Mechanism of Baihu Renshen decoction on T2DM rats based on mitochondrial autophagy mediated by PINK1/Parkin

Background:This study will be aimed at investigating the effects of Baihu Renshen decoction(BHRS)on type 2 diabetes rats and on macromolecular enzyme 1(PINK1)/E3 ubiquitin protein ligase(Parkin)pathway.Methods:The experiment was divided into four groups:control group,model group,metformin group and BHRS low-dose group and high-dose group.Forty male rats were selected as samples and randomly assigned to at least one test group.Finally,there are 18 rats in each group.Except for the control group,the rats within the different teams got a high-fat diet associate in nursing an intraperitoneal injection of streptozotocin to make a type 2 diabetes mellitus(T2DM)rat model.The organic chemistry and inflammatory indexes of rats in every cluster were analyzed and compared once four weeks of intragastric administration of comparable reagents to review the therapeutic impact of BHRS on T2DM.In addition,we determined the pathological changes of ductal gland tissue of T2DM rats after treatment,and compared the expression of mitochondrial phagocytosis related proteins in ductal gland tissue of rats in each group.Results:FBG,LDL-C,TC,TG,MDA,IL-1,IL-6,TNF-,and mitophagy-related proteins COXIV,P62,VDAC1,and TOM20 were elevated in the model group compared to the control group,while HDL-C,SOD,GSH-Px,and mitophagy-related proteins PINK1,Parkin,and LC3II/I were decreased(P<0.05 or P<0.01).The expressions of FBG,TC,TG,LDL-C,MDA,IL-1,IL-6,TNF-,and mitophagy-related proteins COXIV,P62,VDAC1,and TOM20 were lowered in the BHRS group,while the expressions of HOMA-,HDL-C,SOD,GSH-Px,and mitophagy-related proteins PINK1,Parkin,and LC3II/I were(P<0.05 or P<0.01).After therapy with BHRS,hematoxylin-eosin staining showed that the intensity of pancreatic acinar staining increased,and islet cells became clear boundaries that were,regularly arranged,and with reduced vacuoles reduced.Conclusion:BHRS has a clear therapeutic effect on T2DM,which may be achieved by regulating mitochondrial autophagy through the PINK1/Parkin pathway.

Protective effects of Buyinqianzheng Formula on mitochondrial morphology by PINK1/Parkin pathway in SH-SY5Y cells induced by MPP^(+)

Objective:Buyinqianzheng Formula(BYQZF)is clinically employed in traditional Chinese medicine to treat Parkinson's disease(PD)by improving mitochondrial dysfunction.However,the underlying mechanisms by which BYQZF affects mitochondrial morphology remain unknown.Therefore,we observed the effects of BYQZF on mitochondria from the perspective of the PINK1/Parkin pathway.Methods:Cell survival rates were assessed by Cell Counting Kit-8 assay.Expression levels of PINK1 and Parkin mRNA were examined by qRT-PCR.Protein expression levels of PINK1,PINK1-Ser228,Parkin,Parkin-Ser65,Drp1,and Drp1-Ser637 were examined by western blotting.PINK1,Parkin,and MitoTracker?Red CMXRos(MTR)were stained by triple-labeled immunofluorescence,and observed under laser confocal microscopy.Results:Cell survival rate,mitochondrial form factor,mean length and number of mitochondrial network branches,mitochondrial activity,m RNA expression levels of PINK1 and Parkin,and protein expression levels of PINK1,Parkin,and Drp1-Ser637 were reduced after 1-methyl-4-phenylpyridinium(MPP^(+))intervention.In contrast,Pearson's correlation coefficients between PINK1 and Parkin,and between Parkin and MTR,as well as protein expression levels of PINK1-Ser228,Parkin-Ser65,and Drp1 increased significantly after MPP^(+) intervention.Treatment with BYQZF increased cell survival rate,mitochondrial form factor,mean length and number of mitochondrial network branches,mitochondrial activity,m RNA expression levels of PINK1 and Parkin,and expression of PINK1,Parkin,and Drp1-Ser637 proteins.Pearson's correlation coefficients between PINK1 and Parkin,and between Parkin and MTR,as well as protein expression levels of PINK1-Ser228,Parkin-Ser65,and Drp1 decreased after BYQZF treatment.Conclusion:These results demonstrate that BYQZF has a protective effect on mitochondrial molecular mechanisms in the PD cell model,and the mechanism is related to the PINK1/Parkin pathway.

