Protein inhibitor of activated STAT3 (PIAS3) attenuates psoriasis and associated inflammation

Psoriasis is a common chronic inflammatory multisystem disease accompanied by hyperproliferation and inflammation of epidermal keratinocytes. Signal transducer and activator of transcription 3 (STAT3) is constitutively activated and plays an important role in epidermal keratinocytes of human psoriatic skin lesions. In this study, we investigated the effects of an endogenous STAT3 inhibitor, a protein inhibitor of activated STAT3 (PIAS3), on the proliferation and inflammation of psoriatic cells. The expression of PIAS3 in psoriatic tissues and healthy skin was analyzed using the Gene Expression Omnibus database and clinical samples. The human immortalized epidermal (HaCaT) cells were used to establish an in vitro psoriasis-like cell model. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-thethrazolium (MTS) assay was used to detect cell proliferation. Flow cytometry was used to determine apoptosis levels. Real-time PCR, western blotting, and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression levels of related factors. Furthermore, a mouse model of imiquimod (IMQ)-induced psoriatic dermatitis was established to verify the in vitro experimental results. The results showed that the mRNA and protein expression levels of PIAS3 were lower in psoriatic lesions than in normal tissues. PIAS3 inhibited the proliferation and promoted apoptosis of M5-induced HaCaT cells. Simultaneously, the mRNA and protein expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and keratin 17 (K17) were significantly decreased and that of p53 was increased, thereby inhibiting the inflammatory response and promoting apoptosis. PIAS3 inhibited the transcription activity of STAT3 and noncanonical nuclear factor-kappaB (NF-κB). Furthermore, PIAS3 attenuated IMQ-induced psoriasis-like inflammation in mice. Our findings suggest that PIAS3 plays an important role in psoriasis by regulating the STAT3/NF-κB signaling pathway and p53. The lack of PIAS3 may represent a novel mechanism underlying the pathogenesis of psoriasis.

Atmospheric nourishment of global ocean ecosystems

Over the vast open ocean, vital nutrients for phytoplankton growth in the sunlit surface layer are largely provided through physical transport from deep waters, but some nutrients are also provided through atmospheric deposition of desert dust. The extent and magnitude of dust-mediated effects on surface ocean ecosystems have been difficult to estimate globally. In this work, we use global satellite ocean color products to demonstrate widespread responses to atmospheric dust deposition across a diverse continuum of phytoplankton nutritional conditions. The observed responses vary regionally, with some areas exhibiting substantial changes in phytoplankton biomass, whereas in other areas, the response reflects a change in physiological status or health. Climate-driven changes in atmospheric aerosols will alter the relative importance of this nutrient source.

[Survival and disease burden trend analysis of occupational pneumoconiosis from 1963 to 2020 in Shizuishan City]

