families harboring PKD1 mutations indicate that genetic background may account for 32 to 42% of the variance in estimated GFR (eGFR) before ESRD and 43 to 78% of the variance in age at ESRD onset, but the genetic modifiers are unknown. Here, we conducted a high-throughput single-nucleotide polymorphism (SNP) genotyping association study of 173 biological candidate genes in 794 white patients from 227 families with PKD1. We analyzed two primary outcomes: (1) eGFR and (2) time to ESRD (renal survival). For both outcomes, we used multidimensional scaling to correct for population structure and generalized estimating equations to account for the relatedness among individuals within the same family. We found suggestive associations between each of <em>12</em> SNPs and at least one of the renal outcomes. We genotyped these SNPs in a second set of 472 white patients from 229 families with PKD1 and performed a joint analysis on both cohorts. Three SNPs continued to show suggestive/significant association with eGFR at the Dickkopf 3 (DKK3) gene locus; no SNPs significantly associated with renal survival. DKK3 antagonizes <em>Wnt</em>/beta-catenin signaling, which may modulate renal cyst growth. Pending replication, our study suggests that genetic variation of DKK3 may modify severity of ADPKD resulting from PKD1 mutations.
Publication
Journal: Human Pathology
February/23/2006
Abstract
Abrogation of the <em>Wnt</em>-signaling pathway is implicated in the carcinogenesis of several malignancies, especially colorectal cancer where up to 90% of cases are thought to have impaired <em>Wnt</em> signaling. It is less frequently involved in conventional ductal pancreatic adenocarcinoma. This pathway has not been explored in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas previously and formed the basis of this study. A tissue microarray of 18 cases of IPMN was stained for proteins involved in the <em>Wnt</em> pathway: adenomatous polyposis coli (APC), pan-beta-catenin, axin 2, glycogen synthase 3alphabeta and 3beta, c-myc, E-cadherin, and cyclin D1. The IPMNs were classified as 8 adenomas, 3 borderline, and 7 cases with carcinoma in situ and/or invasive carcinoma, occurring in 13 females, and the overall age range was 45 to 73 years. Immunohistochemical analysis showed nuclear beta-catenin staining in 7 (39%) of the 18 cases. The cases with nuclear beta-catenin localization included 1 adenoma, 2 borderline IPMN, and 4 carcinomas in situ and/or invasive carcinomas. Seven cases showed absence of APC immunostaining and these included 4 cases with nuclear beta-catenin localization. Fourteen cases displayed marked diffuse up-regulation of c-myc protein, and <em>12</em> cases also showed diffuse cyclin D1 protein overexpression. E-cadherin expression was intense and membrane in location (comparable to normal tissue) in 6 of 8 adenomas (no tissue was available in 1 case). Decreased E-cadherin staining was noted in 8 cases where tissue was available for assessment. There was progressive decrease in membrane staining of E-cadherin in 2 of 3 borderline lesions, 1 of 2 carcinomas in situ, and 4 of 5 invasive carcinomas. All other immunostains were either normal in distribution or did not show any correlation with beta-catenin or clinicopathologic parameters. In conclusion, 7 (39%) of 18 cases of IPMN in this study demonstrated abnormal localization of beta-catenin, 4 of which also lacked APC expression. Of 5 carcinomas arising in IPMN, 4 displayed a decrease in E-cadherin expression. There was also a trend for the higher grades of IPMN to show nuclear localization of beta-catenin. These findings suggest that a proportion of cases of IPMN may show abnormalities in the <em>Wnt</em>-signaling pathway with consequent altered expression of downstream related proteins.
