bims-mecmid 2022-02-13 papers

bims-mecmid

Biomed News

on Membrane communication in mitochondrial dynamics

Issue of 2022‒02‒13
nine papers selected by
Mauricio Cardenas Rodriguez
University of Padova

A VDAC1-mediated NEET protein chain transfers [2Fe-2S] clusters between the mitochondria and the cytosol and impacts mitochondrial dynamics.
Sevoflurane induced neurotoxicity in neonatal mice links to a GSK3β/Drp1-dependent mitochondrial fission and apoptosis.
Autophagy and mitochondrial dynamics contribute to the protective effect of diosgenin against 3-MCPD induced kidney injury.
Mdivi-1 alleviates cardiac fibrosis post myocardial infarction at infarcted border zone, possibly via inhibition of Drp1-Activated mitochondrial fission and oxidative stress.
PACS-2 Ameliorates Tubular Injury by Facilitating Endoplasmic Reticulum-Mitochondria Contact and Mitophagy in Diabetic Nephropathy.
SOCS6 Promotes Mitochondrial Fission and Cardiomyocyte Apoptosis and Is Negatively Regulated by Quaking-Mediated miR-19b.
PINK1 regulates mitochondrial fission/fusion and neuroinflammation in β-amyloid-induced Alzheimer's disease models.
Use of Fluorescence Recovery After Photobleaching (FRAP) to Measure In Vivo Dynamics of Cell Junction-Associated Polarity Proteins.
Inhibition of mitoNEET attenuates LPS-induced inflammation and oxidative stress.

Proc Natl Acad Sci U S A. 2022 Feb 15. pii: e2121491119. [Epub ahead of print]119(7):

A VDAC1-mediated NEET protein chain transfers [2Fe-2S] clusters between the mitochondria and the cytosol and impacts mitochondrial dynamics.

Ola Karmi, Henri-Baptiste Marjault, Fang Bai, Susmita Roy, Yang-Sung Sohn, Merav Darash Yahana, Faruck Morcos, Konstantinos Ioannidis, Yaakov Nahmias, Patricia A Jennings, Ron Mittler, José N Onuchic, Rachel Nechushtai.

  Mitochondrial inner NEET (MiNT) and the outer mitochondrial membrane (OMM) mitoNEET (mNT) proteins belong to the NEET protein family. This family plays a key role in mitochondrial labile iron and reactive oxygen species (ROS) homeostasis. NEET proteins contain labile [2Fe-2S] clusters which can be transferred to apo-acceptor proteins. In eukaryotes, the biogenesis of [2Fe-2S] clusters occurs within the mitochondria by the iron-sulfur cluster (ISC) system; the clusters are then transferred to [2Fe-2S] proteins within the mitochondria or exported to cytosolic proteins and the cytosolic iron-sulfur cluster assembly (CIA) system. The last step of export of the [2Fe-2S] is not yet fully characterized. Here we show that MiNT interacts with voltage-dependent anion channel 1 (VDAC1), a major OMM protein that connects the intermembrane space with the cytosol and participates in regulating the levels of different ions including mitochondrial labile iron (mLI). We further show that VDAC1 is mediating the interaction between MiNT and mNT, in which MiNT transfers its [2Fe-2S] clusters from inside the mitochondria to mNT that is facing the cytosol. This MiNT-VDAC1-mNT interaction is shown both experimentally and by computational calculations. Additionally, we show that modifying MiNT expression in breast cancer cells affects the dynamics of mitochondrial structure and morphology, mitochondrial function, and breast cancer tumor growth. Our findings reveal a pathway for the transfer of [2Fe-2S] clusters, which are assembled inside the mitochondria, to the cytosol.

Keywords:  CISD3; VDAC1; [2Fe-2S] cluster; mitoNEET; mitochondrial inner NEET protein (MiNT)

DOI:  https://doi.org/10.1073/pnas.2121491119
Free Radic Biol Med. 2022 Feb 02. pii: S0891-5849(22)00042-9. [Epub ahead of print]181 72-81

Sevoflurane induced neurotoxicity in neonatal mice links to a GSK3β/Drp1-dependent mitochondrial fission and apoptosis.

