Serum interleukin (IL)‑17A level is associated with higher microvessel density and poor prognosis in liver cancer. However, the specific mechanism underlying the role of IL‑17A in liver cancer remains controversial. In the present study, the effect of IL‑17A on liver cancer cells was examined. IL‑17A had no evident impact on vascular endothelial growth factor A (VEGFA) production in HepG2 and Huh7.5 cells as determined by reverse transcription‑quantitative PCR and ELISA, but it did stimulate angiogenic CXC chemokine secretion, including chemokine (C‑X‑C motif) ligand 1 (CXCL1), CXCL2, CXCL3, CXCL5, CXCL6 and CXCL8 in Huh7.5 cells and CXCL2 in HepG2 cells. In addition, the production of angiostatic chemokines such as CXCL10 was not affected. The supernatant of Huh7.5‑IL17A cells promoted endothelial cell chemotaxis, which was attenuated by the C‑X‑C chemokine receptor type 2 (CXCR2) inhibitor SB225002. Although there was no role of IL‑17A in promoting in vitro cell proliferation, IL‑17A markedly increased the tumor growth of Huh7.5 cells in both subcutaneous and orthotopic xenograft models with increased vascularization. Taken together, these results demonstrated that IL‑17A may stimulate chemokine‑induced angiogenesis and promote tumor progression, independent of VEGF signaling. The CXCL‑CXCR2 axis may be a novel target for the anti‑angiogenesis treatment of liver cancer.

Colorectal cancer (CRC) is one of the most common cancer worldwide. Chronic inflammation contributes to CRC development and progression. Emodin, is a natural anthraquinone derivative with anti-oxidant, anti-inflammatory, and anti-tumor activities. We used the AOM/DSS model of colitis-associated intestinal tumorigenesis to characterize the effect of Emodin on inflammation and tumorigenesis at weeks 3, 5, and 14 after initiation with AOM. At all three time points, Emodin (50 mg/kg) reduced inflammatory cell (i.e. CD11b⁺ and F4/80⁺) recruitment, cytokine (i.e. TNFα, IL1α/β, IL6, CCL2, CXCL5) and pro-inflammatory enzymes (i.e. COX-2, NOS2) expression in the tumor microenvironment, while promoting recruitment of CD3⁺ T lymphocytes at 14 weeks. Emodin decreased the incidence of premalignant lesions (adenoma) at week 3, the incidence of dysplastic lesions and carcinomas at week 5, and the incidence, size and the invasiveness of carcinomas at week 14. Emodin also reduced the acute clinical intestinal symptoms (i.e. bleeding and diarrhea) during DSS treatment. In vitro, Emodin inhibited the expression of pro-inflammatory mediators by LPS-stimulated RAW 264.7 macrophages, and reduced viability, adhesion, migration, and fibroblasts-induced invasion of SW620 and HCT116 colon cancer cells. In conclusion, this work demonstrates that Emodin suppresses carcinogenesis-associated intestinal inflammation and prevents AOM/DSS-induced intestinal tumorigenesis and progression. These results instigate further studies on Emodin as a natural agent for the prevention or treatment of colorectal cancer.

Keywords: Chinese medicine; T lymphocytes; colorectal cancer; emodin; inflammation; tumor microenvironment.

Accumulating evidence suggests that psoriasis is frequently accompanied by metabolic disorders, such as obesity and diabetes. However, the mechanisms underlying the association between increased psoriasis severity and concomitant metabolic syndrome have not been fully clarified. Herein, we show that imiquimod-induced psoriasiform inflammation was exacerbated and prolonged in diabetic obese mice compared to that in control mice, accompanied by remarkably increased lesional expressions of Cxcl5 and Il-1b. Notably, a large number of CXCL5+ Ly6G+ cells infiltrated the dermis and subcutaneous fat tissue of the diabetic obese mice. Most macrophages in the subcutaneous fat tissues of the diabetic obese mice were positive for expression of IL-1β and GRP78/Bip, an endoplasmic reticulum stress marker. Depletion of Ly6G+ cells and macrophages diminished the imiquimod-induced psoriasiform inflammation. Further, CXCL5 potentiated the secretion of IL-1β from macrophages and palmitic acid, a fatty acid released from subcutaneous adipocytes, further enhanced IL-1β secretion via endoplasmic reticulum stress induction. Combined with the fact that the serum levels of both CXCL5 and palmitic acid are significantly elevated in patients with metabolic syndrome, our results suggest a role for CXCL5 and endoplasmic reticulum stress in the increase of psoriasis severity of patients with concomitant metabolic syndrome.