Objective: To understand the survival status and its influencing factors of occupational pneumoconiosis patients in Shizuishan City, and to analyze the disease burden of occupational pneumoconiosis and its trend, so as to provide scientific basis for formulating comprehensive prevention and treatment measures of occupational pneumoconiosis. Methods: A retrospective survey was conducted during July to December 2020 to explore the survival status of occupational pneumoconiosis patients who had been reported from 1963 to 2020 in Shizuishan City. The Kaplan-Meier method and Life-table method were used for survival analysis, and Cox proportional hazards regression model was used to analyze the influencing factors of survival time. The disability adjusted life years (DALY) was applied to analyze the disease burden of occupational pneumoconiosis and its temporal trend. Results: From 1963 to 2020, a total of 3263 cases of occupational pneumoconiosis were reported in Shizuishan City, of which 1467 died, so that the fatality rate was 44.96%. The median survival time was 26.71 years, average age of death was (70.55±10.92) years old. There were significant differences in the survival rates of occupational pneumoconiosis patients among different types, diagnosis age, exposure time, industry, initial diagnosis stage and whether upgraded (P<0.05) . As the survival time increased, the survival rate of patients decreased gradually. When the survival time was ≥50 years, the cumulative survival rate of patients was 4.20%. Cox regression analysis suggested that the type of pneumoconiosis, industry, diagnosis age, exposure time, initial diagnosis stage and whether upgraded were the influencing factors for the survival time of patients with occupational pneumoconiosis (P<0.05) . The total DALY attributable to occupational pneumoconiosis from 1963 to 2020 in Shizuishan City was 48026.65 person years, of which the years of life lost (YLL) was 15155.39 person years, and the average YLL was 10.33 years/person, and the years lost due to disability (YLD) was 32871.26 person years, and the average YLD was 10.07 years/person. The DALY attributed to coal worker's pneumoconiosis and silicosis were 39408.51 person years and 6565.02 person years, respectively, and they accounted for 82.06% and 13.67% of the total disease burden in Shizuishan City, respectively. The DALY caused by occupational pneumoconiosis in the age group of 40-49 years old and the first diagnosis of stage I occupational pneumoconiosis were higher, which were 20899.71 and 36231.97 person years, respectively. The average YLL and average YLD showed a volatility downtrend over time. Conclusion: The disease burden of occupational pneumoconiosis cannot be ignored in Shizuishan City, and timely targeted measures should be taken for key populations and key industries. It is recommended that life-cycle health management and hierarchical medical should be taken to improve the life quality of patients and prolong their lifes.

Endoscopic submucosal dissection of distal intestinal tumors using grasping forceps for traction

BACKGROUND

The aim of this study was to assess the efficacy of traction device-assisted endoscopic submucosal dissection (ESD) of the rectum and the distal segment of sigmoid colon using grasping forceps.

METHODS

A total of 43 patients scheduled for colonic ESD at our institution were enrolled between January 2013 and June 2017. The patients were randomly allocated to receive conventional ESD (group A) or traction device-assisted ESD (group B). The procedure time, complication rate, and en-block resection rate in the two groups were compared.

RESULTS

A total of 41 patients completed the study. The procedure time, complication rate and en-block resection rate were, respectively, 104.1 ± 34.7 min, 15%, 90% in the routine group (group A) and 84.7 ± 23.5 min, 9.5%, 90.5% in traction device-assisted ESD (group B). The procedure time in group B was significantly less than that in group A (F = 4.442, p < 0.05).

CONCLUSIONS

Traction device-assisted ESD using grasping forceps is safe and effective in distal colon ESD.

Regulation of a TGF-β1-CD147 self-sustaining network in the differentiation plasticity of hepatocellular carcinoma cells

Cellular plasticity has an important role in the progression of hepatocellular carcinoma (HCC). In this study, the involvement of a TGF-β1-CD147 self-sustaining network in the regulation of the dedifferentiation progress was fully explored in HCC cell lines, hepatocyte-specific basigin/CD147-knockout mice and human HCC tissues. We demonstrated that TGF-β1 stimulation upregulated CD147 expression and mediated the dedifferentiation of HCC cells, whereas all-trans-retinoic acid induced the downregulation of CD147 and promoted differentiation in HCC cells. Overexpression of CD147 induced the dedifferentiation and enhanced the malignancy of HCC cells, and increased the transcriptional expression of TGF-β1 by activating β-catenin. CD147-induced matrix metalloproteinase (MMP) production activated pro-TGF-β1. The activated TGF-β1 signaling subsequently repressed the HNF4α expression via Smad-Snail1 signaling and enhanced the dedifferentiation progress. Hepatocyte-specific basigin/CD147-knockout mice decreased the susceptibility to N-nitrosodiethylamine-induced tumorigenesis by suppressing TGF-β1-CD147 signaling and inhibiting dedifferentiation in hepatocytes during tumor progression. CD147 was positively correlated with TGF-β1 and negatively correlated with HNF4α in human HCC tissues. Positive CD147 staining and lower HNF4α levels in tumor tissues were significantly associated with poor survival of patients with HCC. The overexpression of HNF4α and Smad7 and the deletion of CD147 by lentiviral vectors jointly reprogrammed the expression profile of hepatocyte markers and attenuated malignant properties including proliferation, cell survival and tumor growth of HCC cells. Our results highlight the important role of the TGF-β1-CD147 self-sustaining network in driving HCC development by regulating differentiation plasticity, which provides a strong basis for further investigations of the differentiation therapy of HCC targeting TGF-β1 and CD147.

