Research progress of Parkin protein regulating mitochondrial homeostasis through ubiquitination in cardiovascular diseases / 中国药理学通报

In addition to providing energy for cells, mitochondria also participate in calcium homeostasis, cell information transfer, cell apoptosis, cell growth and differentiation. Therefore, maintaining mitochondrial homeostasis is very crucial for the body to carry out normal life activities. Ubiquitination, a post-translational modification of proteins, is involved in various physiological and pathological processes of cells by regulating mitochondrial homeostasis. However, the mechanism by which ubiquitination regulates mitochondrial homeostasis has not been summarized, especially the effect of Parkin protein on cardiovascular diseases. In this paper, the specific mechanism of mitochondrial homeostasis regulated by ubiquitination of Parkin protein is discussed, and the influence of mitochondrial homeostasis imbalance on cardiovascular diseases is reviewed, with a view to providing potential therapeutic strategies for the clinical treatment of cardiovascular diseases.

Bloodletting Acupuncture at Jing-Well Points on Hand Induced Autophagy to Alleviate Brain Injury in Acute Altitude Hypoxic Rats by Activating PINK1/Parkin Pathway / 中国结合医学杂志

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-I ratio 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.

Effects of total saponins from Trillium tschonoskii maxim on cognition impairment and mitochondrial autophagy in aging rats induced by D-Gal / 中国药理学通报

Aim To investigate the effects of total saponins from Trillium tschonoskii maxim(TST)on cognitive impairment and mitochondrial autophagy in aging rats induced by D-galactose(D-gal). Methods Male SD rats were randomly divided into normal control group,model group(D-gal,subcutaneous injection),intervention group(TST,low,medium and high dose groups by intragastric administration),with 10 rats in each group,and administered for 6 weeks. Morris water maze was used to evaluate the cognitive function. HE and Nissl staining were used to test the hippocampal and brain cortex morphology. Immunohistochemistry staining was applied to detect the localization expression of Pink1 and Parkin. Western blot was employed to detect the expressions of Pink1,Parkin,LC3-Ⅱ,p62 and Beclin1. Results Compared with the normal control group,the escape latency time was prolonged and the number of crossing platform decreased in D-gal model group(P<0.05). The number of neurons in hippocampus significantly decreased. The positive cells labeled by Pink1 and Parkin staining in hippocampus significantly decreased. The expressions of Pink1,Parkin,LC3-Ⅱ and Beclin1 were markedly reduced,while the expression of p62 was significantly raised(P<0.05). Compared with D-gal model group,the escape latency time of TST dose groups was shortened,the Times of crossing the platform was more,and the time of staying in the platform quadrant increased(P<0.05). The number of neurons in hippocampus significantly increased. The positive cells labeled by Pink1 and Parkin staining in hippocampus significantly increased. The expressions of Pink1,Parkin,LC3-Ⅱ and Beclin1 in hippocampus were apparently up-regulated,while the protein expression of p62 was evidently down-regulated(P<0.05). Conclusions TST has neuroprotective effects on the learning and memory capacities in aging rats induced by D-gal,which may be related to the increasing levels of Pink1,Parkin,LC3-Ⅱ and Beclin1 proteins and the activation of mitochondrial autophagy.

Mechanism of autophagy induced by osthole through PINK1/Parkin pathway in HeLa cells / 中国药理学通报

Aim To investigate the potential mechanism of osthole promoting autophagy in cervical cancer HeLa cells. Methods HeLa cells were treated with various concentrations of Osthole(0,10,20,40,80,160,240,320 mg·L-1). MTT was used to detect cell vitality. Transmission electron microscopy(TEM)was used to observe the morphology of HeLa cells after osthole intervention. Mondane sulfonyl cadaverine(MDC)staining was used to dectect the level of autophagy. Western blot was employed to analyze the expression levels of mitochondrial protein MFN1 and DPR1. JC-1 flourescence probe was applied to detect mitochondrial membrane potential. Flow cytometry was used to deteminet the release of reactive oxygen species(ROS). A transplanted tumor model of cervical cancer was established in vivo in nude mice. Western blot was used to detect the protein expression levels of PINK1,Parkin and LC3Ⅱ/. Results Osthole could inhibit the proliferation of HeLa cells significantly. Transmission electron microscopy showed that typical autophagosomes were formed in HeLa cells after osthole intervention. The fluorescence intensity of MDC was enhanced. The expression of mitochondrial fusion protein MFN1 was down-regulated after HeLa cells pretreated with osthole,and mitochondrial fission protein DRP1 was up-regulated. Mitochondrial membrane potential decreased. ROS production of HeLa cells was increased by flow cytometry,which could be reversed by autophagy inhibitor 3-MA. Tumor weight in nude mice was inhibited by osthole obviously,which might restrain cervical cancer. Western blot result indicated that the key factors of mitochondrial autophagy PINK1,Parkin and LC3Ⅱ/ratio were up-regulated in HeLa cells. Conclusions Osthole could induce autophagy in HeLa cells and its mechanism may be related to ROS production and PINK1/Parkin pathway.

