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Mitophagy, a highly precise form of autophagy, plays a pivotal role in maintaining cellular homeostasis by selectively targeting and eliminating damaged mitochondria through a process known as mitophagy. Within this tightly regulated mechanism, dysfunctional mitochondria are specifically delivered to lysosomes for degradation. Disruptions in mitophagy have been implicated in a diverse range of pathological conditions, spanning diseases of the nervous system, cardiovascular system, cancer, aging, and metabolic syndrome. The elucidation of mitophagy’s impact on cardiovascular disorders, liver diseases, metabolic syndromes, immune dysfunctions, inflammatory conditions, and cancer has significantly advanced our understanding of the complex pathogenesis underlying these conditions. These studies have shed light on the intricate connections between dysfunctional mitophagy and disease progression. Among the disorders associated with mitochondrial dysfunction, insulin resistance (IR) stands out as a prominent condition linked to metabolic disorders. IR is characterized by a diminished response to normal levels of insulin, necessitating higher insulin levels to trigger a typical physiological reaction. Hyperinsulinemia and metabolic disturbances often coexist with IR, primarily due to defects in insulin signal transduction. Oxidative stress, stemming from mitochondrial dysfunction, exerts dual effects in the context of IR. Initially, it disrupts insulin signaling pathways and subtly contributes to the development of IR. Additionally, by inducing mitochondrial damage and autophagy, oxidative stress indirectly impedes insulin signaling pathways. Consequently, mitophagy acts as a protective mechanism, encapsulating damaged or dysfunctional mitochondria through the autophagy-lysosome pathway. This efficient process eliminates excessive oxidative stress reactive. The intricate interplay between mitochondrial function, oxidative stress, mitophagy, and IR represents a captivating field of investigation in the realm of metabolic disorders. By unraveling the underlying complexities and comprehending the intricate relationships between these intertwined processes, researchers strive toward uncovering novel therapeutic strategies. With a particular focus on mitochondrial quality control and the maintenance of redox homeostasis, these interventions hold tremendous potential in mitigating IR and enhancing overall metabolic health. Emerging evidence from a myriad of studies has shed light on the active involvement of mitophagy in the pathogenesis of metabolic disorders. Notably, interventions such as exercise, drug therapies, and natural products have been documented to induce mitophagy, thereby exerting beneficial effects on metabolic health through the activation of diverse signaling pathways. Several pivotal signaling molecules, including AMPK, PINK1/Parkin, BNIP3/Nix, and FUNDC1, have been identified as key regulators of mitophagy and have been implicated in the favorable outcomes observed in metabolic disorders. Of particular interest is the unique role of PINK1/Parkin in mitophagy compared to other proteins involved in this process. PINK1/Parkin exerts influence on mitophagy through the ubiquitination of outer mitochondrial membrane proteins. Conversely, BNIP3/Nix and FUNDC1 modulate mitophagy through their interaction with LC3, while also displaying certain interrelationships with each other. In this comprehensive review, our objective is to investigate the intricate interplay between mitophagy and IR, elucidating the relevant signaling pathways and exploring the treatment strategies that have garnered attention in recent years. By assimilating and integrating these findings, we aim to establish a comprehensive understanding of the multifaceted roles and intricate mechanisms by which mitophagy influences IR. This endeavor, in turn, seeks to provide novel insights and serve as a catalyst for further research in the pursuit of innovative treatments targeting IR.
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Mitochondrial quality control plays an important role in maintaining homeostasis of mitochondrial network and normal function of mitochondria. ATPase family AAA domain-containing protein 3A (ATAD3A) is one of the mitochondrial membrane proteins involved in the regulation of mitochondrial structure and function, mitochondrial dynamics, mitophagy and other important biological processes. Recent studies show that ATAD3A not only interacts with Mic60/Mitofilin and mitochondrial transcription factor A (TFAM) to maintain mitochondrial cristae morphology and oxidative phosphorylation, but also interacts with dynamin-related protein 1 (Drp1) to positively/negatively regulate mitochondrial fission. In addition, ATAD3A serves as a bridging factor between the translocase of the outer mitochondrial membrane (TOM) complex and translocase of the inner mitochondrial membrane (TIM) complex to facilitate the import of PTEN-induced putative kinase protein 1 (PINK1) into mitochondria and its processing displays a pro-autophagic or anti-autophagic activity. This article reviews the role and mechanism of ATAD3A in regulating mitochondrial quality control. Firstly, as an inner mitochondrial membrane protein, ATAD3A is involved in maintaining the stability of mitochondrial crista structure, and its gene deletion or mutation will cause the loss and breakage of crista. Secondly, ATAD3A is also involved in maintaining mitochondrial respiratory function and mitochondrial nucleoid homeostasis, and its gene deletion or mutation can reduce the activity of mitochondrial respiratory chain complex and enhance the size and movement of nucleoid. Thirdly, ATAD3A participates in the negative regulation of mitochondrial fusion, but its role in mitochondrial fission may dependent on specific cell types, as it can promote and/or inhibit the mitochondrial fission by increasing and/or decreasing phosphorylation or oligomerization of Drp1. Finally, ATAD3A can interact with mitophagy-related proteins (e.g. PINK1, autophagy/beclin-1 regulator 1 (AMBRA1), acylglycerol kinase (AGK)) to enhance/reduce PINK1-Parkin-dependent mitophagy.
