MMP11 and MMP17 are potential biomarkers for uterine corpus endometrial carcinoma prognosis.

BACKGROUND: Matrix metalloproteinases (MMP) are important proteases that degrade the extracellular matrix (ECM) and thus essentially mediate tumor vascularization, metastasis, and invasion. However, their potential roles in uterine corpus endometrial carcinoma (UCEC) are not fully understood. PATIENTS AND METHODS: The expression, prognostic value, and correlation of UCEC patients with MMP were investigated using data from The Cancer Genome Atlas (TCGA) and other databases. Furthermore, differentially expressed genes (DEGs) were identified and their biological functions and correlations with infiltrating immune cells were analyzed. RESULTS: A total of 22 MMPs were found to be abnormally expressed in UCEC tumor tissues, and high expression of MMP11 and MMP17 were associated with a better UCEC prognosis. MMP11 and MMP17 were observed to be significantly enriched in tumor tissue ECM and were associated with pathways involving degradation, glycolytic metabolism, and PI3K-Akt signaling. Infiltration of natural killer (NK), mast, and NK CD56bright cells was enhanced in tumor tissues with high MMP11 and MMP17 expression. CONCLUSION: MMP11 and MMP17 may affect UCEC prognosis by influencing immune cell infiltration and may be potential UCEC biomarkers.

Doxycycline hydrochloride inhibits the progress of malignant rhabdoid tumor of kidney by targeting MMP17 and MMP1 through PI3K-Akt signaling pathway.

OBJECTIVE: To identify therapeutic targets for malignant rhabdoid tumors of kidney (MRTK) and to investigate the effects and underlying mechanism of doxycycline hydrochloride on these tumors. METHODS: Gene expression and clinical data of MRTK were retrieved from the TARGET database. Differentially expressed genes (DEGs) and prognostic-related genes (PRGs) were selected through a combination of statistical analyses. The functional roles of MMP17 and MMP1 were elucidated through RNA overexpression and intervention experiments. Furthermore, in vitro and in vivo studies provided evidence for the inhibitory effect of doxycycline hydrochloride on MRTK. Additionally, transcriptome sequencing was employed to investigate the underlying molecular mechanisms. RESULTS: 3507 DEGs and 690 PRGs in MRTK were identified. Among these, we focused on 41 highly expressed genes associated with poor prognosis and revealed their involvement in extracellular matrix regulatory pathways. Notably, MMP17 and MMP1 stood out as particularly influential genes. When these genes were knocked out, a significant inhibition of proliferation, invasion and migration was observed in G401 cells. Furthermore, our study explored the impact of the matrix metalloproteinase inhibitor, doxycycline hydrochloride, on the malignant progression of G401 both in vitro and in vivo. Combined with sequencing data, the results indicated that doxycycline hydrochloride effectively inhibited MRTK progression, due to its ability to suppress the expression of MMP17 and MMP1 through the PI3K-Akt signaling pathway. CONCLUSION: Doxycycline hydrochloride inhibits the expression of MMP17 and MMP1 through the PI3K-Akt signaling pathway, thereby inhibiting the malignant progression of MRTK in vivo and in vitro.

Mmp17-deficient mice exhibit heightened goblet cell effector expression in the colon and increased resistance to chronic Trichuris muris infection.

Intestinal epithelial homeostasis is maintained by intrinsic and extrinsic signals. The extrinsic signals include those provided by mesenchymal cell populations that surround intestinal crypts and is further facilitated by the extracellular matrix (ECM), which is modulated by proteases such as matrix metalloproteinases (MMPs). Extrinsic signals ensure an appropriate balance between intestinal epithelial proliferation and differentiation. This study explores the role of MMP17, which is preferentially expressed by smooth muscle cells in the intestine, in intestinal homeostasis and during immunity to infection. Mice lacking MMP17 expressed high levels of goblet-cell associated genes and proteins, such as CLCA1 and RELM-ß, which are normally associated with immune responses to infection. Nevertheless, Mmp17 KO mice did not have altered resistance during a bacterial Citrobacter rodentium infection. However, when challenged with a low dose of the helminth Trichuris muris, Mmp17 KO mice had increased resistance, without a clear role for an altered immune response during infection. Mechanistically, we did not find changes in traditional modulators of goblet cell effectors such as the NOTCH pathway or specific cytokines. We found MMP17 expression in smooth muscle cells as well as lamina propria cells such as macrophages. Together, our data suggest that MMP17 extrinsically alters goblet cell maturation which is sufficient to alter clearance in a helminth infection model.