Publication
Journal: International Journal of Oncology
March/23/2003
Abstract
Expression of some members of the trefoil factor (TFF) and the <em>WNT</em> gene families is regulated together by estrogen. We have cloned and characterized human <em>WNT</em> signaling molecules using bioinformatics, cDNA-library screening and cDNA-PCR to investigate expression profile of <em>WNT</em> signaling molecules in human gastric cancer. Here, we investigated expression profile of TFF1/pS2, TFF2/SP and TFF3/ITF in human gastric cancer. Among 7 gastric cancer cell lines, TFF1 was expressed in OKAJIMA, TMK1, MKN45, and KATO-III, TFF2 in KATO-III, and TFF3 in MKN45 and KATO-III. TFFs were preferentially expressed in diffuse-type gastric cancer cell lines. Expression of TFFs in primary gastric cancer was next investigated. TFF1 was down-regulated in 7 cases out of <em>12</em> cases (58.3%) of primary gastric cancer. TFF2 was down-regulated in 10 out of <em>12</em> cases (83.3%) of primary gastric cancer. TFF3 was down-regulated in 2 out of <em>12</em> cases (16.7%) of primary gastric cancer, and was up-regulated in 5 out of <em>12</em> cases (41.7%). TFF1 and TFF2 were frequently down-regulated in primary gastric cancer, while TFF3 was up-regulated in some cases of primary gastric cancer. This is the first report on comprehensive expression analyses on TFFs in gastric cancer.
Publication
Journal: Endocrine Pathology
November/7/2017
Abstract
B -Catenin is closely associated with carcinoma invasion/metastasis and poor survival. Recent studies have demonstrated that abnormal expression of B -catenin, especially its nuclear accumulation, also plays an important role in wingless/<em>Wnt</em> signaling pathway. In this study, we evaluated immunohistochemically the nuclear localization of B -catenin in a total of 93 human-endocrine-related tumors including 1 medullary carcinoma (thyroid gland), <em>12</em> parathyroid tumors, 22 carcinoid tumors (digestive tract and liver), 7 islet cell tumors, 26 adrenocortical tumors, 13 neuroblastoma (adrenal gland), and <em>12</em> pheochromocytoma (adrenal gland), and also studied genetic alterations of the B -catenin gene. Nuclear accumulation of B -catenin was frequently detected in 8 of 22 (36%) carcinoid tumors and 2 of 7 (29%) islet cell tumors. No genetic alteration in exon 3 of the B -catenin gene encoding serine/threonine rich domain, which was phosphorylated by GSK-3 B, was detected in any groups of the endocrine tumors. However, nuclear accumulation of B -catenin in carcinoid tumors was significantly correlated with the proliferative marker Ki-67 (MIB-1) labeling index (p <0.001). Our findings suggest that nuclear transfer and accumulation of the B -catenin may contribute in the tumorigenesis of carcinoid tumor as an oncoprotein.
Publication
Journal: PLoS Genetics
February/20/2013
Abstract
Ileal Crohn's Disease (CD), a chronic small intestinal inflammatory disorder, is characterized by reduced levels of the antimicrobial peptides DEFA5 (HD-5) and DEFA6 (HD-6). Both of these α-defensins are exclusively produced in Paneth cells (PCs) at small intestinal crypt bases. Different ileal CD-associated genes including NOD2, ATG16L1, and recently the β-catenin-dependant <em>Wnt</em> transcription factor TCF7L2 have been linked to impaired PC antimicrobial function. The <em>Wnt</em> pathway influences gut mucosal homeostasis and PC maturation, besides directly controlling HD-5/6 gene expression. The herein reported candidate gene study focuses on another crucial <em>Wnt</em> factor, the co-receptor low density lipoprotein receptor-related protein 6 (LRP6). We analysed exonic single nucleotide polymorphisms (SNPs) in a large cohort (Oxford: n = 1,893) and prospectively tested 2 additional European sample sets (Leuven: n = 688, Vienna: n = 1,628). We revealed an association of a non-synonymous SNP (rs2302685; Ile1062Val) with early onset ileal CD (OR 1.8; p = 0.00034; for homozygous carriers: OR 4.1; p = 0.00004) and additionally with penetrating ileal CD behaviour (OR 1.3; p = 0.00917). In contrast, it was not linked to adult onset ileal CD, colonic CD, or ulcerative colitis. Since the rare variant is known to impair LRP6 activity, we investigated its role in patient mucosa. Overall, LRP6 mRNA was diminished in patients independently from the genotype. Analysing the mRNA levels of PC product in biopsies from genotyped individuals (15 controls, 32 ileal, and <em>12</em> exclusively colonic CD), we found particularly low defensin levels in ileal CD patients who were carrying the variant. In addition, we confirmed a direct relationship between LRP6 activity and the transcriptional expression of HD-5 using transient transfection. Taken together, we identified LRP6 as a new candidate gene in ileal CD. Impairments in <em>Wnt</em> signalling and Paneth cell biology seem to represent pathophysiological hallmarks in small intestinal inflammation and should therefore be considered as interesting targets for new therapeutic approaches.