Mechanism of ophiopogonin D in treatment of pulmonary fibrosis based on network pharmacology and experimental verification / 中国药理学通报

Aim To predict the potential mechanism of ophiopogonin D (OPD) against pulmonary fibrosis by network pharmacology, and further verify it by experiment in vivo. Methods This study found that ophiopogon was the most frequently used drug in the treatment of pulmonary fibrosis with deficiency of Qi and Yin through data mining. In order to explore its material basis, network pharmacology analysis was carried out. A model of pulmonary fibrosis was established by bleomycin, and different concentrations of ophiopogonin D were administered to verify the results of the pharmacological network. Results Firstly, through network pharmacology analysis, it was found that mitophagy might be the potential target for ophiopogon to exert anti-pulmonary fibrosis effect. Meanwhile, network topology analysis showed that OPD had the greatest relationship with mitophagy. Animal experiments showed that OPD could relieve pulmonary fibrosis and reduce collagen deposition in mice. At the same time, the detection of mitophagy related proteins showed that the compound could increase the expression of PINK1 and Parkin proteins, reduce the content of P62 protein in lung tissue, and reduce the intracellular ROS level. Conclusions OPD can improve mitochondrial function and play an anti-pulmonary fibrosis role by promoting PINKl/Parkin dependent mitophagy in lung tissue.

Quality control mechanism of mitochondria by 3,4-dihydroxybenzaldehyde through OGT-PINK1 pathway / 中国中药杂志

Based on the O-GlcNAc transferase(OGT)-PTEN-induced putative kinase 1(PINK1) pathway, the mechanism of 3,4-dihydroxybenzaldehyde(DBD) on mitochondrial quality control was investigated. Middle cerebral artery occlusion/reperfusion(MCAO/R) rats were established. SD rats were randomized into sham operation group(sham), model group(MCAO/R), DBD-L group(5 mg·kg~(-1)), and DBD-H group(10 mg·kg~(-1)). After 7 days of administration(ig), MCAO/R was induced in rats except the sham group with the suture method. Twenty-four h after reperfusion, the neurological function and the percentage of cerebral infarct area were measured. Based on hematoxylin and eosin(HE) staining and Nissl staining, the pathological damage of cerebral neurons was examined. Then the ultrastructure of mitochondria was observed under the electron microscope, and the co-localization of light chain-3(LC3), sequestosome-1(SQSTM1/P62), and Beclin1 was further detected by immunofluorescence staining. It has been reported that the quality of mitochondria can be ensured by inducing mitochondrial autophagy through the OGT-PINK1 pathway. Therefore, Western blot was employed to detect the expression of OGT, mitophagy-related proteins PINK1 and E3 ubiquitin ligase(Parkin), and mitochondrial kinetic proteins dynamin-like protein 1(Drp1) and optic atrophy 1(Opa1). The results showed that MCAO/R group had neurological dysfunction, large cerebral infarct area(P<0.01), damaged morphological structure of neurons, decreased number of Nissl bodies, mitochondrial swelling, disappearance of mitochondrial cristae, decrease of cells with LC3 and Beclin1, rise of cells with P62(P<0.01), inhibited expression of OGT, PINK1, and Parkin, up-regulated expression of Drp1, and down-regulated expression of Opa1 compared with the sham group(P<0.01). However, DBD improved the behavioral deficits and mitochondrial health of MCAO/R rats, as manifested by the improved morphology and structure of neurons and mitochondria and the increased Nissl bodies. Moreover, DBD increased cells with LC3 and Beclin1 and decreased cells with P62(P<0.01). In addition, DBD promoted the expression of OGT, PINK1, Parkin, and Opa1 and inhibited the expression of Drp1, enhancing mitophagy(P<0.05, P<0.01). In conclusion, DBD can trigger PINK1/Parkin-mediated brain mitophagy through the OGT-PINK1 pathway, which plays a positive role in maintaining the health of the mitochondrial network. This may be a mitochondrial therapeutic mechanism to promote nerve cell survival and improve cerebral ischemia/reperfusion injury.

Mechanism of Cinnamaldehyde in Promoting Wound Healing in Diabetes Rats via PINK1/Parkin-mediated Mitochondrial Autophagy / 中国实验方剂学杂志