Gut microbiota and their metabolites are instrumental in regulating homeostasis at intestinal and extraintestinal sites. However, the complex effects of prenatal and early postnatal microbial exposure on adult health and disease outcomes remain incompletely understood. Here, we showed that mice raised under germ-free conditions until weaning and then transferred to specific pathogen-free (SPF) conditions harbored altered microbiota composition, augmented inflammatory cytokine and chemokine expression, and were hyper-susceptible to colitis-associated tumorigenesis later in adulthood. Increased number and size of colon tumors and intestinal epithelial cell proliferation in recolonized germ-free mice were associated with augmented intratumoral CXCL1, CXCL2, and CXCL5 expression and granulocytic myeloid-derived suppressor cell (G-MDSC) accumulation. Consistent with these findings, CXCR2 neutralization in recolonized germ-free mice completely reversed the exacerbated susceptibility to colitis-associated tumorigenesis. Collectively, our findings highlight a crucial role for early-life microbial exposure in establishing intestinal homeostasis that restrains colon cancer in adulthood.

Background: The probability of local tumor control after radiotherapy (RT) remains still miserably poor in pediatric rhabdomyosarcoma (RMS). Thus, understanding the molecular mechanisms responsible of tumor relapse is essential to identify personalized RT-based strategies. Contrary to what has been done so far, a correct characterization of cellular radioresistance should be performed comparing radioresistant and radiosensitive cells with the same isogenic background.

Methods: Clinically relevant radioresistant (RR) embryonal (RD) and alveolar (RH30) RMS cell lines have been developed by irradiating them with clinical-like hypo-fractionated schedule. RMS-RR cells were compared to parental isogenic counterpart (RMS-PR) and studied following the radiobiological concept of the "6Rs", which stand for repair, redistribution, repopulation, reoxygenation, intrinsic radioresistance and radio-immuno-biology.

Results: RMS-RR cell lines, characterized by a more aggressive and in vitro pro-metastatic phenotype, showed a higher ability to i) detoxify from reactive oxygen species; ii) repair DNA damage by differently activating non-homologous end joining and homologous recombination pathways; iii) counteract RT-induced G2/M cell cycle arrest by re-starting growth and repopulating after irradiation; iv) express cancer stem-like profile. Bioinformatic analyses, performed to assess the role of 41 cytokines after RT exposure and their network interactions, suggested TGF-β, MIF, CCL2, CXCL5, CXCL8 and CXCL12 as master regulators of cancer immune escape in RMS tumors.

Conclusions: These results suggest that RMS could sustain intrinsic and acquire radioresistance by different mechanisms and indicate potential targets for future combined radiosensitizing strategies.

Keywords: Immunoescape; Radiobiology; Radioresistance; Radiotherapy; Rhabdomyosarcoma.

The innate immune mechanisms by which adjuvants enhance the potency and protection of vaccine remain at cellular level, but the molecular mechanisms, especially in vivo, are ill-identified. Actinidia eriantha polysaccharide (AEPS) is a potent adjuvant with dual Th1 and Th2 potentiating activity, while Alum elicits a strict Th2 response. The current experiments were designed to compare the innate immune responses in the peritoneal cavity of mice induced by two adjuvants and explore their molecular mechanisms using gene expression microarray including long noncoding RNAs (lncRNAs). AEPS induced the recruitment of monocytes, neutrophils and dendritic cells. However, Alum recruited neutrophils and eosinophils. AEPS and Alum specifically induced the differential expression of 546 and 922 genes in peritoneal cells, respectively. AEPS induced higher mRNA expression of CCL2, CCL3, CCL4, CCL7, CXCL2, CXCL3, CXCL5, CXCL10, IL-12β, and IL-23α in immune effector process, while Alum tended to Th17 response mRNAs such as IL-7A, IL-17F and IL-17RA. Furthermore, a robust adjuvant-specific expression pattern of lncRNAs was found in above mentioned biological processes, suggesting the involvement of lncRNAs in immune responses induced by AEPS and Alum. This study led to a better understanding of different molecular mechanisms of adjuvants and benefited the rational design of effective vaccines.

