BACKGROUND

Neovasculogenesis, vital for wound healing, gets compromised in diabetics patients, which consequently delayed wound healing. Previous studies have shown curcumin as both a stimulatory and an inhibitory agent in the neovasculogenesis process. So, present study was aimed to investigate the effects of curcumin on wound healing in diabetic rats and to explore the expressions of the various factors involved in neovasculogenesis.

METHODS

Open excisional diabetic wound was created in sixty rats and divided into three groups viz. i) control, ii) pluronic gel-treated, and iii) curcumin-treated. The pluronic F-127 gel (25%) and curcumin (0.3%) in the pluronic gel were topically applied once daily for 19 d. The wound healing and neovasculogenesis among these groups were evaluated by gross appearance of wounds and microscopically by hematoxylin and eosin staining, immunohistochemistry for CD31, messenger RNA expressions of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1, hypoxia-inducible growth factor-1 alpha, stromal cell-derived growth factor-1 alpha, and heme oxygenase-1, and Western blotting studies of VEGF and TGF-β1 in granulation and/or healing tissue on days 3, 7, 14, and 19.

RESULTS

Curcumin application caused markedly fast wound closure with well-formed granulation tissue dominated by fibroblast proliferation, collagen deposition, and complete early regenerated epithelial layer. Immunohistochemistry for CD31 revealed well-formed blood vessels with increased microvessel density on days 3, 7, and 14 in the curcumin-treated group. Expressions of VEGF and TGF-β1 on days 3, 7, and 14, hypoxia-inducible growth factor-1 alpha, stromal cell-derived growth factor-1 alpha, and heme oxygenase-1 on days 3 and 7 were increased in curcumin-treated diabetic rats, as compared with other groups.

CONCLUSIONS

Curcumin enhanced the neovasculogenesis and accelerated the wound healing in diabetic rats by increased expressions of various factors.

The identification of genes that are differentially methylated in colorectal cancer (CRC) has potential value for both diagnostic and therapeutic interventions specifically in high-risk populations such as African Americans (AAs). However, DNA methylation patterns in CRC, especially in AAs, have not been systematically explored and remain poorly understood. Here, we performed DNA methylome profiling to identify the methylation status of CpG islands within candidate genes involved in critical pathways important in the initiation and development of CRC. We used reduced representation bisulfite sequencing (RRBS) in colorectal cancer and adenoma tissues that were compared with DNA methylome from a healthy AA subject's colon tissue and peripheral blood DNA. The identified methylation markers were validated in fresh frozen CRC tissues and corresponding normal tissues from AA patients diagnosed with CRC at Howard University Hospital. We identified and validated the methylation status of 355 CpG sites located within 16 gene promoter regions associated with CpG islands. Fifty CpG sites located within CpG islands-in genes ATXN7L1 (2), BMP3 (7), EID3 (15), GAS7 (1), GPR75 (24), and TNFAIP2 (1)-were significantly hypermethylated in tumor vs. normal tissues (P<0.05). The methylation status of BMP3, EID3, GAS7, and GPR75 was confirmed in an independent, validation cohort. Ingenuity pathway analysis mapped three of these markers (GAS7, BMP3 and GPR) in the insulin and TGF-β1 network-the two key pathways in CRC. In addition to hypermethylated genes, our analysis also revealed that LINE-1 repeat elements were progressively hypomethylated in the normal-adenoma-cancer sequence. We conclude that DNA methylome profiling based on RRBS is an effective method for screening aberrantly methylated genes in CRC. While previous studies focused on the limited identification of hypermethylated genes, ours is the first study to systematically and comprehensively identify novel hypermethylated genes, as well as hypomethylated LINE-1 sequences, which may serve as potential biomarkers for CRC in African Americans. Our discovered biomarkers were intimately linked to the insulin/TGF-B1 pathway, further strengthening the association of diabetic disorders with colon oncogenic transformation.

