Dynamin-Related Protein 1-Dependent Mitochondrial Fission Changes in the Dorsal Vagal Complex Regulate Insulin Action

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Mitochondrial Alterations in PINK1 Deficient Cells Are Influenced by Calcineurin-Dependent Dephosphorylation of Dynamin-Related Protein 1

PTEN-induced novel kinase 1 (PINK1) mutations are associated with autosomal recessive parkinsonism. Previous studies have shown that PINK1 influences both mitochondrial function and morphology although it is not clearly established which of these are primary events and which are secondary. Here, we describe a novel mechanism linking mitochondrial dysfunction and alterations in mitochondrial morphology related to PINK1. Cell lines were generated by stably transducing human dopaminergic M17 cells with lentiviral constructs that increased or knocked down PINK1. As in previous studies, PINK1 deficient cells have lower mitochondrial membrane potential and are more sensitive to the toxic effects of mitochondrial complex I inhibitors. We also show that wild-type PINK1, but not recessive mutant or kinase dead versions, protects against rotenone-induced mitochondrial fragmentation whereas PINK1 deficient cells show lower mitochondrial connectivity. Expression of dynamin-related protein 1 (Drp1) exaggerates PINK1 deficiency phenotypes and Drp1 RNAi rescues them. We also show that Drp1 is dephosphorylated in PINK1 deficient cells due to activation of the calcium-dependent phosphatase calcineurin. Accordingly, the calcineurin inhibitor FK506 blocks both Drp1 dephosphorylation and loss of mitochondrial integrity in PINK1 deficient cells but does not fully rescue mitochondrial membrane potential. We propose that alterations in mitochondrial connectivity in this system are secondary to functional effects on mitochondrial membrane potential.     

线粒体分裂蛋白1在人宫颈癌细胞中过表达能促进线粒体裂变并降低细胞的增殖和迁移能力

线粒体是持续进行分裂和融合的动态细胞器。近年来,除了线粒体代谢作用相关的研究之外,线粒体动力学也开始逐渐引起研究的关注。越来越多的研究表明,线粒体动力学与肿瘤细胞生物学行为具有相关性。线粒体分裂蛋白1(mitochondrial fission protein 1, FIS1)介导线粒体分裂复合物的组装,参与线粒体分裂,是线粒体融合分裂过程中重要的蛋白质。然而,鲜有研究揭示FIS1在人宫颈癌中的表达及其作用。本研究对比了宫颈癌组织以及癌旁组织的转录物组数据,结果显示,与癌旁组织相比,人宫颈癌组织中的FIS1 mRNA水平明显降低(P<0.01)。进一步进行宫颈癌组织FIS1高表达组与低表达组的差异基因分析,发现差异基因主要与线粒体功能相关。随后,进行FIS1过表达后HeLa细胞增殖、迁移、线粒体裂变以及ROS水平的相关分析。结果显示,过表达FIS1基因,HeLa细胞增殖及迁移能力显著降低,细胞内线粒体裂变程度加剧并且细胞内ROS水平升高。综合以上结果,FIS1在人宫颈癌细胞中表达水平较低,而过表达FIS1可促使宫颈癌细胞因线粒体动力学失衡而发生一系列生物学功能异常。因此,本研究为进一步研究FIS1在宫颈癌治疗中的作用奠定了重要基础。     

Genetic Defects in Surfactant Protein A2 Are Associated with Pulmonary Fibrosis and Lung Cancer

Idiopathic pulmonary fibrosis (IPF) is a lethal scarring lung disease that affects older adults. Heterozygous rare mutations in the genes encoding telomerase are found in ~15% of familial cases. We have used linkage to map another disease-causing gene in a large family with IPF and adenocarcinoma of the lung to a 15.7 Mb region on chromosome 10. We identified a rare missense mutation in a candidate gene, SFTPA2, within the interval encoding surfactant protein A2 (SP-A2). Another rare mutation in SFTPA2 was identified in another family with IPF and lung cancer. Both mutations involve invariant residues in the highly conserved carbohydrate-recognition domain of the protein and are predicted to disrupt protein structure. Recombinant proteins carrying these mutations are retained in the endoplasmic reticulum and are not secreted. These data are consistent with SFTPA2 germline mutations that interfere with protein trafficking and cause familial IPF and lung cancer.     