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Objective To detect the changes of mitophagy level in rats with endplate cartilage degeneration induced by spinal instability,and explore the role of PINK1/Parkin-mediated mitophagy in endplate cartilage and intervertebral disc degeneration.Methods The rat spinal instability model was established by surgically removing the superspinal and interspinal ligaments of L2 to L5,and cleaning the bilateral articular processes of the L2 to L5.Eighteen SD rats were divided into the normal group,the degenerative group,and the carbonyl cyanide 3-chlorophenylhydrazone(CCCP)group,with 6 rats in each group.The rats in the normal group had no special treatment,the rats in the degenerative group constructed a rat spinal instability model,and the rats in the CCCP group were injected with 5 μL of CCCP(10 μmol/L)in the intervertebral disc after the construction of spinal instability model.The changes of histomorphology in the endplate cartilage and intervertebral disc were abserved by HE staining,and the change of extracellular matrix of endplate cartilage was observed by safranin O-fast green staining.RT-PCR detected the mRNA expression of type Ⅱ collagen(COL-2A),aggrecan(ACAN),PINK1 and Parkin in each group.The changes of the protein expression levels of COL-2A,ACAN,PINK1,Parkin and mitochondrial membrane proteins of Tomm20 and Timm23 were detected by Western blot.Results Compared with the normal group,the intervertebral disc nucleus pulposus of rats in the degenerative group was significantly destroyed and the secretion of extracellular matrix of endplate chondrocytes decreased;while the structure of intervertebral discs for rats in the CCCP group was more intact,and the secretion of extracellular matrix of endplate chondrocytes was significantly increased compared with that in the degenerative group.Compared with the normal group,the expression of COL-2A and ACAN in endplate cartilage tissues of rats in the degenerative group were significantly down-regulated(P<0.05),the expression of mitochon-drial autophagy-related genes of PINK1 and Parkin were significantly decreased(P<0.05),and the expression of mitochondrial membrane proteins of Tomm20 and Timm23 were increased(P<0.05).Compared with the degenerative group,the expression of COL-2A,ACAN,PINKI and Parkin in the endplate cartilage tissue of rats in the CCCP group were significantly up-regulated(P<0.05),and the protein levels of Tomm20 and Timm23 were significantly down-regulated(P<0.05).Conclusion Rat spinal instability leads to a decrease level of mitophagy mediated by PINK1/Parkin signaling pathway in endplate cartilage,thereby inducing endplate cartilage and intervertebral disc degeneration,and the activation of mitophagy can significantly reduce endplate cartilage and intervertebral disc degeneration.
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Objective:To investigate the effects of macrophage(Mφ)polarization on the cementogenic differentiation of human perio-dontal ligament stem cells(hPDLSCs)and the underlying mechanism.Methods:Human monocytic THP-1 cells were induced to M0,M1 and M2 Mφ subsets,then RPM1 1640 medium or supernatants of different Mφ phenotypes were mixed with an equal volume of ce-mentoblastic induction medium to generate conditioned mediums(CMs),and termed as CM-Control,CM-M0,CM-M1 and CM-M2,respectively.hPDLSCs were cultured with different CMs,and the hPDLSCs sheets were then wrapped around treated dentin matrix(TDM)to generate cell sheet/dentin complexes.The complexes were subcutaneously implanted into nude mice.The cementum-like tissue formation was evaluated by HE staining,immunofluorescent staining(IMF)and qRT-PCR were used to detect the expression level of cementogenic differentiation-related markers bone sialoprotein(BSP),cementum attachment protein(CAP)and cementum pro-tein-1(CEMP-1),oxidant-antioxidant system-related markers superoxide dismutase 1(SOD1)and nuclear factor erythroid 2-related factor 2(NRF2),mitophagy-related markers PTEN induced putative kinase 1(PINK1)and microtubule asso ciated proteins 1A/1B light chain 3(LC3).Results:In vivo,CM-M2-treated hPDLSCs(CM-M2)group formed more cementum-like tissues and expressed higher protein levels of CAP,CEMP-1,SOD1,PINK1 and LC3 than that in other groups.In vitro tests showed that,compared with CM-Control group,hPDLSCs incubated with CM-M2 increased the levels of BSP(P＜0.01),CAP(P＜0.001),CEMP-1(P＜0.01)and SOD1(P＜0.05),while no statistically significant difference was detected for NRF2(P＞0.05),and increasedthe expression of PINK1(P＜0.05).Conclusion:M2 Mφ regulate the cementogenic differentiation of hPDLSCs possibly via modulating oxidant-antioxidant system and mitophagy.
