[Aqueous extract of Epimedium sagittatum mitigates pulmonary fibrosis in mice].

This study aims to investigate the intervention effect of the aqueous extract of Epimedium sagittatum Maxim on the mouse model of bleomycin(BLM)-induced pulmonary fibrosis, so as to provide data support for the clinical treatment of pulmonary fibrosis. Ninety male C57BL/6N mice were randomized into normal(n=10), model(BLM, n=20), pirfenidone(PFD, 270 mg·kg~(-1), n=15), and low-, medium-, and high-dose E. sagittatum extract(1.67 g·kg~(-1), n=15; 3.33 g·kg~(-1), n=15; 6.67 g·kg~(-1), n=15) groups. The model of pulmonary fibrosis was established by intratracheal instillation of BLM(5 mg·kg~(-1)) in the other five groups except the normal group, which was treated with an equal amount of normal saline. On the day following the modeling, each group was treated with the corresponding drug by gavage for 21 days. During this period, the survival rate of the mice was counted. After gavage, the lung index was calculated, and the morphology and collagen deposition of the lung tissue were observed by hematoxylin-eosin(HE) and Masson staining, respectively. The levels of reactive oxygen species(ROS) in lung cell suspensions were measured by flow cytometry. The levels of glutathione peroxidase(GSH-Px), total superoxide dismutase(T-SOD), and malondialdehyde(MDA) the in lung tissue were measured. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling(TUNEL) was employed to examine the apoptosis of lung tissue cells. The content of interleukin-6(IL-6), chemokine C-C motif ligand 2(CCL-2), matrix metalloproteinase-8(MMP-8), transforming growth factor-beta 1(TGF-ß1), alpha-smooth muscle actin(α-SMA), E-cadherin, collagen Ⅰ, and fibronectin in the lung tissue was measured by enzyme-linked immunosorbent assay(ELISA). The expression levels of F4/80, Ly-6G, TGF-ß1, and collagen Ⅰ in the lung tissue were determined by immunohistochemistry. The mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue were determined by qRT-PCR. The content of hydroxyproline(HYP) in the lung tissue was determined by alkaline hydrolysation. The expression of α-SMA and E-cadherin was detected by immunofluorescence, and the protein levels of α-SMA, vimentin, E-cadherin in the lung tissue were determined by Western blot. The results showed the aqueous extract of E. sagittatum increased the survival rate, decreased the lung index, alleviated the pathological injury, collagen deposition, and oxidative stress in the lung tissue, and reduced the apoptotic cells. Furthermore, the aqueous extract of E. sagittatum down-regulated the protein levels of F4/80 and Ly-6G and the mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue, reduced the content of IL-6, CCL-2, and MMP-8 in the alveolar lavage fluid. In addition, it lowered the levels of HYP, TGF-ß1, α-SMA, collagen Ⅰ, fibronectin, and vimentin, and elevated the levels of E-cadherin in the lung tissue. The aqueous extract of E. sagittatum can inhibit collagen deposition, alleviate oxidative stress, and reduce inflammatory response by regulating the expression of the molecules associated with epithelial-mesenchymal transition, thus alleviating the symptoms of bleomycin-induced pulmonary fibrosis in mice.

Interplay between EZH2/ß-catenin in stemness of cisplatin-resistant HNSCC and their role as therapeutic targets.

The Wnt/ß-catenin signaling pathway is associated with the regulation of cancer stem cells, and it can be driven by epigenetic modifications. Here, we aim to identify epigenetic modifications involved in the control of the Wnt/ß-catenin signaling and investigate the role of this pathway in the accumulation of cancer stem cells (CSC) and chemoresistance of Head and Neck Squamous Cell Carcinoma (HNSCC). Quantitative-PCR, western blot, shRNA assay, viability assay, flow cytometry assay, spheres formation, xenograft model, and chromatin immunoprecipitation were employed to evaluate the Wnt/ß-catenin pathway and EZH2 in wild-type and chemoresistant oral carcinoma cell lines, and in the populations of CSC and non-stem cells. We demonstrated that ß-catenin and EZH2 were accumulated in cisplatin-resistant and CSC population. The upstream genes of the Wnt/ß-catenin signaling (APC and GSK3ß) were decreased, and the downstream gene MMP7 was increased in the chemoresistant cell lines. The inhibition of ß-catenin and EZH2 combined effectively decreased the CSC population in vitro and reduced the tumor volume and CSC population in vivo. EZH2 inhibition increased APC and GSK3ß, and the Wnt/ß-catenin inhibition reduced MMP7 levels. In contrast, EZH2 overexpression decreased APC and GSK3ß and increased MMP7. EZH2 and ß-catenin inhibitors sensitized chemoresistant cells to cisplatin. EZH2 and H3K27me3 bounded the promoter of APC, leading to its repression. These results suggest that EZH2 regulates ß-catenin by inhibiting the upstream gene APC contributing to the accumulation of cancer stem cells and chemoresistance. Moreover, the pharmacological inhibition of the Wnt/ß-catenin combined with EZH2 can be an effective strategy for treating HNSCC.