Multi-walled carbon nanotubes (MWCNT) are new materials with a wide range of industrial and commercial applications. However, their nano-scaled size and fiber-like shape render them respirable and potentially fibrogenic if inhaled into the lungs. To understand MWCNT fibrogenesis, we analyzed the pathologic and molecular aspects of the early phase response to MWCNT in mouse lungs. MWCNT induced rapid and pronounced lesions in the lungs characterized by increased cellularity and formation of fibrotic foci, most notably near where MWCNT deposited, within 14 days post-exposure. Deposition of collagen fibers was markedly increased in the alveolar septa and fibrotic foci, accompanied by elevated expression of fibrotic genes Col1a1, Col1a2, and Fn1 at both mRNA and protein levels. Fibrosis was induced rapidly at 40 μg, wherein fibrotic changes were detected on day 1 and reached a maximal intensity on day 7 through day 14. Induction of fibrosis was dose-dependent at the dose range of 5-40 μg, 7 days post-exposure. MWCNT elicited rapid and prominent infiltrations of neutrophils and macrophages alongside fibrosis implicating acute inflammation in the fibrotic response. At the molecular level, MWCNT induced elevated expression of proinflammatory cytokines TNFα, IL1α, IL1β, IL6, and CCL2 in lung tissues as well as the bronchoalveolar lavage fluid, in a dose- and time-dependent manner. MWCNT also increased the expression of fibrogenic growth factors TGF-β1 and PDGF-A in the lungs significantly. These findings underscore the interplay between acute inflammation and the early fibrotic response in the initiation and propagation of pulmonary fibrosis induced by MWCNT.

The identification of cancer-associated fibroblast (CAF)-derived proteins that mediate interactions between the tumor stroma and cancer cells is a crucial step toward the discovery of new molecular targets for therapy or molecular signatures that improve tumor classification and predict clinical outcome. CAF are α-smooth muscle actin positive, representing a myofibroblast phenotype that may differentiate from multiple precursor cells, including bone marrow-derived mesenchymal stem cells (MSC). Transforming growth factor-β1 (TGF-β1) is a crucial inducer of α-smooth muscle actin positive CAFs. In this study, we aimed to identify CAF-derived regulators of colon cancer progression by performing a high-throughput differential secretome profiling between CAF compared to noncancer-activated bone marrow-derived MSC. In addition, we explored the effect of TGF-β1 on the secretion of proteins by bone marrow-derived MSC in comparison with the protein secretion profile of CAF. TGF-β1 induced de novo secretion of 84 proteins in MSC, of which 16 proteins, including stromal-derived factor-1α and Rantes, were also present in CAF secretome. Immunohistochemistry further validated the expression of selected candidates such as tenascin C, fibronectin ED-A domain and stromal-derived factor-1 in clinical colon cancer specimens. In conclusion, this differential secretome approach enabled us to identify a series of candidate biomarkers for colon cancer that are associated with a CAF-specific phenotype.

Chronic renal failure (CRF) is a major public health problem worldwide. Earlier studies have revealed salutary effects of rhubarb extracts in CRF. In this study, we employed lipidomic and metabolomic approaches to identify the plasma biomarkers and to determine the effect of treatment with petroleum ether, ethyl acetate and n-butanol extracts of rhubarb in a rat model of CRF with adenine-induced chronic tubulointerstitial nephropathy. In addition, clinical biochemistry, histological evaluation and pro-fibrotic protein expression were analyzed. Significant changes were found between the CRF and control groups representing characteristic phenotypes of rats with CRF. Treatment with the three rhubarb extracts improved renal injury and dysfunction, either fully or partially reversed the plasma metabolites abnormalities and attenuated upregulation of pro-fibrotic proteins including TGF-β1, α-SMA, PAI-1, CTGF, FN and collagen-1. The nephroprotective effect of ethyl acetate extract was better than other extracts. The differential metabolites were closely associated with glycerophospholipid, fatty acid and amino acid metabolisms. The results revealed a strong link between renal tubulointerstitial fibrosis and glycerophospholipid metabolism and L-carnitine metabolism in the development of CRF. Amelioration of CRF with the three rhubarb extracts was associated with the delayed development and/or reversal the disorders in key metabolites associated with adenine-induced CRF.

OBJECTIVE

IgG4-related disease (IgG4-RD) is a chronic, systemic, inflammatory condition of unknown aetiology. We have recently described clonally expanded circulating CD4+ cytotoxic T lymphocytes (CTLs) in IgG4-RD that infiltrate affected tissues where they secrete interleukin (IL)-1β and transforming growth factor -β1 (TGF-β1). In this study, we sought to examine the role of CD4+ CTLs in the pathogenesis of IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS) and to determine whether these cells secrete interferon-gamma (IFN-γ) at lesional sites.

METHODS

Salivary glands of 25 patients with IgG4-DS, 22 patients with Sjögren's syndrome (SS), 12 patients with chronic sialoadenitis (CS) and 12 healthy controls were analysed in this study. Gene expression analysis was performed on submandibular glands (SMGs) from five patients with IgG4-DS, three with CS and three healthy controls. Infiltrating CD4+ CTLs were examined by quantitative multicolour imaging in tissue samples from 20 patients with IgG4-DS, 22 patients with SS, 9 patients with CS and 9 healthy controls.