Jinsheng Liu, Li Li, Ping Xie, Xiaoyan Zhao, Dongjing Shi, Yan Zhang, Chuxiong Pan, Tianzuo Li.

  Mitochondria damage and apoptosis were found associated with sevoflurane induced neurotoxicity in developing brains of rodent and neuro cell lines. The detailed upstream mechanism remains unclear. This study explored whether sevoflurane induces neurotoxicity by activating a GSK3β (glycogen synthase kinase 3β)/Drp1 (dynamin-related protein-1)-dependent mitochondrial fission and apoptosis. Our results showed that sevoflurane exposure promoted mitochondria fission in hippocampus of neonatal mice, resulted in a prolonged escape latency from P32 (32-day-postnatal) to P35, and decreased platform crossing times on P36 as compared to the control treatment. Additionally, sevoflurane upregulated GSK3β stability and activation, promoted phosphorylation of Drp1 at Ser616 along with its translocation to mitochondria and resulted in increasing cytochrome c and cleaved casepase-3 in hippocampus of neonatal mice and in human SK-N-SH cells. Simultaneously, sevoflurane promoted the interaction between Drp1 and GSK3β. Furthermore, GSK3β activated phosphorylation of Drp1 at Ser616, induced mitochondrial fission, loss of mitochondrial membrane potential (MMP) and apoptosis in SK-N-SH cells, which was attenuated by TDZD-8, an inhibitor of GSK3β. In conclusion, sevoflurane induced neurotoxicity links to a GSK3β/Drp1 dependent mitochondrial fission and apoptosis.

Keywords:  Apoptosis; Drp1 protein; Glycogen Synthase Kinase 3 beta; Mitochondria; Mitochondrial fission; Neurotoxicity; Sevoflurane

DOI:  https://doi.org/10.1016/j.freeradbiomed.2022.01.031
Chem Biol Interact. 2022 Feb 08. pii: S0009-2797(22)00055-2. [Epub ahead of print] 109850

Autophagy and mitochondrial dynamics contribute to the protective effect of diosgenin against 3-MCPD induced kidney injury.

Yujie Zhong, Dianjun Sun, Yanpeng Yao, Qi Liu, Tianmin Guo, Xin Wang, Xiaoli Peng.

  3-Chloro-1, 2-propanediol (3-MCPD) is a widespread food contaminant with kidney as the main target organ. The exploration of ingredients as intervention strategy towards 3-MCPD induced nephrotoxicity is needed. Diosgenin (DIO) is a steroidal saponin presented in several plants and foods. Here we assessed whether DIO attenuates nephrotoxicity induced by 3-MCPD using Human embryonic kidney 293 (HEK293) cells and Sprague-Dawley (SD) rats. The results showed that DIO (2, 6, 8 μM) increased cell viability and exerted inhibitory effect on caspase 3 and caspase 9 activities. Histological examination of rats showed that 15 mg/kg bw DIO ameliorated renal pathological changes caused by 3-MCPD (30 mg/kg bw). DIO also induced autophagy and the blockade of autophagy with 3-Methyladenine (3-MA) aggravated mitochondrial apoptosis induced by 3-MCPD in HEK293 cells. Moreover, treatment with DIO caused an increase in p-LKB1/LKB1 and p-AMPK/AMPK expressions and a decrease in p-mTOR/mTOR, p-ULK1(Ser757), p-P70S6K and p-4EBP1 expressions. Additionally, DIO improved mitochondrial dynamics mainly through inhibiting the relocation of DRP1 on mitochondria and enhancing MFN1 and MFN2 expressions. In conclusion, our study demonstrated for the first time that DIO protected against kidney injury induced by 3-MCPD through the induction of autophagy via LKB1-AMPK-mTOR pathway and the improvement of mitochondrial fission and fusion.

Keywords:  3-MCPD; Apoptosis; Autophagy; Diosgenin; Mitochondrial fission/fusion

DOI:  https://doi.org/10.1016/j.cbi.2022.109850
Arch Biochem Biophys. 2022 Feb 07. pii: S0003-9861(22)00032-7. [Epub ahead of print] 109147

Mdivi-1 alleviates cardiac fibrosis post myocardial infarction at infarcted border zone, possibly via inhibition of Drp1-Activated mitochondrial fission and oxidative stress.

