Estrogen Activation of G-Protein–Coupled Estrogen Receptor 1 Regulates Phosphoinositide 3-Kinase and mTOR Signaling to Promote Liver Growth in Zebrafish and Proliferation of Human Hepatocytes

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Telocytes in human fetal skeletal muscle interstitium during early myogenesis

A new peculiar stromal cell type called telocyte (TC)/CD34-positive stromal cell (i.e. cell with distinctive prolongations named telopodes) has recently been described in various tissues and organs, including the adult skeletal muscle interstitium of mammals. By forming a resident stromal three-dimensional network, TCs have been suggested to participate in different physiological processes within the skeletal muscle tissue, including homeostasis maintenance, intercellular signaling, tissue regeneration/repair and angiogenesis. Since a continuous interplay between the stromal compartment and skeletal muscle fibers seems to take place from organogenesis to aging, the present study was undertaken to investigate for the first time the presence of TCs in the human skeletal muscle during early myogenesis. In particular, we describe the morphological distribution of TCs in human fetal lower limb skeletal muscle during early stages of myogenesis (9–12 weeks of gestation). TCs were studied on tissue sections subjected to immunoperoxidase-based immunohistochemistry for CD34. Double immunofluorescence was further performed to unequivocally differentiate TCs (CD34-positive/CD31-negative) from vascular endothelial cells (CD34-positive/CD31-positive). Our findings provide evidence that stromal cells with typical morphological features and immunophenotype of TCs are present in the human skeletal muscle during early myogenesis, revealing differences in either CD34 immunopositivity or TC numbers among different gestation ages. Specifically, few TCs weakly positive for CD34 were found between 9 and 9.5 weeks. From 10 to 11.5 weeks, TCs were more numerous and strongly reactive and their telopodes formed a reticular network in close relationship with blood vessels and primary and secondary myotubes undergoing separation. On the contrary, a strong reduction in the number and immunopositivity of TCs was observed in fetal muscle sections from 12 weeks of gestation, where mature myotubes were evident. The muscle stroma showed parallel changes in amount, density and organization from 9 to 12 weeks. Moreover, blood vessels appeared particularly numerous between 10 and 11.5 weeks. Taken together, our findings suggest that TCs might play a fundamental role in the early myogenetic period, possibly guiding tissue organization and compartmentalization, as well as angiogenesis and maturation of myotubes.     

Reduced migration of fibroblasts in inflammatory bowel disease: role of inflammatory mediators and focal adhesion kinase

BACKGROUND & AIMS: Crohn's disease (CD) and ulcerative colitis (UC) are associated with chronic tissue damage and continuous tissue repair. A central, but not well-characterized, event during this process is the migration of activated fibroblasts to the wound. METHODS: Human colonic lamina propria fibroblasts (CLPF) were isolated from patients with CD and UC and from healthy controls and were characterized by immunocytochemistry. Migration assays of CLPF were performed in the modified 48-well Boyden chamber. Focal adhesion kinase (FAK) and FAK autophosphorylation in migrating CLPF were determined by Western blotting. FAK mRNA expression was investigated by Northern blotting. RESULTS: The migration of CD-CLPF and UC-CLPF was significantly reduced when compared with control-CLPF. This was correlated with a decrease in FAK phosphorylation, whereas, in migrating control-CLPF, an increase was found. Similarly, the presence of the inflammatory mediators interferon (IFN)-gamma (50 ng/mL) or tumor necrosis factor (TNF) (30 ng/mL) in conditioned medium significantly reduced the migration of control-CLPF to 41% +/- 4% or 30% +/- 7%, respectively. Preincubation of control-CLPF with TNF (20 ng/mL) and IFN-gamma (10 ng/mL) for 3 days reduced their migratory response to 10% of control (P < 0.001), which also was correlated with a decrease in FAK phosphorylation. Culture of IFN-gamma/TNF-treated CLPF for a further 7 days without cytokines did not restore the migratory potential and FAK phosphorylation, indicating a persistent functional change. CONCLUSIONS: CD- and UC-CLPF have a reduced migratory potential compared with normal CLPF. That may be caused by contact with IFN-gamma and TNF. This loss of migratory potential was correlated with diminished FAK phosphorylation.     