Bloodletting Acupuncture at Jing-Well Points on Hand Induced Autophagy to Alleviate Brain Injury in Acute Altitude Hypoxic Rats by Activating PINK1/Parkin Pathway

Objective: To explore the protective effect of bloodletting acupuncture at twelve Jing-well points on hand(BAJP) on acute hypobaric hypoxia(AHH)-induced brain injury in rats and its possible mechanisms.Methods: Seventy-five Sprague Dawley rats were divided into 5 groups by a random number table(n=15),including control, model, BAJP, BAJP+3-methyladenine(3-MA), and bloodletting acupuncture at non-acupoint(BANA, tail tip blooding) groups. After 7-day pre-treatment, AHH models were established using hypobaric oxygen chambers. The levels of S100B, glial fibrillary acidic protein(GFAP), superoxide dismutase(SOD), and malondialdehyde(MDA) in serum were measured by enzyme-linked immunosorbent assay. Hematoxylin-eosin staining and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method were used to assess hippocampal histopathology and apoptosis. Transmission electron microscopy assay was used to observe mitochondrial damage and autophagosomes in hippocampal tissues. Flow cytometry was used to detect mitochondrial membrane potential(MMP). The mitochondrial respiratory chain complexes Ⅰ, Ⅲ and Ⅳ activities and ATPase in hippocampal tissue were evaluated, respectively. Western blot analysis was used to detect the protein expressions of Beclin1, autophagy protein 5(ATG5), microtubule-associated protein 1 light chain 3 beta(LC3B), phosphatase and tensin homolog induced kinase 1(PINK1), and Parkin in hippocampal tissues. The mRNA expressions of Beclin1, ATG5 and LC3-Ⅱ were analyzed by quantitative real-time polymerase chain reaction. Results: BAJP treatment reduced hippocampal tissue injury and inhibited hippocampal cell apoptosis in AHH rats. BAJP reduced oxidative stress by decreasing S100B, GFAP and MDA levels and increasing SOD level in the serum of AHH rats(P<0.05 or P<0.01). Then, BAJP increased MMP, the mitochondrial respiratory chain complexes Ⅰ, Ⅲ and Ⅳ activities, and the mitochondrial ATPase activity in AHH rats(all P<0.01). BAJP improved mitochondrial swelling and increased the autophagosome number in hippocampal tissue of AHH rats. Moreover,BAJP treatment increased the protein and mRNA expressions of Beclin1 and ATG5 and LC3-Ⅱ/LC3-Ⅰratio in AHH rats(all P<0.01) and activated the PINK1/Parkin pathway(P<0.01). Finally, 3-MA attenuated the therapeutic effect of BAJP on AHH rats(P<0.05 or P<0.01). Conclusion: BAJP was an effective treatment for AHH-induced brain injury, and the mechanism might be through reducing hippocampal tissue injury via increasing the PINK1/Parkin pathway and enhancement of mitochondrial autophagy.