ObjectiveTo establish a rat model of diabetic wound by feeding on a high-fat and high-sugar diet combined with intraperitoneal injection of streptozotocin （STZ） and surgical preparation of full-thickness skin defects， observe the effect of cinnamaldehyde on the wound healing of diabetes rats， and explore the therapeutic mechanism of cinnamaldehyde in improving wound healing of diabetes rats based on the PTEN-induced putative kinase （PINK1）/Parkin pathway-mediated mitochondrial autophagy. MethodForty-eight male SD rats were randomly divided into blank group （n=12） and diabetes group （n=36）. The diabetes group was further randomly divided into model group， cinnamaldehyde group， and Beifuxin group， with 12 rats in each group. The blank group and the model group received routine disinfection with physiological saline after creating the wounds， while the cinnamaldehyde group received topical application of polyethylene glycol 400 （PEG 400） gel containing 4 μmol·L-1 cinnamaldehyde， and the Beifuxin group received topical application of Beifuxin gel. Dressings were changed once daily. The wound healing rate of each group was observed. On the 7th and 14th days after intervention， the wound tissues of the rats were collected. Hematoxylin and eosin （HE） staining was performed to observe the pathological changes in the local tissues. Immunohistochemistry （IHC） was used to detect the expression of interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， vascular endothelial growth factor （VEGF）， and collagen fibers. Immunofluorescence （IF） and Real-time polymerase chain reaction （Real-time PCR） were used to detect the protein， and mRNA expression of PINK1， Parkin， microtubule-associated protein 1 light chain 3 Ⅱ （LC3 Ⅱ）. ResultAfter intraperitoneal injection of STZ， compared with the blank group， the random blood glucose values of rats in the diabetic group increased significantly （P<0.01）， all higher than 16.7 mmol·L-1， and persistently hyperglycemic for some time after modeling. Compared with the blank group， the model group showed poor growth and healing of granulation tissue in the wounds， and the wound healing rate decreased （P<0.01）. On the 7th day after intervention， the blank group had squamous epithelial coverage on the wounds. Compared with the blank group， the model group only had a small amount of scab at the wound edges， with a large number of infiltrating inflammatory cells in the wounds. The protein expression levels of IL-6 and TNF-α in the tissues increased （P<0.01）， and the protein and mRNA levels of PINK1， Parkin， and LC3Ⅱ decreased （P<0.01）. On the 14th day after the intervention， the granulation tissue in the wounds of the blank group was mature and well-healed. Compared with the blank group， the model group still had infiltrating inflammatory cells and red blood cell exudation. The protein expression levels of VEGF and collagen fibers in the tissues decreased （P<0.01）， and the protein and mRNA expression levels of PINK1， Parkin， and LC3Ⅱ increased （P<0.01）. Compared with the model group， the cinnamaldehyde group and the Beifuxin group showed better wound healing， with increased wound healing rates （P<0.01）. On the 7th day after intervention， the protein expression levels of IL-6 and TNF-α in the tissues decreased （P<0.01）， and the protein and mRNA expression levels of PINK1， Parkin， and LC3Ⅱ increased （P<0.01）. On the 14th day after intervention， the protein expression levels of VEGF and collagen fibers in the tissues increased （P<0.01）， and the protein and mRNA expression levels of PINK1， Parkin， and LC3Ⅱ decreased （P<0.01）. ConclusionCinnamaldehyde can promote the wound healing of diabetes rats by increasing the wound healing rate， reducing the levels of inflammatory factors IL-6 and TNF-α， and increasing the levels of VEGF and collagen fibers. Its mechanism may be related to the regulation of the PINK1/Parkin signaling pathway， activation of mitochondrial autophagy， inhibition of inflammatory responses， and promotion of angiogenesis and collagen synthesis， thereby promoting the wound healing of diabetes rats.

Effect on Danggui Shaoyao Powder on mitophagy in rat model of Alzheimer's disease based on PINK1-Parkin pathway / 中国中药杂志

This study investigated the mechanism of Danggui Shaoyao Powder(DSP) against mitophagy in rat model of Alzheimer's disease(AD) induced by streptozotocin(STZ) based on PTEN induced putative kinase 1(PINK1)-Parkin signaling pathway. The AD rat model was established by injecting STZ into the lateral ventricle, and the rats were divided into normal group, model group, DSP low-dose group(12 g·kg~(-1)·d~(-1)), DSP medium-dose group(24 g·kg~(-1)·d~(-1)), and DSP high-dose group(36 g·kg~(-1)·d~(-1)). Morris water maze test was used to detect the learning and memory function of the rats, and transmission electron microscopy and immunofluorescence were employed to detect mitophagy. The protein expression levels of PINK1, Parkin, LC3BⅠ/LC3BⅡ, and p62 were assayed by Western blot. Compared with the normal group, the model group showed a significant decrease in the learning and memory function(P<0.01), reduced protein expression of PINK1 and Parkin(P<0.05), increased protein expression of LC3BⅠ/LC3BⅡ and p62(P<0.05), and decreased occurrence of mitophagy(P<0.01). Compared with the model group, the DSP medium-and high-dose groups notably improved the learning and memory ability of AD rats, which mainly manifested as shortened escape latency, leng-thened time in target quadrants and elevated number of crossing the platform(P<0.05 or P<0.01), remarkably activated mitophagy(P<0.05), up-regulated the protein expression of PINK1 and Parkin, and down-regulated the protein expression of LC3BⅠ/LC3BⅡ and p62(P<0.05 or P<0.01). These results demonstrated that DSP might promote mitophagy mediated by PINK1-Parkin pathway to remove damaged mitochondria and improve mitochondrial function, thereby exerting a neuroprotective effect.