RESULTS

In IgG4-DS tissues, nine genes associated with CD4+ CTLs were overexpressed. The expression of granzyme A (GZMA) mRNA was significantly higher in samples from patients with IgG4-RD compared with corresponding tissues from SS and healthy controls. Quantitative imaging showed that infiltrating CD4+ GZMA+ CTLs were more abundant in patients with IgG4-DS than in the other groups. The ratio of CD4+GZMA+ CTLs in SMGs from patients with IgG4-DS correlated with serum IgG4 concentrations and the number of affected organs. A large fraction of CD4+GZMA+ CTLs in SMGs from patients with IgG4-DS secreted IFN-γ.

CONCLUSIONS

The pathogenesis of IgG4-DS is associated with tissue infiltration by CD4+GZMA+ CTLs that secrete IFN-γ.

Discoidin domain receptor 2 (DDR2) is a collagen receptor that is expressed during epithelial-mesenchymal transition (EMT), a cellular transformation that mediates many stages of embryonic development and disease. However, the functional significance of this receptor in EMT is unknown. Here we show that Transforming Growth Factor-beta1 (TGF-β1), a common stimulator of EMT, promotes increased expression of type I collagen and DDR2. Inhibiting expression of COL1A1 or DDR2 with siRNA is sufficient to perturb activity of the NF-κB and LEF-1 transcription factors and to inhibit EMT and cell migration induced by TGF-β1. Furthermore, knockdown of DDR2 expression with siRNA inhibits EMT directly induced by type I collagen. These data establish a critical role for type I collagen-dependent DDR2 signaling in the regulation of EMT.

Transforming growth factor-b1 (TGF-beta1), a multi-function polypeptide, is a double-edged sword in cancer. For some tumor cells, TGF-beta1 is a potent growth inhibitor and apoptosis inducer. More commonly, TGF-beta1 loses its growth-inhibitory and apoptosis-inducing effects, but stimulates the metastatic capacity of tumor cells. It is currently little known about TGF-beta1-promoted cell migration in hepatocellular carcinoma (HCC) cells, let alone its mechanism. In this study, we found that TGF-beta1 lost its tumor-suppressive effects, but significantly stimulated cell migration in SMMC-7721 human HCC cells. By FACS and Western blot analysis, we observed that TGF-beta1 enhanced the expression of alpha5beta1 integrin obviously, and subsequently stimulated cell adhesion onto fibronectin (Fn). Furthermore, we observed that TGF-beta1 could also promote SMMC-7721 cells adhesion onto laminin (Ln). Our data also provided evidences that TGF-beta1 induced epithelial-to-mesenchymal transformation (EMT) in SMMC-7721 cells. First, SMMC-7721 cells clearly switched to the spindle shape morphology after TGF-beta1 treatment. Furthermore, TGF-beta1 induced the down-regulation of E-cadherin and the nuclear translocation of beta-catenin. These results indicated that TGF-beta1-promoted cell adhesion and TGF-beta1-induced epithelial-to-mesenchymal transformation might be both responsible for TGF-beta1-enhanced cell migration.

Natural killer (NK) cells are key components of the innate immune system, providing potent antitumor immunity. Here, we show that the tumor growth factor-β (TGF-β)/SMAD signaling pathway is an important mechanism for NK cell immune evasion in childhood B-acute lymphoblastic leukemia (ALL). We characterized NK cells in 50 consecutive children with B-ALL at diagnosis, end induction and during maintenance therapy compared with age-matched controls. ALL-NK cells at diagnosis had an inhibitory phenotype associated with impaired function, most notably interferon-γ production and cytotoxicity. By maintenance therapy, these phenotypic and functional abnormalities partially normalized; however, cytotoxicity against autologous blasts remained impaired. We identified ALL-derived TGF-β1 to be an important mediator of leukemia-induced NK cell dysfunction. The TGF-β/SMAD signaling pathway was constitutively activated in ALL-NK cells at diagnosis and end induction when compared with healthy controls and patients during maintenance therapy. Culture of ALL blasts with healthy NK cells induced NK dysfunction and an inhibitory phenotype, mediated by activation of the TGF-β/SMAD signaling pathway, and abrogated by blocking TGF-β. These data indicate that by regulating the TGF-β/SMAD pathway, ALL blasts induce changes in NK cells to evade innate immune surveillance, thus highlighting the importance of developing novel therapies to target this inhibitory pathway and restore antileukemic cytotoxicity.

