Diagnosis and treatment recommendations of dialysis patients with SARS-CoV-2 infection for primary care clinicians / 西安交通大学学报(医学版)

End-stage renal disease (ESRD) patients undergoing outpatient hemodialysis (HD) and home peritoneal dialysis (PD) are high risk population of severe and critical types caused by SARS-CoV-2 infection. In order to improve the quality of diagnosis and treatment in dialysis patients with SARS-CoV-2 infection, we wrote this recommendation for primary care clinicians. During the epidemic period of SARS-CoV-2 infection, all patients should be instructed to strengthen self-management. Once the SARS-CoV-2 infection was found in dialysis patients, early stratified management should be carried out within 72 hours after the first positive nucleic acid or antigen test results, which includes early antiviral therapy, early recognition, and transferring severe patients from community or primary hospital to a referral hospital promptly. Guidance for dietary and sports rehabilitation after SARS-CoV-2 infection should also be started as soon as possible.

Molecular mechanism of benign biliary stricture inhibition by rosiglitazone-activated peroxisome proliferator-activated receptor gamma

SUMMARY OBJECTIVE: The aim of this study was to investigate whether rosiglitazone-activated peroxisome proliferator-activated receptor gamma can inhibit the occurrence of benign biliary stricture and further elucidate the relevant molecular signaling mechanism. METHODS: The primary cultured rat biliary fibroblasts following experiments were performed using within the fifth generation cells, which were separated from the bile ducts of Sprague-Dawley rats. The primary cultured rat biliary fibroblasts were co-cultured with 10 ng/mL transforming growth factor-beta 1 for stimulating collagen formation. Competent cells were transfected with siRNA that specifically target Smad3 or connective tissue growth factor to inhibit the expression of the corresponding proteins. The cells were incubated with 10 μmol/L rosiglitazone to activate peroxisome proliferator-activated receptor gamma. The cells were incubated with 10 μmol/L GW9662 in the pretreatment session to inactivate peroxisome proliferator-activated receptor gamma. ELISA was used to determine the levels of connective tissue growth factor and type I collagen in the cell supernatant. Western blotting was used to detect the levels of intracellular p-Smad3/t-Smad3. RESULTS: Rosiglitazone-activated peroxisome proliferator-activated receptor gamma inhibited the secretion of type I collagen induced by transforming growth factor-beta 1. Peroxisome proliferator-activated receptor gamma inhibitor GW9662 could significantly reverse the rosiglitazone-triggered inhibition of transforming growth factor-beta 1-induced type I collagen secretion by suppressing peroxisome proliferator-activated receptor gamma activation (p<0.01). Furthermore, we also found that the activation of peroxisome proliferator-activated receptor gamma was accompanied by the inhibition of transforming growth factor-beta 1-induced Smad3 phosphorylation (p<0.01), increased connective tissue growth factor expression (p<0.01), and production of type I collagen (p<0.01), all of which effects elicited by rosiglitazone could be reversed by peroxisome proliferator-activated receptor gamma inhibitor GW9662. CONCLUSION: Peroxisome proliferator-activated receptor gamma activated by rosiglitazone inhibits the transforming growth factor-beta1 -induced phosphorylation of Smad3 and the increased connective tissue growth factor expression as well as inhibits the secretion of type I collagen in biliary fibroblasts.

Metformin inhibits collagen production in rat biliary fibroblasts: the molecular signaling mechanism / 南方医科大学学报