Alteration of N-glycoproteins/N-glycosites in human hepatic stellate cells activated with transforming growth factor-β1

Proteins N-glycosylation is significantly increased in the activated human hepatic stellate cells (HSCs) stimulated by transforming growth factor-β1 (TGF-β1) compared to the quiescent HSCs according to our previous study. However, little is known about the alteration of N-glycoprotein profiles in the activated HSCs. Profiles of N-glycopeptides / N-glycoproteins / N-glycosites in LX-2 cells, with and without activation by TGF-β1, were identified and compared using hydrazide chemistry enrichment coupled with liquid chromatography - mass spectrometry analysis. Western blot and immunohistochemistry were further used for validation. A total of 103 non-redundant N-glycopeptides, with 107 glycosylation sites from 86 N-glycoproteins, were identified in activated and quiescent LX-2 cells respectively. Among these, 23 proteins were known N-glycoproteins, and 58 were newly identified N-glycoproteins. In addition, 43 proteins (e.g., pigment epithelium-derived factor and clathrin heavy chain 1) were solely identified or up-regulated in the activated LX-2 cells, which participated in focal adhesion and glycosaminoglycan degradation pathways and were involved in interaction clusters of cytoskeletal proteins (e.g., myosin light chains and keratins). The increased expression of glucosamine (N-acetyl)-6-sulfatase and phospholipase C beta 2 and the decreased expression of zinc finger and BTB domain-containing protein 1 were validated in the activated compared to the quiescent LX-2 cells. In conclusion, increased expression of N-glycoproteins and N-glycosites play important roles in cellular contractility, signal transduction, and responses to stimuli in the activated HSCs, which might provide useful information for discovering novel molecular mechanism of HSC activation and therapeutic targets in liver fibrosis.

I148M variant of PNPLA3 increases the susceptibility to non-alcoholic fatty liver disease caused by obesity and metabolic disorders

BACKGROUND

The patatin-like phospholipase 3 (PNPLA3) rs738409 gene polymorphism is an important genetic determinant of non-alcoholic fatty liver disease (NAFLD). However, the associations between liver fat and metabolic traits in rs738409 G allele carriers and the allelic influence on this association have not been fully studied.

AIM

To investigate the influence of the PNPLA3 gene polymorphism on the association of liver fat with serum metabolic factors and carotid atherosclerosis.

METHODS

Liver fat was measured by quantitative ultrasound in 4300 subjects in the Shanghai Changfeng community and analysed for its association with obesity and metabolic factors in individuals with the PNPLA3 CC, CG and GG genotypes.

RESULTS

Non-alcoholic fatty liver disease occurred in 37.9% and 28.8% of the subjects with the GG and CC genotypes respectively (P < 0.001). Liver fat was significantly associated with body mass index, waist circumference, serum triglycerides, high-density lipoprotein cholesterol, fasting blood glucose and insulin in the PNPLA3 rs738409 G allele carriers (P < 0.001). Compared with the CC homozygotes, the GG homozygotes presented higher liver fat and liver fibrosis scores despite their better metabolic status (comparison of regression line slopes, P < 0.05). An increase in liver fat was accompanied by a significant increase in the average and maximum carotid intima-media thickness in subjects with the PNPLA3 CC genotype but not in those with the GG genotype.

CONCLUSIONS

PNPLA3 rs738409 G allele carriers were found to be more susceptible to the metabolic-related hepatic steatosis, and developed NAFLD and liver fibrosis despite presenting relatively better metabolic statuses and lower risks for carotid atherosclerosis.