OBJECTIVE

The accumulation of extracellular matrix (ECM) is a characteristic of diabetic nephropathy, and is partially caused by profibrotic proteins TGF-β and connective tissue growth factor (CTGF). We aimed to identify microRNAs (miRNAs) targeting CTGF on podocytes in diabetic nephropathy.

METHODS

We investigated miRNAs targeting CTGF on podocytes with miRNA array analysis and identified a candidate miRNA, miR-26a. Using overexpression and silencing of miR-26a in cultured podocytes, we examined changes of ECM and its host genes. We further investigated glomerular miR-26a expression in humans and in mouse models of diabetic nephropathy.

RESULTS

miR-26a, which was downregulated by TGF-β1, was expressed in glomerular cells including podocytes and in tubules by in situ hybridisation. Glomerular miR-26a expression was downregulated by 70% in streptozotocin-induced diabetic mice. Transfection of miR-26a mimics in cultured human podocytes decreased the CTGF protein level by 50%, and directly inhibited CTGF expression in podocytes, as demonstrated by a reporter assay with the 3'-untranslated region of the CTGF gene. This effect was abolished by a mutant plasmid. miR-26a mimics also inhibited TGF-β1-induced collagen expression, SMAD-binding activity and expression of its host genes CTDSP2 and CTDSPL. Knockdown of CTDSP2 and CTDSPL increased collagen expression in TGF-β-stimulated podocytes, suggesting that host genes also regulate TGF-β/SMAD signalling. Finally, we observed a positive correlation between microdissected glomerular miR-26a expression levels and estimated GFR in patients with diabetic nephropathy.

CONCLUSIONS

The downregulation of miR-26a is involved in the progression of diabetic nephropathy both in humans and in mice through enhanced TGF-β/CTGF signalling.

TGF-β signaling in T cells is critical for peripheral T-cell tolerance by regulating effector CD4(+) T helper (Th) cell differentiation. However, it is still controversial to what extent TGF-β signaling in Foxp3(+) regulatory T (Treg) cells contributes to immune homeostasis. Here we showed that abrogation of TGF-β signaling in thymic T cells led to rapid type 1 diabetes (T1D) development in NOD mice transgenic for the BDC2.5 T-cell receptor. Disease development in these mice was associated with increased peripheral Th1 cells, whereas Th17 cells and Foxp3(+) Treg cells were reduced. Blocking of IFN-γ signaling alone completely suppressed diabetes development in these mice, indicating a critical role of Th1 cells in this model. Furthermore, deletion of TGF-β signaling in peripheral effector CD4(+) T cells, but not Treg cells, also resulted in rapid T1D development, suggesting that conventional CD4(+) T cells are the main targets of TGF-β to suppress T1D. TGF-β signaling was dispensable for Treg cell function, development, and maintenance, but excessive IFN-γ production due to the absence of TGF-β signaling in naive CD4(+) T cells indirectly caused dysregulated Treg cell homeostasis. We further showed that T cell-derived TGF-β1 was critical for suppression of Th1 cell differentiation and T1D development. These results indicate that autocrine/paracrine TGF-β signaling in diabetogenic CD4(+) T cells, but not Treg cells, is essential for controlling T1D development.

Neutrophil elastase plays pivotal roles in the pathogenesis of pulmonary fibrosis. The neutrophil elastase inhibitor, sivelestat, could alleviate pulmonary fibrosis; however, the antifibrotic mechanisms have not yet been clarified. We examined the antifibrotic mechanisms, mainly focusing on a key fibrotic cytokine, transforming growth factor (TGF)-β1, in this study. To elucidate the antifibrotic mechanisms of sivelestat, we examined a murine model of bleomycin-induced early-stage pulmonary fibrosis. After intratracheal instillation of bleomycin, sivelestat was administered intraperitoneally once a day for 7 or 14 days. Bronchoalveolar lavage fluid and lung samples were examined on day 7 or day 14 after bleomycin instillation. In the bleomycin-induced early-stage pulmonary fibrosis model, the neutrophil elastase level was increased in the lungs. Sivelestat significantly inhibited the increase in lung collagen content, fibrotic changes, the numbers of total cells (including macrophages, neutrophils and lymphocytes), the levels of the active form of TGF-β1 and phospho-Smad2 in bleomycin-induced early-stage pulmonary fibrosis. The total TGF-β1 levels and relative changes of TGF-β1 mRNA expression, however, were not decreased significantly by sivelestat. These results suggest that sivelestat alleviated bleomycin-induced pulmonary fibrosis via inhibition of both TGF-β activation and inflammatory cell recruitment in the lung.