OBJECTIVE@#To clarify the molecular signaling mechanism underlying the inhibitory effect of metformin on transforming growth factor-β1 (TGF-β1)-stimulated collagen I production in rat biliary fibroblasts.@*METHODS@#Primary biliary fibroblasts were isolated under aseptic condition from 50 Sprague-Dawley rats (half male and half female), and microscopic observation identified no obvious difference in the morphology or viability of the cells from rats with different sexes or body weight. The cells were treated with TGF-β1 (10 ng/mL), Smad3 siRNA+TGF-β1, CTGF siRNA+TGF-β1, metformin (10 mmol/L)+ TGF-β1, or Compound C (10 μmol/L)+metformin+TGF-β1. The expressions of CTGF and collagen I in the treated cells were determined using ELISA kit or Western blotting; the phorsphorylated and total Smad3 and AMPK expressions were detected using immunoblotting.@*RESULTS@#TGF-β1 time- and dose-dependently induced collagen I production in rat biliary fibroblasts. The activated AMPK by metformin dose-dependently inhibited TGF-β1-induced collagen I production. Pre-incubation of cells with the AMPK inhibitor Compound C restored the inhibitory effect of AMPK on TGF-β1-induced collagen I secretion ( < 0.01). Activation of AMPK by metformin significantly reduced TGF-β1-induced collagen I production by suppressing Smad3-driven CTGF expression ( < 0.01), and the application of Compound C reversed such changes in the fibroblasts ( < 0.01).@*CONCLUSIONS@#Metformin inhibits TGF-β1-stimulated collagen I production by activating AMPK and inhibiting Smad3- driven CTGF expression in rat biliary fibroblasts.

Foxp3(+)Treg cells mediate immune protection of Humulus pollen allergy DNA vaccine pcDNA3.1-Hum in asthmatic mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a humulus pollen allergy DNA vaccine pcDNA3.1-Hum and investigate its effect for immune protection mediated by Foxp3(+)Treg cells in asthmatic mice.</p><p><b>METHODS</b>The target humulus gene obtained from pTripIEx2-Hum plasmid by double enzyme digestion was inserted sequentially into pcDNA3.1(-) vector to generate the recombinant plasmid pcDNA3.1-Hum, which was validated by sequencing. The pcDNA3.1-Hum plasmid was transfected into COS-7 cells and the expression of the ectopic protein was analyzed using Western blotting. Co-cultured dendritic cells and CD4(+)CD25(-) T cells were stimulated with the expressed protein to test its efficacy in inducing Foxp3(+)Treg cells. The levels of humulus-specific IgE and IgG2a were assayed to evaluate the allergenicity and immunogenicity of pcDNA3.1-Hum in mice. The immunoprotective effect of pcDNA3.1-Hum was assessed in a mouse model of humulus-specific asthma.</p><p><b>RESULTS</b>The constructed pcDNA3.1-Hum plasmid was validated by sequencing and Western blotting, and the expressed protein was shown to induce Foxp3(+)Treg cells in the co-culture. In normal mice, pcDNA3.1-Hum induced a significant increase of humulus-specific IgG2a but had no effect on IgE. In the asthmatic mice, pcDNA3.1-Hum significantly decreased inflammatory cell counts and eosinophil percentages in the BALF, ameliorated lung inflammation, and lowered AHR and IL-4 levels; immunization of the mice with pcDNA3.1-Hum reversed humulus-induced reduction of serum IFN-γ and prevented the humulus-triggered reduction of Foxp3(+)Treg cell percentage in the spleen.</p><p><b>CONCLUSION</b>We have successfully constructed a highly immunogenic pcDNA3.1-Hum DNA vaccine that can mediate immune protection by inducing Foxp3(+)Treg cells.</p>

Advances in research on molecular mechanisms for the proliferation of pulmonary artery smooth muscle cells and their intervention / 西安交通大学学报(医学版)

Pulmonary artery hypertension (PAH)is a common clinical syndrome.The over-proliferation of pulmonary arterial smooth muscle cells (PASMCs)is a hallmark of pulmonary vascular remodeling which is a critical and fundamental pathogenesis in the development of a variety of pulmonary artery hypertension.Here,we review the advances in studies on signaling transduction pathways mediating the proliferation of PASMCs and also introduce the existing approaches in inhibiting their proliferation and relevant research advances.