Identification of therapeutic targets of ischemic stroke with DNA microarray

OBJECTIVE

Ischemic stroke (IS) is a complex disease that resulting from the interaction of various environmental and genetic risk factors. As genetic factors exerting a direct contributory role in IS, it is one of the focus areas of identification the genetic factors of IS. This study aimed to screen bio-targets of ischemic stroke (IS), and to identify related drug molecules.

MATERIALS AND METHODS

The gene expression profile GSE22255 was downloaded from Gene Expression Omnibus (GEO) database, including 20 whole blood samples from IS patients (IS group) and 20 samples from healthy controls (control group). Differentially expressed genes (DEGs) were screened out using limma package in R. Hierarchical clustering and differences between the groups analysis were conducted for confirming these DEGs. Database for Annotation, Visualization and Integrated Discovery (DAVID) and Kyoto Enrichment of Genes and Genomes (KEGG) were used to obtain the functional genes and pathways respectively. The DEGs were then entered into the WebGestalt database and related drug molecules were retrieved.

RESULTS

Compared with the control group, 27 DEGs were identified from IS group including 25 up- and 2 down-regulated genes. Then functions and pathways enrichment analysis for DEGs were conducted and TNF, IL1B and TNFAIP3 were found to be both participate in apoptosis and NOD-like receptor signaling pathway. Finally, collagenase and other most-related drug molecules were identified from the DEGs.

CONCLUSIONS

In addition to DEGs, several drug molecules were retrieved, which may be related with stroke. Our study provides some underlying bio-targets such as TNF, IL1B and TNFAIP3 for IS and potential drug molecules such as collagenase for the treatment of IS.

Effects of basic fibroblast growth factor on the expression of extracellular matrix and matrix metalloproteinase-1 in wound healing

BACKGROUND

Basic fibroblast growth factor (bFGF) has shown potential in clinical practice to accelerate wound healing, but the underlying biomolecular mechanism remains largely unknown. Fibroblasts are the most important cells involved in producing and remodelling the extracellular matrix (ECM) in wound healing, and are one of the major target cells of bFGF in wound repair. To date, however, we have little idea of whether there is any specific relationship between bFGF and ECM metabolism. This study aimed to investigate whether bFGF improves wound repair by regulating the balance of ECM synthesis and degradation.

OBJECTIVE

To investigate the effects of bFGF on the expression of fibronectin, collagen and matrix metalloproteinase (MMP)-1 of human skin fibroblasts (HSFs) and to evaluate whether it contributes to improving the quality of wound healing.

METHODS

HSFs were stimulated with bFGF for 72 h, and then production of fibronectin, collagen and MMP-1 was detected, using reverse transcription PCR at the transcriptional level and Western blot analysis at post-transcriptional level.

RESULTS

bFGF stimulation resulted in increases in fibronectin expression of 1.31-, 1.47-, 1.57- and 1.62-fold in a dose-dependent manner in response to 10 ng/mL, 50 ng/mL, 100 ng/mL and 500 ng/mL of bFGF, respectively, but had no effect on the expression of collagen. Further investigation revealed that bFGF dose-dependently upregulated the expression of MMP-1.

CONCLUSION

This study supports the hypothesis that bFGF has the potential to accelerate wound healing and improve the quality of wound healing by regulating the balance of ECM synthesis and degradation, suggesting a potential antiscarring role in wound healing.

CSF biomarkers in frontotemporal lobar degeneration with known pathology

OBJECTIVE

To evaluate the diagnostic value of CSF biomarkers in patients with known pathology due to frontotemporal lobar degeneration (FTLD).

BACKGROUND

It is important to distinguish FTLD from other neurodegenerative diseases like Alzheimer disease (AD), but this may be difficult clinically because of atypical presentations.