Publication
Journal: Journal of Nutritional Biochemistry
February/16/2010
Abstract
Conjugated linoleic acid (CLA) describes a group of isomers of linoleic acid and has variable effects on bone formation and adiposity in vivo and in vitro. The variability may be due to individual effects of the predominant bioactive 9cis,11trans (9,11) and 10trans,<em>12</em>cis (10,<em>12</em>) CLA isomers. Osteoblasts and adipocytes are derived from mesenchymal stem cells (MSCs), and bone loss is accompanied by an increase in marrow adiposity. Osteoblast differentiation from MSCs requires activation of <em>Wnt</em>/beta-catenin signaling by <em>Wnt</em>10b, which inhibits adipocyte differentiation by suppressing CCAAT/enhancer-binding protein (C/EBP) alpha. The objective of this study was to determine if 9,11 and 10,<em>12</em> CLA affect osteoblast and adipocyte differentiation from MSCs and to determine whether any effects are associated with changes in <em>Wnt</em>10b and C/EBPalpha expression. Osteoblast differentiation was assessed by calcium deposition, alkaline phosphatase (ALP) activity, and the expression of <em>Wnt</em>10b, runx2 and osteocalcin. Adipocyte differentiation was assessed by oil red O staining and C/EBPalpha, PPARgamma and FABP4 expression. Compared to vehicle, 9,11 CLA decreased calcium deposition ( approximately 15%), increased oil red O staining ( approximately 21-28%) and increased FABP4 (AP2) expression ( approximately 58-75%). In contrast, 10,<em>12</em> CLA increased calcium deposition ( approximately <em>12</em>-60%), ALP activity ( approximately 2.1-fold) and the expression of <em>Wnt</em>10b ( approximately 60-80%) and osteocalcin ( approximately 90%), but decreased oil red O staining ( approximately 30%) and the expression of C/EBPalpha ( approximately 24-38%) and PPARgamma ( approximately 60%) (P<.05). Thus, our findings demonstrate isomer-specific effects of CLA on MSC differentiation, and suggest that 10,<em>12</em> CLA may be a useful therapeutic agent to promote osteoblast differentiation from MSCs.
Publication
Journal: Genome Biology
December/13/2006
Abstract
BACKGROUND
In human breast cancer normal mammary cells typically develop into hyperplasia, ductal carcinoma in situ, invasive cancer, and metastasis. The changes in gene expression associated with this stepwise progression are unclear. Mice transgenic for mouse mammary tumor virus (MMTV)-Wnt-1 exhibit discrete steps of mammary tumorigenesis, including hyperplasia, invasive ductal carcinoma, and distant metastasis. These mice might therefore be useful models for discovering changes in gene expression during cancer development.
RESULTS
We used cDNA microarrays to determine the expression profiles of five normal mammary glands, seven hyperplastic mammary glands and 23 mammary tumors from MMTV-Wnt-1 transgenic mice, and 12 mammary tumors from MMTV-Neu transgenic mice. Adipose tissues were used to control for fat cells in the vicinity of the mammary glands. In these analyses, we found that the progression of normal virgin mammary glands to hyperplastic tissues and to mammary tumors is accompanied by differences in the expression of several hundred genes at each step. Some of these differences appear to be unique to the effects of Wnt signaling; others seem to be common to tumors induced by both Neu and Wnt-1 oncogenes.
