ABSTRACT
Objective To investigate the protective effect and mechanism of active vitamin D3 on podocyte injury in type 1 diabetic rats.Methods Animals were randomly divided into normal control group (NC group),diabetic nephropathy group (DN group),diabetes nephropathy plus active vitamin D3 group (DN + VD group).Random tail vein blood glucose was measured and 24 hours of urine was collected every 3 weeks to observe the dynamic changes of blood glucose and 24-hour urine volume and urinary albumin.Rats were sacrificed at the end of 18th week,the kidney weight to body weight ratio,serum creatinine,blood urea nitrogen,serum calcium,and serum phosphorus levels were measured.Pathological in glomeruli were observed by PAS staining.Immunohistochemistry and Western blotting were used to observe the expression of slit diaphragms proteins including Nephrin,Podocin,and vitamin D receptor protein VDR.The mRNA level of autophagy-related protein P62 was detected by realtime quantitative PCR,and expression of autophagy-related protein including LC3B/A,Beclin1,and P62 were detected by Western blotting.Ultrastructure of podocytes and autopbagosomes in podocytes were observed by electron microscopy.Results Levels of serum creatinine,blood urea nitrogen,and blood glucose in diabetic rats were higher than those in NC group (P＜0.05),but without significant difference between DN and DN+VD groups (P＞0.05).Compared with the DN group,the urinary protein and kidney weight to body weight ratio in the DN +VD group were significantly lower (P＜ 0.05).Mesangial matrix hyperplasia and basement membrane thickening were improved,and podocyte fusion and shedding were partially reversed.The expressions of Nephrin,Podocin,VDR,LC3B/A and Beclin1 were increased,and P62 mRNA and protein were down-regulated (P ＜ 0.05).The number of autophagosomes in podocytes increased.Besides,positive correlations were found between Nephrin and Beclin 1 (r =0.939 8,P＜0.05),as well as Nephrin and VDR (r=0.948 3,P＜0.05),and Beclin1 andVDR (r=0.9093,P＜0.05).Conclusion Active vitamin D3 inhibits the injury of diabetic nephropathy podocytes by up-regulating VDR expression and enhancing autophagy activity,thereby reducing proteinuria and delaying the development of diabetic nephropathy.
ABSTRACT
Objective:To explore the function of IL-9 and PU.1 on genesis and development of pulmonary fibrosis,and the effect of active vitamin D3[1,25(OH)2VD3] on the expression levels of this two factors during the pathogenesis of fibrosis.Methods: 90 male SD rats were randomly divided into model group,treatment group,control group (n=30).Bleomycin(5 mg/kg) was injected into the trachea of rats to establish the model of pulmonary fibrosis in the model group and treatment group,while the control group was injected with isopyknic sterile saline.The treatment group,the model group and the control group were injected intraperitoneally with active vitamin D3,solvent of vitamin D3 (propylene glycol) and sterile saline on the 2nd day after surgery respectively.All injections were carried out once every other day.10 rats were euthanized at 14th,21st and 28th day in each group in turn.After obtaining lung tissues from experimental rats,the pathological change of lung was compared by hematoxylin-eosin staining.The difference of collagen fiber and hydroxyproline content were compared by the Masson staining and basic-hydrolysis method respectively.The mRNA and protein expression of IL-9 and PU.1 in lung tissue were detected by Real-time PCR and immunohistochemical technology respectively.The expression of IL-9 in serum was detected by ELISA.Results: Fibrosis appeared in lungs of experimental rats treated with bleomycin after 14 days,and more and more aggravated with time.At three time points,the hydroxyproline content in model group and treatment group were significantly higher than that of control group,and the treatment group was significantly lower than the model group.At three time points,the expression of IL-9 and PU.1 in model group and treatment group were risen gradually,and obviously higher than that in control group.On the 14th and 21st day,the expression of two factors in treatment group was significantly lower than model group;on the 28th day,there was no statistically significant difference between treatment group and model group(P>0.05).In model group and treatment group,the expression of two factors on 21st day was significantly higher than that on 14th day;there was no statistically significant difference between the 28th day and the 21st day.Conclusion: IL-9 and PU.1 may play a profibrotic role at early stage of pulmonary fibrosis induced by bleomycin.The active vitamin D3 may lower the expression level of PU.1,and then reduce the secretion of IL-9,thus may play an inhibiting effect on genesis and development of pulmonary fibrosis in rats.
ABSTRACT
Objective To observe the correlation between active vitamin D3 level and sarcopenia development in elderly patients in plateau regions and the changes in the correlation factors for sarcopenia under the invention of active vitamin D3 (Calcitriol,Cal),and to observe whether Cal could improve the muscle function.Methods 90 patients were assigned to the normal control (Con) arm,and 120 patients with sarcopenia were assigned to the sarcopenia (Sar) arm to receive different oral doses of Cal as intervention (0.25 ug/d for low dose group including 60 patients and 0.25ug bid for high dose group including 60 patients) Before and after the intervention,levels of 1,25-(OH)2D3 and the inflammatory factors TNF-α,IL-6,IL-10,and hs-CRP were detected using ELISA;HOMA-IR,BMI,and ASMI were calculated;and walking speed and grip strength were measured to observe the correlation between 1,25-(OH) 2D3 level and sarcopenia,the changes in these indicators from before to after intervention,and the efficacy and safety of oral Cal for sarcopenia.Results Prior to intervention,compared with the Con arm,1,25-(OH)2D3 level,IL-10 level,ASMI,walking speed and grip strength were significantly reduced (P＜0.01),and HOMA-IR,IL-6,TNF-α and hs-CRP were significantly elevated (P＜0.01) in both dose groups;intervention with Cal produced significant increases in 1,25-(OH)2D3 and IL-10 levels,significantly improved walking speed and grip strength (P ＜0.05),significant decreases in HOMA-IR,IL-6,TNF-α,and hs-CRP (P＜0.05),which were more marked with higher dose,but no significant changes in ASMI.From before to after intervention,there were no significant changes in BMI or hepatic/renal function,blood calcium,or blood phosphorus in either group.Conclusions The development of sarcopenia is associated with reduced 1,25-(OH)2D3 level.Cal can lower the inflammatory factors IL-6,TNF-α,and hs-CRP,and elevate IL-10,providing anti-inflammatory and immunoregulatory actions;improve muscle function and strength;and improve insulin resistance.BMI is irrelevant to the management of sarcopenia.Cal is safe at the oral dose up to 0.5 tμg/d.