Impaired IL-17 signaling pathway contributes to the increased collagen expression in scleroderma fibroblasts

Among IL-17 families, IL-17A and IL-17F share amino acid sequence similarity and bind to IL-17R type A. IL-17 signaling is implicated in the pathogenesis of various autoimmune diseases, but its role in the regulatory mechanism of extracellular matrix expression and its contribution to the phenotype of systemic sclerosis (SSc) both remain to be elucidated. This study revealed that IL-17A expression was significantly increased in the involved skin and sera of SSc patients, whereas the IL-17F levels did not increase. In contrast, the expression of IL-17R type A in SSc fibroblasts significantly decreased in comparison with that in normal fibroblasts, due to the intrinsic TGF-β1 activation in these cell types. Moreover, IL-17A, not IL-17F, reduced the protein expression of α1(I) collagen and connective tissue growth factor. miR-129-5p, one of the downregulated microRNAs in SSc fibroblasts, increased due to IL-17A and mediated the α1(I) collagen reduction. These results suggest that IL-17A signaling, not IL-17F, has an antifibrogenic effect via the upregulation of miR-129-5p and the downregulation of connective tissue growth factor and α1(I) collagen. IL-17A signaling is suppressed due to the downregulation of the receptor by the intrinsic activation of TGF-β1 in SSc fibroblasts, which may amplify the increased collagen accumulation and fibrosis characteristic of SSc. Increased IL-17A levels in the sera and involved skin of SSc may be due to negative feedback. Clarifying the novel regulatory mechanisms of fibrosis by the cytokine network consisting of TGF-β and IL-17A may lead to a new therapeutic approach for this disease.     

Effect of healthy aging on left ventricular relaxation and diastolic suction

Doppler ultrasound measures of left ventricular (LV) active relaxation and diastolic suction are slowed with healthy aging. It is unclear to what extent these changes are related to alterations in intrinsic LV properties and/or cardiovascular loading conditions. Seventy carefully screened individuals (38 female, 32 male) aged 21-77 were recruited into four age groups (young: <35; early middle age: 35-49; late middle age: 50-64 and seniors: ≥65 yr). Pulmonary capillary wedge pressure (PCWP), stroke volume, LV end-diastolic volume, and Doppler measures of LV diastolic filling were collected at multiple loading conditions, including supine baseline, lower body negative pressure to reduce LV filling, and saline infusion to increase LV filling. LV mass, supine PCWP, and heart rate were not affected significantly by aging. Measures of LV relaxation, including isovolumic relaxation time and the time constant of isovolumic pressure decay increased progressively, whereas peak early mitral annular longitudinal velocity decreased with advancing age (P < 0.001). The propagation velocity of early mitral inflow, a noninvasive measure of LV suction, decreased with aging with the greatest reduction in seniors (P < 0.001). Age-related differences in LV relaxation and diastolic suction were not attenuated significantly when PCWP was increased in older subjects or reduced in the younger subjects. There is an early slowing of LV relaxation and diastolic suction beginning in early middle age, with the greatest reduction observed in seniors. Because age-related differences in LV dynamic diastolic filling parameters were not diminished significantly with significant changes in LV loading conditions, a decline in ventricular relaxation is likely responsible for the alterations in LV diastolic filling with senescence.     

Photooxidative cleavage of zinc 20-substituted chlorophyll derivatives: conformationally P-helix-favored formation of regioselectively 19-20 opened linear tetrapyrroles

Photoreaction of zinc methyl 20-substituted meso(pyro)pheophorbide-a prepared by modifying naturally occurring chlorophyll-a in the presence of oxygen molecules gave its C19-C20 oxidative cleavage (1-carbonyl-19-oxo-bilatrienes) as the major products and the regioisomeric C1-C20 cleavage (19-carbonyl-1-oxo-bilatrienes) as the minor products. The resulting zinc complexes of linear tetrapyrroles took a helical conformation and the P-conformers were preferential over the M-stereoisomers due to the presence of their 17S,18S-chiral centers. The helical conformers (diastereomers) of the corresponding nickel complexes were separated by reverse-phase or chiral HPLC and their conformational changes were observed in solution.     