Prognostic risk factors of serous ovarian carcinoma based on mesenchymal stem cell phenotype and guidance for therapeutic efficacy.

BACKGROUND: Epithelial ovarian cancer is the leading cause of death from gynecologic cancer, in which serous ovarian carcinoma (SOC) is the most common histological subtype. Although PARP inhibitors (PARPi) and antiangiogenics have been accepted as maintenance treatment in SOC, response to immunotherapy of SOC patients is limited. METHODS: The source of transcriptomic data of SOC was from the Cancer Genome Atlas database and Gene Expression Omnibus. The abundance scores of mesenchymal stem cells (MSC scores) were estimated for each sample by xCell. Weighted correlation network analysis is correlated the significant genes with MSC scores. Based on prognostic risk model construction with Cox regression analysis, patients with SOC were divided into low- and high-risk groups. And distribution of immune cells, immunosuppressors and pro-angiogenic factors in different risk groups was achieved by single-sample gene set enrichment analysis. The risk model of MSC scores was further validated in datasets of immune checkpoint blockade and antiangiogenic therapy. In the experiment, the mRNA expression of prognostic genes related to MSC scores was detected by real-time polymerase chain reaction, while the protein level was evaluated by immunohistochemistry. RESULTS: Three prognostic genes (PER1, AKAP12 and MMP17) were the constituents of risk model. Patients classified as high-risk exhibited worse prognosis, presented with an immunosuppressive phenotype, and demonstrated high micro-vessel density. Additionally, these patients were insensitive to immunotherapy and would achieve a longer overall survival with antiangiogenesis treatment. The validation experiments showed that the mRNA of PER1, AKAP12, and MMP17 was highly expressed in normal ovarian epithelial cells compared to SOC cell lines and there was a positive correlation between protein levels of PER1, AKAP12 and MMP17 and metastasis in human ovarian serous tumors. CONCLUSION: This prognostic model established on MSC scores can predict prognosis of patients and provide the guidance for patients receiving immunotherapy and molecular targeted therapy. Because the number of prognostic genes was fewer than other signatures of SOC, it will be easily accessible on clinic.

Molecular Mechanisms Driven by MT4-MMP in Cancer Progression.

MT4-MMP (or MMP-17) belongs to the membrane-type matrix metalloproteinases (MT-MMPs), a distinct subset of the MMP family that is anchored to the cell surface, in this case by a glycosylphosphatidylinositol (GPI) motif. Its expression in a variety of cancers is well documented. However, the molecular mechanisms by which MT4-MMP contributes to tumor development need further investigation. In this review, we aim to summarize the contribution of MT4-MMP in tumorigenesis, focusing on the molecular mechanisms triggered by the enzyme in tumor cell migration, invasiveness, and proliferation, in the tumor vasculature and microenvironment, as well as during metastasis. In particular, we highlight the putative substrates processed and signaling cascades activated by MT4-MMP that may underlie these malignancy processes and compare this with what is known about its role during embryonic development. Finally, MT4-MMP is a relevant biomarker of malignancy that can be used for monitoring cancer progression in patients as well as a potential target for future therapeutic drug development.

Elevated Plasma Levels of MT4-MMP and MT6-MMP; A New Observation in Patients with Thyroid Nodules.