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BACKGROUND:Aging is associated with increased susceptibility to cardiovascular disease,and mitochondrial dysfunction plays a key role in the pathogenesis of cardiovascular disease.Regular physical activity is beneficial to cardiovascular health and can prevent and treat chronic heart disease.However,the specific mechanism of mitochondria in the protective effect of exercise on the aging heart has not yet been clarified. OBJECTIVE:To explore the effect of aerobic exercise on cardiac pathological remodeling in aging rats and to investigate the possible mechanism of mitochondrial quality control system. METHODS:Sixty Wistar rats were randomly divided into young sedentary group(6 months old),old sedentary group(20 months old)and old exercise group(20 months old)with 20 rats in each group.Rats in the young sedentary and old sedentary groups were fed in cages for 12 weeks,while those in the old exercise group underwent moderate-intensity aerobic treadmill exercise(60%of the maximal running speed,slope 0°,60 minute per day,5 days per week)for 12 weeks.After the experiment,the heart was extracted for relevant indicator tests. RESULTS AND CONCLUSION:Cardiac morphology and myocardial histopathology:compared with the young sedentary group,the rats in the old sedentary group presented with concentric cardiac hypertrophy,myocardial fibrosis,myocardial cell apoptosis and loss,and cardiac diastolic dysfunction(P＜0.05);compared with the old sedentary group,animals in the old exercise group showed reduced myocardial fibrosis and apoptosis rates,increased cell numbers,improved cardiac function(P＜0.05),and a transition in cardiac phenotype from pathological to physiological hypertrophy.Mitochondrial function:compared with the young sedentary group,the generation rate of mitochondrial hydrogen peroxide increased(P＜0.05),respiration rate and respiratory control ratio of state 3 and state 4 decreased(P＜0.05),activities of respiratory chain complexes Ⅰ,Ⅱ and Ⅳ decreased(P＜0.05),mitochondrial calcium retention capacity decreased(P＜0.05),and mitochondrial permeability transition pore opening increased(P＜0.05)in the old sedentary group.Compared with the old sedentary group,all of the above indicators were significantly improved in the old exercise group(P＜0.05).Mitochondrial quality control:compared with the young sedentary group,mitochondrial biogenesis decreased(P＜0.05),mitophagy activity increased(P＜0.05),mitochondrial fusion reduced(P＜0.05),and fission raised(P＜0.05)in the old sedentary group;compared with the old sedentary group,mitochondrial biogenesis and mitophagy activity increased(P＜0.05),mitochondrial fusion raised(P＜0.05)and fission decreased(P＜0.05)in the old exercise group.To conclude,regular aerobic exercises exert cardioprotective effects in aging rats by regulating the mitochondrial quality control system,thus reversing pathological cardiac remodeling and improving cardiac function.
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BACKGROUND:During intervertebral disc degeneration,mitophagy plays an extremely important role in preventing the progression of intervertebral disc degeneration.Regulating the level of mitophagy may be a new strategy for the treatment of intervertebral disc degeneration. OBJECTIVE:To review the relationship between mitophagy and intervertebral disc,in order to provide a reference for the treatment of intervertebral disc degeneration by regulating the level of mitophagy. METHODS:A literature search was performed in CNKI,Wanfang,VIP,and PubMed using"intervertebral disc degeneration,mitophagy,targeted therapy,inflammation,signaling pathways"as Chinese and English search terms.Finally,54 articles were included and summarized. RESULTS AND CONCLUSION:(1)At present,the specific mechanism of intervertebral disc degeneration is not clear.A large number of studies have shown that intervertebral disc degeneration is closely related to mitophagy,which involves a relatively complex mechanism and pathway.Among various pathways,PINK1/Parkin is the most widely studied signaling pathway for mitophagy regulation.(2)Some drugs,such as Salidroside,Urolithin A,Honokiol,MitoQ,have been found to have the potential to treat intervertebral disc degeneration by regulating the level of mitophagy.These drugs have shown positive preclinical results.(3)At present,the targeted therapy of mitophagy is mainly preclinical research and has achieved positive results.Further clinical research is needed to explore its clinical efficacy and safety.