Effect of ligustrazine on hypoxic-ischemic encephalopathy in neonatal rats by regulating autophagy through the PINK1/Parkin pathway / 中国当代儿科杂志

OBJECTIVES@#To study the effect of ligustrazine injection on mitophagy in neonatal rats with hypoxic-ischemic encephalopathy (HIE) and its molecular mechanism.@*METHODS@#Neonatal Sprague-Dawley rats, aged 7 days, were randomly divided into a sham-operation group with 8 rats, a model group with 12 rats, and a ligustrazine group with 12 rats. The rats in the model group and the ligustrazine group were used to establish a neonatal rat model of HIE by ligation of the left common carotid artery followed by hypoxia treatment, and blood vessels were exposed without any other treatment for the rats in the sham-operation group. The rats in the ligustrazine group were intraperitoneally injected with ligustrazine (20 mg/kg) daily after hypoxia-ischemia, and those in the sham-operation group and the model group were intraperitoneally injected with an equal volume of normal saline daily. Samples were collected after 7 days of treatment. Hematoxylin and eosin staining and Nissl staining were used to observe the pathological changes of neurons in brain tissue; immunohistochemical staining was used to observe the positive expression of PINK1 and Parkin in the hippocampus and cortex; TUNEL staining was used to measure neuronal apoptosis; Western blotting was used to measure the expression levels of the mitophagy pathway proteins PINK1 and Parkin and the autophagy-related proteins Beclin-1, microtubule-associated protein 1 light chain 3 (LC3), and ubiquitin-binding protein (P62).@*RESULTS@#Compared with the sham-operation group, the model group had a significant reduction in the number of neurons, an increase in intercellular space, loose arrangement, lipid vacuolization, and a reduction in Nissl bodies. The increased positive expression of PINK1 and Parkin, apoptosis rate of neurons, and protein expression levels of PINK1, Parkin, Beclin1 and LC3 (P<0.05) and the decreased protein expression level of P62 in the hippocampus were also observed in the model group (P<0.05). Compared with the model group, the ligustrazine group had a significant increase in the number of neurons with ordered arrangement and an increase in Nissl bodies, significant reductions in the positive expression of PINK1 and Parkin, the apoptosis rate of neurons, and the protein expression levels of PINK1, Parkin, Beclin1, and LC3 (P<0.05), and a significant increase in the protein expression level of P62 (P<0.05).@*CONCLUSIONS@#Ligustrazine can alleviate hypoxic-ischemic brain damage and inhibit neuronal apoptosis in neonatal rats to a certain extent, possibly by inhibiting PINK1/Parkin-mediated autophagy.

Polydatin alleviates allergic rhinitis by regulating PINK1-Parkin-mediated mitophagy / 中国药理学通报

Objective To investigate the protective effect and mechanism of polydatin ( PD) on allergic rhinitis (AH) by regulating mitophagy through PINK1- Parkin signaling pathway, and to provide a new target for clinical treatment of AH.Methods Thirty-two BALB/c murine were randomly divided into 4 groups: control group, OVA group, PD low-dose (30 mg • kg 1 ) and high-dose ( 45 mg • kg 1 ) treatment groups.At the end of modeling, the total number of sneezing and nasal nibbing of murine was recorded.HE staining was used to observe the morphology of na- sal mucosal epithelium and eosinophil infiltration.Western blot was used to detect the expression of P1NK1 , Parkin, TOM20 and mitochondrial apoptosis- related proteins Bax, Bcl-2, caspase-3, cleaved- caspase-3 and Cytochrome C.Hie expression of P1NK1 and cleaved-caspase-3 in nasal epithelial cells (HNEpC) was observed by immunofluorescence.Re¬sults The frequency of sneezing and nasal rubbing movements was significantly increased, the nasal mu¬cosa epithelium was thickened, and eosinophils were accumulated in AH murine , these results were reversed after PD treatment.Western blot results shower] that signaling proteins PINK1/Parkin anrl pro-apoptotie pro¬teins, including Bax, caspase-3, cleaved-caspase-3 and Cytochrome C were significantly overexpressed, the expression of TOM20 and Bcl-2 was decreased in OVA group, and PD up-regulated the levels of P1NK1 , Parkin, as well as Bcl-2 and inhibited the expression of TDM20 and pro-apoptotic proteins, while after pre- treatment with mitochondrial division inhibitor 1 ( Mdi- vi-1 ) , the expression of P1NK1 and Parkin was re¬duced , the expression of TOM20 was increased, while PD treatment did not significantly affect this effect.From the immunofluorescence results, it can be seen that the level of P1NK1 was increased after IL-13 stim¬ulation of HNEpCs compared with the control group, and PD further up-regulated the expression of P1NK1 , which was suppressed after pretreatment with Mdivi-1 , while PD did not change this phenomenon.Western blot results for P1NK1 and cleaved-caspase-3 were con¬firmed by immunofluorescence.Conclusion PD may activate mitophagy through the P1NK1 -Parkin signaling pathway, thereby protecting against AR.