Jie Ding, Zhihao Zhang, Sui Li, Wei Wang, Tingyi Du, Qin Fang, Yan Wang, Dao Wen Wang.

  Mitochondrial division inhibitor 1(Mdivi-1) has been shown to play a beneficial role in a variety of diseases, mainly by inhibiting Drp1-mediated mitochondrial fission. The effects of Mdivi-1 on cardiac fibrosis at infarcted border zone area and its possible mechanism remain unclear. This study aimed to investigate the effects of Mdivi-1 on reactive cardiac fibrosis and cardiac function post myocardial infarction and its potential mechanisms. Mice were randomly divided into six groups(n = 9 for each group): Sham; Mdivi-1; MI 7d; MI 14d; MI 28d; MI 28d + Mdivi-1. The MI model was induced by ligation of LAD coronary artery. Mdivi-1 (1mg/kg) was administered to mice every other day at a time from the second day until the sacrifice of the mice (total 14 injection of Mdivi-1). In vitro experiments, the effect of Mdivi-1 on TGF-β1-induced fibrosis-related pathophysiological changes of fibroblasts was examined in NIH3T3 cells. We found that Mdivi-1 significantly attenuated fibroblast activation, collagen production and fibrosis at infarcted border zone after MI, improved impaired heart function. Mechanistically, we observed that Mdivi-1 reduced the protein expression of P-Drp1-S616 and abnormal mitochondrial fission of cardiac fibroblasts in the infarcted border zone area. In addition, we found that the effects of Mdivi-1 partially relied on increasing the expression of Hmox1 and inhibiting oxidative stress. In conclusion, Mdivi-1 could attenuate cardiac fibrosis at infarcted border zone and improve impaired heart function partially through attenuation of Drp1-mediated mitochondrial fission. Moreover, inhibition of oxidative stress, which is possible due to the up-regulation of Hmox1, may be another potential mechanism of action of Mdivi-1.

Keywords:  Cardiac fibrosis; Hmox1; Mdivi-1; Mitochondrial fission; Myocardial infarction; Oxidative stress

DOI:  https://doi.org/10.1016/j.abb.2022.109147
Diabetes. 2022 Feb 08. pii: db210983. [Epub ahead of print]

PACS-2 Ameliorates Tubular Injury by Facilitating Endoplasmic Reticulum-Mitochondria Contact and Mitophagy in Diabetic Nephropathy.

Chenrui Li, Li Li, Ming Yang, Jinfei Yang, Chanyue Zhao, Yachun Han, Hao Zhao, Na Jiang, Ling Wei, Ying Xiao, Yan Liu, Xiaofen Xiong, Yiyun Xi, Shilu Luo, Fei Deng, Wei Chen, Shuguang Yuan, Xuejing Zhu, Li Xiao, Lin Sun.

Mitochondria-associated endoplasmic reticulum membrane (MAM) is emerging as a novel insight into tubular injury in diabetic nephropathy (DN), but the precise mechanism remains unclear. Here, we demonstrate that the expression of phosphofurin acidic cluster sorting protein 2 (PACS-2), a critical regulator of MAM formation, is significantly decreased in renal tubules of patients with DN, which is positively correlated with renal function and negatively correlated with degrees of tubulointerstitial lesions. Conditional deletion of Pacs-2 in proximal tubules (PT) aggravates albuminuria and tubular injury in streptozotocin (STZ)-induced diabetic mice. Mitochondrial fragmentation, MAM disruption and defective mitophagy accompanied by altered expression of mitochondrial dynamics and mitophagic protein including DRP1 and BECN1 are observed in tubules from diabetic mice, while these changes are more pronounced in PT-specific Pacs-2 knockout mice. In vitro, overexpression of PACS-2 in HK-2 cells alleviates excessive mitochondrial fission induced by high glucose through blocking mitochondrial recruitment of DRP1, and subsequently restores MAM integrity and enhances mitophagy. Mechanistically, PACS-2 binds to BECN1 and mediates the relocalization of BECN1 to MAM where it promotes the formation of mitophagosome. Together, these data highlight an important but previously unrecognized role of PACS-2 in ameliorating tubular injury in DN by facilitating MAM formation and mitophagy.