BACKGROUND: Based on the critical role of MT4-MMP and MT6-MMP in carcinogenesis, we focused on MT4-MMP and MT6-MMP circulating levels in patients with thyroid nodules. METHODS: Plasma samples were collected from three groups, including papillary thyroid cancer (PTC; n=30), multinodular goiter (MNG; n=30), and healthy subjects (n=22). Enzyme-linked immunosorbent assay (ELISA) was used to obtain the concentration of MT4-MMP and MT6-MMP in the three groups. RESULTS: Analysis of data demonstrated increased levels of MT4-MMP (PTC: 4.90±1.35, MNG: 4.89±1.37, and healthy: 3.13±1.42) and MT6-MMP (PTC: 8.29±2.50, MNG: 7.34±2.09, and healthy:5.01±2.13) in thyroid nodules by comparison with healthy subjects (P<0.05). There were no significant differences in the levels of the two MT-MMPs between PTC and MNG (P>0.05). Increased plasma levels of MT4-MMP (odds ratio=2.48; 95% CI: 1.46-4.19; P=0.001) or MT6-MMP (odds ratio=1.81; 95% CI: 1.29-2.53; P=0.001) were associated with increased risk of PTC tumorigenesis. Interestingly, a strong positive association was observed between MT4-MMP and MT6-MMP in the three groups (PTC: r=0.766**, P=0.000; MNG: r=0.856**, P=0.000; healthy r=0.947**, P=0.000). Areas under the ROC curve for MT4-MMP and MT6-MMP were 0.82 and 0.96, respectively. At the cutoff value>4.7 (ng/mL), MT4-MMP and MT6-MMP showed a sensitivity of 63.3% and 90.0%, respectively, with 100% specificity. CONCLUSION: Our work has led us to imply that the higher levels of MT4-MMP and MT6-MMP are closely linked with both PTC and MNG tumorigenesis. They may probably promote the development of thyroid lesions; however, more research is needed to further clarify the current findings.

Expression and clinical significance of TYRP1, ABCB5, and MMP17 in sinonasal mucosal melanoma.

BACKGROUND: Sinonasal mucosal melanoma (SNMM) is a lethal malignancy with poor prognosis. Treatment outcomes of SNMM are poor. Novel prognostic or progression markers are needed to help adjust therapy. METHODS: RNA-seq was used to analyze the mRNA expression of tumor tissues and normal nasal mucosa from primary SNMM patients (n= 3). Real-time fluorescent quantitative PCR (qRT-PCR) was used to validate the results of RNA-seq (n= 3), while protein expression was analyzed by immunohistochemistry (IHC, n= 31) and western blotting (n= 3). Retrospective studies were designed to determine the clinical parameters and the total survival rate, and correlation between the protein expression levels of the most significant key genes and prognosis was analyzed. RESULTS: In total, 668 genes were upregulated and 869 genes were downregulated in SNMM (fold change ⩾ 2, adjusted p value < 0.01). Both mRNA and protein expression levels of the key genes in SNMM tumor tissues were higher than those in the normal control nasal mucosal tissues. The expression rates of TYRP1, ABCB5, and MMP17 in 31 primary SNMM cases were 90.32%, 80.65%, and 64.52%, respectively. In addition, age, typical symptoms, and AJCC stage were related to overall survival rate of patients with SNMM (p< 0.05). Furthermore, the expression of ABCB5 was age-related (p= 0.002). Compared with individuals with negative ABCB5 expression, those with positive expression exhibited significantly poor overall survival (p= 0.02). CONCLUSION: The expression levels of TYRP1, ABCB5, and MMP17 were significantly upregulated in SNMM tissues, and the expression of ABCB5 was related to poor prognosis in SNMM. Thus, ABCB5 may serve as a progression marker and can predict unfavorable prognosis in patients with SNMM.

Increased expression of MMP17 predicts poor clinical outcomes in epithelial ovarian cancer patients.