Pancreatic ductal adenocarcinoma (PDAC) tumors are characterized by a desmoplastic reaction resulting in dense deposition of collagen that is known to promote cancer progression. A central mediator of pro-tumorigenic collagen signaling is the receptor tyrosine kinase discoid domain receptor 1 (DDR1). DDR1 is a critical driver of a mesenchymal and invasive cancer cell PDAC phenotype. Previous studies have demonstrated that genetic or pharmacologic inhibition of DDR1 reduces PDAC tumorigenesis and metastasis. Here, we investigated whether DDR1 signaling has cancer cell non-autonomous effects that promote PDAC progression and metastasis. We demonstrate that collagen-induced DDR1 activation in cancer cells is a major stimulus for CXCL5 production, resulting in the recruitment of tumor-associated neutrophils (TANs), the formation of neutrophil extracellular traps (NETs) and subsequent cancer cell invasion and metastasis. Moreover, we have identified that collagen-induced CXCL5 production was mediated by a DDR1-PKCθ-SYK-NFkB signaling cascade. Together, these results highlight the critical contribution of collagen I-DDR1 interaction in the formation of an immune microenvironment that promotes PDAC metastasis.

Keywords: Cytokines; Neutrophils; Oncology; Signal transduction.

Background: Previous studies reported that mild inflammation promotes retinal ganglion cell (RGC) survival and axonal regeneration after optic nerve (ON) injury with involvement of infiltrating macrophages and neutrophils. Here we aimed to evaluate the involvement and regulation of the main inflammatory chemokine pathway Cxcl5/Cxcr2 in the inflammation-mediated RGC survival and axonal regeneration in mice after ON injury.

Methods: The expressions and cellular locations of Cxcl5 and Cxcr2 were confirmed in mouse retina. Treatment effects of recombinant Cxcl5 and Cxcr2 antagonist SB225002 were studied in the explant culture and the ON injury model with or without lens injury. The number of RGCs, regenerating axons, and inflammatory cells were determined, and the activation of Akt and Stat3 signaling pathways were evaluated.

Results: Cxcr2 and Cxcl5 expressions were increased after ON and lens injury. Addition of recombinant Cxcl5 promoted RGC survival and neurite outgrowth in retinal explant culture with increase in the number of activated microglia, which was inhibited by SB225002 or clodronate liposomes. Recombinant Cxcl5 also alleviated RGC death and promoted axonal regeneration in mice after ON injury, and promoted the lens injury-induced RGC protection with increase in the number of activated CD68⁺ cells. SB225002 inhibited lens injury-induced cell infiltration and activation, and attenuated the promotion effect on RGC survival and axonal regeneration through reduction of lens injury-induced Akt activation.

Conclusions: Cxcl5 promotes RGC survival and axonal regeneration after ON injury and further enhances RGC protection induced by lens injury with CD68⁺ cell activation, which is attenuated by Cxcr2 antagonist. Cxcl5/Cxcr2 could be a potential therapeutic target for RGC survival promotion after ON injury.

Keywords: Cxcl5; axon regeneration; microglia; retinal ganglion cells; survival.

CXCL3 belongs to the CXC-type chemokine family and is known to play a multifaceted role in various human malignancies. While its clinical significance and mechanisms of action in uterine cervical cancer (UCC) remain unclear. This investigation demonstrated that the UCC cell line HeLa expressed CXCL3, and strong expression of CXCL3 was detected in UCC tissues relative to nontumor tissues. In addition, CXCL3 expression was strongly correlated with CXCL5 expression in UCC tissues. In vitro, HeLa cells overexpressing CXCL3, HeLa cells treated with exogenous CXCL3 or treated with conditioned medium from WPMY cells overexpressing CXCL3, exhibited enhanced proliferation and migration activities. In agreement with these findings, CXCL3 overexpression was also associated with the generation of HeLa cell tumor xenografts in athymic nude mice. Subsequent mechanistic studies demonstrated that CXCL3 overexpressing influenced the expression of extracellular signal-regulated kinase (ERK) signaling pathway associated genes, including ERK1/2, Bcl-2, and Bax, whereas the CXCL3-induced proliferation and migration effects were attenuated by exogenous administration of the ERK1/2 blocker PD98059. The data of the current investigation support that CXCL3 appears to hold promise as a potential tumor marker and interference target for UCC.