Effect of CUX1 on the Proliferation of Hu Sheep Dermal Papilla Cells and on the Wnt/ß-Catenin Signaling Pathway.

CUT-like homeobox 1 protein (CUX1), also called CUX, CUTL1, and CDP, is a member of the DNA-binding protein homology family. Studies have shown that CUX1 is a transcription factor that plays an important role in the growth and development of hair follicles. The aim of this study was to investigate the effect of CUX1 on the proliferation of Hu sheep dermal papilla cells (DPCs) to reveal the role of CUX1 in hair follicle growth and development. First, the coding sequence (CDS) of CUX1 was amplified by PCR, and then CUX1 was overexpressed and knocked down in DPCs. A Cell Counting Kit-8 (CCK8), 5-ethynyl-2-deoxyuridine (EdU), and cell cycle assays were used to detect the changes in the proliferation and cell cycle of DPCs. Finally, the effects of overexpression and knockdown of CUX1 in DPCs on the expression of WNT10, MMP7, C-JUN, and other key genes in the Wnt/ß-catenin signaling pathway were detected by RT-qPCR. The results showed that the 2034-bp CDS of CUX1 was successfully amplified. Overexpression of CUX1 enhanced the proliferative state of DPCs, significantly increased the number of S-phase cells, and decreased the number of G0/G1-phase cells (p < 0.05). CUX1 knockdown had the opposite effects. It was found that the expression of MMP7, CCND1 (both p < 0.05), PPARD, and FOSL1 (both p < 0.01) increased significantly after overexpression of CUX1 in DPCs, while the expression of CTNNB1 (p < 0.05), C-JUN, PPARD, CCND1, and FOSL1 (all p < 0.01) decreased significantly. In conclusion, CUX1 promotes proliferation of DPCs and affects the expression of key genes of the Wnt/ß-catenin signaling pathway. The present study provides a theoretical basis to elucidate the mechanism underlying hair follicle development and lambskin curl pattern formation in Hu sheep.

Synergistic Protective Effect of Interactions of Quercetin with Lycopene Against Ochratoxin A-Induced Ulcerative Colitis.

Ulcerative colitis is a type of inflammatory bowel disease responsible for the inflammation of the innermost lining of the colon and rectum. The present study's objective is to determine the potential synergistic impact of quercetin (QR) and lycopene (LP) in ulcerative colitis (UC) induced in rats by ochratoxin A (OTA) by biochemical and morphological alterations. QR and LP were administered alone and in combination with the OTA for 7 days. OTA administration caused UC generation, resulting in significant changes in body weight percentage, disease activity index (DAI), macroscopic evaluation, colon weight/length ratio, and histological score. In addition to the above parameters, it also leads to elevated oxidative stress, i.e. increased malondialdehyde (MDA), nitric oxide (NO), myeloperoxidase (MPO), and hydroxyproline levels and decreased superoxide dismutase (SOD) and reduced glutathione (GSH) levels. Histological changes in the colon architecture were also observed suggestive of extensive mucosal damage. In addition, a high level of matrix metalloproteinase 7 (MMP7) was observed in immunohistochemistry, and a high level of gene expression of osteopontin (OPN), runt-related transcription factor 2 (RUNX2), MMP-7, and interleukin-6 (IL-6) was observed in OTA administered animals. The combination of QR and LP significantly restored the per cent body weight loss and DAI score and improved macroscopic and histological changes, colon weight/length ratio, and macroscopic damages. It also improved the biochemical parameters to near-normal levels, i.e. reduced MDA, NO, MPO, and hydroxyproline levels and increased SOD and GSH levels. In addition, OPN, Runx2, MMP-7, and IL-6 gene expression decreased compared to the OTA-induced UC group. Outcomes of the present study indicate the potential of QR + LP as anti-inflammatory and immunomodulatory agents against OTA-induced UC in rats.