OBJECTIVE

The mechanisms of progression in biliary tract cancer (BTC) with inflammation, including epithelial-mesenchymal transition (EMT), are not well understood. We focused on two inflammation-associated cytokines, interleukin-6 (IL-6) and transforming growth factor-beta 1 (TGF-β1), and investigated their expression and activity, as well as their relationship to key features of malignancy, in tumour samples from patients with BTC and in cultured BTC cells.

METHODS

We employed five BTC cell lines (MzChA-1, gemcitabine-resistant MzChA-1, HuCCT-1, KMCH and CCLP-1) to evaluate IL-6/TGF-β1 expression, tumour cell invasion, EMT and chemoresistance to gemcitabine in the presence or absence of recombinant human (rh) IL-6 and TGF-β1. Possible pathways were evaluated with specific pathway inhibitors and small interfering RNA (siRNA). We also used 20 resected specimens from patients with BTC to verify the results in vitro.

RESULTS

IL-6 and TGF-β1 expression was associated with features of malignancy such as EMT and chemoresistance in the four BTC cell lines. Addition of rh IL-6 and TGF-β1 increased endogenous IL-6 and TGF-β1 expression through crosstalk and induced cell invasion, EMT and chemoresistance. Smad4 functioned in this process in a dominant manner, and inhibition by SMAD4 siRNA reduced IL-6 and TGF-β1 expression, blocked invasion, and reversed EMT and chemoresistance in cells exposed to rh IL-6 and TGF-β1 and in gemcitabine-resistant cells. Immunohistochemistry in resected specimens revealed IL6, TGF-β1, N-cadherin and Smad4 staining at the invasion front.

CONCLUSIONS

Crosstalk between IL-6 and TGF-β1 is associated with malignant features, including EMT, and Smad4 works in a dominant manner to promote these features.

OBJECTIVE

Left ventricular remodeling is a frequent complication of hypertension with no therapeutic treatment available for the subsequent onset of myocardial fibrosis. Pirfenidone is an antifibrotic small-molecular-size drug with anti-inflammatory properties that is used as a treatment for fibrotic diseases, but its effects on hypertension-induced myocardial fibrosis are unknown. Therefore, we tested whether pirfenidone could ameliorate hypertension-induced left ventricular remodeling and whether hypertension-induced NLRP3 (Nod-like receptor pyrin domain containing 3), a critical protein in NLRP3 inflammasome formation, is involved in the therapeutic mechanism.

METHODS

A TAC-induced mouse model of hypertension and left ventricular hypertrophy was treated with pirfenidone, and survival, collagen deposition by histopathologic examination, heart function by echocardiography, concentrations of fibrosis-related inflammatory cytokines TGF-β1, IL-1β in heart homogenate and in vitro cell cultures by ELISA, levels of ROS and inflammatory cells by flow cytometry, and levels of NLRP3 by Western blotting and immunohistochemistry were measured.

RESULTS

Pirfenidone increased the survival rate and attenuated myocardial fibrosis and inflammatory mediators in the TAC-induced hypertension-complicated left ventricular remodeling mouse model. The inhibition of NLRP3 expression by pirfenidone attenuated the expression of IL-1β and IL-1β-induced inflammatory and profibrotic responses.

CONCLUSIONS

Pirfenidone may be useful in the treatment of hypertension-induced myocardial fibrosis by inhibiting NLRP3-induced inflammation and fibrosis.

Major depressive disorder (MDD) is a common condition that afflicts the general population across a broad spectrum of ages and social backgrounds. The inflammatory hypothesis of depression posits that immune hyperactivation and dysregulated cytokine production are involved in depression. To investigate cytokine profiles in patients with MDD, we examined the levels of the pro-inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α, and those of the anti-inflammatory cytokines IL-10 and transforming growth factor (TGF)-β1 in antidepressant drug-naïve patients with MDD. Compared to healthy controls, patients with MDD had significantly higher levels of IL-1β, IL-10, and TNF-α, but significantly lower levels of IL-8. There were no significant differences in the levels of IL-6 or TGF-β1. We found linear correlations between IL-1β, TNF-α, and IL-8, and the severity of depression, as well as between IL-8 and anxiety level in patients with comorbid anxiety disorder. In addition, higher IL-1β and TNF-α levels were associated with higher Hamilton Depression Rating Scale (HAMD) scores, while higher IL-8 levels were associated with lower HAMD and Hamilton Anxiety Rating Scale scores. Here we present evidence of changes in cytokine levels in antidepressant drug-naïve patients with MDD. Abnormal expression of inflammatory cytokines in patients with depression suggests that depression activates an inflammatory process. Immunological abnormalities may be involved in the pathophysiology of depression.