Background: Stanford type A aortic dissection (AAD) is a catastrophic disease. An immune infiltrate has been found within the aortic wall of dissected aortic specimens. The recall and activation of macrophages are key events in the early phases of AAD. Herein, the immune filtration profile of AAD was uncovered. Methods: Gene expression data from the GSE52093, GSE98770 and GSE153434 datasets were downloaded from the Gene Expression Omnibus (GEO). The differentially expressed genes (DEGs) of each dataset were calculated and then integrated. A protein-protein interaction (PPI) network was established with the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), and the hub genes were identified in Cytoscape. Furthermore, gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of hub genes were performed. Finally, we set GSE52093 and GSE98770 as the training set and GSE153434 as the validation set to assess immune infiltration in AAD using CIBERSORTx and analyzed the correlations between immune cells and hub genes in both the training and validation sets. Results: Sixty-one integrated DEGs were identified. The top 10 hub genes were selected from the PPI network, and 140 biological process (BP) terms and 12 pathways were enriched among the top 10 hub genes. The proportions of monocytes and macrophages were significantly higher in AAD tissues than in normal tissues. Notably, this result was consistent in the training set and the validation set. In addition, we found that among the hub genes, CA9, CXCL5, GDF15, VEGFA, CCL20, HMOX1, and SPP1 were positively correlated with CD14, a cell marker of monocytes, while CA9, CXCL5, GDF15, and VEGFA were positively correlated with CD68, a cell marker of macrophages in the training set. Finally, according to the results of the GO and KEGG analysis of hub genes, we found that the monocyte/macrophage-related genes were involved in immune-inflammatory responses through degradation of the extracellular matrix, endothelial cell apoptosis, hypoxia and the interaction of cytokines and chemokines. Conclusion: The monocyte-macrophage system plays a major role in immune-inflammatory responses in the development of AAD. Several hub genes are involved in this process via diverse mechanisms.

Keywords: aortic dissection; bioinformactics; hub gene; immune infiltration; monocyte—macrophage.

Mesenchymal stromal cells (MSCs) have shown significant heterogeneity in terms of therapeutic efficacy for inflammatory bowel disease (IBD) treatment, which may be due to an insufficient number of MSCs homing to the damaged tissue of the colon. Engineering MSCs with specific chemokine receptors can enhance the homing ability by lentiviral transduction. However, the unclear specific chemokine profile related to IBD and the safety concerns of viral-based gene delivery limit its application. Thus, a new strategy to modify MSCs to express specific chemokine receptors using mRNA engineering is developed to evaluate the homing ability of MSCs and its therapeutic effects for IBD. We found that CXCL2 and CXCL5 were highly expressed in the inflammatory colon, while MSCs minimally expressed the corresponding receptor CXCR2. Transient expression of CXCR2 in MSC was constructed and exhibited significantly enhanced migration to the inflamed colons, leading to a robust anti-inflammatory effect and high efficacy. Furthermore, the high expression of semaphorins7A on MSCs were found to induce the macrophages to produce IL-10, which may play a critical therapeutic role. This study demonstrated that the specific chemokine receptor CXCR2 mRNA-engineered MSCs not only improves the therapeutic efficacy of IBD but also provides an efficient and safe MSC modification strategy.

Keywords: CXCL2; CXCL5; CXCR2; IBD; mesenchymal stromal cells; sema7A.

In cancer genomics, gene expression levels provide important molecular signatures for all types of cancer, and this could be very useful for predicting the survival of cancer patients. However, the main challenge of gene expression data analysis is high dimensionality, and microarray is characterised by few number of samples with large number of genes. To overcome this problem, a variety of penalised Cox proportional hazard models have been proposed. We introduce a novel network regularised Cox proportional hazard model and a novel multiplex network model to measure the disease comorbidities and to predict survival of the cancer patient. Our methods are applied to analyse seven microarray cancer gene expression datasets: breast cancer, ovarian cancer, lung cancer, liver cancer, renal cancer and osteosarcoma. Firstly, we applied a principal component analysis to reduce the dimensionality of original gene expression data. Secondly, we applied a network regularised Cox regression model on the reduced gene expression datasets. By using normalised mutual information method and multiplex network model, we predict the comorbidities for the liver cancer based on the integration of diverse set of omics and clinical data, and we find the diseasome associations (disease-gene association) among different cancers based on the identified common significant genes. Finally, we evaluated the precision of the approach with respect to the accuracy of survival prediction using ROC curves. We report that colon cancer, liver cancer and renal cancer share the CXCL5 gene, and breast cancer, ovarian cancer and renal cancer share the CCND2 gene. Our methods are useful to predict survival of the patient and disease comorbidities more accurately and helpful for improvement of the care of patients with comorbidity. Software in Matlab and R is available on our GitHub page: https://github.com/ssnhcom/NetworkRegularisedCox.git.