Knockdown of CENPU inhibits cervical cancer cell migration and stemness through the FOXM1/Wnt/ß-catenin pathway.

Currently, the clinical outcome of cervical cancer (CC) is still undesirable, and it is urgent to explore more treatment strategies for CC. In this study, the effects of CENPU on migration and stemness of CC was studied. The CENPU expression were retrieved from The Cancer Genome Atlas (TCGA). The effects of CENPU on the viability and proliferation of cells were evaluated by CCK-8 assay and colony formation assay. Wound healing assay and invasion assay were chosen to assess migration and invasion of cells. Tumorsphere-forming assay was applied for testing the stemness. Western blot analysis was applied for assessing the level of CENPU, Nanog, Oct4, FOXM1, ß-catenin, c-myc and MMP-7. The tumor sizes and volumes were also measured. The TCGA data and WB assay suggested that CENPU was upregulated in CC. CENPU knockdown would inhibit the viability of CC cells and prohibit the migration and invasion of cells. Tumorsphere-forming assay and WB results suggested that CENPU silencing decreased the sphere formation rate and the expression of Nanog and Oct4. Moreover, CENPU knockdown suppressed the expression of FOXM1, ß-catenin, c-myc and MMP-7 by WB. In vivo study demonstrated that CENPU knockdown inhibited the growth of CC, indicated by reduced sizes and volumes of CC. In summary, our results suggested that knockdown of CENPU inhibited CC migration and stemness through the FOXM1/Wnt/ß-catenin pathway.

Anti-proliferative action, molecular investigation and computational studies of novel fused heterocyclic cellulosic compounds on human cancer cells.

Reactivity of MCEC (3) with diazonium chloride, DMF-DMA and NH2NH2 to afford fused heterocyclic cellulosic derivative which confirmed through spectral analysis. Also, the cellulosic compounds were evaluated their growth inhibitory activity contra cancer cells A549 and Caco2 using neutral red uptake assay. Compounds, MCEN(6), MCPT(5a), MCPT(5b) showed better growth inhibitory activity on A549 and Caco2 growth compared to control values. While compound MCPY(7) exerted the best cytotoxic activity against A549 cells after 48 h. The expression levels of HIF-1α, ß-Catenin, MYC, Cyclin D1 and MMP7 genes in A549 cells were examined using QRT-PCR. The compounds MCEN(6) and MCPY(7) down regulated levels of ß-Catenin, MYC, Cyclin D1 and MMP7 genes and up-regulated levels of HIF-1α when treated with A549 cells compared to control values. Also, these biological studies confirmed through docking stimulation with different proteins and showed least binding energy with amino acids and attached with NH2 and OH of cellulose with hydrogen bond interaction. Moreover, optimization of compounds using DFT/6-311(G) showed the stability of them and identifies their physical descriptors which showed excellent correlation with experimental results. Noteworthy, compounds, MCEN(6) and MCPY(7) were most promising anticancer agents against lung cancer through the regulation of apoptosis, cell cycle, proliferation, progression, chemo-resistance, and angiogenesis.

S100A8-mediated metabolic adaptation controls HIV-1 persistence in macrophages in vivo.

HIV-1 eradication is hindered by viral persistence in cell reservoirs, established not only in circulatory CD4+T-cells but also in tissue-resident macrophages. The nature of macrophage reservoirs and mechanisms of persistence despite combined anti-retroviral therapy (cART) remain unclear. Using genital mucosa from cART-suppressed HIV-1-infected individuals, we evaluated the implication of macrophage immunometabolic pathways in HIV-1 persistence. We demonstrate that ex vivo, macrophage tissue reservoirs contain transcriptionally active HIV-1 and viral particles accumulated in virus-containing compartments, and harbor an inflammatory IL-1R+S100A8+MMP7+M4-phenotype prone to glycolysis. Reactivation of infectious virus production and release from these reservoirs in vitro are induced by the alarmin S100A8, an endogenous factor produced by M4-macrophages and implicated in "sterile" inflammation. This process metabolically depends on glycolysis. Altogether, inflammatory M4-macrophages form a major tissue reservoir of replication-competent HIV-1, which reactivate viral production upon autocrine/paracrine S100A8-mediated glycolytic stimulation. This HIV-1 persistence pathway needs to be targeted in future HIV eradication strategies.