Ovarian cancer has the highest fatality rate among female reproductive system cancers, which is due to lack of biomarker for diagnosis and prognosis. We aimed to evaluate the role of matrix metalloproteinase 17 (MMP17) in ovarian cancer tumorigenesis and prognosis. Based on the epithelial ovarian cancer (EOC) in The Cancer Genome Atlas database, we determined the expression of MMP17 using the Wilcoxon rank-sum test. The biological functions of MMP17 were evaluated using the Metascape database and Gene Set Enrichment Analysis. The association between MMP17 and immune cell infiltration was investigated by single sample Gene Set Enrichment Analysis. Logistic analysis was applied to study the correlation between MMP17 expression and clinicopathological characteristics. Finally, Cox regression analysis, Kaplan-Meier analysis, and nomograms were used to determine the predictive value of MMP17 on clinical outcomes in EOC patients. The expression of MMP17 was much higher in EOC patients than in pericarcinomatous tissues (P < .001). MMP17-associated differentially expressed genes were significantly enriched in cell extracellular matrix (ECM) degrading and corresponding pathways in the high MMP17 expression phenotype. MMP17 has a high sensitivity and specificity for EOC diagnosis, with an area under the curve of 0.988. MMP17 expression was found to be an independent risk factor for overall survival (hazard ratio [HR]: 1.488, P < .001), progression-free interval (HR: 1.347, P < .01), and disease-specific survival (HR: 1.548, P < .01). Increased MMP17 expression in EOC may contribute to carcinogenesis by degrading ECM and provide diagnostic and prognostic value for clinical outcomes.

p38 MAPK priming boosts VSMC proliferation and arteriogenesis by promoting PGC1α-dependent mitochondrial dynamics.

Vascular smooth muscle cell (VSMC) proliferation is essential for arteriogenesis to restore blood flow after artery occlusion, but the mechanisms underlying this response remain unclear. Based on our previous findings showing increased VSMC proliferation in the neonatal aorta of mice lacking the protease MT4-MMP, we aimed at discovering new players in this process. We demonstrate that MT4-MMP absence boosted VSMC proliferation in vitro in response to PDGF-BB in a cell-autonomous manner through enhanced p38 MAPK activity. Increased phospho-p38 in basal MT4-MMP-null VSMCs augmented the rate of mitochondrial degradation by promoting mitochondrial morphological changes through the co-activator PGC1α as demonstrated in PGC1α-/- VSMCs. We tested the in vivo implications of this pathway in a novel conditional mouse line for selective MT4-MMP deletion in VSMCs and in mice pre-treated with the p38 MAPK activator anisomycin. Priming of p38 MAPK activity in vivo by the absence of the protease MT4-MMP or by anisomycin treatment led to enhanced arteriogenesis and improved flow recovery after femoral artery occlusion. These findings may open new therapeutic opportunities for peripheral vascular diseases.

Smooth muscle-specific MMP17 (MT4-MMP) regulates the intestinal stem cell niche and regeneration after damage.

Smooth muscle is an essential component of the intestine, both to maintain its structure and produce peristaltic and segmentation movements. However, very little is known about other putative roles that smooth muscle cells may have. Here, we show that smooth muscle cells may be the dominant suppliers of BMP antagonists, which are niche factors essential for intestinal stem cell maintenance. Furthermore, muscle-derived factors render epithelium reparative and fetal-like, which includes heightened YAP activity. Mechanistically, we find that the membrane-bound matrix metalloproteinase MMP17, which is exclusively expressed by smooth muscle cells, is required for intestinal epithelial repair after inflammation- or irradiation-induced injury. Furthermore, we propose that MMP17 affects intestinal epithelial reprogramming after damage indirectly by cleaving diffusible factor(s) such as the matricellular protein PERIOSTIN. Together, we identify an important signaling axis that establishes a role for smooth muscle cells as modulators of intestinal epithelial regeneration and the intestinal stem cell niche.

MT4-MMP deficiency increases patrolling monocyte recruitment to early lesions and accelerates atherosclerosis.