METHODS

Patients with FTLD (n = 30) and AD (n = 19) were identified at autopsy or on the basis of genetic testing at University of Pennsylvania and Erasmus University Medical Center. CSF was obtained during a diagnostic lumbar puncture and was analyzed using assays for total tau and amyloid-beta 1-42 (A beta(42)). Patients also were assessed with a brief neuropsychological battery.

RESULTS

CSF total tau level and the ratio of CSF total tau to A beta(42) (tau/A beta(42)) were significantly lower in FTLD than in AD. Receiver operating characteristic curve analyses confirmed that the CSF tau/A beta(42) ratio is sensitive and specific at discriminating between FTLD and AD, and is more successful at this than CSF total tau alone. Although some neuropsychological measures are significantly different in autopsy-proven FTLD and AD, combining these neuropsychological measures with CSF biomarkers did not improve the ability to distinguish FTLD from AD.

CONCLUSIONS

The ratio of CSF tau/A beta(42) is a sensitive and specific biomarker at discriminating frontotemporal lobar degeneration from Alzheimer disease in patients with known pathology.

[Summarization of studies on Chinese marine medicinal animal Syngnthus acus]

Syngnthus acus L. is a kind of very important traditional Chinese-medicine from sea. It has plentiful amino acid, protein, trace element, poly-carbon non-saturation fat acid, etc. Syngnthus acus has sexual-hormones-like, anti-cancer and resisting fatigue effects; It can resist fatigue. It can also improve organism immunity and enhance the systolic strength of heart muscle. It can be widely used in many fields such as food field, medical field and aquatic products industry. Its classification, resources, chemical composition and its medical value have been summarized in this article.

Microsomal prostaglandin E synthase is regulated by proinflammatory cytokines and glucocorticoids in primary rheumatoid synovial cells

The selective induction of PGE(2) synthesis in inflammation suggests that a PGE synthase may be linked to an inducible pathway for PG synthesis. We examined the expression of the recently cloned inducible microsomal PGE synthase (mPGES) in synoviocytes from patients with rheumatoid arthritis, its modulation by cytokines and dexamethasone, and its linkage to the inducible cyclooxygenase-2. Northern blot analysis showed that IL-1beta or TNF-alpha treatment induces mPGES mRNA from very low levels at baseline to maximum levels at 24 h. IL-1beta-induced mPGES mRNA was inhibited by dexamethasone in a dose-dependent fashion. Western blot analysis demonstrated that mPGES protein was induced by IL-1beta, and maximum expression was sustained for up to 72 h. There was a coordinated up-regulation of cyclooxygenase-2 protein, although peak expression was earlier. Differential Western blot analysis of the microsomal and the cytosolic fractions revealed that the induced expression of mPGES protein was limited to the microsomal fraction. The detected mPGES protein was catalytically functional as indicated by a 3-fold increase of PGES activity in synoviocytes following treatment with IL-1beta; this increased synthase activity was limited to the microsomal fraction. In summary, these data demonstrate an induction of mPGES in rheumatoid synoviocytes by proinflammatory cytokines. This novel pathway may be a target for therapeutic intervention for patients with arthritis.

[The sonochemical-degradation mechanism of toluene in aqueous solution]

The sonochemical degradation of toluene in the airproof aqueous solution was studied, and the mechanism and course of degradation was explored. It was found that the sonication time had great effect on the removal rate of toluene, and the degradation followed a pseudo-first-order kinetic law, and 90%-95% of toluene was removed only after being irradiated for 40 min, types of dissolved gas and pH also had some effects. After aqueous solution was analyzed pH and scanned UV-wavelength and identified components with SMPE-GC-MS, results confirmed that radical-oxidation controlled the sonochemical-oxidation of toluene, and main middle-products included benzaldehyde, bibenzyl, dibutyl phthalate, et al., final products were carbon dioxide and water.