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Objective To observe the effects of different concentration and intervention time of triptolide(TP)on ovarian oxidative stress and mitophagy in rats.Methods Fifty 3-month-old female Sprague-Dawley rats were observed for 2 consecutive estrus cycles,and 25 rats with normal estrus cycles were selected and divided into the blank control group,experiment group 1,experiment group 2,experiment group 3 and experiment group 4 according to random number table method,with 5 rats in each group.Rats in experiment group 1 were administered intragastrically 400 μg·kg-1 TP once a day for 30 d.Rats in experiment group 2 were given 400 μg·kg-1 TP once a day for 40 d.Rats in experiment group 3 were given 500 μg·kg-1 TP once a day for 30 d.Rats in the experiment group 4 were given 500 μg·kg-1 TP once a day for 40d.Rats in the blank control group were given 10 mL·kg-1 distilled water once a day for 40 d.Serum anti-mullerian hormone(AMH),estradiol(E2)and follicle-stimulating hormone(FSH)levels were detected by enzyme-linked immunosorbent assay;hematoxylin-eosin staining was used to observe the pathological changes of ovarian tissue;malondialdehyde(MDA)level and superoxide dismutase(SOD)activity in ovarian tissue were detected by microplate reader.The morphological and structural changes of mitochondria in ovarian granulosa cells of rats in each group were observed by transmission electron microscope,and the apoptosis rate of ovarian granulosa cells was detected by flow cytometer.Results Compared with the blank control group,the levels of AMH and E2 in serum and SOD activity in ovarian tissue of rats in the experiment groups 1,2,3 and 4 significantly decreased,while the levels of FSH in serum and MDA in ovarian tissue significantly increased(P＜0.05).Compared with the experiment group 1,the levels of AMH and E2 in serum and SOD activity in ovarian tissue of rats in experiment groups 2,3 and 4 significantly decreased,while the levels of FSH in serum and MDA in ovarian tissue significantly increased(P＜0.05).There was no significant difference in the levels of AMH,E2 and FSH in serum,SOD activity and MDA level in ovarian tissue of rats among experiment groups 2,3 and 4(P＞0.05).The apoptosis rate of ovarian granulosa cells in experiment groups 1,2,3 and 4 was significantly higher than that in the blank control group(P＜0.05);the apoptosis rate of ovarian granulosa cells in experiment groups 2,3 and 4 was significantly higher than that in experiment group 1(P＜0.05);the apoptosis rate of ovarian granulosa cells in experiment groups 3 and 4 was significantly higher than that in experiment group 2(P＜0.05);the apoptosis rate of ovarian granulosa cells in experiment group 4 was significantly higher than that in experiment group 3(P＜0.05).In the blank control group,the ovarian tissue capsule was intact,and the number and development of primordial,primary and secondary follicles in the cortex were normal,with rare atretic follicles and less corpus luteum.The fibrous connective tissue in the medullary area was closely arranged,and no obvious edema or necrosis was observed.In experiment groups 1,2,3 and 4,the number of follicles in ovarian tissue decreased,the number of atretic follicles increased,and necrosis and shedding of follicles in the granular layer and cystic dilatation of follicles were observed.The pathological changes of ovarian tissue in experiment group 1 were relatively light,with fewer atretic follicles and less cell necrosis in the granulosa cell layer.The degree of ovarian tissue lesions in experiment group 4 was the most severe,with more atretic follicles and cell necrosis and shedding in the granulosa cell layer.The degree of ovarian tissue lesions in experiment groups 2 and 3 was less than that in experiment group 4,with fewer atretic follicles,necrosis of granulosa cell layer and follicle cystic dilatation.In the blank control group,the ovarian granulosa cells were normal in morphology and structure,with irregular polygon nuclei,uniform distribution of chromatin,mainly euchromatin,clear and complete nuclear membrane,mitochondria and other organelles with complete and clear structure visible in the cytoplasm.Different degrees of mitophagy were observed in the cytoplasm of granulosa cells of rats in experiment groups 1,2,3 and 4;the mitophagy of rats in experiment groups 2,3 and 4 was more severe than that in experiment group 1;that in experiment groups 3 and 4 was more severe than experiment group 2;the mitophagy of rats in experiment group 3 was similar to that in experiment group 4.Under electron microscopy,more mitochondrial autophagosomes were found in the cytoplasm of ovarian granulosa cells in experiment groups 3 and 4.Most mitochondria were mildly swollen,some mitochondrial crista structures disappeared,and the rough endoplasmic reticulum showed cystic dilatation.Conclusion The ovarian dysfunc-tion model in rats can be successfully established by TP intragastric administration.The ovarian injury of rats is related to TP dose and intervention time.TP-induced ovarian oxidative stress may be an important factor triggering ovarian hypofunction,and it may work through oxidative stress affecting ovarian endocrine function and inducing granulosa cell apoptosis and other patho-physiological processes.With the aggravation of oxidative stress damage,the mitophagy increases.After reaching a certain de-gree,mitophagy will not continue to increase with the increase of TP intervention time.