During inflammation, proteins and lipids act in a concerted fashion, calling for combined analyses. Fibroblasts are powerful mediators of chronic inflammation. However, little is known about eicosanoid formation by human fibroblasts. The aim of this study was to analyze the formation of the most relevant inflammation mediators including proteins and lipids in human fibroblasts upon inflammatory stimulation and subsequent treatment with dexamethasone, a powerful antiphlogistic drug. Label-free quantification was applied for proteome profiling, while an in-house established data-dependent analysis method based on high-resolution mass spectrometry was applied for eicosadomics. Furthermore, a set of 188 metabolites was determined by targeted analysis. The secretion of 40 proteins including cytokines, proteases, and other inflammation agonists as well as 14 proinflammatory and nine anti-inflammatory eicosanoids was found significantly induced, while several acylcarnithins and sphingomyelins were found significantly downregulated upon inflammatory stimulation. Treatment with dexamethasone downregulated most cytokines and proteases, abrogated the formation of pro- but also anti-inflammatory eicosanoids, and restored normal levels of acylcarnithins but not of sphingomyelins. In addition, the chemokines CXCL1, CXCL5, CXCL6, and complement C3, known to contribute to chronic inflammation, were not counter-regulated by dexamethasone. Similar findings were obtained with human mesenchymal stem cells, and results were confirmed by targeted analysis with multiple reaction monitoring. Comparative proteome profiling regarding other cells demonstrated cell-type-specific synthesis of, among others, eicosanoid-forming enzymes as well as relevant transcription factors, allowing us to better understand cell-type-specific regulation of inflammation mediators and shedding new light on the role of fibroblasts in chronic inflammation.

OBJECTIVE

Prosthetic Joint Infection (PJI) is a serious complication of Total Joint Arthroplasty (TJA). The Th-17 immune response characterised by IL (interleukin)-17A, IL-17F, IL-23, chemotactic cytokines and their receptors, plays a prominent role in the immune response to invading bacteria. In addition, high expression of IL-17A has been reported in PJI. The aim of this study was to investigate whether genetic variation in the key molecules of the Th-17 immune response can affect the risk for PJI.

METHODS

Altogether ten Single Nucleotide Polymorphisms (SNPs) of IL17A (rs2275913), IL17F (rs763780), IL4 (rs2243250), IL12A (rs583911), IL12B (rs3212227 and (rs17860508), IL23R (rs7517847), CXCL1 (rs4074), CXCL5 (rs425535) and CXCR2 (rs2230054) genes were genotyped by PCR with sequence specific primers (SSP) in 98 patients with PJI and two control groups 1) an aseptic TJA control (253 patients with TJA that did not develop PJI at least 6 yrs. after the surgery) and 2) a population control (185 healthy control subjects without TJA).

RESULTS

Allele, genotype and phenotype frequencies of investigated SNPs did not differ between the patients with PJI and control patients with aseptic TJA (p>0.05). There was no difference in the distribution of tested SNPs between patients with PJI and population controls without TJA (p>0.05) or between the two controls groups (p>0.05).

CONCLUSIONS

We cannot nominate any of studied polymorphisms in IL17A, IL17F, IL4, IL12A, IL12B, IL23R, CXCL1, CXCL5 and CXCR2 genes as risk factors for PJI in the Czech TJA patients examined.

OBJECTIVE

To determine if exacerbation of pre-existing chronic colitis in Winnie (Muc2 mutant) mice induces colonic dysplasia.