[The clinical importance of persistent elevation of electrocardiographic ST segment in acute myocardial infarction patients after reperfusion therapy]

OBJECTIVE

To observe the clinical importance of persistent elevation of electrocardiographic ST segment in acute myocardial infarction (AMI) patients receiving direct percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Thirty patients with a first AMI successfully treated with direct coronary angioplasty were selected. The extent of the ST segment elevation and resolution in electrocardiograms on admission and one hour after direct PTCA was analyzed. All the patients were divided into two groups according to the extent of ST segment elevation and resolution. Group A: resolution of ST segment elevation >or=50%, n = 19; Group B: resolution of ST segments elevation < 50%, n = 11. Low-dose dobutamine stress echocardiogram was taken at (7 +/- 2) days after AMI and echocardiogram checked at 1, 2 and 3 months after AMI.

RESULTS

Left ventricular ejection fraction (LVEF) in group A was higher than that in group B at the first week and the first, second and third month after AMI. Aortic blood peak acceleration, cardiac output and cardiac output index of group A were all significantly higher than those in group B at stress. Global wall motion score index (GWMSI) and infarct-zone wall motion score index (IWMSI) in group A were smaller than those in group B at baseline and stress. GWMSI in group A was smaller than that in group B at 1, 2 and 3 months after AMI. There was no significant difference of IWMSI between group A and group B at 1 and 2 months after AMI. IWMSI in group A was smaller than that in group B at the third month after AMI.

CONCLUSIONS

The patients in group B had lower left ventricular contractile function and contractile reserve function and less recovery of infarct-zone wall motion than that in group A.

Critical role of C/EBPdelta and C/EBPbeta factors in the stimulation of the cyclooxygenase-2 gene transcription by interleukin-1beta in articular chondrocytes

The activity of the [-831; +103] promoter of the human cyclooxygenase-2 gene in cultured rabbit chondrocytes is stimulated 2.9 +/- 0.3-fold by interleukin-1beta and this stimulation depends on [-132; -124] C/EBP binding-and [-223; -214] NF-kappaB binding-sites. The C/EBPbeta and C/EBPdelta factors bind to the [-132; -124] sequence. The [-61; -53] sequence is also recognized by C/EBPbeta and C/EBPdelta as well as USF. Mutation of the whole [-61; -53] sequence abolished the stimulation of transcription but single mutations of the C/EBP or USF site did not alter the activity of the promoter, suggesting that the factors bound to the proximal [-61; -53] sequence interact with different members of the general transcription machinery. The [-223; -214] site binds only the p50/p50 homodimer and a non-rel-related protein, but not the transcriptionally active heterodimer p50/p65. The p50/p50 homodimer could interact with the C/EBP family members bound to the [-132; -124] sequence for full stimulation of the COX-2 transcription by interleukin-1beta in chondrocytes. By contrast, the [-448; -449] sequence binds with a low affinity both the p50/p50 homodimeric and p50/p65 heterodimeric forms of NF-kappaB but has no role in the regulation of the human COX-2 promoter in chondrocytes.

Alloantibody-mediated class I signal transduction in endothelial cells and smooth muscle cells: enhancement by IFN-gamma and TNF-alpha

Chronic rejection is the major limiting factor to long term survival of solid organ allografts. The hallmark of chronic rejection is transplant atherosclerosis, which is characterized by the intimal proliferation of smooth muscle cells, endothelial cells, and fibroblasts, leading to vessel obstruction, fibrosis, and eventual graft loss. The mechanism of chronic rejection is poorly understood, but it is suspected that the associated vascular changes are a result of anti-HLA Ab-mediated injury to the endothelium and smooth muscle of the graft. In this study we have investigated whether anti-HLA Abs, developed by transplant recipients following transplantation, are capable of transducing signals via HLA class I molecules, which stimulate cell proliferation. In this report we show that ligation of class I molecules with Abs to distinct HLA-A locus and HLA-B locus molecules results in increased tyrosine phosphorylation of intracellular proteins and induction of fibroblast growth factor receptor expression on endothelial and smooth muscle cells. Treatment of cells with IFN-gamma and TNF-alpha up-regulated MHC class I expression and potentiated anti-HLA Ab-induced fibroblast growth factor receptor expression. Engagement of class I molecules also stimulated enhanced proliferative responses to basic fibroblast growth factor, which augmented endothelial cell proliferation. These findings support a role for anti-HLA Abs and cytokines in the transduction of proliferative signals, which stimulate the development of myointimal hyperplasia associated with chronic rejection of human allografts.