Nicotinamide mononucleotide attenuates ischemia-reperfusion injury induced by donor liver from cardiac death through Sirt3 / 器官移植

Objective To evaluate the effect and mechanism of nicotinamide mononucleotide (NMN) on ischemia-reperfusion injury (IRI) induced by donor liver after cardiac death in rat models. Methods Rat models of orthotopic liver transplantation were established by "magnetic ring + double cuff" method. SD rats were randomly divided into the sham operation group (Sham group), orthotopic liver transplantation group (OLT group), NMN treatment + orthotopic liver transplantation group (NMN group), NMN+sirtuin-3 (Sirt3) inhibitor (3-TYP) + orthotopic liver transplantation group (NMN+3-TYP group), respectively. Pathological changes and hepatocyte apoptosis of the rats were observed in each group. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were determined. Superoxide dismutase (SOD) and malondialdehyde (MDA) contents in liver tissues were detected. The expression levels of Sirt3, microtubule-associated protein 1 light chain 3 (LC3)Ⅱ, PTEN-induced putative kinase 1 (PINK1), Parkin and translocase of the outer mitochondrial membrane 20 (TOMM20) in liver tissues were measured. Postoperative survival of the rats in each group was analyzed. Results Compared with the Sham group, serum ALT and AST levels were higher in the OLT group. Compared with the OLT group, the levels of ALT and AST were decreased in the NMN group. Compared with the NMN group, the levels of ALT and AST were increased in the NMN +3-TYP group (all P < 0.05). The liver tissue structure of rats in the Sham group was basically normal. In the OLT group, pathological changes, such as evident congestion, vacuolar degeneration and hepatocyte necrosis, were observed in the liver tissues. Compared with the Sham group, Suzuki score and apoptosis rate were higher in the OLT group. Suzuki score and apoptosis rate in the NMN group were lower than those in the OLT group. Suzuki score and apoptosis rate in the NMN+3-TYP group were higher compared with those in the NMN group (all P < 0.05). Compared with the Sham group, the SOD content was decreased, whereas the MDA content was increased in the OLT group. Compared with the OLT group, the SOD content was increased, whereas the MDA content was decreased in the NMN group. Compared with the NMN group, the SOD content was decreased, whereas the MDA content was increased in the NMN+3-TYP group (all P < 0.05). Compared with the Sham group, the relative expression levels of Sirt3 and TOMM20 proteins were down-regulated, whereas those of PINK1, Parkin and LC3Ⅱproteins were up-regulated in the OLT group. Compared with the OLT group, the relative expression levels of Sirt3, PINK1, Parkin and LC3Ⅱproteins were up-regulated, whereas that of TOMM20 protein was down-regulated in the NMN group. Compared with the NMN group, the relative expression levels of PINK1, Parkin and LC3Ⅱproteins were down-regulated, whereas that of TOMM20 protein was up-regulated in the NMN+3-TYP group (all P < 0.05). In the Sham group, the 7 d survival rate of rats was 100%, 50% in the OLT group, 75% in the NMN group and 58% in the NMN+3-TYP group, respectively. Conclusions NMN may enhance the antioxidative capacity of the liver, induce PINK1/Parkin-mediated mitochondrial autophagy, and alleviate IRI of the liver by up-regulating Sirt3, thereby playing a protective role in the donor liver after cardiac death.

Effect of Gandou Decoction on Mitophagy in Toxic Milk （TX） Mouse Model of Wilson Disease Based on Pink1/Parkin Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effects of Gandou decoction （GDD） on the mitophagy of hippocampal neurons in toxic milk （TX） mouse model of Wilson disease and explore the protective mechanism of GDD against neuron injury through the PTEN induced kinase 1 （Pink1） /E3 ubiquitin ligase （Parkin） pathway. MethodSixty mice were randomly divided into a blank group， a model group， a penicillamine group （0.09 g·kg-1）， and low- （5.5 g·kg-1）， medium- （11 g·kg-1）， and high-dose （22 g·kg-1） GDD groups， and treated correspondingly by gavage for 8 weeks. Morris water maze， traction test， and pole test were used for the evaluation of animal behaviors. Hematoxylin-eosin （HE） staining and transmission electron microscopy were used to observe cell apoptosis， ultrastructure， autophagy， and mitochondrial structure. The levels of superoxide dismutase （SOD）， reactive oxygen species （ROS）， and malondialdehyde （MDA） were detected by enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence-based quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of Pink1， Parkin， autophagy-associated protein Beclin-1， microtubule-associated protein 1 light chain 3Ⅱ （LC3Ⅱ）， and p62. Western blot was conducted to detect the protein expression of Pink1， Parkin， Beclin-1， LC3Ⅱ/Ⅰ， and p62. ResultCompared with the blank group， the model group showed prolonged escape latency， decreased times of platform crossing， lower score in the traction test， and longer pole climbing time （P<0.01）. Compared with the model group， the medium- and high-dose GDD groups and the penicillamine group showed shortened escape latencies， increased times of platform crossing， higher scores in the traction test， and shortened pole climbing time （P<0.01）. Compared with the blank group， the model group displayed severely damaged neurons and increased autophagosomes. Compared with the model group， the medium- and high-dose GDD groups and the penicillamine group showed improved neuron damage and reduced autophagosomes. The levels of ROS and MDA were higher and SOD was lower in the model group than those in the blank group （P<0.01）， while the levels of the above indicators were reversed by GDD intervention as compared with the model group （P<0.01）. Compared with the blank group， the model group exhibited up-regulated mRNA and protein expression of Pink1， Parkin， LC3Ⅱ， and Beclin-1 and down-regulated p62 （P<0.05）. Compared with the model group， the medium- and high-dose GDD groups showed reduced mRNA and protein expression of Pink1， Parkin， LC3Ⅱ， and Beclin-1 and increased p62 （P<0.05， P<0.01）. ConclusionGDD can significantly inhibit the excessive mitophagy in neurons of TX mice and protect neurons from damage. The mechanism may be related to the regulation of the Pink1/Parkin pathway.