Overexpressed LINC01510 Attenuates Epithelial-Mesenchymal Transition in High Glucose-Induced Renal Tubular Epithelial Cells via Inactivating MMP7.

OBJECTIVE: Matrix metallopeptidase 7 (MMP7) can promote renal fibrosis in diabetic kidney disease (DKD). A study found that LINC01510 overexpression inhibits MMP7 to play a role in renal cancer, but the relationship between the two in DKD had not been revealed, and the function of LINC01510 also needed to be explored, which was also the focus of this study. METHODS: The morphological changes of HK-2 cells induced by high glucose were observed by an inverted microscope, and fluorescence in situ hybridization was used to determine the subcellular localization of LINC01510. Quantitative realtime polymerase chain reaction was used to detect the levels of LINC01510 and MMP7. The effect of LINC01510 and MMP7 overexpression on high glucose-induced HK-2 cell migration and epithelial-mesenchymal transition (EMT)-related protein changes was confirmed by wound healing experiments and western blot. RESULTS: High glucose induced HK-2 cells to gradually lose their epithelial phenotype, and decreased LINC01510 in a time-dependent manner. LINC01510 was located in the nucleus of HK-2 cells. LINC01510 overexpression increased the level of LINC01510, inhibited cell migration, and reduced the expression of MMP-7, Vimentin, α-SMA, and Fibronectin protein, and promoted the expression of E-cadherin protein in high glucose-induced cells. The effect of MMP7 overexpression on migration and EMT-related proteins was opposite to the effect of LINC01510 overexpression, and partially reversed the effect of LINC01510 overexpression in high glucose-induced cells. CONCLUSION: Our research shows that LINC01510 overexpression inactivates MMP7 to attenuate high glucose-induced EMT of renal tubular epithelial cells.

Human amniotic fluid mesenchymal stem cells attenuate pancreatic cancer cell proliferation and tumor growth in an orthotopic xenograft mouse model.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a malignant cancer and chemotherapy ineffectively treats PDAC, leading to the requirement for alternative tumor-targeted treatment. Human amniotic fluid mesenchymal stem cells (hAFMSCs) have been revealed to suppress tumor growth in various cancers and they are a strong candidate for treating PDAC. METHODS: To evaluate the effects of hAFMSCs on human pancreatic carcinoma cells (PANC1, AsPC1 and BxPC3 cell lines) and the possible mechanism involved, an in vitro cell coculture system was used. A PANC1 orthotopic xenograft mouse model was established and hAFMSCs were injected intravenously at 4 weeks post-xenograft. RESULTS: An in vitro coculture assay showed that hAFMSCs inhibited PANC1 cell proliferation by inducing S phase cell cycle arrest and increased cell apoptosis in a time-dependent manner. In PANC1 cells, hAFMSCs caused the downregulation of Cyclin A and Cyclin B1 as well as the upregulation of p21 (CDKN1A) at 24 h post coculture. The upregulation of pro-apoptotic factors Caspase-3/-8 and Bax at 24 h post coculture reduced the migration and invasion ability of PANC1 cells through inhibiting the epithelial-mesenchymal transition (EMT) process. In a PANC1 orthotopic xenograft mouse model, a single injection of hAFMSCs showed significant tumor growth inhibition with evidence of the modulation of cell cycle and pro-apoptotic regulatory genes and various genes involved in matrix metallopeptidase 7 (MMP7) signaling-triggered EMT process. Histopathological staining showed lower Ki67 levels in tumors from hAFMSCs-treated mice. CONCLUSIONS: Our data demonstrated that hAFMSCs strongly inhibit PDAC cell proliferation, tumor growth and invasion, possibly by altering cell cycle arrest and MMP7 signaling-triggered EMT.

The effects of Jiawei Duhuo Jisheng mixture on Wnt/ß-catenin signaling pathway in the synovium inflamed by knee osteoarthritis: An in vitro and in vivo experiment.