Matrix metalloproteinases are involved in vascular remodeling. Little is known about their immune regulatory role in atherosclerosis. Here we show that mice deficient for MT4-MMP have increased adherence of macrophages to inflamed peritonea, and larger lipid deposits and macrophage burden in atherosclerotic plaques. We also demonstrate that MT4-MMP deficiency results in higher numbers of patrolling monocytes crawling and adhered to inflamed endothelia, and the accumulation of Mafb+ apoptosis inhibitor of macrophage (AIM)+ macrophages at incipient atherosclerotic lesions in mice. Functionally, MT4-MMP-null Mafb+AIM+ peritoneal macrophages express higher AIM and scavenger receptor CD36, are more resistant to apoptosis, and bind acLDL avidly, all of which contribute to atherosclerosis. CCR5 inhibition alleviates these effects by hindering the enhanced recruitment of MT4-MMP-null patrolling monocytes to early atherosclerotic lesions, thus blocking Mafb+AIM+ macrophage accumulation and atherosclerosis acceleration. Our results suggest that MT4-MMP targeting may constitute a novel strategy to boost patrolling monocyte activity in early inflammation.

miRNA­27a regulates arthritis via PPARγ in vivo and in vitro.

The present study investigated the role of microRNA (miR)­27a in the development of arthritis and its mechanism of action. Initially, collagen was used to develop an in vivo rat model of arthritis. Changes in the miRs in the rats were analyzed. It was subsequently observed that miR­27a expression was reduced in patients with arthritis, compared with the control group. In the present study an in vitro miR­27a overexpression model of arthritis was established and it was observed that miR­27a increased the proliferation of osteoblast­like cells in vitro. miR­27a overexpression promoted osteogenic differentiation, increased alkaline phosphatase (ALP) and osteoporosis (OST) content, induced insulin­like growth factor binding protein-5 (IGFBP­5) protein expression, reduced inflammation and suppressed peroxisome proliferator­activated receptor Î³ (PPARγ) and matrix metalloproteinase-17 (MMP­17) protein expression in arthritis. However, miR­27a downregulation inhibited osteogenic differentiation, increased inflammation and PPARγ and MMP­17 protein expression and suppressed ALP and OST content in an in vitro model of arthritis. The PPARγ inhibitor reduced the function of miR­27a downregulation on arthritis. Therefore the results of the present study revealed that miR­27a regulates arthritis via PPARγ.

MT4-MMP Modulates the Expression of miRNAs in Breast Cancer Cells.

BACKGROUND: MT4-MMP is a member of the metalloproteinases family, although with a controversial role in the extracellular matrix remodelation. Overexpression of this metalloproteinase has been observed in breast cancer and it has been suggested that it can regulate tumor growth and cancer progression. The mechanisms by which MT4-MMP participates in breast cancer includes tumor blood vessels desestabilization, the activation of an angiogenic switch, and increase of EGFR signaling. However, all the mechanisms by which MT4-MMP participates in breast cancer are still unknowns. AIM OF THE STUDY: To study if MT4-MMP could modulate the expression of microRNAs (miRNAs) related to biological processes associated with tumor formation and progression. METHODS: MT4-MMP was ectopically overexpressed in MDA-MB-231 cells and the miRNAs expression profile modulated by the metalloproteinase was studied by using miRNAs microarrays. Microarray data were analyzed with different tools to find the molecular and cellular functions related to the differentially expressed miRNAs. The clinical relevance of some miRNAs was analyzed using a public database. RESULTS: MT4-MMP overexpression in breast cancer cells induced the modulation of 65 miRNAs, which were related to the alteration of pathways dependent of p53, TGF-ß, MAPK, ErbB, and Wnt, as well as processes such as cell cycle, adherens junctions, apoptosis, and focal adhesion. Several of the upregulated miRNAs were associated to a worse prognosis in breast cancer patients. CONCLUSIONS: In breast cancer cells, the overexpression of MT4-MMP modulates the expression of miRNAs involved in several biological processes associated with tumor formation and progression and with clinical relevance.