Ginsenoside Rg_1 protects PC12 cells against Aβ-induced injury through promotion of mitophagy by PINK1/parkin activation / 中国中药杂志

Amyloid β-protein(Aβ) deposition in the brain is directly responsible for neuronal mitochondrial damage of Alzheimer's disease(AD) patients. Mitophagy, which removes damaged mitochondria, is a vital mode of neuron protection. Ginsenoside Rg_1(Rg_1), with neuroprotective effect, has displayed promising potential for AD treatment. However, the mechanism underlying the neuroprotective effect of Rg_1 has not been fully elucidated. The present study investigated the effects of ginsenoside Rg_(1 )on the autophagy of PC12 cells injured by Aβ_(25-35) to gain insight into the neuroprotective mechanism of Rg_1. The autophagy inducer rapamycin and the autophagy inhi-bitor chloroquine were used to verify the correlation between the neuroprotective effect of Rg_1 and autophagy. The results showed that Rg_1 enhanced the viability and increased the mitochondrial membrane potential of Aβ-injured PC12 cells, while these changes were blocked by chloroquine. Furthermore, Rg_(1 )treatment increased the LC3Ⅱ/Ⅰ protein ratio, promoted the depletion of p62 protein, up-regulated the protein levels of PINK1 and parkin, and reduced the amount of autophagy adaptor OPTN, which indicated the enhancement of autophagy. After the silencing of PINK1, a key regulatory site of mitophagy, Rg_1 could not increase the expression of PINK1 and parkin or the amount of NDP52, whereas it can still increase the LC3Ⅱ/Ⅰ protein ratio and promote the depletion of OPTN protein which indicated the enhancement of autophagy. Collectively, the results of this study imply that Rg_1 can promote autophagy of PC12 cells injured by Aβ, and may reduce Aβ-induced mitochondrial damage by promoting PINK1-dependent mitophagy, which may be one of the key mechanisms of its neuroprotective effect.

Expression and Significance of Mitochondrial Autophagy-associated Protein PINK1 and Parkin in Parotid Pleomorphic Adenoma and Carcinoma ex Pleomorphic Adenoma / 肿瘤防治研究

Objective To investigate the expression of mitochondrial autophagy-associated protein PINK1 and Parkin in parotid pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma(CA-EX-PA). Methods The expression of PINK1 and Parkin were detected by immunohistochemistry in 24 cases of normal parotid gland tissues, 32 cases of PA tissues and 42 cases of CA-EX-PA tissues. The correlations of PINK1 and Parkin expression with the clinicopathologic characteristics of CA-EX-PA patients were analyzed. Results The positive rates of PINK1 in normal parotid gland, PA and CA-EX-PA tissues were 100%, 91% and 67% respectively; and those of Parkin were 100%, 88% and 52% respectively. The expression rates of PINK1 and Parkin in PA and CA-EX-PA tissues were significantly lower than those in normal tissues (P < 0.05). The expression of PINK1 and Parkin protein were positively correlated in CA-EX-PA tissues (r=0.877, P < 0.01). In CA-EX-PA tissues, the expression of PINK1 and Parkin were associated with tumor invasion, lymph node metastasis and TNM stage (P < 0.05). Conclusion The expression of PINK1 and Parkin are decreased in PA and CA-EX-PA tissues. The decrease of mitochondrial autophagy activity might play important roles in the development, invasion and metastasis of parotid gland tumors.