细胞自噬与肿瘤耐药

细胞自噬是一种细胞自我降解的过程,在适应代谢应激、保持基因组完整性及维持内环境稳定方面发挥重要作用. 在肿瘤治疗中,凋亡耐受是产生肿瘤耐药的重要机制. 细胞自噬可防止抗肿瘤药诱导的凋亡,促进肿瘤耐药. 然而,自噬性细胞死亡可能是凋亡耐受肿瘤细胞的一种死亡方式. 因此,细胞自噬对肿瘤细胞的耐药性有双重影响. 本文综述了细胞自噬的分子机制、细胞自噬与凋亡的关系、细胞自噬与肿瘤耐药以及治疗的主要研究进展.     

The Mitochondrial Fission Adaptors Caf4 and Mdv1 Are Not Functionally Equivalent

Mitochondrial fission in eukaryotes is mediated by protein complexes that encircle and divide mitochondrial tubules. In budding yeast, fission requires the membrane-anchored protein Fis1 and the dynamin-related GTPase Dnm1. Dnm1 is recruited to mitochondria via interactions with the adaptor proteins Caf4 and Mdv1, which bind directly to Fis1. Unlike Mdv1, a function for Caf4 in mitochondrial membrane scission has not been established. In this study, we demonstrate that Caf4 is a bona fide fission adaptor that assembles at sites of mitochondrial division. We also show that fission complexes may contain Caf4 alone or both Caf4 and Mdv1 without compromising fission function. Although there is a correspondence between Caf4 and Mdv1 expression levels and their contribution to fission, the two adaptor proteins are not equivalent. Rather, our functional and phylogenetic analyses indicate that Caf4 mitochondrial fission activity has diverged from that of Mdv1.     

Identification and Characterization of Unique Proline-rich Peptides Binding to the Mitochondrial Fission Protein hFis1

Mammalian mitochondrial fission requires at least two proteins, hFis1 and the dynamin-like GTPase DLP1/Drp1. The mitochondrial protein hFis1 is anchored at the outer membrane by a C-terminal transmembrane domain. The cytosolic domain of hFis1 contains six α helices [α1–α6] out of which [α2–α5] form tetratricopeptide repeat (TPR)-like motifs. DLP1 and possibly other proteins are thought to interact with the hFis1 TPR region during the fission process. It has also been suggested that the α1-helix regulates protein-protein interactions at the TPR. We performed random peptide phage display screening using the hFis1[α2–α6] as the target and identified ten different peptide sequences. Phage ELISA using mutant hFis1 indicates that the peptide binding requires the α2 and α3 helices and the intact TPR structure. Competition experiments and surface plasmon resonance analyses confirmed that a subset of free peptides enriched with proline residues directly bind to the target. Two of these peptides bind to the α1-containing intact cytosolic domain of hFis1 with decreased affinity. Peptide microinjection into cells abolished the mitochondrial swelling induced by overexpression of α1-deleted hFis1, and significantly decreased cytochrome c release from mitochondria upon apoptotic induction. Our data demonstrate that hFis1 can bind to multiple amino acid sequences selectively, and that the TPR constitutes the main binding region of hFis1, providing a first insight into the hFis1 TPR as a potential therapeutic target.     

Reduced Basal Autophagy and Impaired Mitochondrial Dynamics Due to Loss of Parkinson's Disease-Associated Protein DJ-1

Background

Mitochondrial dysfunction and degradation takes a central role in current paradigms of neurodegeneration in Parkinson''s disease (PD). Loss of DJ-1 function is a rare cause of familial PD. Although a critical role of DJ-1 in oxidative stress response and mitochondrial function has been recognized, the effects on mitochondrial dynamics and downstream consequences remain to be determined.

Methodology/Principal Findings

Using DJ-1 loss of function cellular models from knockout (KO) mice and human carriers of the E64D mutation in the DJ-1 gene we define a novel role of DJ-1 in the integrity of both cellular organelles, mitochondria and lysosomes. We show that loss of DJ-1 caused impaired mitochondrial respiration, increased intramitochondrial reactive oxygen species, reduced mitochondrial membrane potential and characteristic alterations of mitochondrial shape as shown by quantitative morphology. Importantly, ultrastructural imaging and subsequent detailed lysosomal activity analyses revealed reduced basal autophagic degradation and the accumulation of defective mitochondria in DJ-1 KO cells, that was linked with decreased levels of phospho-activated ERK2.