Developmental expression of membrane type 4-matrix metalloproteinase (Mt4-mmp/Mmp17) in the mouse embryo.

Matrix metalloproteinases (MMPs) constitute a large group of endoproteases that play important functions during embryonic development, tumor metastasis and angiogenesis by degrading components of the extracellular matrix. Within this family, we focused our study on Mt4-mmp (also called Mmp17) that belongs to a distinct subset that is anchored to the cell surface via a glycosylphosphatidylinositol (GPI) moiety and with the catalytic site exposed to the extracellular space. Information about its function and substrates is very limited to date, and little has been reported on its role in the developing embryo. Here, we report a detailed expression analysis of Mt4-mmp during mouse embryonic development by using a LacZ reporter transgenic mouse line. We showed that Mt4-mmp is detected from early stages of development to postnatal stages following a dynamic and restricted pattern of expression. Mt4-mmp was first detected at E8.5 limited to the intersomitic vascularization, the endocardial endothelium and the dorsal aorta. Mt4-mmpLacZ/+ cells were also observed in the neural crest cells, somites, floor plate and notochord at early stages. From E10.5, expression localized in the limb buds and persists during limb development. A strong expression in the brain begins at E12.5 and continues to postnatal stages. Specifically, staining was observed in the olfactory bulb, cerebral cortex, hippocampus, striatum, septum, dorsal thalamus and the spinal cord. In addition, LacZ-positive cells were also detected during eye development, initially at the hyaloid artery and later on located in the lens and the neural retina. Mt4-mmp expression was confirmed by quantitative RT-PCR and western blot analysis in some embryonic tissues. Our data point to distinct functions for this metalloproteinase during embryonic development, particularly during brain formation, angiogenesis and limb development.

Loss of smooth muscle cell disintegrin and metalloproteinase 17 transiently suppresses angiotensin II-induced hypertension and end-organ damage.

Hypertension is associated with hypertrophy and hyperplasia of smooth muscle cells (SMCs). Disintegrin and metalloproteinase 17 (ADAM17) is a membrane-bound enzyme reported to mediate SMC hypertrophy through activation of epidermal growth factor receptor (EGFR). We investigated the role of ADAM17 in Ang II-induced hypertension and end-organ damage. VSMC was isolated from mice with intact ADAM17 expression (Adam17f/f) or lacking ADAM17 in the SMC (Adam17f/f/CreSm22). Human VSMCs were isolated from the aorta of donors, and ADAM17 deletion was achieved by siRNA transfection. Ang II suppressed proliferation and migration of Adam17-deficient SMCs, but did not affect apoptosis (mouse and human), this was associated with reduced activation of EGFR and Erk1/2 signaling. Adam17f/f/CreSm22 and littermate Adam17f/f mice received saline or Ang II (Alzet pumps, 1.5mg/kg/d; 2 or 4weeks). Daily blood pressure measurement in conscious mice (telemetry) showed suppressed hypertension in Adam17f/f/CreSm22 mice during the first week of Ang II infusion, but by the second week, it become comparable to that in Adam17f/f mice. EGFR activation remained suppressed in Adam17f/f/CreSm22-Ang II arteries. Ex vivo vascular function and compliance assessed in mesenteric arteries were comparable between genotypes. Consistent with the transient protection against Ang II-induced hypertension, Adam17f/f/CreSm22 mice exhibited significantly lower cardiac hypertrophy and fibrosis, and renal fibrosis at 2weeks post-Ang II, however this protection was abolished by the fourth week of Ang II infusion. In conclusion, while Adam17-deficiency suppresses Ang II-induced SMC remodeling in vitro, in vivo Adam17-deficiency provides only a transient protective effect against Ang II-mediated hypertension and end-organ damage.

A disintegrin and metalloprotease-17 and galectin-9 are important regulators of local 4-1BB activity and disease outcome in rheumatoid arthritis.