METHODS

Winnie mice and C57BL6 as a genotype control, were administered 1% w/v dextran sulphate sodium (DSS) orally, followed by drinking water alone in week-long cycles for a total of three cycles. After the third cycle, mice were killed and colonic tissue collected for histological and immunohistochemical evaluation. Inflammation and severity of dysplasia in the colonic mucosa were assessed in H&E sections of the colon. Epithelial cell proliferation was assessed using Ki67 and aberrant β-catenin signalling assessed with enzyme-based immunohistochemistry. Extracted RNA from colonic segments was used for the analysis of gene expression using real-time quantitative PCR. Finally, the distribution of Cxcl5 was visualised using immunohistochemistry.

RESULTS

Compared to controls, Winnie mice exposed to three cycles of DSS displayed inflammation mostly confined to the distal-mid colon with extensive mucosal hyperplasia and regenerative atypia resembling epithelial dysplasia. Dysplasia-like changes were observed in 100% of Winnie mice exposed to DSS, with 55% of these animals displaying changes similar to high-grade dysplasia, whereas high-grade changes were absent in wild-type mice. Occasional penetration of the muscularis mucosae by atypical crypts was observed in 27% of Winnie mice after DSS. Atypical crypts however displayed no evidence of oncogenic nuclear β-catenin accumulation, regardless of histological severity. Expression of Cav1, Trp53 was differentially regulated in the distal colon of Winnie relative to wild-type mice. Expression of Myc and Ccl5 was increased by DSS treatment in Winnie only. Furthermore, increased Ccl5 expression correlated with increased complexity in abnormal crypts. While no overall difference in Cxcl5 mucosal expression was observed between treatment groups, epithelial Cxcl5 protein appeared to be diminished in the atypical epithelium.

CONCLUSIONS

Alterations to the expression of Cav1, Ccl5, Myc and Trp53 in the chronically inflamed Winnie colon may influence the transition to dysplasia.

Hassall's corpuscles (HCs) are composed of cornifying, terminally differentiated medullary thymic epithelial cells (mTECs) that are developed under the control of Aire. Here, we demonstrated that HC-mTECs show features of cellular senescence and produce inflammatory cytokines and chemokines including CXCL5, thereby recruiting and activating neutrophils to produce IL-23 in the thymic medulla. We further indicated that thymic plasmacytoid dendritic cells (pDCs) expressing IL-23 receptors constitutively produced Ifna, which plays a role in single positive (SP) cell maturation, in an Il23a-dependent manner. Neutrophil depletion with anti-Ly6G antibody injection resulted in a significant decrease of Ifna expression in the thymic pDCs, suggesting that thymic neutrophil activation underlies the Ifna expression in thymic pDCs in steady state conditions. A New Zealand White mouse strain showing HC hyperplasia exhibited greater numbers and activation of thymic neutrophils and pDCs than B6 mice, whereas Aire-deficient B6 mice with defective HC development and SP thymocyte maturation showed significantly compromised numbers and activation of these cells. These results collectively suggested that HC-mTECs with cell-senescence features initiate a unique cell activation cascade including neutrophils and pDCs leading to the constitutive IFNα expression required for SP T-cell maturation in the thymic medulla.

BACKGROUND

Platelet-derived growth factor (PDGF) is a multifunctional growth factor that exerts its biological effects on cellular chemotaxis, proliferation, matrix synthesis, antiapoptosis, and vascularization. PDGF is clinically approved to treat neuropathic diabetic ulcers and osseous defects due to periodontal disease.

OBJECTIVE

The short half-life in vivo of PDGF limits the efficacy of its biological functions. Solving this problem remains a key obstacle for PDGF clinical application. Therefore, the development of an optimized controlled release delivery system offers significant potential.

UNASSIGNED

In this article, we highlight the development of a polymeric delivery system of nanofibrous scaffolds containing PDGF-encapsulated microspheres for tissue engineering. The designed scaffolds were evaluated in a subcutaneous implantation model for tissue neogenesis, vascularization, and chemokine gene expression, as well as soft-tissue repair. PDGF was found to strongly upregulate in vivo gene expression of the CXC chemokine family members such as CXC chemokine ligand CXCL1, CXCL2, and CXCL5 that are important in angiogenesis, inflammation, and wound repair.