HLA class I-mediated induction of cell proliferation involves cyclin E-mediated inactivation of Rb function and induction of E2F activity

Chronic rejection of transplanted organs is manifested as atherosclerosis of the blood vessels of the allograft. HLA class I Ags have been implicated to play a major role in this process, since signaling via HLA class I molecules can induce the proliferation of aortic endothelial as well as smooth muscle cells. In this study, we show that HLA class I-mediated induction of cell proliferation correlates with inactivation of the Rb protein in the T cell line Jurkat as well as human aortic endothelial cells. HLA class I-mediated inactivation of Rb can be inhibited specifically by neutralizing Abs to basic fibroblast growth factor (bFGF), suggesting a role for FGF receptors in the signaling process. Signaling through HLA class I molecules induced cyclin E-associated kinase activity within 4 h in quiescent endothelial cells, and appeared to mediate the inactivation of Rb. A cdk2 inhibitor, Olomoucine, as well as a dominant-negative cdk2 construct prevented HLA class I-mediated inactivation of Rb; in contrast, dominant-negative cdk4 and cdk6 constructs had no effect. Furthermore, there was no increase in cyclin D-associated kinase activity upon HLA class I ligation, suggesting that cyclin E-dependent kinase activity mediates Rb inactivation, leading to E2F activation and cell proliferation.

Ligation of HLA class I molecules on smooth muscle cells with anti-HLA antibodies induces tyrosine phosphorylation, fibroblast growth factor receptor expression and cell proliferation

The development of transplant atherosclerosis, a manifestation of chronic rejection, is the major obstacle to long-term survival of cardiac and renal allografts. The incidence of transplant atherosclerosis is increased in transplant recipients producing antidonor HLA antibodies following transplantation, suggesting that anti-HLA antibodies play a role in the pathogenesis of the disease. We have postulated that anti-HLA antibodies mediate the development of transplant atherosclerosis by binding to class I molecules on the endothelium and smooth muscle of the graft and transducing signals which stimulate cell proliferation. In this report we demonstrate that anti-HLA class I antibodies transduce signals in smooth muscle cells stimulating increased tyrosine phosphorylation of intracellular proteins and up-regulation of fibroblast growth factor (FGF) receptors. Antibody binding to class I molecules on smooth muscle cells is also accompanied by increased responsiveness to basic FGF and augmented cell proliferation. These findings may explain the increased occurrence of transplant atherosclerosis in recipients producing anti-donor HLA antibodies.

Induction of high affinity fibroblast growth factor receptor expression and proliferation in human endothelial cells by anti-HLA antibodies: a possible mechanism for transplant atherosclerosis

The major limitation to long term survival of organ allografts is chronic rejection, which is manifested as atherosclerosis of the vessels of the transplanted organ. There is a significant association between transplant atherosclerosis and the development of Abs to the disparate HLA Ags present on the graft vasculature. We have investigated the effect of anti-HLA Abs on endothelial cells (EC) and smooth muscle cells cultured in vitro. Ab ligation of class I molecules on ECs results in increased high affinity fibroblast growth factor receptor mRNA expression, and enhanced basic fibroblast growth factor ligand binding. Ab binding to class I molecules on EC and smooth muscle cells is also accompanied by augmented cell proliferation. These results suggest that the intimal thickening observed in transplant atherosclerosis is the result of the proliferative effects of anti-HLA Abs.