ETHNOPHARMACOLOGICAL RELEVANCE: Knee osteoarthritis (KOA) is one of the common age-degenerative diseases. Recent studies have demonstrated that the pathogenesis of KOA is closely related to synovial lesions. Jiawei Duhuo Jisheng mixture (JDJM) has shown great potential in the treatment of KOA. However, the effect and mechanism of JDJM on synovial lesions of KOA remain unclear. AIM OF THE STUDY: The regulatory effect of JDJM on the Wnt/ß-catenin signaling pathway in KOA inflamed synovium was studied via in vitro and in vivo experiments, respectively. MATERIALS AND METHODS: For the in vitro experiment, fibroblasts were isolated from the rabbit synovium with KOA. The fibroblasts were grouped as follows: the vehicle group was given 0.5% FBS; the inhibitor group was treated with 0.5% volume fraction of XAV939; the normal serum groups and JDJM serum groups were treated with 5%, 10%, and 20% volume fractions of normal serum and JDJM-containing serum. The expression levels of Wnt3a, ß-catenin, Cyclin D1, metalloproteinase-7(MMP-7) and cyclooxygenase-2(COX-2) were detected by different assays 48 and 72 h after the intervention. For the in vivo experiment, the rabbit KOA model was prepared using the improved Hulth modeling method, whereby all rabbits were randomly divided into normal control, model control, positive control, and traditional Chinese medicine (TCM) groups. The expression levels of Wnt3a, ß-catenin, Cyclin D1, MMP-7 and COX-2 were detected by different assays in the 2, 4, and 8 weeks of treatment. RESULTS: In the two test results of in vitro experiments, the normal serum group was compared with the JDJM-containing serum group with the same volume fraction, demonstrating that mRNA transcription and protein expression levels of Wnt3a, ß-catenin, Cyclin D1, MMP-7, and COX-2 in the latter decreased (P < 0.05), with more pronounced effects observed in the group treated with 20% volume fraction of JDJM serum. Compared with the inhibitor group, there was no significant difference (P > 0.05) in the mRNA transcription and protein expression levels, i.e., Wnt3a, ß-catenin, Cyclin D1, and MMP-7 were observed in the JDJM serum groups, except for a significant decrease (P < 0.05) in the level of mRNA transcription and protein expression of COX-2. Based on the in vivo experiment, compared to the model control group, articular cartilage, synovial hyperplasia, and the inflammatory reaction of the TCM group at different treatment times were significantly improved. The mRNA transcription level of Wnt3a, ß-catenin, Cyclin D1, MMP-7 and COX-2 detected by RT-qPCR and the protein expression level of Wnt3a, ß-catenin, Cyclin D1, MMP-7 and COX-2 detected by Western blot were significantly reduced (P < 0.05), and the effect was more evident at the eighth week. CONCLUSION: JDJM can regulate the synovial Wnt/ß-catenin signaling pathway in KOA models, reduce the mRNA transcription and protein expression levels of Wnt3a, ß-catenin, Cyclin D1, MMP-7, and COX-2 in the synovium, thus inhibiting synovial inflammation and protecting articular cartilage, which could be the key mechanism of action in treating this disease.

Effects of BMI1 Gene on Regulating Apoptosis, Invasion, and Migration of HEC-1B Cells Induced by Ionizing Radiation.

The aim of this study was to examine the role of B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1) gene in regulating the apoptosis, invasion, and migration of human endometrial adenocarcinoma cell line (HEC-1B) cells induced by ionizing radiation. The expression of BMI1 mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR), and the positive expression of BMI1 was detected by immunohistochemistry (IHC) staining. HEC-1 B cells were randomly divided into three groups: control group, BMI1 overexpression group, and BMI1 inhibitor group. Cell proliferation was detected by cell counting kit-8 (CCK-8); cell migration and invasion were detected by Transwell test; cell apoptosis was detected by flow cytometry; and the expression of MMP2, MMP7, MMP9, Rock1, RhoA, P53, P21, and Bax protein was detected by the western blot. The results suggested that the expression of BMI1 mRNA and tissue positive in endometrial cancer tissues was increased significantly. After ionizing radiation, compared with the control group, the proliferation, cell migration, and invasion of HEC-1B cells were increased significantly in the BMI1 overexpression group, while the proliferation, cell migration, and invasion of HEC-1B cells were decreased significantly in BMI1 inhibitor group. The apoptosis rate of BMI1 overexpression group was decreased significantly, while the BMI1 inhibitor group was increased significantly. The levels of MMP2, MMP7, MMP9, Rock1, RhoA and p53, p21, Bax protein in BMI1 overexpression group were significantly increased, while the levels of MMP2, MMP7, MMP9, Rock1, RhoA and p53, p21, Bax protein in BMI1 inhibitor group were significantly decreased. BMI1 is highly expressed in endometrial cancer tissues, and inhibiting BMI1 expression can reduce the proliferation, migration, and invasion of HEC-1B cells after ionizing radiation and promote apoptosis, which offers new insights into the clinical radiotherapy of tumors.