OBJECTIVE: Co-stimulatory T cell cytokines are important in the progression of RA. This study investigates the interplay between 4-1BB, a disintegrin and metalloprotease-17 (ADAM17) and galectin-9 (Gal-9) in RA. METHODS: Stimulated mononuclear cells from patients with chronic RA (n = 12) were co-incubated with tissue inhibitor of metalloproteinase, 4-1BB ligand and Gal-9. Plasma samples were examined for soluble 4-1BB (s4-1BB) in newly diagnosed, treatment-naïve patients with RA (n = 97). The 28-joint DAS with CRP (28DAS-CRP), total Sharp score, erosion score and joint space narrowing were used to evaluate treatment outcome serially over a 2-year period. RESULTS: RA CD4(+) and CD8(+) synovial T cells express high levels of 4-1BB. The addition of TNF-α to cultured synovial mononuclear cells increased shedding of 4-1BB. 4-1BB ligand only increased TNF-α shedding in combination with Gal-9. RNA interference-mediated knockdown of ADAM17 or the addition of an ADAM17 inhibitor reduced the 4-1BB shedding. Shedding of 4-1BB was not influenced by Gal-9. Plasma levels of s4-1BB were increased in early RA and correlated with the number of swollen joints at baseline. After 3 months of treatment, the plasma levels of s4-1BB were equal to those of the controls. Baseline plasma levels of s4-1BB were inversely correlated with DAS28-CRP after 2 years of treatment, but not with total Sharp score, erosion score or joint space narrowing. CONCLUSION: ADAM17 induces 4-1BB shedding in RA. Gal-9 is pivotal for the function of 4-1BB and induction of TNF-α. Furthermore, high plasma levels of s4-1BB were associated with the number of swollen joints, but also with a low DAS28-CRP after 2 years treatment in early RA.

Effects of thymoquinone on STZ-induced diabetic nephropathy: an immunohistochemical study.

BACKGROUND: Thymoquinone (TQ) is the most abundant and active ingredient of Nigella sativa (NS) seeds. Its hepatic, renal, and cardiac protective effects have been demonstrated in animal models. Streptozotocin (STZ) is an antibiotic that is widely used experimentally as an agent capable of inducing insulin-dependent diabetes mellitus (IDDM), also known as type I diabetes mellitus (T1DM). OBJECTIVES: This study was carried out in an attempt to highlight the possible beneficial effects of TQ in STZ-induced diabetes in rats and to determine the predictive value of mesenchymal and epithelial markers in the response of diabetic nephropathy to TQ. MATERIALS AND METHODS: Sixty adult male albino rats were divided in 3 groups: control, diabetic untreated, and diabetic treated with TQ. RESULTS: Diabetic rats exhibited morphological changes in both renal glomeruli and tubules with immunohistochemical expression of the mesenchymal markers Fsp1, desmin, and MMP-17 and disappearance of the epithelial marker ZO-1 largely in the glomeruli of diabetic kidneys. Treatment with TQ significantly attenuated renal morphological and immunohistochemical changes in STZ-induced diabetic rats. CONCLUSIONS: Thymoquinone has protective effects on experimental diabetic nephropathy. Both mesenchymal and epithelial markers serve as excellent predictors of early kidney damage and indicators of TQ responsiveness in STZ-induced diabetic nephropathy.

Hepatocytes contribute to immune regulation in the liver by activation of the Notch signaling pathway in T cells.