Mechanism of exogenous hydrogen sulfide-induced reduction of apoptosis in neurons during focal cerebral ischemia-reperfusion in rats: PINK1/Parkin pathway-mediated mitochondrial autophagy / 中华麻醉学杂志

Objective:To investigate the relationship between the mechanism of exogenous hydrogen sulfide (H 2S)-induced reduction of apoptosis in neurons during focal cerebral ischemia-reperfusion (I/R) and PINK1/Parkin pathway-mediated mitochondrial autophagy in rats. Methods:Two hundred and sixteen healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 250-270 g, were divided into 4 groups ( n=54 each) using a random number table method: control group (group C), I/R group, H 2S group and H 2S plus 3-methyladenine (3-MA) group (H 2S+ 3-MA group). Focal cerebral ischemia was induced by middle cerebral artery occlusion in anesthetized rats.In group H 2S+ 3-MA, 3-MA 10 mg/kg was intraperitoneally injected at 15 min before the onset of reperfusion, while the equal volume of normal saline was given instead in the other groups.In H 2S and H 2S+ 3-MA groups, 0.25% NaSH (a donor of exogenous H 2S) 10 mg/kg was intraperitoneally injected at the onset of reperfusion, while the equal volume of normal saline was given instead in the other groups.At 1, 3 and 7 days of reperfusion, neural function was scored, and corner test (the percentage of left turn was calculated) was performed.Brains were removed and brain tissues were obtained for determination of the cerebral infarct size, Bax, Bcl-2 and caspase-3 positive cells, cell apoptosis, and expression of mitophagy-related protein microtubule-associated protein 1 light chain 3 (LC3), PINK1 and Parkin (by Western blot). The percentage of cerebral infarct size, rate of Bax, Bcl-2 and caspase-3 positive cells and apoptosis rate were calculated.The ratio of LC3-Ⅱexpression to LC3-Ⅰexpression (LC3-Ⅱ/LC3-Ⅰ) was also calculated. Results:Compared with group C, the neural function score was significantly decreased, the percentage of left turn, percentage of cerebral infarct size, rate of Bax, Bcl-2 and caspase-3 positive cells, apoptosis rate of neurons, and LC3-Ⅱ/LC3-Ⅰ were increased, and the expression of PINK1 and Parkin was up-regulated at each time point of reperfusion in group I/R ( P<0.05). Compared with group I/R, the neural function score and rate of Bcl-2 positive cells were significantly increased, the percentage of left turn, percentage of cerebral infarct size, rate of Bax and caspase-3 positive cells, and apoptosis rate of neurons were decreased, the expression of PINK1 and Parkin was up-regulated, and LC3-Ⅱ/LC3-Ⅰ were increased at each time point of reperfusion in group H 2S ( P<0.05), and no significant change was found in the parameters mentioned above in group H 2S+ 3-MA ( P>0.05). Compared with group H 2S, the neural function score and rate of Bcl-2 positive cells were significantly decreased, the percentage of left turn, percentage of cerebral infarct size, rate of Bax and caspase-3 positive cells, and apoptosis rate of neurons were increased, the expression of PINK1 and Parkin was down-regulated, and LC3-Ⅱ/LC3-Ⅰ was decreased at each time point of reperfusion in H 2S+ 3-MA group ( P<0.05). Conclusion:The mechanism by which exogenous H 2S inhibits apoptosis in neurons during focal cerebral I/R is related to enhancing mitochondrial autophagy mediated by the PINK1/Parkin pathway in rats.

Study on the Effects of Tenuifolin on Brain Mitochondrial Autophagy in AD Model Mice Based on PINK 1/Parkin Signaling Pathway / 中国药房

OBJECTIVE：To investig ate the effects of tenuifolin （TEN）on brain mitochondrial autophagy in Aizheimer ’s disease（AD）model mice. METHODS ：Totally 50 male APP/PS1 double transgenic mice were randomly divided into model group，TEN medium-dose+ 3-MA group [TEN 40 mg/（kg·d）+autophagy inhibitor 3-MA 30 mg/（kg·d）] and TEN low-dose ， medium-dose and high-dose groups [ 20，40，80 mg/（kg·d）]，with 10 mice in each group. In addition ，10 wild-type homologous mice were included in normal control group. Administration groups were intragastrically given corresponding drug solution ；normal control group and model group were intragastrically given 0.3％ sodium carboxymethyl cellulose solution ，once a day ，0.01 mL/g， for consecutive 3 months. After last administration ，positive expression [measured by integrated optical density （IOD）] of microtubule associated protein 1 light chain 3（LC3）in neuron was detected ；mRNA expressions of LC3，ubiquitin-binding protein p62，Cathepsin D ，Rab7，phosphatase and tensin homolog deleted on chromosome ten gene-induced putative kinase 1（PINK1） and E 3 ligase（Parkin）as well as protein expressions of LC 3，p62，PINK1 and Parkin were detected in brain mitochondria. RESULTS：Compared with normal control group ，IOD value of LC 3 in neuron as well as mRNA and protein expressions of LC 3， p62，PINK1 and Parkin in brain mitochondria were all increased significantly in model group （P＜0.05 or P＜0.01），while mRNA expressions of Cathepsin D and Rab 7 were decreased significantly （P＜0.05 or P＜0.01）. Compared wit h model group ，IOD values of LC 3（except for TEN low-dose and medium-dose groups ） in neuron ，mRNA expressions of LC 3，Cathepsin D ，Rab7， PINK1（except for TEN low-dose group ）and Parkin （except for TEN low-dose group ） in brain mitochondria as well as protein expressions of LC 3 （except for TEN medium-dose group），PINK1（except fo r TEN high-dose group decreased significantly）and Parkin （except for TEN low-dose group decreased significantly ）were increased significantly in TEN low-dose ， medium-dose and high-dose groups （P＜0.05 or P＜0.01）；mRNA（except for TEN low-dose group ）and protein expressions of p62 were decreased significantly （P＜0.05 or P＜0.01）. Compared with TEN medium-dose group ，the changes of above indexes were inhibited significantly in TEN medium-dose + 3-MA group （P＜0.05 or P＜0.01）. CONCLUSIONS ：TEN can induce mitophagy in brain tissue of AD model mice by activating PINK 1/Parkin signaling pathway and improve lysosome function.