Conclusions/Significance

We show that loss of DJ-1 leads to impaired autophagy and accumulation of dysfunctional mitochondria that under physiological conditions would be compensated via lysosomal clearance. Our study provides evidence for a critical role of DJ-1 in mitochondrial homeostasis by connecting basal autophagy and mitochondrial integrity in Parkinson''s disease.     

Dynamin-related Protein 1 Oligomerization in Solution Impairs Functional Interactions with Membrane-anchored Mitochondrial Fission Factor

Mitochondrial fission is a crucial cellular process mediated by the mechanoenzymatic GTPase, dynamin-related protein 1 (Drp1). During mitochondrial division, Drp1 is recruited from the cytosol to the outer mitochondrial membrane by one, or several, integral membrane proteins. One such Drp1 partner protein, mitochondrial fission factor (Mff), is essential for mitochondrial division, but its mechanism of action remains unexplored. Previous studies have been limited by a weak interaction between Drp1 and Mff in vitro. Through refined in vitro reconstitution approaches and multiple independent assays, we show that removal of the regulatory variable domain (VD) in Drp1 enhances formation of a functional Drp1-Mff copolymer. This protein assembly exhibits greatly stimulated cooperative GTPase activity in solution. Moreover, when Mff was anchored to a lipid template, to mimic a more physiologic environment, significant stimulation of GTPase activity was observed with both WT and ΔVD Drp1. Contrary to recent findings, we show that premature Drp1 self-assembly in solution impairs functional interactions with membrane-anchored Mff. Instead, dimeric Drp1 species are selectively recruited by Mff to initiate assembly of a functional fission complex. Correspondingly, we also found that the coiled-coil motif in Mff is not essential for Drp1 interactions, but rather serves to augment cooperative self-assembly of Drp1 proximal to the membrane. Taken together, our findings provide a mechanism wherein the multimeric states of both Mff and Drp1 regulate their collaborative interaction.     

Following Mitochondrial Footprints through a Long Mucosal Path to Lung Cancer

Background

Mitochondrial DNA (mtDNA) mutations are reported in different tumors. However, there is no information on the temporal development of the mtDNA mutations/content alteration and their extent in normal and abnormal mucosa continuously exposed to tobacco smoke in lung cancer patients.

Methodology

We examined the pattern of mtDNA alteration (mtDNA mutation and content index) in 25 airway mucosal biopsies, corresponding tumors and normal lymph nodes obtained from three patients with primary lung cancers. In addition, we examined the pattern of mtDNA mutation in corresponding tumors and normal lymph nodes obtained from eight other patients with primary lung cancers. The entire 16.5 kb mitochondrial genome was sequenced on Affymetrix Mitochip v2.0 sequencing platform in every sample. To examine mtDNA content index, we performed real-time PCR analysis.

Principal Findings

The airway mucosal biopsies obtained from three lung cancer patients were histopathologically negative but exhibited multiple clonal mtDNA mutations detectable in the corresponding tumors. One of the patients was operated twice for the removal of tumor from the right upper and left lower lobe respectively within a span of two years. Both of these tumors exhibited twenty identical mtDNA mutations. MtDNA content increased significantly (P<0.001) in the lung cancer and all the histologically negative mucosal biopsies except one compared to the control lymph node.

Conclusions/Significance:

Our results document the extent of massive clonal patches that develop in lifetime smokers and ultimately give rise to clinically significant cancers. These observations shed light on the extent of disease in the airway of smokers traceable through mtDNA mutation. MtDNA mutation could be a reliable tool for molecular assessment of respiratory epithelium exposed to continuous smoke as well as disease detection and monitoring. Functional analysis of the pathogenic mtDNA mutations may be useful to understand their role in lung tumorigenesis.     