The effect of the selective cyclooxygenase-2 inhibitor rofecoxib on human colorectal cancer liver metastases

BACKGROUND & AIMS: Cyclooxygenase-2 (COX-2) is a potential target for chemotherapy of colorectal cancer (CRC). We tested the antineoplastic activity of the selective COX-2 inhibitor rofecoxib on human CRC liver metastases by measuring surrogate markers of tumor growth and angiogenesis in a randomized, double-blind, placebo-controlled trial. METHODS: Patients undergoing liver resection surgery for metastatic disease were randomized to receive rofecoxib 25 mg daily or placebo before surgery (duration, >14 days). The apoptosis index (AI; neocytokeratin 18), proliferation index (PI; Ki-67), and microvessel density (MVD; CD31) were measured in metastases by immunohistochemistry. The effect of rofecoxib on COX-2-positive HCA-7 human CRC cell PGE(2) synthesis, proliferation, and apoptosis in vitro was also investigated. RESULTS: Patients who received rofecoxib (n = 23) and placebo (n = 21) were well matched regarding clinical and metastasis characteristics. The mean (range) duration of rofecoxib therapy was 26 (14-46) days. Rofecoxib-treated metastases had a 29% decrease in MVD (mean, 25.1 [SEM, 2.7] per hpf) compared with placebo-treated tissue (32.5 [SEM, 4.5] per hpf; P = 0.15). There was little difference in AI (rofecoxib mean, 2.03% [SEM, 0.43%] vs. placebo 1.39% [SEM, 0.39%]) or PI (rofecoxib 54.7% [SEM, 5.1%] vs. placebo 52.6% [SEM, 5.6%]). Rofecoxib-induced growth arrest and apoptosis of HCA-7 cells occurred only at concentrations (>10 micromol/L), which were significantly higher than the IC(50) for COX-2 inhibition. CONCLUSIONS: Rofecoxib may negatively regulate angiogenesis in human CRC liver metastases. The absence of a significant, direct effect of rofecoxib on epithelial cells in liver metastases in vivo mirrors the lack of activity on human CRC cells at pharmacologically relevant concentrations in vitro.     

Clinical Characteristics of Biopsy-Proven IgA Vasculitis in Children and Adults: A Retrospective Cohort Study

ObjectiveTo describe the differences in clinical characteristics and outcome between adult- and childhood-onset biopsy-proven IgA vasculitis (IgAV) in North America.Patients and MethodsPatients with IgAV diagnosed from January 1, 1997, through December 31, 2016, were retrospectively identified. Data were abstracted from direct medical record review. Kaplan-Meier methods were used to estimate survival rates.ResultsA total of 243 patients with IgAV were included (227 [93.4%] white, 141 [58.0%] male); 174 patients were adults (≥21 years), and 69 were younger than 21 years. Compared with patients younger than 21 years, adults at baseline more frequently had ulcerative skin lesions (19 [10.9%] vs 1 [1.4%]; P=.02) and nephrotic-range proteinuria (21 of 96 [21.9%] vs 1 of 38 [2.6%]; P=.007) but less commonly had abdominal pain (59 [33.9%] vs 42 [60.9%]; P<.001), ischemic gastrointestinal tract involvement (18 [10.3%] vs 14 [20.3%]; P=.04), and arthralgias (66 [37.9%] vs 42 [60.8%]; P<.001). During 389 person-years of follow-up, 29 deaths were observed. Five-year survival rates for patients aged younger than 21, 21 to 50, and 51 years or older were 100%, 94%, and 40%, respectively. In comparison to data from the United States life tables for whites, patients 51 years or older at diagnosis had a greater than 7-fold increased risk of mortality (standardized mortality, 7.60 [95% CI, 5.01-11.06]; P<.001).ConclusionIgA vasculitis in adults is associated with more severe skin/kidney involvement and poorer renal outcome. Among adults with IgAV, patients aged 51 years or older at diagnosis have significantly higher mortality (P<.001).