UNASSIGNED

Recombinant human PDGF is approved by the Food and Drug Administration for patients afflicted with diabetic foot ulcers or compromised periodontal wounds. Challenges related to the transient biological activity of bolus PDGF administration using currently available release systems continue. Thus, it is necessary to explore new delivery systems to optimize biological activity and bioavailability of tissue growth factors.

CONCLUSIONS

The use of a controlled, "dial-able" delivery system allows for a more tightly regulated release of factors to promote repair of soft- and hard-tissue defects for clinical application.

Alveolar macrophages orchestrate pulmonary innate immunity and are essential for early immune surveillance and clearance of microorganisms in the airways. Inflammatory signaling must be sufficiently robust to promote host defense but limited enough to prevent excessive tissue injury. Macrophages in the lungs utilize multiple transcriptional and post-transcriptional mechanisms of inflammatory gene expression to delicately balance the elaboration of immune mediators. RNA terminal uridyltransferases (TUTs), including the closely homologous family members Zcchc6 (TUT7) and Zcchc11 (TUT4), have been implicated in the post-transcriptional regulation of inflammation from studies conducted in vitro. In vivo, we observed that Zcchc6 is expressed in mouse and human primary macrophages. Zcchc6-deficient mice are viable and born in Mendelian ratios and do not exhibit an observable spontaneous phenotype under basal conditions. Following an intratracheal challenge with S. pneumoniae, Zcchc6 deficiency led to a modest but significant increase in the expression of select cytokines including IL-6, CXCL1, and CXCL5. These findings were recapitulated in vitro whereby Zcchc6-deficient macrophages exhibited similar increases in cytokine expression due to bacterial stimulation. Although loss of Zcchc6 also led to increased neutrophil emigration to the airways during pneumonia, these responses were not sufficient to impact host defense against infection.

Chemokines induce migration of inflammatory cells. In the synovial tissue of rheumatoid arthritis (RA), abundant chemokines are expressed, which contribute migration of lymphocytes and monocytes/macrophages, stimulation of synovial cells, and angiogenesis. Blockade of CCL2, CCL3, CCL5, CCR1, CCR9, CXCL2, CXCL5, CXCL13, CXCL16, CXCR3, CXCR4, CXCR7, and CX3CL1 showed improvement of arthritis of animal models. Moreover, CCR1 antagonist and anti-CXCL10 antibody reduced arthritis of patients with RA. Chemokine is a promising target for RA therapy.

Interleukin-1α is mainly expressed on the cell membrane, but can also be secreted during inflammation. The roles of secreted and membrane IL-1α in acute liver inflammation are still not known. Here, we examined the functions of secreted and membrane IL-1α in a mouse model of carbon tetrachloride-induced acute liver injury. We show that secreted IL-1α aggravates liver damage and membrane IL-1α slightly protects mice from liver injury. Further studies showed that secreted IL-1α promotes T-cell activation. It also increased the expansion of CD11b(+) Gr1(+) myeloid cells, which may serve as a negative regulator of acute liver inflammation. Moreover, secreted IL-1α induced IL-6 production from hepatocytes. IL-6 neutralization reduced the proliferation of CD11b(+) Gr1(+) myeloid cells in vivo. CCL2 and CXCL5 expression was increased by secreted IL-1α in vitro and in vivo. Antagonists of the chemokine receptors for CCL2 and CXCL5 significantly reduced the migration of CD11b(+) Gr1(+) myeloid cells. These results demonstrate that secreted and membrane IL-1α play different roles in acute liver injury. Secreted IL-1α could promote T-cell activation and the recruitment and expansion of CD11b(+) Gr1(+) myeloid cells through induction of CCL2, CXCL5, and IL-6. The controlled release of IL-1α could be a critical regulator during acute liver inflammation.

OBJECTIVE

To analyze three kinds of genotype hepatitis C virus (HCV) core protein expressed in human hepatoma (Huh-7) cell line and to recognize HCV core proteins biological function and its pathogenic mechanism.

METHODS

The Huh-7 cell expressed three kinds of core proteins were established respectively. Affymetrix human gene chip was used for identifying the gene expression dependently on Affymetrix's protocol. All genes changed by 3 or 1.5 folds between the transfected cells and a control cells were further analyzed, and annotated by using NetAffx analysis through Affymetrix website and were categorized based on their biological processes.