Abnormal Sperm Parameters in Humans Are Indicative of an Abortive Apoptotic Mechanism Linked to the Fas-Mediated Pathway

The life cycle of many cell types can hinge on the presence of death factors that can control programmed cell death. The Fas-mediated apoptotic pathway has been implicated in controlling apoptosis during spermatogenesis in a number of mammalian species. In the human, the presence of nuclear DNA damage in ejaculated spermatozoa has pointed to a possible role for apoptosis during spermatogenesis. The presence of other molecular markers of apoptosis has, however, not been shown. More importantly, differences in these markers have not been investigated in men with normal and abnormal sperm parameters. In this study we examine for the presence of the cell surface protein Fas in ejaculated human spermatozoa. Ejaculated spermatozoa (55 samples) were labeled with anti-human Fas antibody and the number of spermatozoa displaying Fas were counted using a fluorescence-activated cell sorter (FACS). In 30/31 (96.8%) normal males (>20 million sperm per milliliter), less than 10% of the spermatozoa were Fas positive. In contrast, 14/24 (58.3%) oligozoospermic samples (<20 million sperm per milliliter) contained more than 10% Fas-positive spermatozoa. Similar differences were observed in men whose spermatozoa had poor motility and morphology. These results indicate that apoptosis is a major mechanism in regulating spermatogenesis in the human and that there are clear differences in molecular markers of apoptosis between males with normal and abnormal sperm parameters. We propose that the presence of Fas-labeled spermatozoa in the ejaculate of these men is indicative of an "abortive apoptosis" having taken place, whereby the normal apoptotic mechanisms have misfunctioned, have been overridden, or have not been completed.     

Autophagy Exacerbates Muscle Wasting in Cancer Cachexia and Impairs Mitochondrial Function

Cancer cachexia is a multifactorial syndrome characterized by anorexia, weight loss and muscle wasting that impairs patients' quality of life and survival. Aim of this work was to evaluate the impact of either autophagy inhibition (knocking down beclin-1) or promotion (overexpressing TP53INP2/DOR) on cancer-induced muscle wasting. In C26 tumor-bearing mice, stress-induced autophagy inhibition was unable to rescue the loss of muscle mass and worsened muscle morphology. Treating C26-bearing mice with formoterol, a selective β2-agonist, muscle sparing was paralleled by reduced static autophagy markers, although the flux was maintained. Conversely, the stimulation of muscle autophagy exacerbated muscle atrophy in tumor-bearing mice. TP53INP2 further promoted atrogene expression and suppressed mitochondrial dynamics-related genes. Excessive autophagy might impair mitochondrial function through mitophagy. Consistently, tumor-induced mitochondrial dysfunction was detected by reduced ex vivo muscle fiber respiration. Overall, the results evoke a central role for muscle autophagy in cancer-induced muscle wasting.     

Deregulation of Apoptotic Factors Bcl-xL and Bax Confers Apoptotic Resistance to Myeloid-derived Suppressor Cells and Contributes to Their Persistence in Cancer

Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature myeloid cells that accumulate in response to tumor progression. Compelling data from mouse models and human cancer patients showed that tumor-induced inflammatory mediators induce MDSC differentiation. However, the mechanisms underlying MDSC persistence is largely unknown. Here, we demonstrated that tumor-induced MDSCs exhibit significantly decreased spontaneous apoptosis as compared with myeloid cells with the same phenotypes from tumor-free mice. Consistent with the decreased apoptosis, cell surface Fas receptor decreased significantly in tumor-induced MDSCs. Screening for changes of key apoptosis mediators downstream the Fas receptor revealed that expression levels of IRF8 and Bax are diminished, whereas expression of Bcl-xL is increased in tumor-induced MDSCs. We further determined that IRF8 binds directly to Bax and Bcl-x promoter in primary myeloid cells in vivo, and IRF8-deficient MDSC-like cells also exhibit increased Bcl-xL and decreased Bax expression. Analysis of CD69 and CD25 levels revealed that cytotoxic T lymphocytes (CTLs) are partially activated in tumor-bearing hosts. Strikingly, FasL but not perforin and granzymes were selectively activated in CTLs in the tumor-bearing host. ABT-737 significantly increased the sensitivity of MDSCs to Fas-mediated apoptosis in vitro. More importantly, ABT-737 therapy increased MDSC spontaneous apoptosis and decreased MDSC accumulation in tumor-bearing mice. Our data thus determined that MDSCs use down-regulation of IRF8 to alter Bax and Bcl-xL expression to deregulate the Fas-mediated apoptosis pathway to evade elimination by host CTLs. Therefore, targeting Bcl-xL is potentially effective in suppression of MDSC persistence in cancer therapy.     