CONCLUSIONS
We described gene-expression patterns associated with breast-cancer development in mice, and identified genes that may be significant targets for oncogenic events. The expression data developed provide a resource for illuminating the molecular mechanisms involved in breast cancer development, especially through the identification of genes that are critical in cancer initiation and progression.
Publication
Journal: Cellular oncology : the official journal of the International Society for Cellular Oncology
September/7/2010
Abstract
OBJECTIVE
The Wnt-pathway dominates the sporadic carcinogenesis whereas p53 plays a pivotal role in the colitis-associated counterpart. The expression of Wnt-signaling proteins and p53 during colitis-associated carcinogenesis was determined.
METHODS
A tissue microarray was constructed with colonic samples from 5 groups of patients: controls (C, n=10), IBD without neoplasia (IBD, n=12), non-dysplastic IBD with neoplasia elsewhere in the colon (IBD-NE, n=12), dysplastic lesion in IBD (IBD-DYS, n=12), and IBD-associated colorectal cancer (IBD-CRC, n=10). Immunohistochemistry was performed for beta-catenin, cyclin D1 and p53. p53 sequence analysis was performed in some cases.
RESULTS
Nuclear beta-catenin expression was found in 0%, 0%, 50%, 55% and 100% of the patients in the C-, IBD-, IBD-NE-, IBD-DYS- and IBD-CRC-groups, respectively. Non-dysplastic IBD mucosa with neoplasia detected elsewhere showed nuclear expression in 50% of the cases compared to 0% in IBD mucosa without neoplasia (p=0.02). Cyclin D1 staining had similar expression patterns. Overexpression of p53 was only detected in the IBD-DYS (66.7%) and IBD-CRC groups (50%).
CONCLUSIONS
In contrast to previous findings, our results suggest activation of the Wnt-pathway in the early phase of colitis-associated carcinogenesis. Furthermore, as Wnt activation was observed in 50% of the IBD-NE cases, nuclear beta-catenin may facilitate detection of neoplasia.
Publication
Journal: Journal of Biological Chemistry
March/24/2012
Abstract
Of the 1,328 genes revealed by microarray to be differentially regulated by disuse, or at 8 h following a single short period of osteogenic loading of the mouse tibia, analysis by predicting associated transcription factors from annotated affinities revealed the transcription factor EGR2/Krox-20 as being more closely associated with more pathways and functions than any other. Real time quantitative PCR confirmed up-regulation of Egr2 mRNA expression by loading of the tibia in vivo. In vitro studies where strain was applied to primary cultures of mouse tibia-derived osteoblastic cells and the osteoblast UMR106 cell line also showed up-regulation of Egr2 mRNA expression. In UMR106 cells, inhibition of β1/β3 integrin function had no effect on strain-related Egr2 expression, but it was inhibited by a COX2-selective antagonist and imitated by exogenous prostaglandin E2 (PGE2). This response to PGE(2) was mediated chiefly through the EP1 receptor and involved stimulation of PKC and attenuation by cAMP/PKA. Neither activators nor inhibitors of nitric oxide, estrogen signaling, or LiCl had any effect on Egr2 mRNA expression, but it was increased by both insulin-like growth factor-1 and high, but not low, dose parathyroid hormone and exogenous <em>Wnt</em>-3a. The increases by strain, PGE2, <em>Wnt</em>-3a, and phorbol <em>12</em>-myristate 13-acetate were attenuated by inhibition of MEK-1. EGR2 appears to be involved in many of the signaling pathways that constitute early responses of bone cells to strain. These pathways all have multiple functions. Converting their strain-related responses into coherent "instructions" for adaptive (re)modeling is likely to depend upon their contextual activation, suppression, and interaction probably on more than one occasion.