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OBJECTIVE To study the mechanism of oxymatrine inducing apoptosis of osteosarcoma MG63 cell line based on mitophagy mediated by cyclooxygenase-2 （COX-2）/PTEN-induced putative kinase-1 （PINK1）/Parkinson disease protein-2 （Parkin） signaling pathway. METHODS MG63 cells were treated with 2.0， 4.0， 8.0 mg/mL oxymatrine and 6 μmol/L 5-fluorouracil， then the apoptotic rate， the expression of apoptosis-related proteins [B-cell lymphoma-2 （Bcl-2）， Bcl-2 related X protein （Bax）]， the proportion of decrease in mitochondrial membrane potential， the level of mitophagy as well as the protein expressions of PINK1， Parkin， and microtubule-associated protein 1 light chain-3Ⅱ （LC3-Ⅱ） were detected. PINK1 small interfering RNA （siRNA） was adopted to intervene in the expression of PINK1， the cells were divided into control group， PINK1 siRNA group， oxymatrine group， and PINK1 siRNA+oxymatrine group； the protein expressions of PINK1， Parkin， and LC3-Ⅱ， the proportion of decrease in mitochondrial membrane potential （MMP） as well as apoptotic rate were detected. The lentivirus infection technique was used to overexpress COX-2， the cells were divided into control group， oxymatrine group， COX-2 group， and COX-2+oxymatrine group. The protein expressions of COX-2， PINK1， and Parkin， as well as the proportion of decrease in MMP were detected. RESULTS After being treated with oxymatrine， the apoptotic rate， the protein expressions of Bax， PINK1， Parkin， and LC3-Ⅱ， the level of mitophagy as well as the proportion of decrease in MMP were significantly increased （P＜0.05）， while the protein expression of Bcl-2 was significantly decreased （P＜0.05）. Compared with the oxymatrine group， the protein expressions of PINK1， Parkin， and LC3-Ⅱ， apoptotic rate and the proportion of decrease in MMP were significantly decreased in PINK1 siRNA+oxymatrine group （P＜0.05）. Compared with the oxymatrine group， the protein expression of COX-2 in the COX-2+oxymatrine group was increased significantly （P＜0.05）， while the protein expressions of PINK1 and Parkin as well as the proportion of 526087266@qq.com decrease in MMP were decreased significantly （P＜0.05）. CONCLUSIONS Oxymatrine can mediate the overactivity of mitophagy based on the PINK1/Parkin signaling pathway by inhibiting COX-2 expression， thus promoting the apoptosis of the MG63 osteosarcoma cell line.
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Mitophagy is a type of selective autophagy during which cells specifically remove damaged mitochondria in response to nutrient deficiency or external stimulation and thus maintain the integrity of mitochondrial function and cellular homeostasis. In recent years， a large number of studies have shown that dysfunction of mitophagy is closely associated with the development and progression of various liver-related diseases such as nonalcoholic fatty liver disease， drug-related liver injury， viral hepatitis， and hepatocellular carcinoma. This article summarizes the specific mechanisms of mitophagy in regulating liver-related diseases and further elaborates on the potential therapeutic targets of mitophagy in liver-related diseases， in order to provide more effective therapeutic strategies for the clinical treatment of liver diseases.
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Macroautophagy (referred to as autophagy hereafter) is a major intracellular lysosomal degradation pathway that is responsible for the degradation of misfolded/damaged proteins and organelles. Previous studies showed that autophagy protects against acetaminophen (APAP)-induced injury (AILI) via selective removal of damaged mitochondria and APAP protein adducts. The lysosome is a critical organelle sitting at the end stage of autophagy for autophagic degradation via fusion with autophagosomes. In the present study, we showed that transcription factor EB (TFEB), a master transcription factor for lysosomal biogenesis, was impaired by APAP resulting in decreased lysosomal biogenesis in mouse livers. Genetic loss-of and gain-of function of hepatic TFEB exacerbated or protected against AILI, respectively. Mechanistically, overexpression of TFEB increased clearance of APAP protein adducts and mitochondria biogenesis as well as SQSTM1/p62-dependent non-canonical nuclear factor erythroid 2-related factor 2 (NRF2) activation to protect against AILI. We also performed an unbiased cell-based imaging high-throughput chemical screening on TFEB and identified a group of TFEB agonists. Among these agonists, salinomycin, an anticoccidial and antibacterial agent, activated TFEB and protected against AILI in mice. In conclusion, genetic and pharmacological activating TFEB may be a promising approach for protecting against AILI.
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Aim To explore the effect of berberine (B E) on RSV infected HEp-2 cells and the related mechanism. Methods HEp-2 cells were infected with RSV and treated with BE. Cell viability was assessed using the CCK-8 assay. Protein expression levels of NLRP3, ASC, caspase-1, PINK1, Parkin, Beclinl, p62, LC3 I,LC3 II,and BNIP3 in HEp-2 cells were detected by Western blot. The secretion level of IL-1 p in HEp-2 cells was measured using ELISA. Apoptosis rate and mitochondrial membrane potential of HEp-2 cells were examined by flow cytometry. Mitochondrial ROS (mtROS) in HEp-2 cells was detected through MitoSOX staining. Colocalization of mitochondria and autophagosomes in HEp-2 cells was investigated using immunofluorescence staining. Cyclosporin A was used for validation experiments. Results BE could significantly improve the activity of RSV-infected HEp-2 cells,reduce the apoptosis rate (P < 0. 05), and decrease the activation level of NLRP3 inflammasomes and IL-lp level (P <0. 05); BE improved mitochondrial function by increasing mitochondrial membrane potential and ATP levels,and reduced mtROS. BE significantly promoted the colocalization of mitochondria-autophagosome in RSV infected cells, inducing PINK1/ Parkin and BNIP3 to mediate mitochondrial autophagy; cyclosporine A aggravated RSV infection. Conclusions BE has protective effects on HEp-2 cells infected by RSV. The mechanism may be related to the inhibitory effect of BE on the production of mtROS and the activation of NLRP3 inflammasomes by inducing PINK1/ Parkin and BNIP3-mediated mitochondrial autophagy.