微小RNA与肺癌耐药

肺癌细胞对化疗药物产生耐药性是目前肺癌化疗过程中遇到的主要问题。微小RNA（miRNA）是一类内源性非编码短链小分子RNA,它能调节细胞生长、凋亡和信号转导。miRNA的多态性与药物代谢和耐药形成密切相关,异常表达的miRNA对预测肺癌化疗药物敏感性有重要作用。调节特异miRNA的表达,将为克服肺癌耐药和选择个体化治疗开辟新的途径。     

Antiapoptotic and Oncogenic Potentials of Hepatitis C Virus Are Linked to Interferon Resistance by Viral Repression of the PKR Protein Kinase

Hepatitis C virus (HCV) is prevalent worldwide and has become a major cause of liver dysfunction and hepatocellular carcinoma. The high prevalence of HCV reflects the persistent nature of infection and the large frequency of cases that resist the current interferon (IFN)-based anti-HCV therapeutic regimens. HCV resistance to IFN has been attributed, in part, to the function of the viral nonstructural 5A (NS5A) protein. NS5A from IFN-resistant strains of HCV can repress the PKR protein kinase, a mediator of the IFN-induced antiviral and apoptotic responses of the host cell and a tumor suppressor. Here we examined the relationship between HCV persistence and resistance to IFN therapy. When expressed in mammalian cells, NS5A from IFN-resistant HCV conferred IFN resistance to vesicular stomatitis virus (VSV), which normally is sensitive to the antiviral actions of IFN. NS5A blocked viral double-stranded RNA (dsRNA)-induced PKR activation and phosphorylation of eIF-2alpha in IFN-treated cells, resulting in high levels of VSV mRNA translation. Mutations within the PKR-binding domain of NS5A restored PKR function and the IFN-induced block to viral mRNA translation. The effects due to NS5A inhibition of PKR were not limited to the rescue of viral mRNA translation but also included a block in PKR-dependent host signaling pathways. Cells expressing NS5A exhibited defective PKR signaling and were refractory to apoptosis induced by exogenous dsRNA. Resistance to apoptosis was attributed to an NS5A-mediated block in eIF-2alpha phosphorylation. Moreover, cells expressing NS5A exhibited a transformed phenotype and formed solid tumors in vivo. Disruption of apoptosis and tumorogenesis required the PKR-binding function of NS5A, demonstrating that these properties may be linked to the IFN-resistant phenotype of HCV.     

Hepatic Mitochondrial Defects in a Nonalcoholic Fatty Liver Disease Mouse Model Are Associated with Increased Degradation of Oxidative Phosphorylation Subunits

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Highlights

• •Stability of oxidative phosphorylation subunits are reduced in a diet-induced mouse model of NAFLD.
• •These changes are associated with impaired activities of electron transport chain complexes and ATP synthesis.
• •Increased mitophagy contributed to enhanced degradation of mitochondrial proteins.

     

Gefitinib-mediated Reactive Oxygen Specie (ROS) Instigates Mitochondrial Dysfunction and Drug Resistance in Lung Cancer Cells

Therapeutic benefits offered by tyrosine kinase inhibitors (TKIs), such as gefitinib (Iressa) and erlotinib (Tarceva), are limited due to the development of resistance, which contributes to treatment failure and cancer-related mortality. The aim of this study was to elucidate mechanistic insight into cellular perturbations that accompany acquired gefitinib resistance in lung cancer cells. Several lung adenocarcinoma (LAD) cell lines were screened to characterize epidermal growth factor receptor (EGFR) expression and mutation profile. To circumvent intrinsic variations between cell lines with respect to response to drug treatments, we generated gefitinib-resistant H1650 clone by long-term, chronic culture under gefitinib selection of parental cell line. Isogenic cells were analyzed by microarray, Western blot, flow cytometry, and confocal and transmission electron microscope. We observed that although chronic gefitinib treatment provided effective action against its primary target (aberrant EGFR activity), secondary effects resulted in increased cellular reactive oxygen species (ROS). Gefitinib-mediated ROS correlated with epithelial-mesenchymal transition, as well as striking perturbation of mitochondrial morphology and function. However, gefitinib treatment in the presence of ROS scavenger provided a partial rescue of mitochondrial aberrations. Furthermore, withdrawal of gefitinib from previously resistant clones correlated with normalized expression of epithelial-mesenchymal transition genes. These findings demonstrate that chronic gefitinib treatment promotes ROS and mitochondrial dysfunction in lung cancer cells. Antioxidants may alleviate ROS-mediated resistance.     