Publication
Journal: Cellular and Molecular Neurobiology
July/7/2014
Abstract
Two kinds of dental stem cells (DSCs), dental pulp stem cells (DPSCs) and stem cells from human-exfoliated deciduous teeth (SHED), have been identified as novel populations of mesenchymal stem cells that can be induced to differentiate into osteoblasts, chondrocytes, adipocytes, and neuron-like cells in vitro. As we know, both of them originate from the neural crest, but have distinct characteristics and functions in vitro and in vivo. The regeneration potential of DSCs declines with advanced age; however, the mechanism of the impaired potential in DSCs has not been fully explored. In this study, we investigated whether declined neurogenic differentiation capacity is associated with an altered expression of <em>Wnt</em> signaling-related proteins in vitro. We compared stem cells isolated from human dental pulp in two age groups: the exfoliated deciduous teeth (5-<em>12</em> years), and the third permanent teeth (45-50 years). We found that the expression levels of neuron markers, such as βIII-tubulin, microtubule-associated protein 2(MAP2), tyrosine hydroxylase (TH), and Nestin were lower in the DPSCs group compared with that in the SHED group; however, in supplementation with human recombinant <em>Wnt</em>1 in the medium, the DPSCs were prone to neural differentiation and expressed higher levels of neurogenic markers. In summary, our study demonstrated that <em>Wnt</em>/β-catenin signaling may play a vital role in the age-dependent neural differentiation of DSCs. Therefore, DSCs may provide an ideal source of stem cells that can further extend their therapeutic application in nerve injury and neurodegenerative diseases.
Publication
Journal: Nature Communications
April/4/2016
Abstract
Here we report that mice deficient for the proteasome activator, REGγ, exhibit a marked resistance to TPA (<em>12</em>-O-tetradecanoyl-phorbol-13-acetate)-induced keratinocyte proliferation, epidermal hyperplasia and onset of papillomas compared with wild-type counterparts. Interestingly, a massive increase of REGγ in skin tissues or cells resulting from TPA induces activation of p38 mitogen-activated protein kinase (MAPK/p38). Blocking p38 MAPK activation prevents REGγ elevation in HaCaT cells with TPA treatment. AP-1, the downstream effector of MAPK/p38, directly binds to the REGγ promoter and activates its transcription in response to TPA stimulation. Furthermore, we find that REGγ activates <em>Wnt</em>/β-catenin signalling by degrading GSK-3β in vitro and in cells, increasing levels of CyclinD1 and c-Myc, the downstream targets of β-catenin. Conversely, MAPK/p38 inactivation or REGγ deletion prevents the increase of cyclinD1 and c-Myc by TPA. This study demonstrates that REGγ acts in skin tumorigenesis mediating MAPK/p38 activation of the <em>Wnt</em>/β-catenin pathway.
Publication
Journal: Aging
October/24/2016
Abstract
Aging is a multifactorial process associated with an increased susceptibility to neurodegenerative disorders which can be related to chronic inflammation. Chronic inflammation, however, can be characterized by the persistent elevated glucocorticoid (GCs) levels, activation of the proinflammatory transcription factor NF-кB, as well as an increase in cytokines. Interestingly, both NF-кB and cytokines can be even modulated by Glycogen Synthase Kinase 3 beta (GSK-3β) activity, which is a key protein that can intermediate inflammation and metabolism, once it has a critical role in AKT signaling pathway, and can also intermediate <em>WNT</em>/β-CATENIN signaling pathway. The aim of this study was to verify age-related changes in inflammatory status, as well as in the AKT and <em>WNT</em> signaling pathways. Results showed an age-related increase in neuroinflammation as indicated by NF-кB activation, TNF-α and GCs increased levels, a decrease in AKT activation and an increase in GSK-3β activity in both <em>12</em>- and 24- month old animals. Aging also seems to induce a progressive decrease in canonical <em>WNT</em>/β-CATENIN signaling pathway once there is a decrease in DVL-2 levels and in the transcription of Axin2 gene. Little is known about the DVL-2 regulation as well as its roles in <em>WNT</em> signaling pathway, but for the first time it was suggested that DVL-2 expression can be changed along aging.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
June/21/2017
Abstract