In this study, we have showed that GCNT2, a gene-encoding glucosaminyl (N-acetyl) transferase 2, I-branching enzyme, is overexpressed in highly metastatic breast cancer cell lines of human and mouse origin and basal-like breast tumor samples. GCNT2 expression is also significantly correlated to the metastatic phenotype in breast tumor samples. Functional studies showed that ectopic expression of GCNT2 enhances cell detachment, adhesion to endothelial cells, cell migration and invasion in vitro, and lung metastasis of breast cancer cells in vivo. Knockdown of GCNT2 expression decreases cell migration and invasion in vitro and lung metastasis in vivo. We have further shown the involvement of GCNT2 in the epithelial-to-mesenchymal transition (EMT). Specifically, the expression of E-cadherin is significantly changed upon GCNT2 expression at the protein level but not at the RNA level. Moreover, we have shown that GCNT2 is a direct target of the TGF-β-smad pathway and that change in GCNT2 expression modulates EMT induced by TGF-β1 treatment. Finally, we have shown that diminution of the glycosyltransferase activity of I-branching β-1, 6-N-acetylglucosaminyl transferase 2 (GCNT2) abrogates its cell migration and invasion-promoting function and synergistic effect with TGF-β to induce EMT. Our study for the first time showed that GCNT2 is a novel gene contributing to breast cancer metastasis with preferential expression in basal-like breast cancer. Moreover, we discovered that involvement of GCNT2 in EMT and TGF-β signaling, and further glycosylation modification of E-cadherin by GCNT2, are the underlying integrative mechanisms for breast cancer metastasis, implying that blocking TGF-β/GCNT2 signaling is a promising approach for targeting metastatic breast cancer.

Human endogenous retrovirus type K (HERV-K) Env protein was previously demonstrated to be overexpressed in human breast cancer (BC) cells and tissues. However, the molecular pathways driving the specific alterations are unknown. We now show that knockdown of its expression with an shRNA (shRNAenv) blocked BC cell proliferation, migration, and invasion. shRNAenv transduction also attenuated the ability of BC cells to form tumors, and notably prevented metastasis. Mechanistically, downregulation of HERV-K blocked expression of tumor-associated genes that included Ras, p-RSK, and p-ERK. The major upstream regulators influenced by HERV-K knockdown were p53, TGF- β1, and MYC. Of interest, when the HERV-K env gene was overexpressed in shRNAenv-transduced BC cells using an HERV-K env expression vector, Ras/Raf/MEK/ERK pathway signaling was restored. CDK5, which alters p53 phosphorylation in some cancers, was upregulated and p53 was downregulated when HERV-K was overexpressed. CDK5 is also a mediator of TGF-β1-induced epithelial-mesenchymal transition and migration in cancer cells, and is involved in tumor formation. Importantly, reductions in migration, invasion, and transformation of BC cells stably transduced with shRNAenv was reversed after adding back a vector with a synonymous mutation of HERV-K env. Taken together, these results indicate that HERV-K Env protein plays an important role in tumorigenesis and metastasis of BC.

In the last several years a large number of studies have demonstrated the neurobiological and clinical continuum between depression and Alzheimer's disease (AD). Depression is a risk factor for the development of AD, and the presence of depressive symptoms significantly increases the conversion of Mild Cognitive Impairment (MCI) into AD. Common pathophysiological events have been identified in depression and AD, including neuroinflammation with an aberrant Tumor Necrosis Factor-α (TNF-α) signaling, and an impairment of Brain-Derived Neurotrophic Factor (BDNF) and Transforming-Growth-Factor-β1 (TGF-β1) signaling. TGF-β1 is an anti-inflammatory cytokine that exerts neuroprotective effects against amyloid-β (Aβ)-induced neurodegeneration, and it has a key role in memory formation and synaptic plasticity. TGF-β1 plasma levels are reduced in major depressed patients (MDD), correlate with depression severity, and significantly contribute to treatment resistance in MDD. The deficit of Smad-dependent TGF-β1 signaling is also an early event in AD pathogenesis, which contributes to inflammaging and cognitive decline in AD. A long-term treatment with antidepressants such as selective-serotonin-reuptake inhibitors (SSRIs) is known to reduce the risk of AD in patients with depression and, SSRIs, such as fluoxetine, increase the release of TGF-β1 from astrocytes and exert relevant neuroprotective effects in experimental models of AD. We propose the TGF-β1 signaling pathway as a common pharmacological target in depression and AD, and discuss the potential rescue of TGF-β1 signaling by antidepressants as a way to prevent the transition from depression to AD.