Co-editing PINK1 and DJ-1 Genes Via Adeno-Associated Virus-Delivered CRISPR/Cas9 System in Adult Monkey Brain Elicits Classical Parkinsonian Phenotype / 神经科学通报·英文版

Whether direct manipulation of Parkinson’s disease (PD) risk genes in the adult monkey brain can elicit a Parkinsonian phenotype remains an unsolved issue. Here, we used an adeno-associated virus serotype 9 (AAV9)-delivered CRISPR/Cas9 system to directly co-edit PINK1 and DJ-1 genes in the substantia nigras (SNs) of two monkey groups: an old group and a middle-aged group. After the operation, the old group exhibited all the classic PD symptoms, including bradykinesia, tremor, and postural instability, accompanied by key pathological hallmarks of PD, such as severe nigral dopaminergic neuron loss (>64%) and evident α-synuclein pathology in the gene-edited SN. In contrast, the phenotype of their middle-aged counterparts, which also showed clear PD symptoms and pathological hallmarks, were less severe. In addition to the higher final total PD scores and more severe pathological changes, the old group were also more susceptible to gene editing by showing a faster process of PD progression. These results suggested that both genetic and aging factors played important roles in the development of PD in the monkeys. Taken together, this system can effectively develop a large number of genetically-edited PD monkeys in a short time (6–10 months), and thus provides a practical transgenic monkey model for future PD studies.

Co-editing PINK1 and DJ-1 Genes Via Adeno-Associated Virus-Delivered CRISPR/Cas9 System in Adult Monkey Brain Elicits Classical Parkinsonian Phenotype / 神经科学通报·英文版

Whether direct manipulation of Parkinson's disease (PD) risk genes in the adult monkey brain can elicit a Parkinsonian phenotype remains an unsolved issue. Here, we used an adeno-associated virus serotype 9 (AAV9)-delivered CRISPR/Cas9 system to directly co-edit PINK1 and DJ-1 genes in the substantia nigras (SNs) of two monkey groups: an old group and a middle-aged group. After the operation, the old group exhibited all the classic PD symptoms, including bradykinesia, tremor, and postural instability, accompanied by key pathological hallmarks of PD, such as severe nigral dopaminergic neuron loss (>64%) and evident α-synuclein pathology in the gene-edited SN. In contrast, the phenotype of their middle-aged counterparts, which also showed clear PD symptoms and pathological hallmarks, were less severe. In addition to the higher final total PD scores and more severe pathological changes, the old group were also more susceptible to gene editing by showing a faster process of PD progression. These results suggested that both genetic and aging factors played important roles in the development of PD in the monkeys. Taken together, this system can effectively develop a large number of genetically-edited PD monkeys in a short time (6-10 months), and thus provides a practical transgenic monkey model for future PD studies.

Synergistic effects of autophagy/mitophagy inhibitors and magnolol promote apoptosis and antitumor efficacy

Mitochondria as a signaling platform play crucial roles in deciding cell fate. Many classic anticancer agents are known to trigger cell death through induction of mitochondrial damage. Mitophagy, one selective autophagy, is the key mitochondrial quality control that effectively removes damaged mitochondria. However, the precise roles of mitophagy in tumorigenesis and anticancer agent treatment remain largely unclear. Here, we examined the functional implication of mitophagy in the anticancer properties of magnolol, a natural product isolated from herbal

PINK1/Parkin-mediated mitophagy and its mechanism of action in the development and progression of liver diseases / 临床肝胆病杂志

Mitophagy is the process of selective clearance of damaged mitochondria by autophagy. There are several regulatory mechanisms for mitophagy, and the PINK1/Parkin pathway is considered the main pathway for mitophagy. Recent studies have shown that PINK1/Parkin-mediated mitophagy plays an important role in the pathogenesis of various diseases including Parkinson’s disease. This article introduces the mechanism of PINK1/Parkin-mediated mitophagy and its role in various liver diseases including nonalcoholic fatty liver disease, liver fibrosis, and hepatocellular carcinoma, in order to provide new clues and ideas for the treatment of diseases.