Osteoarthritis (OA) is a major cause of disability and morbidity in the aging population. Joint injury leads to cartilage damage, a known determinant for subsequent development of posttraumatic OA, which accounts for <em>12</em>% of all OA. Understanding the early molecular and cellular responses postinjury may provide targets for therapeutic interventions that limit articular degeneration. Using a murine model of controlled knee joint impact injury that allows the examination of cartilage responses to injury at specific time points, we show that intraarticular delivery of a peptidic nanoparticle complexed to NF-κB siRNA significantly reduces early chondrocyte apoptosis and reactive synovitis. Our data suggest that NF-κB siRNA nanotherapy maintains cartilage homeostasis by enhancing AMPK signaling while suppressing mTORC1 and <em>Wnt</em>/β-catenin activity. These findings delineate an extensive crosstalk between NF-κB and signaling pathways that govern cartilage responses postinjury and suggest that delivery of NF-κB siRNA nanotherapy to attenuate early inflammation may limit the chronic consequences of joint injury. Therapeutic benefits of siRNA nanotherapy may also apply to primary OA in which NF-κB activation mediates chondrocyte catabolic responses. Additionally, a critical barrier to the successful development of OA treatment includes ineffective delivery of therapeutic agents to the resident chondrocytes in the avascular cartilage. Here, we show that the peptide-siRNA nanocomplexes are nonimmunogenic, are freely and deeply penetrant to human OA cartilage, and persist in chondrocyte lacunae for at least 2 wk. The peptide-siRNA platform thus provides a clinically relevant and promising approach to overcoming the obstacles of drug delivery to the highly inaccessible chondrocytes.
Publication
Journal: Critical Reviews in Food Science and Nutrition
January/11/2019
Abstract
Curcumin is a naturally occurring polyphenolic compound present in rhizome of Curcuma longa belonging to the family zingiberaceae. Growing experimental evidence revealed that curcumin exhibit multitarget biological implications signifying its crucial role in health and disease. The current review highlights the recent progress and mechanisms underlying the wide range of pharmacological effects of curcumin against numerous diseases like neuronal, cardiovascular, metabolic, kidney, endocrine, skin, respiratory, infectious, gastrointestinal diseases and cancer. The ability of curcumin to modulate the functions of multiple signal transductions are linked with attenuation of acute and chronic diseases. Numerous preclinical and clinical studies have revealed that curcumin modulates several molecules in cell signal transduction pathway including PI3K, Akt, mTOR, ERK5, AP-1, TGF-β, <em>Wnt</em>, β-catenin, Shh, PAK1, Rac1, STAT3, PPARγ, EBPα, NLRP3 inflammasome, p38MAPK, Nrf2, Notch-1, AMPK, TLR-4 and MyD-88. Curcumin has a potential to prevent and/or manage various diseases due to its anti-inflammatory, anti-oxidant and anti-apoptotic properties with an excellent safety profile. In contrast, the anti-cancer effects of curcumin are reflected due to induction of growth arrest and apoptosis in various premalignant and malignant cells. This review also carefully emphasized the pharmacokinetics of curcumin and its interaction with other drugs. Clinical studies have shown that curcumin is safe at the doses of <em>12</em> g/day but exhibits poor systemic bioavailability. The use of adjuvant like piperine, liposomal curcumin, curcumin nanoparticles and curcumin phospholipid complex has shown enhanced bioavailability and therapeutic potential. Further studies are warranted to prove the potential of curcumin against various ailments.
Publication
Journal: Cancer Science
June/18/2008
Abstract
The Drosophila Notum gene, which is regulated by the Wingless pathway, encodes a secreted hydrolase that modifies heparan sulfate proteoglycans. In comparative analysis of the gene expression profiles in primary human hepatocellular carcinomas (HCC) and normal organs, we observed that the human ortholog of Drosophila Notum was overexpressed markedly in a subset of HCC, but expressed rarely in adult normal tissues. Immunoblotting confirmed the overexpression of NOTUM protein in <em>12</em> of 40 primary HCC cases (30%). High levels of NOTUM protein were significantly associated with intracellular (nuclear or cytoplasmic) accumulation of beta-catenin protein: all 10 HCC with high intracellular beta-catenin also had high NOTUM expression, whereas only 2 of 30 cases (6.7%) without intracellular beta-catenin had high NOTUM expression (P < 0.00001). NOTUM expression in HepG2 cells was downregulated significantly by induction of a dominant-negative mutant of TCF4, a beta-catenin partner. In vivo binding of the beta-catenin/TCF complex to the NOTUM promoter was demonstrated by chromatin immunoprecipitation in HepG2 and SW480 cells, where canonical <em>Wnt</em> signaling is activated constitutively. These findings provide evidence that NOTUM is a novel target of beta-catenin/TCF4 and is upregulated in <em>Wnt</em>/beta-catenin signaling-activated HCC.