Calcineurin/NFAT signaling pathway mediates endothelin-1-induced pulmonary artery smooth muscle cell proliferation by regulating phosphodiesterase-5 / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine whether calcineurin/NFAT signaling pathway mediates endothelin-1 (ET-1)-induced proliferation of pulmonary artery smooth muscle cells (PASMCs) by regulating phosphodiesterase-5 (PDE5) and the effect of the selective calcineurin inhibitor cyclosporine A and PDE5 inhibitor sildenafil on ET-1-induced PASMC proliferation.</p><p><b>METHODS</b>PASMCs were treated with ET-1 to stimulate their proliferation with or without prior treatment of the cells with CsA or sildenafil. Calcineurin activity in the cells was measured using a calcineurin activity assay kit, PDE5 expression examined using immunoblotting, and cGMP level detected using a cGMP direct immunoassay kit. PASMC proliferation following the treatments was determined using [(3)H]thymidine incorporation assay.</p><p><b>RESULTS</b>ET-1 caused a 2.05-fold increase in the cellular calcineurin activity, a 1.80-fold increase in PDE5 expression, and a 3.20-fold increase in the DNA synthesis rate, and reduced the cGMP level by 67%. Pretreatment of the cells with Cyclosporine blocked the effects of ET-1, and PDE5 inhibition by sildenafil pretreatment also abolished ET-1-induced reduction of cGMP level in the cells. Both Cyclosporine and sildenafil suppressed ET-1-stimulated PASMC proliferation.</p><p><b>CONCLUSION</b>Activation of calcineurin/NFAT signaling pathway mediates ET-1-induced PASMC proliferation by stimulating PDE5 expression, which further degrades cGMP. Both Cyclosporine and sildenafil can suppress ET-1-stimulated PASMC proliferation in vitro.</p>

Immunological characteristics of the recombinant major pollen allergen pTSX2 of Humulus scandens / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify the immunological characteristics of the recombinant major pollen allergen pTSX2 of Humulus scandens and evaluate its safety in immunotherapy of allergic asthma in mice.</p><p><b>METHODS</b>Western blotting was used to characterize the immunological properties of pTSX2, and its immunogenicity in normal mice was evaluated by detecting sIgG and sIgE levels. The mouse models of allergic asthma were immunized with pTSX2 and examined for sIgE and sIgG levels, total cells and eosinophils percentage in BALF, interleukin-4 (IL-4) and interferon-γ (IFN-γ) levels in BALF and spleen homogenate, and changes in lung pathologies.</p><p><b>RESULTS</b>Western blotting showed that pTSX2 reacted with the majority (about 70%) of sera from patients allergic to Humulus pollen. In normal mice, pTSX2 mainly induced the production of sIgG. In mouse models of allergic asthma, intervention with pTSX2 caused a significant reduction of sIgE and an increase of sIgG (P<0.05), significantly decreased the total cells and eosinophils in BALF (P<0.05), obviously lowered IL-4 but increased IFN-γ in BALF and spleen homogenate (P<0.05), and diminished inflammatory cell infiltration and percentage of eosinophils in the lung tissues.</p><p><b>CONCLUSIONS</b>pTSX2 shows a definite therapeutic effect and safety in the treatment of allergic asthma in mice possibly by inhibiting sIgE and inducing sIgG production, suppressing airway allergic inflammation and regulating the balance between Thl and Th2.</p>

Establishment of a mouse model of Humulus pollen allergen-induced allergic asthma / 西安交通大学学报(医学版)

Objective To develop a mouse model of allergic airway inflammation by using crude Humulus pollen extract.Methods A total of 24 Balb/c mice were divided randomly into two groups: control group and asthma model group with 12 in each.After sensitization by intraperitoneal injection,the mice were challenged by intranasal instillation of crude Humulus pollen extract.The total cell number and eosinophile percentage of bronchoalveolar lavage fluid(BALF) samples were determined.The lungs of mice were stained with hematoxylin and eosin to evaluate the degree of allergic inflammation.The cytokines in BALF and spleen homogenate were assayed by enzyme-linked immunoassay(ELISA).The total IgE in the serum was also measured by ELISA.Results Compared with the mice in normal control group,those in asthma group developed obvious allergic inflammation in the airways.Histological scoring for pulmonary inflammation significantly differed between normal group and asthma group(P