RESULTS

The HCV-1b core protein caused 16 genes up/down-regulated expression, of which the immune response genes of PF4V1 and SPP1 were up-regulated 3.4 or 4.4 folds respectively. The HCV-2a core protein had caused the immune response gene CXCL5 and apoptosis gene BTF a down-regulated expression of 3.4 and 3.1 folds respectively, but caused the apoptosis genes of HRK and LZTS1 an up-regulated expression of 3.2 and 3.4 folds respectively. As compared with HCV 1b or 2a core protein, HCV-4b core protein caused 111 genes expression changing and it had more obvious effects on gene expression. If we applied 1.5 fold change for a comparison gene expression, a few of the same gene expression profiles might be caused by these two core proteins.

CONCLUSIONS

The three kinds of HCV core protein should have its own expression character and be mainly shown in immune responses, signal transduction, apoptosis, etc. It should be helpful for our recognizing the HCV core protein biological function and its pathogenic mechanism.

Neutrophil chemotactic protein (NCP) is a rabbit CXC chemokine with activating and chemotactic properties on neutrophilic granulocytes. Although its selective activity on neutrophils is demonstrated, its interactions with specific chemokine receptors are not defined. For further functional characterization, NCP was chemically synthesized and was found to be equipotent as natural NCP in neutrophil chemotaxis. To identify its human homologue, we separately expressed two potential rabbit NCP receptors (CXCR1 and CXCR2) in Jurkat cells. Pure synthetic NCP was equally efficient to promote chemotaxis through either rabbit CXCR1 or CXCR2. Moreover, chemotaxis assays on rabbit CXCR1 and CXCR2 transfectants showed that NCP uses the same receptors as interleukin-8 (IL-8), a major rabbit CXC chemokine, but not rabbit GROalpha, which only recognized CXCR2. In addition, specific inhibitors for CXCR1 or CXCR2 reduced rabbit neutrophil chemotaxis induced by NCP and rabbit IL-8. Furthermore, NCP and the structurally related human CXCR1/CXCR2 agonist CXCL6/GCP-2 (granulocyte chemotactic protein-2) cross-desensitized each other in intracellular calcium release assays on human neutrophils, further indicating that both chemokines share the same receptors. The inflammatory role of NCP was also evidenced by its potent granulocytosis inducing capacity in rabbits upon systemic administration. This study provides in vitro and in vivo evidences that NCP is the functional rabbit homologue for human CXCL6/GCP-2 rather than the most related CXCR2 agonist CXCL5/ENA-78 (epithelial cell-derived neutrophil activating peptide-78). It is concluded that the rabbit is a better model to study human neutrophil activation compared to mice, which lack CXCL8/IL-8.

Pregnancy rate of women decreases with age due to declining quality of oocytes and embryos. However, there is no established method to improve pregnancy rate in aging women. In this study, we identified a senescence-associated secretory phenotype (SASP) factor partially responsible for the decline in embryo implantation potential. Based on microarray analysis using young and aging human embryos at the same morphological grade, 702 genes showed >fivefold increases in aging human blastocysts. Among these genes, C-X-C motif chemokine 5 (CXCL5) showed 7.7-fold increases in aging human blastocysts. However, no-age-dependent changes in expression of the CXCR2, the cognate receptor for CXCL5, were found. In aging mice, Cxcl5 transcript levels were also increased in oocytes and embryos. Treatment of young mouse embryos with CXCL5 decreased implantation rates, together with increased expression of aging markers (P53, P21, Pai-1, and Il-6). Moreover, CXCL5 treatment suppressed trophoblast outgrowth in young mouse blastocysts. Conversely, suppression of CXCL5-CXCR2 signaling in aging mouse embryos using neutralizing antibodies and a receptor antagonist improved the implantation rate, leading to increases in pregnancy and delivery of normal pups. The gene expression pattern of these embryos was comparable to that in young mouse embryos showing enriched cell proliferation-related pathways. In conclusion, we identified CXCL5 as a SASP factor in human and mouse embryos and suppression of CXCL5-CXCR2 signaling during embryo culture improved pregnancy success in aging mice. Future analysis on CXCL5-CXCR2 signaling suppression in human embryos could be the basis to improve embryo development and pregnancy outcome in middle-aged infertile patients.

Keywords: CXCL5; CXCR2; SASP; aging; infertility; preimplantation embryo.