Induction of Cellular Senescence in Rat Vaginal Fibroblasts and Treatment With Senolytics: An in Vitro Model for the Study of Pelvic Organ Prolapse.

OBJECTIVE: The objective of this study was to develop an in vitro model of cellular senescence using rat vaginal fibroblasts and determine the effects of treatment with senolytics. METHODS: Rat vaginal tissue biopsies were collected. Primary vaginal fibroblasts were isolated and characterized by immunofluorescence. To induce cellular senescence, fibroblasts were treated with etoposide at 3, 10, and 20 mM for 24 hours, followed by treatment with the senolytics dasatinib (1 mM) and/or quercetin (20 mM). After treatment, RNA was extracted and the expression of selected genes was quantified. Immunostaining of senescence markers was also performed. RESULTS: Fibroblasts were confirmed by positive immunostaining for α-smooth muscle actin and vimentin, and negative immunostaining for pan-cytokeratin. Treatment with etoposide resulted in a dose-dependent increase in expression of the senescence-associated secretory phenotype markers MMP-7, MMP-9, and IL-b1 (P < 0.05) compared with controls. Immunostaining showed increased expression of γ-H2A and p21 after treatment with etoposide. Cells treated with dasatinib and quercetin after etoposide treatment had decreased expression of p21, MMP-7, MMP-9, and IL-1b compared with cells treated only with etoposide (P < 0.05). CONCLUSIONS: Upregulation of senescence-associated factors provided evidence that senescence can be induced in vaginal fibroblasts in vitro. Furthermore, treatment with the senolytics dasatinib and quercetin abrogated the senescence phenotype induced by etoposide in rat vaginal fibroblasts. Our findings provide a novel model for the study and development of new therapies targeting the disordered extracellular matrix associated with pelvic organ prolapse.

Matrilysin (MMP-7) inhibition of BMP-7 induced renal tubular branching morphogenesis suggests a role in the pathogenesis of human renal dysplasia.

Congenital renal dysplasia (RD) is a severe form of congenital renal malformation characterized by disruption of normal renal development with cyst formation, reduced or absent nephrons, and impaired renal growth. The authors previously identified that matrilysin (matrix metalloproteinase-7) was overexpressed in a microarray gene expression analysis of human RD compared to normal control kidneys. They now find that active matrilysin gene transcription and protein synthesis occur within dysplastic tubules and epithelial cells lining cysts in human RD by RT-PCR and immunohistochemistry. Similar staining patterns were seen in obstructed kidneys of pouch opossums that show histological features similar to that of human RD. In vitro, matrilysin inhibits formation of branching structures in mIMCD-3 cells stimulated by bone morphogenetic protein-7 (BMP-7) but does not inhibit hepatocyte growth factor-stimulated branching. BMP-7 signaling is essential for normal kidney development, and overexpression of catalytically active matrilysin in human embryonic kidney 293 cells reduces endogenous BMP-7 protein levels and inhibits phosphorylation of BMP-7 SMAD signaling intermediates. These findings suggest that matrilysin expression in RD may be an injury response that disrupts normal nephrogenesis by impairing BMP-7 signaling.

Constitutive expression and enzymatic cleavage of ICAM-1 in the spontaneously hypertensive rat.

BACKGROUND/AIMS: Leukocyte adhesion to the endothelium is abnormal in hypertension. We have recently shown that spontaneously hypertensive rats (SHRs) have circulating leukocytes with enhanced CD18 receptor cleavage. In the current study, we investigate expression levels of its counter receptor, intercellular adhesion molecule (ICAM-1), and its possible proteolytic cleavage in the SHR and control Wistar rat. METHODS: ICAM-1 was labeled on tissue sections with two antibodies targeting its extracellular and intracellular domains and evaluated by light absorption measurements. The in situ cleavage of ICAM-1 was assessed by treating vessel sections with matrix metalloproteinase (MMP)-7, MMP-9 and elastase. RESULTS: SHRs showed a significant increase in ICAM-1 expression in liver and kidney compared with Wistar rats. The liver and kidney glomeruli exhibit a discrepancy in label density between intra- and extracellular antibodies, which suggests that enzymatic cleavage may be a factor determining ICAM-1 distribution. MMP-7 and MMP-9, which are elevated in SHR plasma, and elastase, which has elevated activity in SHR neutrophils, cleave the extracellular domain of ICAM-1 when applied to the tissue. CONCLUSION: ICAM-1 expression in SHRs is upregulated in a tissue-specific manner. Proteolytic cleavage of the extracellular domain of ICAM-1 and accumulation in kidney glomeruli may play a role in the renal involvement of inflammation.