Mimulone-Induced Autophagy through p53-Mediated AMPK/mTOR Pathway Increases Caspase-Mediated Apoptotic Cell Death in A549 Human Lung Cancer Cells

Anticancer properties and mechanisms of mimulone (MML), C-geranylflavonoid isolated from the Paulownia tomentosa fruits, were firstly elucidated in this study. MML prevented cell proliferation in a dose- and time-dependent way and triggered apoptosis through the extrinsic pathway in A549 human lung adenocarcinoma cells. Furthermore, MML-treated cells displayed autophagic features, such as the formation of autophagic vacuoles, a primary morphological feature of autophagy, and the accumulation of microtubule-associated protein 1 light chain 3 (LC3) puncta, another typical maker of autophagy, as determined by FITC-conjugated immunostaining and monodansylcadaverine (MDC) staining, respectively. The expression levels of LC3-I and LC3-II, specific markers of autophagy, were also augmented by MML treatment. Autophagy inhibition by 3-methyladenine (3-MA), pharmacological autophagy inhibitor, and shRNA knockdown of Beclin-1 reduced apoptotic cell death induced by MML. Autophagic flux was not significantly affected by MML treatment and lysosomal inhibitor, chloroquine (CQ) suppressed MML-induced autophagy and apoptosis. MML-induced autophagy was promoted by decreases in p53 and p-mTOR levels and increase of p-AMPK. Moreover, inhibition of p53 transactivation by pifithrin-α (PFT-α) and knockdown of p53 enhanced induction of autophagy and finally promoted apoptotic cell death. Overall, the results demonstrate that autophagy contributes to the cytotoxicity of MML in cancer cells harboring wild-type p53. This study strongly suggests that MML is a potential candidate for an anticancer agent targeting both autophagy and apoptotic cell death in human lung cancer. Moreover, co-treatment of MML and p53 inhibitor would be more effective in human lung cancer therapy.     

线粒体大麻素受体1在大鼠海马神经元缺氧复氧损伤中对线粒体分裂的影响

目的:探讨线粒体CB1受体(mitochondrial cannabinoid receptor1,mtCB1)在大鼠海马神经元缺氧复氧损伤中对线粒体分裂的影响。方法:原代培养新生的Wistar大鼠海马神经元,将培养至第8天的海马神经元采用随机数字表分为5组(n=60):正常组(N组):正常培养,不做任何处理;缺氧复氧组(H/R组):采用氧糖剥夺法构建海马神经元缺氧复氧损伤模型,缺氧6h,复氧20 h;缺氧复氧组+ACEA+AM251组(H/R+ACEA+AM251组):缺氧6 h结束后立即加入ACEA和AM251,终浓度分别为1μmol/L、10μmol/L,复氧20 h;缺氧复氧+ACEA+Hemopressin(H/R+ACEA+Hemo组):缺氧6h结束后立即加入ACEA和Hemopressin,终浓度分别为1μmol/L、10μmol/L,复氧20 h;缺氧复氧+赋形剂组(H/R+V组):同样于缺氧6h结束后立即加入二甲基亚砜(DMSO),终浓度0.1%,复氧20 h。使用激光共聚焦显微镜检测细胞内Ca~(2+)的浓度,流式细胞仪检测细胞凋亡率,Western blot检测凋亡诱导因子(AIF)、线粒体分裂相关蛋白Drp1、Fis1,细胞凋亡相关蛋白细胞色素C(Cytc)和Rho相关的卷曲蛋白激酶1(ROCK1)的表达。结果:与N组相比,H/R组、H/R+ACEA+AM251组、H/R+ACEA+Hemo组和H/R+V组的细胞内Ca~(2+)浓度、细胞凋亡率、以及AIF、Drp1、Fis1、Cytc、ROCK1蛋白的表达水平均明显增加(P0.05);与H/R组相比,H/R+ACEA+Hem组上述各检测指标明显降低(P0.05),H/R+ACEA+AM251组和H/R+V组各指标比较差异无统计学意义(P0.05)。结论:线粒体CB1受体(mtCB1受体)可能通过降低细胞内ROS的含量来减少细胞内Ca~(2+)浓度和ROCK1的表达,进而抑制线粒体分裂,并最终减轻海马神经元缺氧复氧损伤。