Publication
Journal: Human Mutation
July/29/2009
Abstract
The X-linked dominant trait focal dermal hypoplasia (FDH, Goltz syndrome) is a developmental defect with focal distribution of affected tissues due to a block of <em>Wnt</em> signal transmission from cells carrying a detrimental PORCN mutation on an active X-chromosome. Molecular characterization of 24 unrelated patients from different ethnic backgrounds revealed 23 different mutations of the PORCN gene in Xp11.23. Three were microdeletions eliminating PORCN and encompassing neighboring genes such as EBP, the gene associated with Conradi-Hünermann-Happle syndrome (CDPX2). <em>12</em>/24 patients carried nonsense mutations resulting in loss of function. In one case a canonical splice acceptor site was mutated, and 8 missense mutations exchanged highly conserved amino acids. FDH patients overcome the consequences of potentially lethal X-chromosomal mutations by extreme skewing of X-chromosome inactivation in females, enabling transmission of the trait in families, or by postzygotic mosaicism both in male and female individuals. Molecular characterization of the PORCN mutations in cases diagnosed as Goltz syndrome is particularly relevant for genetic counseling of patients and their families since no functional diagnostic test is available and carriers of the mutation might otherwise be overlooked due to considerable phenotypic variability associated with the mosaic status.
Publication
Journal: Biomedicines
April/10/2019
Abstract
Platelet rich plasma (PRP) and Micrografts containing human follicle mesenchymal stem cells (HF-MSCs) were tried as a potential treatment for androgenetic alopecia (AGA). However, little to no work has yet to be seen wherein the bio-molecular pathway of HF-MSCs or PRP treatments were analyzed. The aims of this work are to report the clinical effectiveness of HF-MSCs and platelet-rich plasma evaluating and reviewing the most updated information related to the bio-molecular pathway. Twenty-one patients were treated with HF-MSCs injections and 57 patients were treated with A-PRP. The <em>Wnt</em> pathway and Platelet derived-growth factors effects were analyzed. 23 weeks after the last treatment with mean hair thickness increments (29 ± 5.0%) over baseline values for the targeted area. <em>12</em> weeks after the last injection with A-PRP mean hair count and hair density (31 ± 2%) increases significantly over baseline values. The increment of <em>Wnt</em> signaling in Dermal Papilla Cells evidently is one of the principal factors that enhances hair growth. Signaling from mesenchymal stem cells and platelet derived growth factors positively influences hair growth through cellular proliferation to prolong the anagen phase (FGF-7), inducing cell growth (ERK activation), stimulating hair follicle development (β-catenin), and suppressing apoptotic cues (Bcl-2 release and Akt activation).