Soluble factors from IL-1ß-stimulated astrocytes activate NR1a/NR2B receptors: implications for HIV-1-induced neurodegeneration.

Astrocytes play an important role in astrocyte-neuron homeostasis. In HIV-1-infected brain, interleukin 1 beta (IL-1ß) activation of astrocytes contributes to neurodegeneration. However, the molecular mechanisms underlying IL-1ß-activated-astrocytes-induced neurodegeneration in HIV-1-infected brain are largely unknown. We hypothesize that secretory factors from the activated astrocytes affect N-methyl-d-aspartate (NMDA) receptor, a major pathway implicated in HIV-1-associated neurodegeneration. To test this hypothesis, we studied effects of IL-1ß-stimulated astrocyte conditioned medium (ACM+) for its ability to activate NR1a/NR2B receptors expressed on Xenopus oocytes. Astrocytes treated with IL-1ß 20ng/ml for 24h induced CXCL8, CCL2, MMP1 and MMP7. Pressure ejection of the ACM(+) produced an inward current in NR1a/NR2B-expressing oocytes. The inward current produced by ACM(+) was blocked by NMDA receptor antagonist, APV but not by non-NMDA receptor antagonist, CNQX. These results suggest that IL-1ß stimulated astrocytes activate NR1a/NR2B receptors which may have implications in HIV-1-associated neurodegeneration.

Elevation of intact and proteolytic fragments of acute phase proteins constitutes the earliest systemic antiviral response in HIV-1 infection.

The earliest immune responses activated in acute human immunodeficiency virus type 1 infection (AHI) exert a critical influence on subsequent virus spread or containment. During this time frame, components of the innate immune system such as macrophages and DCs, NK cells, beta-defensins, complement and other anti-microbial factors, which have all been implicated in modulating HIV infection, may play particularly important roles. A proteomics-based screen was performed on a cohort from whom samples were available at time points prior to the earliest positive HIV detection. The ability of selected factors found to be elevated in the plasma during AHI to inhibit HIV-1 replication was analyzed using in vitro PBMC and DC infection models. Analysis of unique plasma donor panels spanning the eclipse and viral expansion phases revealed very early alterations in plasma proteins in AHI. Induction of acute phase protein serum amyloid A (A-SAA) occurred as early as 5-7 days prior to the first detection of plasma viral RNA, considerably prior to any elevation in systemic cytokine levels. Furthermore, a proteolytic fragment of alpha-1-antitrypsin (AAT), termed virus inhibitory peptide (VIRIP), was observed in plasma coincident with viremia. Both A-SAA and VIRIP have anti-viral activity in vitro and quantitation of their plasma levels indicated that circulating concentrations are likely to be within the range of their inhibitory activity. Our results provide evidence for a first wave of host anti-viral defense occurring in the eclipse phase of AHI prior to systemic activation of other immune responses. Insights gained into the mechanism of action of acute-phase reactants and other innate molecules against HIV and how they are induced could be exploited for the future development of more efficient prophylactic vaccine strategies.

Chronic exposure to exogenous matrilysin induces chemoresistance and enhances Bcl-2 expression in A549 lung adenocarcinoma cells.

Matrix metalloproteinase (MMP) family member matrilysin (matrilysin) has been indicated to induce apoptosis-resistance and chemoresistance. The purpose of current study was to investigate the potential capacity of induction cisplatin-resistance upon the unremitting exposure to exogenic matrilysin. At the same time, the expressions of apoptosis-related genes were examined to clarify the underlying mechanisms. A549 lung adenocarcinoma cells was used to establish our chronic exposure models. The viability of A549 lung adenocarcinoma cells was determinated by MTT and the apoptosis was assessed by Hoechst 33342 staining and Annexin V-FITC/PI apoptosis kit. The expressions of apoptosis-relative genes were evaluated by flow cytometry, immunocytochemistry staining and real-time quantitative RT-PCR, respectively. Overall, chronic exposure to crescenting level of exogenous matrilysin (10, 50, 100, 200 ng/ml) did not significantly alter the growth rates of A549 cells. However, a certain range of matrilysin might protect tumor cells from cisplatin-medicated death. The underlying mechanism may due to the Bcl-2 overexpression and imbalance in the ratio of Bcl-2/Bax. Our results offer a potential mechanism to explain the impact of matrilysin on apoptosis and provide new insights into the profound mechanisms of acquired cisplatin-resistance. Further researches are highly suggestive of this association which has great clinical implications.