Induction of high affinity fibroblast growth factor receptor expression and proliferation in human endothelial cells by anti-HLA antibodies: a possible mechanism for transplant atherosclerosis

The major limitation to long term survival of organ allografts is chronic rejection, which is manifested as atherosclerosis of the vessels of the transplanted organ. There is a significant association between transplant atherosclerosis and the development of Abs to the disparate HLA Ags present on the graft vasculature. We have investigated the effect of anti-HLA Abs on endothelial cells (EC) and smooth muscle cells cultured in vitro. Ab ligation of class I molecules on ECs results in increased high affinity fibroblast growth factor receptor mRNA expression, and enhanced basic fibroblast growth factor ligand binding. Ab binding to class I molecules on EC and smooth muscle cells is also accompanied by augmented cell proliferation. These results suggest that the intimal thickening observed in transplant atherosclerosis is the result of the proliferative effects of anti-HLA Abs.

Anti-HLA antibody ligation to HLA class I molecules expressed by endothelial cells stimulates tyrosine phosphorylation, inositol phosphate generation, and proliferation

The major threat to long-term survival of solid organ allografts is chronic rejection. Progressive narrowing and ultimate luminal occlusion of the arteries and arterioles of the transplanted organ are the hallmarks of the disease. The mechanism of chronic rejection is poorly understood, but it is suspected that the associated vascular changes are a result of anti-HLA antibody-mediated injury to the endothelium. We have postulated that anti-HLA antibodies initiate chronic rejection by binding to class I molecules on the endothelium and transducing signals that result in endothelial cell activation and proliferation. Our data demonstrate that anti-HLA class I antibodies transduce signals in endothelial cells stimulating increased tyrosine phosphorylation of intracellular proteins. Antibody binding to class I antigens also leads to the generation of inositol phosphate and endothelial cell proliferation. These results indicate that anti-HLA antibodies can deliver functionally important signals to endothelial cells, a finding that may be fundamental to an understanding of the mechanisms of chronic rejection.

[Effects of buyang huan wu decoction on rat hyperlipemia model]

Buyang Huan Wu Decoction can obviously lower the blood-lipid in rat hyperlipemia model, as well as drop the cholesterol in the aortic wall. Moreover, the decoction can drop the rising specific viscosity of blood and plasma, raise SOD and lower LPO in the blood.

Transient cold shock induces the heat shock response upon recovery at 37 degrees C in human cells

We evaluated the effects of a transient cold shock followed by recovery and incubation at 37 degrees C on the regulation of heat shock gene expression in the IMR-90 human diploid fibroblasts and HeLa cells in tissue culture. We showed that preincubation of cells at 4 degrees C induced the synthesis and accumulation of the heat shock proteins (HSPs) upon recovery at 37 degrees C, and the degree of this induction was directly related to the time that the cells spent at 4 degrees C. Assays on the abundance of the hsp 70 transcript, the hsp 70 gene promoter activity, and the trimerization and activation of heat shock factor (HSF) to bind to its consensus heat shock element (HSE) provided evidence that this induction of the heat shock response in cells recovering from a transient cold shock is attributable to a transcriptional event mediated by the activation of HSF. Further, the induction was a response to the temperature upshift from 4 to 37 degrees C as opposed to the 4 degrees C treatment itself; quantitation of the HSE-binding activity of cells incubated at 4 degrees C without recovery and incubation at 37 degrees C gave no evidence of an activated response. Analysis of the effects of protein synthesis inhibitors demonstrated that neither cycloheximide nor puromycin was effective in blocking the induction of HSE-binding activity in cells recovering from a transient cold shock. Experiments on the time course and temperature dependence of this induction of HSE-binding activity showed that the onset, magnitude, and duration of this induction were directly proportional to the severity of the cold stress (measured by time and temperature). We discuss the possible mechanism(s) involved in this induction of the heat shock genes at 37 degrees C by a transient cold shock and the biological implications of this observation.