The interaction between glomerular endothelial cells (GECs) and glomerular mesangial cells (GMCs) is an essential aspect of diabetic nephropathy (DN). Therefore, understanding how GECs communicate with GMCs in the diabetic environment is crucial for the development of new targets for the prevention and treatment of DN. Exosomes, nanometer-sized extracellular membrane vesicles secreted by various cell types, play important roles in cell-to-cell communication via the transfer of mRNA, microRNA and protein. In this study, we demonstrate that high glucose (HG)-treated GECs secrete a higher number of exosomes highly enriched in TGF-β1 mRNA compared with normal glucose (NG)-treated GECs. Exosomes released by HG-treated GECs can promote α-smooth muscle actin (α-SMA) expression, proliferation and extracellular matrix protein overproduction in GMCs through the TGF-β1/Smad3 signaling pathway. Thus, we provide new insights into the pathogenesis of DN that involves intercellular transfer of TGF-β1 mRNA in the GEC-to-GMC direction via exosomes.

OBJECTIVE

Radiation-induced lung injury (RILI) commonly occurs in patients with thoracic cancer. However, an effective treatment option has not yet been established. Adipose-derived mesenchymal stromal cells (Ad-MSCs) have significant potential for clinical use, but their role in RILI is currently unknown. We aimed to evaluate the therapeutic capacity of Ad-MSCs to heal acute RILI in rats.

METHODS

Sprague-Dawley rats were used in this study. Rat Ad-MSCs were delivered through the tail veins of rats 2 h after thorax irradiation. Lung histopathologic findings, pulmonary levels of inflammatory cytokines (interleukin [IL]-1, IL-6, IL-10 and tumor necrosis factor-α), pro-fibrotic factors (transforming growth factor [TGF]-β1, connective tissue growth factor, α-smooth muscle actin and type 1 collagen), pro- or anti-apoptotic mediators (Bcl-2, Bax and caspase-3) and the multifunctional factor hepatocyte growth factor were evaluated after Ad-MSC transplant.

RESULTS

Intravenous delivery of Ad-MSCs attenuated acute RILI. Further studies showed that Ad-MSCs had anti-inflammation and anti-fibrotic effects and maintained lung epithelium integrity, as indicated by reduced serum levels of the pro-inflammatory cytokines IL-1, IL-6 and tumor necrosis factor-α, increased levels of the anti-inflammatory cytokine IL-10, and downregulated transforming growth factor -β1, α-smooth muscle actin and type 1 collagen levels in irradiated lung tissues. Ad-MSCs also regulated the expression of pro- and anti-apoptotic mediators (Bcl-2, Bax and caspase-3) to protect lung cells from apoptosis.

CONCLUSIONS

Intravenous Ad-MSC delivery attenuated acute RILI through anti-inflammation, anti-fibrosis and anti-apoptosis mechanisms.

Type 2 diabetes mellitus (T2DM) is associated with hyperglycemia and a risk to develop pancreatic ductal adenocarcinoma (PDAC), one of the most fatal malignancies. Cancer stem cells (CSC) are essential for initiation and maintenance of tumors, and acquisition of CSC-features is linked to epithelial-mesenchymal-transition (EMT). The present study investigated whether hyperglycemia promotes EMT and CSC-features in premalignant and malignant pancreatic ductal epithelial cells (PDEC). Under normoglycemia (5 mM d-glucose), Panc1 PDAC cells but not premalignant H6c7-kras cells exhibited a mesenchymal phenotype along with pronounced colony formation. While hyperglycemia (25 mM d-glucose) did not impact the mesenchymal phenotype of Panc1 cells, CSC-properties were aggravated exemplified by increased Nanog expression and Nanog-dependent formation of holo- and meroclones. In H6c7-kras cells, high glucose increased secretion of Transforming-Growth-Factor-beta1 (TGF-β1) as well as TGF-β1 signaling, and in a TGF-β1-dependent manner reduced E-cadherin expression, increased Nestin expression and number of meroclones. Finally, reduced E-cadherin expression was detected in pancreatic ducts of hyperglycemic but not normoglycemic mice. These data suggest that hyperglycemia promotes the acquisition of mesenchymal and CSC-properties in PDEC by activating TGF-β signaling and might explain how T2DM facilitates pancreatic tumorigenesis.