Publication
Journal: Cancer Letters
October/14/2019
Abstract
Colorectal cancer (CRC) is among the top 3 leading causes of cancer-related deaths, and tumor malignant progression and metastases contribute to the high mortality of advanced CRC. Immune components in the tumor microenvironment can modulate tumor progression and are attractive therapeutic targets. Recently, intra-tumor mutational diversification of colorectal cancer cells at the single cell level was conducted. However, single cell transcriptome analysis of the microenvironment composition and characteristics in CRC liver metastases has yet to be performed. In this study, samples of liver metastasis cancer tissue and adjacent tissue from CRC patients were examined by single cell RNA sequencing. A total of <em>12</em> clusters corresponding to 6 cell types, including cancer cells, T cells, myeloid cells, endothelial cells, fibroblasts and B cells, were identified. Expression clustering of 445 cell cluster deregulated genes (CCDGs) identified 6 gene modules and functional enrichment was conducted to analyse the pathways in cancer cell and T cell populations. Next, the clinical significance of the expression of 93 cell cluster specifically deregulated genes (CCSDGs) in tumor-infiltrating immune cells and the correlation of the expression of these genes with patients' survival rates were investigated with the TCGA dataset. Then, the mechanisms for increased proportion of granulocytes in the cancer sample were explored, and abnormal ferroptosis-mediated granulocyte cell death was proposed. Finally, the <em>Wnt</em> signalling pathway was found to be activated and promote granulocytes migration. This single cell RNA sequencing study may shed light on the tumor microenvironment composition and pave the way for CRC liver metastasis therapy.
Publication
Journal: Clinical Reviews in Allergy and Immunology
August/27/2015
Abstract
Our aim was to compare bone gene expression in rheumatoid arthritis (RA) and primary osteoporosis (OP) patients. Secondary aims were to determine the association of gene expression of the <em>Wnt</em>/β-catenin signaling pathway with inflammatory cytokines in the bone microenvironment and to assess the serum levels of <em>Wnt</em>/β-catenin proteins in both groups. RA patients referred for hip replacement surgery were recruited. Primary OP patients were used as controls. Gene expression of <em>Wnt</em> pathway mediators, matrix proteins, and pro-inflammatory cytokines were analyzed in bone samples. Bone turnover markers, inflammatory cytokines, and <em>Wnt</em> mediators were measured in serum. Twenty-two patients were included: 10 with RA and <em>12</em> with primary OP. The expressions of <em>Wnt</em>10b (p = 0.034), its co-receptor LRP6 (p = 0.041), and its negative regulator DKK1 (p = 0.008) were upregulated in RA bone. IL17 gene expression in bone was upregulated in RA patients (p = 0.031) and correlated positively with <em>Wnt</em>10b (r = 0.810, p = 0.015), DKK2 (r = 0.800, p = 0.010), and RANKL/OPG ratio (r = 0.762, p = 0.028). DKK2 (p = 0.04) was significantly decreased in RA serum compared with primary OP. In conclusion, bone fragility in RA patients is induced by an unbalanced bone microenvironment and is associated with a specific gene expression pattern, namely, the upregulation of IL17 and DKK1, suggesting that the modulation of these two pathways might prevent RA systemic bone loss.
Publication
Journal: Inhalation Toxicology
October/18/2010
Abstract
Cigarette smoking adversely affects the immune system, and is a risk factor for developing osteoporosis. How smoking contributes to osteoporosis is unclear, but since lymphocytes help maintain bone homeostasis and lymphocyte depletion results in bone loss, one potential mechanism for how smoke exposure promotes osteoporosis is by reducing bone marrow lymphocytes. Since the risk for developing osteoporosis is reportedly greater in smokers with polymorphisms in LRP5, a gene involved in canonical <em>Wnt</em> signaling that regulates bone metabolism, smoking-induced effects on lymphocytes may be influenced by Lrp5 functionality. To test these possibilities, we examined how the duration and cessation of cigarette smoke exposure affects lymphocyte distribution and function in normal mice and mice predisposed to low or high bone mass due to disruption or mutation of Lrp5. We find that, independent of genotype, mice exposed to cigarette smoke for 3-<em>12</em> weeks showed a significant reduction in bone marrow B220(+)CD43(-) B cells and splenic transitional T1 B cells, and exhibited a splenic CD4(+):CD8(+) T-cell ratio that was skewed toward CD8(+) T cells. Smoke exposure had little or no effect on other lymphocyte subsets or on lymphocyte function ex vivo. Interestingly, these differences were no longer apparent after 6 weeks without smoke exposure, except in mice with high bone mass where bone marrow B220(+)CD43(-) B cells failed to fully recover. These data provide the first evidence that smoke exposure reduces bone marrow B cells, providing a plausible mechanism for how smoking contributes to osteoporosis.
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