基于Pink-1/Parkin信号通路补青颗粒含药血清对高糖诱导人晶状体上皮细胞线粒体自噬的影响

目的:探讨补青颗粒含药血清对高糖诱导的人晶状体上皮(HLE)细胞线粒体自噬的影响。方法:体外培养HLE细胞,空白组将HLE细胞在正常培养液中培养48 h,模型组在空白组培养液中添加30 mmol·L^(-1)葡萄糖,实验组在模型组基础上加入不同含药血清刺激培养48 h。采用CCK-8法检测不同含药血清对高糖诱导的HLE细胞增殖活力的影响;利用免疫荧光技术及蛋白免疫印迹(Western blot)法检测Pink-1,Parkin,p62蛋白表达。结果:CCK-8法结果显示模型组较空白组HLE细胞增殖活力增强(P<0.01);与模型组比较,杞菊组与补青颗粒高、中、低剂量组细胞增殖活力均降低(P<0.01);与杞菊组比较,补青颗粒中剂量组细胞增殖活力明显降低(P<0.01);补青颗粒不同剂量组间比较,补青颗粒中剂量组细胞增殖活力显著降低(P<0.01)。细胞免疫荧光结果显示Pink-1,Parkin,p62蛋白主要在细胞胞浆表达,细胞核内亦有少量表达。Western blot结果显示与空白组比较,模型组Pink-1,Parkin表达增加(P<0.01),p62表达降低(P<0.01);与模型组比较,杞菊组与补青颗粒中剂量组Pink-1,Parkin表达增加(P<0.01),p62表达降低(P<0.01);与杞菊组比较,补青颗粒中剂量组Pink-1,Parkin表达增加(P<0.01,P<0.05),p62表达降低(P<0.01)。结论:补青颗粒对高糖诱导的HLE细胞线粒体自噬相关蛋白的表达有显著影响,线粒体自噬的改变可能是补青颗粒改善白内障发病的机制之一。

Effects of Qingguang’an Granules on mitochondrial autophagy of retinal ganglion cells in rats with chronic ocular hypertension

Objective To investigate the effect and underlying mechanism of Qingguang’an Granules(青光安颗粒剂,QGAG)on mitochondrial autophagy(mitophagy)of retinal ganglion cells(RGCs)in rats with chronic ocular hypertension(COH).Methods Sixty Sprague Dawley(SD)rats,half males and half females,were randomly assigned to three groups:the control,model,and QGAG(2.5 g/kg)groups,with 20 rats in each group.Rats’model of COH was established by cauterizing episcleral veins in the model group and QGAG group.Three weeks after successful modeling,rats in the QGAG group were intra-gastrically administered with QGAG,while rats in the control group and the model group received an equal dose of normal saline.After three months of intragastric administration,intraocular pressure(IOP)of all rats was measured.The mitophagy was monitored by the immunofluorescence method,the mitochondrial membrane potential was measured using the JC-1 method,and the morphological changes of mitophagy in RGCs were observed by transmission electron microscopy.Meanwhile,rat RGCs were labeled using the fluorescent gold method,and RGCs density in each group was calculated.Moreover,RGCs apoptosis was observed by TdT-mediated dUTP Nick-End Labeling(TUNEL)assay.Finally,the expression levels of Parkin,optineurin,microtubule-associated protein 1 light chain 3-Ⅱ/microtubule-associated protein 1 light chain 3-Ⅰ(LC3-Ⅱ/LC3-Ⅰ),recombinant lysosomal associated membrane protein 1(LAMP1),and B-cell lymphoma-2(Bcl-2)in RGCs were determined by Western blot assay.The corresponding mRNAs were detected through quantitative real-time polymerase chain reaction(qRT-PCR).Results The QGAG reduced IOP in COH rats,and inhibited mitophagy and apoptosis of RGCs(P<0.05).Besides,the QGAG significantly increased the expression levels of Parkin and Bcl-2(P<0.05),and inhibited the expression levels of optineurin,LAMP1,and LC3-Ⅱ/LC3-Ⅰ(P<0.05)in RGCs of COH rats.Conclusion The QGAG can inhibit mitophagy in RGCs of COH rats and show a protective effect against optic nerve damage caused by glaucoma,which may be mediated through the mitophagy ubiquitination via the Parkin/PINK1-related pathway.