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Aim To investigate the targeting mechanism of miR-23b on PINKl/Parkin pathway in transdifferentiation of NRK-52E cellsinduced by TGF-β1, and to elucidate the intervention mechanism of Qingshen granules drug-containing serum on NRK-52E cell transdifferentiation. Methods Ultra-high performance liquid chromatography ( UPLC ) fingerprinting method was used to analyze Qingshen granules. The NRK-52E transdifferentiation model induced by TGF-β1 was constructed. The NRK-52E cells were divided into simulated no-load control group, miR-23b-5p simulated group, inhibitor no-load control group, and miR-23b-5p inhibitor group, after transfection with siRNA, and the effect of miR-23b-5p on PINK1 expression was ob-served. The NRK-52E cells were then divided into normal group, TGF-(31 group, Qingshen granule group, miR-23 b-mimic group, miR-23 b-mimic group, and miR-23b-mimic + Qingshen granule group. Western blot was used to detect the expression of Pinkl, Parkin, LC3 n, Beclin-1, P62 and a-SMA proteins, and RT- PCR was used to detect the expression of miR-23 b-5p, Pinkl, Parkin, Beclin-1 and a-SMA mRNA in NRK- 52E cells. Dual-Luciferase Reporter gene experiment was used to detect the targeting relationship between miR-23b-5p and PINKL Results UPLC fingerprinting method found 11 active components in Qingshen granules. After overexpression of miR-23b-5p, the expression of PINkl mRNA significantly increased (P 0. 05 ). The experimental results showed that the expressions of miR- 23b-5p, Pinkl, Parkin, Beclin-1, LC3 II and LC3 II/ I ratio in TGF-β1 group were significantly lower than those in normal group, but the expressions of P62 and a-SMA were significantly higher than those in normal group ( P <0.05). The expressions of miR-23 b-5 p, Pinkl, Parkin, Beclin-1, LC3 II and LC3 11/ I ratio in Qingshen granule group and miR-23 b-mimic group were significantly higher than those in TGF-β1 group, and the expressions of P62 and a-SMA were significantly lower than those in TGF-β1 group (P < 0. 05 ). The performance of miR-23 b-mimic + Qingshen granule group was better than that of miR-23 b-mimic group (P < 0. 05 ). Conclusions Qingshen granules can up- regulate the expression of miR-23b-5p in NRK-52E cellsand inhibit the transdifferentiation process of NRK- 52E cells by enhancing the mitochondrial autophagy activity mediated by PINKl/Parkin pathway.
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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.
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Aim To research the neuroprotective effect of Haikun Shenxi (HKSX) medicated serum on N2a/ App695 cells and the underlying mechanism. Methods HKSX medicated serum was prepared and carbohydrate components in it was analyzed using high performance thin layer chromatography (HPTLC) . N2a/ App695 cells were intervened with HKSX medicated serum, the cytotoxicity of HKSX medicated serum was measured by MTT; AP[_
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Objectives:To investigate the effect of inhibition of long non-coding RNA(lnc RNA)in human metastasis associated lung adenocarcinoma transcript 1(MALAT1)on glycolipitoxicity-induced human umbilical vein endothelial cell dysfunction. Methods:Human umbilical vein endothelial cells were treated with glucose and palmitic acid in vitro to establish the glycolipitoxic endothelial cell models.Following groups were examined:control group,high-glucose and high-fat group,high-glucose and high-fat + non-targeting RAN control group,high-glucose and high-lipid+MALAT1 siRNA group,and high-glucose and high-lipid+MAPK1 siRNA group.RT-qPCR was used to detect the mRNA expression of MALAT1 and MAPK1.Western blot was used to detect the expression levels of autophagy,mitochondrial fusion division,apoptosis,and pathway-related proteins.Immunofluorescence confocal localization was used to detect the fluorescence colocalization of autophagy and lysosome-related proteins.The number of autophagolysosomes in endothelial cells was observed by transmission electron microscopy.Mitochondrial probe staining was used to detect mitochondrial morphology,immunofluorescence was used to detect intracellular reactive oxygen species(ROS)production,flow cytometry was used to detect the apoptosis of cells in each group,cell proliferation and scratch assays were used to detect the proliferation and migration ability of cells in different groups at different time points.The angiogenesis was quantified by counting the number of new blood vessels in each group. Results:Compared with the control group,the expression of lncRNA MALAT1 mRNA and the expression of phosphorylated mito-activated protein kinase 1(p-MAPK1)were upregulated(both P＜0.05)and the expression of phosphorylated mammalian target protein(p-mTOR)was downregulated in the high-glucose and high-fat group and the high-sugar and high-fat control group(all P＜0.01).Compared with the high-glucose and high-fat non-targeting RNA control group,the expressions of microtubule-associated protein 1A/1B-light chain 3(LC3)and p62 were downregulated(P＜0.01,P＜0.05),LC3 and lysosome-associated membrane protein 2(LAMP2)protein co-localized positive fluorescence particles were increased(both P＜0.01),number of lysosomes were decreased,the expression of ROS was decreased(P＜0.01),the expression level of mitochondrial fusion protein optic nerve atrophin 1(OPA1)was increased(P＜0.05),the expressions of cleaved caspase-3 and BCL-2-related X protein(BAX)were decreased and BCL-2 was increased(all P＜0.05),cell proliferation,migration,and tube-forming ability were increased(all P＜0.01),and the expression of p-MAPK1 was decreased(P＜0.05)and p-mTOR expression was increased(both P＜0.05)in the high-glucose and high-lipid+si-MALAT1 group.Compared with the high-glucose and high-fat non-targeting RNA control group,the expression of p-MAPK1 in endothelial cells was decreased and the expression of p-mTOR was increased in the high-glucose and high-lipid+si-MAPK1 group(both P＜0.01). Conclusions:Inhibition of lncRNA MALAT1 expression can reduce the level of mitophagy in glycolipidotoxic environments,reduce apoptosis of endothelial cells and improve endothelial cell function,which may be related to the regulation of MAPK1/mTOR signaling pathway.