The "liver tolerance effect" has been attributed to a unique potential of liver-resident nonprofessional APCs including hepatocytes (HCs) to suppress T cell responses. The exact molecular mechanism of T cell suppression by liver APCs is still largely unknown. In mice, IL-10-dependent T cell suppression is observed after Th1-mediated hepatitis induced by Con A. In this study, we show that HCs, particularly those from regenerating livers of Con A-pretreated mice, induced a regulatory phenotype in naive CD4(+) T cells in vitro. Using reporter mice, we observed that these T regulatory cells released substantial amounts of IL-10, produced IFN-γ, failed to express Foxp3, but suppressed proliferation of responder T cells upon restimulation with anti-CD3 mAb. Hence, these regulatory cells feature a similar phenotype as the recently described IL-10-producing Th1 cells, which are generated upon activation of Notch signaling. Indeed, inhibition of γ-secretase and a disintegrin and metalloproteinase 17 but not a disintegrin and metalloproteinase 10, respectively, which blocked Notch activation, prevented IL-10 secretion. HCs from Con A-pretreated mice showed enhanced expression of the Notch ligand Jagged1 and significantly increased receptor density of Notch1 on CD4(+) T cells. However, HCs from Con A-pretreated IFN regulatory factor 1(-/-) mice, which cannot respond to IFN-γ, as well as those from IFN-γ(-/-) mice failed to augment IL-10 production by CD4(+) T cells. In conclusion, it seems that HCs fine-tune liver inflammation by upregulation of Jagged1 and activation of Notch signaling in Th1 cells. This mechanism might be of particular importance in the regenerating liver subsequent to Th1-mediated hepatitis.

Mmp17b is essential for proper neural crest cell migration in vivo.

The extracellular matrix plays a critical role in neural crest (NC) cell migration. In this study, we characterize the contribution of the novel GPI-linked matrix metalloproteinase (MMP) zebrafish mmp17b. Mmp17b is expressed post-gastrulation in the developing NC. Morpholino inactivation of mmp17b function, or chemical inhibition of MMP activity results in aberrant NC cell migration with minimal change in NC proliferation or apoptosis. Intriguingly, a GPI anchored protein with metalloproteinase inhibitor properties, Reversion-inducing-Cysteine-rich protein with Kazal motifs (RECK), which has previously been implicated in NC development, is expressed in close apposition to NC cells expressing mmp17b, raising the possibility that these two gene products interact. Consistent with this possibility, embryos silenced for mmp17b show defective development of the dorsal root ganglia (DRG), a crest-derived structure affected in RECK mutant fish sensory deprived (sdp). Taken together, this study has identified the first pair of MMP, and their putative MMP inhibitor RECK that functions together in NC cell migration.

Restoration of caveolin-1 expression suppresses growth, membrane-type-4 metalloproteinase expression and metastasis-associated activities in colon cancer cells.

Caveolin-1 (cav-1) and flotillin-1 are two major structural proteins associated with lipid rafts in mammalian cells. The membrane-type matrix metalloproteinases (MT-MMPs) are expressed at the cell surface, hydrolyze extracellular matrix, and play an important role in cancer cell migration and metastasis. Expression of cav-1, flotillin-1, and MT4-MMP in lysates and lipid rafts of LS174T and HM-7 colon cancer cells was determined. The impact of restoration of cav-1 expression on proliferation, adhesion, motility in vitro, and growth of implanted tumors in vivo was characterized. Cav-1 is not expressed in lipid rafts of the highly metastatic colon cancer cell line (HM-7), but expressed in cytosolic fractions of the parental lower metastatic cell line (LS174T). In contrast, MT4-MMP was expressed in lipid rafts of HM-7 cells but not in LS174T cells. Overexpression of cav-1 in HM-7 cells down-regulate proliferation, viability, wound closure, adhesion to laminin, invasion, and development of filopodial and lamellipodial structures in a dose-dependent manner. Cav-1 positive HM-7 clones ceased to express MT4-MMP in their lipid rafts. Comparative proteomic analyses of lipid rafts from cav-1 positive and cav-1 negative cells demonstrated de novo expression of flotillin-1 only on the cells expressing cav-1. Xenografting control cells devoid of cav-1 in nude mice induced development of bigger tumors expressing higher levels of proliferating cell nuclear antigen as compared to mice injected with cells expressing the highest cav-1 levels. We conclude that cav-1 orchestrates and reorganize several proteins in lipid rafts, activities directly associated with reduced tumorigenic and metastatic ability of colon cancer cells.