Matrix metalloproteinase-7 modulates synaptic vesicle recycling and induces atrophy of neuronal synapses.

Matrix metalloproteinase-7 (MMP-7) belongs to a family of zinc dependent endopeptidases that are expressed in a variety of tissues including the brain. MMPs are known to be potent mediators of pericellular proteolysis and likely mediators of dynamic remodelling of neuronal connections. While an association between proteases and the neuronal synapse is emerging, a full understanding of this relationship is lacking. Here, we show that MMP-7 alters the structure and function of presynaptic terminals without affecting neuronal survival. Bath application of recombinant MMP-7 to cultured rat neurons induced long-lasting inhibition of vesicular recycling as measured by synaptotagmin 1 antibody uptake assays and FM4-64 optical imaging. MMP-7 application resulted in reduced abundance of vesicular and active zone proteins locally within synaptic terminals although their general levels remained unaltered. Finally, chronic application of the protease resulted in synaptic atrophy, including smaller terminals and fewer synaptic vesicles, as determined by electron microscopy. Together these results suggest that MMP-7 is a potent modulator of synaptic vesicle recycling and synaptic ultrastructure and that elevated levels of the enzyme, as may occur with brain inflammation, may adversely influence neurotransmission.

Cleavage of neuronal synaptosomal-associated protein of 25 kDa by exogenous matrix metalloproteinase-7.

Matrix metalloproteinases (MMPs) belong to a family of zinc dependent enzymes best studied for their role in cancer and inflammation. Though MMPs typically target extracellular proteins, here we show that MMP-7, an MMP family member which lacks a C-terminal hemopexin-like domain, can cleave an intraneuronal protein that is critical to vesicular fusion and neurotransmitter release, synaptosomal-associated protein of 25 kDa (SNAP-25). Western blot analysis using an N-terminal specific antibody on extracts from cultured neurons suggests that cleavage occurs towards the C-terminal portion of SNAP 25. Additional studies with recombinant SNAP-25 demonstrate that cleavage occurs at amino acid 129. The ability of MMP-7 to cleave SNAP-25 is diminished by chlorpromazine and phenylarsine oxide, inhibitors of clathrin dependent endocytosis. Together, these results imply that exogenous MMP-7 can access an intraneuronal substrate and suggest that additional studies may be warranted to determine if SNAP function is impaired with brain inflammation.

Matrix metalloproteinase-7 triggers the matricrine action of insulin-like growth factor-II via proteinase activity on insulin-like growth factor binding protein 2 in the extracellular matrix.

Many growth factors and cytokines are immobilized on the extracellular matrix (ECM) by binding to glycosaminoglycans and are stored in an inactive form in the cellular microenvironment. However, the mechanisms of ECM-bound growth factor or cytokine activation have not been well documented. We showed that the insulin-like growth factor type-1 receptor (IGF-1R) was rapidly phosphorylated after the addition of matrix metalloproteinase (MMP)-7 to a serum-starved human colon cancer cell line (HT29) and that phosphorylation was completely inhibited by an IGF-II neutralizing antibody. In the ECM of this cell line, IGF-II and IGF binding protein (BP)-2 coexisted, but IGFBP-2 disappeared from the ECM fraction after treatment with MMP-7 or heparinase III. On the other hand, in a cell line in which IGF-1R was overexpressed, IGF-1R was phosphorylated by supernatant from the MMP-7-treated ECM fraction of HT29 but not by that from a heparinase-III-treated ECM fraction. We also demonstrated that MMP-7 degrades IGFBP-2 in vitro at three cleavage sites (peptide bonds E(151)-L(152), G(175)-L(176) and K(181)-L(182)), which have not been documented previously. Taken together, these results demonstrate that MMP-7 generates bioactive IGF-II by degrading the IGF-II/IGFBP-2 complex binding to heparan sulfate proteoglycan in the ECM, resulting in IGF-II-induced signal transduction. This evidence indicates that some ECM-associated growth factors enhance their ability to bind to their receptors by some proteases in the tumor microenvironment. This mechanism of action ('protease-triggered matricrine') represents an attractive model for understanding ECM-tumor interactions.