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OBJECTIVE To investigate the protective effect of artesunate(Art)against apoptosis and mitophagy induced by NaF in osteocytes MLO-Y4,and to explore the molecular mechanism.METHODS MLO-Y4 cells were treated with NaF(2 mmol·L-1)for 48 h to establish an in vitro model of osteocytes injuries,and the cells were divided into the cell control group,NaF(2 mmol·L-1)group and NaF+Art 0.25,0.50 and 1.00 μmol·L-1 groups.The cells were pretreated for 2 h and NaF was added for 48 h.The cell survival of MLO-Y4 cells was detected by MTT assay.The cell viability of MLO-Y4 cells was measured by Calcein-AM staining.The lactate dehydrogenase(LDH)content in the supernatant was examined by the LDH detection kit.The level of intracellular reactive oxygen species(ROS)was examined by DCFH-DA staining.The malondialdehyde(MDA)content and superoxide dismutase(SOD)activity were detected by chemical colorimetry.Apoptosis was measured by Hoechst33342 staining and Annexin-V/PI staining.The level of mitochondrial membrane potential(MMP)was measured by JC-1 staining.The formation of autophagic vacuoles and morphological mitochondrial changes were observed via Lyso-tracker staining and Mito-Tracker staining.The ATP content was detected with the luciferase method.The expression of microtubule-associated protein light chain 3(LC-3)in mitochon-dria was examined by immunofluorescence staining.Protein expressions of LC-3,P62,E3 ubiquitin-ligase(Parkin)and PTEN-induced putative kinase 1(PINK1)were detected by Western blotting.RESULTS Compared with the cell control group,the cell survival rate and cell viability were significantly reduced in the NaF group(P<0.01),LDH content in the supernatant,the level of intracellular ROS,the MDA content,apoptosis rate and autophagic vesicle formation were remarkably increased(P<0.01),protein levels of Parkin and PINK1,and the conversion of LC-3Ⅱ from LC-3Ⅰ were markedly upregulated along with the elevation of LC-3 in damaged mitochondria(P<0.01),while P62 levels,SOD activity,MMP and ATP contents were reduced in NaF cells(P<0.05,P<0.01).Compared with NaF group,the cell viability and survival rate of MLO-Y4 cells in NaF+Art 0.25,0.50 and 1.00 μmol·L-1 groups were significantly increased(P<0.01);the content of LDH in supernatants was decreased obviously(P<0.01);the levels of intracellular ROS and MDA content were markedly reduced(P<0.05,P<0.01);the apoptosis rate and autophagic vesicle formation were remarkably decreased(P<0.05,P<0.01);protein levels of Parkin and PINK1,and the conversion of LC-3Ⅱ from LC-3Ⅰ were markedly down-regulated along with the accumulation of LC-3 in damaged mitochondria(P<0.01);MMP and ATP content were also reduced(P<0.05,P<0.01);while SOD activityand P62 levelwere significantly increased(P<0.05,P<0.01).CONCLU-SION Art has a protective effect against oxidative damage induced by NaF in MLO-Y4 cells,which might be related to the inhibition of apoptosis and mitophagy.
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Heart failure is a group of complex clinical syndromes in the middle and late stages of cardiovascular diseases.Mitochondrial homeostasis imbalance is one of the pathological mechanisms in the occurrence and development of heart failure.This article revolved around the"yin-yang theory"in TCM and explained the pathological mechanism of heart failure through mitochondrial homeostasis.Heart failure is the syndrome of deficiency in nature and excess in superficiality fundamental.Its basic pathogenesis is"yang deficiency and yin excess".Based on the deficiency of heart yang qi and the stagnation of yin pathogens,the combination of deficiency and excess runs through the entire disease.Mitochondrial homeostasis imbalance is a manifestation of yin-yang imbalance at the cellular micro level,mainly manifested as inhibition of mitochondrial biosynthesis,mitochondrial dynamics imbalance,mitophagy disorder,etc.,which affects mitochondrial structure and function and leads to abnormal myocardial energy metabolism.Therefore,based on the"yin-yang theory",the basic treatment method is to"tonify deficiency and damage excess"to regulate mitochondrial biosynthesis,mitochondrial dynamics,and mitophagy,thereby maintaining mitochondrial homeostasis and improving myocardial energy metabolism,which is of great significance for the prevention and treatment of heart failure.