Bacteroides thetaiotaomicron VPI-5482 glycoside hydrolase family 66 homolog catalyzes dextranolytic and cyclization reactions

Bacteroides?thetaiotaomicron VPI-5482 harbors a gene encoding a putative cycloisomaltooligosaccharide glucanotransferase (BT3087) belonging to glycoside hydrolase family?66. The goal of the present study was to characterize the catalytic properties of this enzyme. Therefore, we expressed BT3087 (recombinant endo-dextranase from Bacteroides?thetaiotaomicron VPI-5482) in Escherichia?coli and determined that recombinant endo-dextranase from Bacteroides?thetaiotaomicron VPI-5482 preferentially synthesized isomaltotetraose and isomaltooligosaccharides (degree of polymerization >?4) from dextran. The enzyme also generated large cyclic isomaltooligosaccharides early in the reaction. We conclude that members of the glycoside hydrolase?66 family may be classified into three types: (a) endo-dextranases, (b) dextranases possessing weak cycloisomaltooligosaccharide glucanotransferase activity, and (c) cycloisomaltooligosaccharide glucanotransferases.     

Cross tolerance to etorphine in rats tolerant to morphine-induced antidiuresis

Previously in the analgesic tail flick assay, mice and rats implanted with morphine pellets were shown to be highly tolerant to subcutaneously administered morphine but not to etorphine. The present purpose was to see whether the same differential response would be found to the antidiuretic response of morphine and etorphine in water-loaded rats because the presence of such a differential response would be of value in studying mechanisms of tolerance. Etorphine injected subcutaneously was about 1000x more potent than morphine in producing an antidiuretic response. Following chronic administration of morphine by pellet implantation, where the pellets remained in place during the drug challenge, profound tolerance developed to the antidiuretic effect of both morphine and etorphine. The dose-response curves for both were shifted to the right in non-parallel fashion with decreased slopes and antidiuretic efficacies. The large degree of tolerance developed to the antidiuretic effect of etorphine in morphine pellet implanted rats in contrast to the lack of development of tolerance to etorphine in the tail flick assay indicated that different mechanisms of development of tolerance exist for the two responses.     

Cadmium toxicity on cultured neonatal rat hepatocytes: biochemical and ultrastructural analyses.

The effects of cadmium exposure on the protein secretory functions of cultured neonatal rat hepatocytes were analyzed by both two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and electron microscopy. [35S]Methionine-labelled protein secretion was significantly depressed by cadmium exposure in a dose-dependent manner (1, 10 and 100 microM). Protein secretory patterns resolved by 2D-PAGE and analyzed by autoradiography showed that besides albumin and transferrin, three polypeptide spots decreased their radiolabelling intensities, whereas four spots appeared due to cadmium exposure. Ultrastructural alterations in cultured neonatal rat hepatocytes induced by cadmium exposure were characterized by condensation of the nuclear chromatin, appearance of intra-nuclear inclusions, decrease in number of microvilli, increase in number of intra-mitochondrial granules and transformation of rough endoplasmic reticulum to cytoplasmic vesicles in a dose-dependent manner. Both biochemical and ultrastructural findings indicate that cadmium adversely affects the protein secretory functions of cultured neonatal rat hepatocytes.     

Growth retardation in Wolf-Hirschhorn syndrome

Summary Postnatal growth records of 13 patients with Wolf-Hirschhorn syndrome indicate that the syndrome is associated with continuing severe growth retardation and marked microcephaly. In spite of severe retardation, these patients (with one exception) survived beyond infancy.     

Defects in the archenteron of mouse embryos homozygous for the T–mutation

Abstract. The development of the head process was studied in mouse embryos homozygous for the Brachyury (7) mutation at stages between days 7¹/₂ and 8¹/₂ using scanning electron microscopy. Intact T/T embryos removed from deciduae were distinguished from their normal littermates at the presomite stage on the basis of an abnormally short allantois. In the homozygotes so distinguished, the prenotochordal cells were fewer in the archenteron area, and the typical indentation of the archenteron was not observed. These defects are probably early indicators of the abnormality of the notochord previously described for later stages of development.