Epithelial-mesenchymal transition (EMT) is a major factor that facilitates the invasiveness and metastasis of cancer. Recent studies have demonstrated that EMT plays a key role in generating cancer stem cells (CSCs). This study aimed to investigate the effect of EMT on CSCs that were identified as positive for aldehyde dehydrogenase (ALDH) in cholangiocarcinoma (CCA). We demonstrated that transforming growth factor-β1 (TGF-β1)-induced EMT in the human cholangiocarcinoma (CCA) cell line, TFK-1, resulted in the acquisition of mesenchymal traits, as well as the expression of ALDH, which was accompanied by decreased sensitivity to the chemotherapeutic agent, 5-fluorouracil. ALDH-positive cells isolated from TFK-1 cells had higher proliferation potential in vitro and tumourigenic ability in vivo. They also expressed mesenchymal markers. Moreover, the expression levels of TGF-β1 and ALDH1 were correlated with poor prognosis in patients. We conclude that ALDH acts as a marker for CSCs in CCA, and TGF-β1-induced EMT is involved in the generation of CSCs. These findings offer a new tool for the study of CCA stem cells and illustrate a direct link between EMT and the gain of stem-cell properties.

This study determined the contribution of extracellular matrix (ECM) remodeling to the protective adaptation of human skeletal muscle known as the repeated-bout effect (RBE). Muscle biopsies were obtained 3 hours, 2 days, and 27 days following an initial bout (B1) of lengthening contractions (LCs) and 2 days following a repeated bout (B2) in 2 separate studies. Biopsies from the nonexercised legs served as controls. In the first study, global transcriptomic analysis indicated widespread changes in ECM structural, deadhesive, and signaling transcripts, 3 hours following LC. To determine if ECM remodeling is involved in the RBE, we conducted a second study by use of a repeated-bout paradigm. TNC immunoreactivity increased 10.8-fold following B1, was attenuated following B2, and positively correlated with LC-induced strength loss (r(2) = 0.45; P = 0.009). Expression of collagen I, III, and IV (COL1A1, COL3A1, COL4A1) transcripts was unchanged early but increased 5.7 ± 2.5-, 3.2 ± 0.9-, and 2.1 ± 0.4-fold (P < 0.05), respectively, 27 days post-B1 and were unaffected by B2. Likewise, TGF-β signaling demonstrated a delayed response following LC. Satellite cell content increased 80% (P < 0.05) 2 days post-B1 (P < 0.05), remained elevated 27 days post-B1, and was unaffected by B2. Collectively, the data suggest sequential ECM remodeling characterized by early deadhesion and delayed reconstructive activity that appear to contribute to the RBE.

Mitochondria dysfunction has been reported in various kidney diseases but how it leads to kidney fibrosis and how this is regulated is unknown. Here we found that mitochondrial uncoupling protein 2 (UCP2) was induced in kidney tubular epithelial cells after unilateral ureteral obstruction in mice and that mice with ablated UCP2 resisted obstruction-induced kidney fibrosis. We tested this association further in cultured NRK-52E cells and found that TGF-β1 remarkably induced UCP2 expression. Knockdown of UCP2 largely abolished the effect of TGF-β1, whereas overexpression of UCP2 promoted tubular cell phenotype changes. Analysis using a UCP2 mRNA-3'-untranslated region luciferase construct showed that UCP2 mRNA is a direct target of miR-30e. MiR-30e was downregulated in tubular cells from fibrotic kidneys and TGF-β1-treated NRK-52E cells. A miR-30e mimic significantly inhibited TGF-β1-induced tubular-cell epithelial-mesenchymal transition, whereas a miR-30e inhibitor imitated TGF-β1 effects. Finally, genipin, an aglycone UCP2 inhibitor, significantly ameliorated kidney fibrosis in mice. Thus, the miR-30e/UCP2 axis has an important role in mediating TGF-β1-induced epithelial-mesenchymal transition and kidney fibrosis. Targeting this pathway may shed new light for the future of fibrotic kidney disease therapy.