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Background The senescence of renal tubular epithelial cells (RTECs) is crucial in the progression of diabetic kidney disease (DKD). Accumulating evidence suggests a close association between insufficient mitophagy and RTEC senescence. Yeast mitochondrial escape 1-like 1 (YME1L), an inner mitochondrial membrane metalloprotease, maintains mitochondrial integrity. Its functions in DKD remain unclear. Here, we investigated whether YME1L can prevent the progression of DKD by regulating mitophagy and cellular senescence. Methods We analyzed YME1L expression in renal tubules of DKD patients and mice, explored transcriptomic changes associated with YME1L overexpression in RTECs, and assessed its impact on RTEC senescence and renal dysfunction using an HFD/STZ-induced DKD mouse model. Tubule-specific overexpression of YME1L was achieved through the use of recombinant adeno-associated virus 2/9 (rAAV 2/9). We conducted both in vivo and in vitro experiments to evaluate the effects of YME1L overexpression on mitophagy and mitochondrial function. Furthermore, we performed LC-MS/MS analysis to identify potential protein interactions involving YME1L and elucidate the underlying mechanisms. Results Our findings revealed a significant decrease in YME1L expression in the renal tubules of DKD patients and mice. However, tubule-specific overexpression of YME1L significantly alleviated RTEC senescence and renal dysfunction in the HFD/STZ-induced DKD mouse model. Moreover, YME1L overexpression exhibited positive effects on enhancing mitophagy and improving mitochondrial function both in vivo and in vitro. Mechanistically, our LC- MS/MS analysis uncovered a crucial mitophagy receptor, BCL2-like 13 (BCL2L13), as an interacting partner of YME1L. Furthermore, YME1L was found to promote the phosphorylation of BCL2L13, highlighting its role in regulating mitophagy. Conclusions This study provides compelling evidence that YME1L plays a critical role in protecting RTECs from cellular senescence and impeding the progression of DKD. Overexpression of YME1L demonstrated significant therapeutic potential by ameliorating both RTEC senescence and renal dysfunction in the DKD mice. Moreover, our findings indicate that YME1L enhances mitophagy and improves mitochondrial function, potentially through its interaction with BCL2L13 and subsequent phosphorylation. These novel insights into the protective mechanisms of YME1L offer a promising strategy for developing therapies targeting DKD.
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Purpose: XinJiaCongRongTuSiZiWan (XJCRTSZW) is a traditional Chinese medicine compound for invigorating the kidney, nourishing blood, and promoting blood circulation. This study aimed to explore the effect of XJCRTSZW on triptolide (TP)-induced oxidative stress injury. Methods: Adult female Sprague-Dawley rats and human ovarian granulosa cell lines were treated with TP and XJCRTSZW. Hematoxylin and eosin staining, enzyme-linked immunosorbent assay, flow cytometry, CCK-8, JC-1 staining, transmission electron microscopy, reverse transcription-quantitative polymerase chain reaction, and Western blotting were performed in this study. Results: XJCRTSZW treatment observably ameliorated the TP-induced pathological symptoms. Furthermore, XJCRTSZW treatment observably enhanced the TP-induced reduction of estradiol, anti-Mullerian hormone, progesterone, superoxide dismutase, ATP content, mitochondrial membrane potential, p62, and Hsp60 mRNA, and protein levels in vivo and in vitro (p < 0.05). However, TP-induced elevation of follicle stimulating hormone and luteinizing hormone concentrations, malondialdehyde levels, reactive oxygen species levels, apoptosis rate, mitophagy, and the mRNA and protein expressions of LC3-II/LC3-I, PTEN-induced kinase 1 (PINK1), and Parkin were decreased (p < 0.05). In addition, XJCRTSZW treatment markedly increased cell viability in vitro (p < 0.05). Conclusions: XJCRTSZW protects TP-induced rats from oxidative stress injury via the mitophagy-mediated PINK1/Parkin pathway.
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Animaux , Rats , Plaies et blessures , Stress oxydatif , Mitophagie , Animaux de laboratoire , Médecine traditionnelle chinoiseRésumé
Mitochondrial function is essential for the viability of aerobic eukaryotic cells, as mitochondria provide energy through the generation of adenosine triphosphate(ATP), regulate cellular metabolism, provide redox balancing, participate in immune signaling, and initiate apoptosis. Mitophagy refers to the selective elimination of dysfunctional mitochondria in cells, thereby achieving mitochondrial quality control and maintaining cell homeostasis. Recent studies have indicated that abnormal mitophagy is involved in the development of various eye diseases, such as diabetic retinopathy(DR), age-related macular degeneration and glaucoma. In this review, we summarize the current knowledge on the definition of mitophagy, and present the results of various studies using cell culture, animal, and human tissue models. Additionally, we review the molecular process of mitophagy and its role in DR, thus providing novel ideas for the treatment of DR.