DOI: https://doi.org/10.2337/db21-0983
Oxid Med Cell Longev. 2022 ;2022 1121323

SOCS6 Promotes Mitochondrial Fission and Cardiomyocyte Apoptosis and Is Negatively Regulated by Quaking-Mediated miR-19b.

Peng Zhang, Ping Guan, Xiaomiao Ye, Yi Lu, Yanwen Hang, Yanling Su, Wei Hu.

Background: Mitochondrial dysfunction and abnormal mitochondrial fission have been implicated in the complications associated with I/R injury as cardiomyocytes are abundant in mitochondria. SOCS6 is known to participate in mitochondrial fragmentation, but its exact involvement and the pathways associated are uncertain.Methods and Results: The expression of SOCS6 was analyzed by western blot in cardiomyocytes under a hypoxia and reoxygenation (H/R) model. A dual-luciferase reporter assay was used to confirm the direct interaction between miR-19b and the 3'-UTR of Socs6. In the present study, we found that Socs6 inhibition by RNA interference attenuated H/R-induced mitochondrial fission and apoptosis in cardiomyocytes. A luciferase assay indicated that Socs6 is a direct target of miR-19b. The overexpression of miR-19b decreased mitochondrial fission and apoptosis in vitro. Moreover, the presence of miR-19b reduced the level of SOCS6 and the injury caused by I/R in vivo. There were less apoptotic cells in the myocardium of mice injected with miR-19b. In addition, we found that the RNA-binding protein, Quaking (QK), participates in the regulation of miR-19b expression.
Conclusions: Our results indicate that the inhibition of mitochondrial fission through downregulating Socs6 via the QK/miR-19b/Socs6 pathway attenuated the damage sustained by I/R. The QK/miR-19b/Socs6 axis plays a vital role in regulation of mitochondrial fission and cardiomyocyte apoptosis and could form the basis of future research in the development of therapies for the management of cardiac diseases.

DOI: https://doi.org/10.1155/2022/1121323
Neurochem Int. 2022 Feb 05. pii: S0197-0186(22)00023-7. [Epub ahead of print]154 105298

PINK1 regulates mitochondrial fission/fusion and neuroinflammation in β-amyloid-induced Alzheimer's disease models.

Xiaojuan Wang, Yongqiang Xue, Yang Yao, Yang Li, Xuefei Ji, Tianyan Chi, Peng Liu, Libo Zou.

  Disrupted mitochondrial fission/fusion balance is consistently involved in neurodegenerative diseases, including Alzheimer's disease. PTEN-induced putative kinase 1 (PINK1), a mitochondrial kinase, has been reported to prevent mitochondrial injury, oxidative stress, apoptosis, and inflammation. However, to the best of our knowledge, the contribution of PINK1 to Aβ-induced mitochondrial fission/fusion has not been reported. In the present study, we showed that PINK1 deficiency promoted mitochondrial fission and fusion, aggravated mitochondrial dysfunction, and promoted neuroinflammatory cytokine factor production induced by intracerebroventricular (ICV) injection of Aβ25-35 in rats. In vitro experiments have also showed that Aβ25-35 caused more severe cell injury in PINK1-knockdown PC12 cells. These cells suffered more extensive death when exposed to proinflammatory cytokines. Lastly, we found that PINK1 overexpression significantly inhibited mitochondrial fusion, improved mitochondrial dysfunction, and reduced neuroinflammatory cytokine production induced by Aβ25-35. The current study suggests the involvement of PINK1 in Aβ25-35-mediated mitochondrial dynamics and that PINK1 may be a potential target for therapies aimed at enhancing neuroprotection to ameliorate Aβ25-35-induced insults.

Keywords:  Alzheimer's disease; Mitochondrial fission and fusion; Neuroinflammation; PINK1; β-Amyloid

DOI:  https://doi.org/10.1016/j.neuint.2022.105298
Methods Mol Biol. 2022 ;2438 1-30

Use of Fluorescence Recovery After Photobleaching (FRAP) to Measure In Vivo Dynamics of Cell Junction-Associated Polarity Proteins.

Samantha J Warrington, Helen Strutt, David Strutt.

  Here, we present a detailed protocol for fluorescence recovery after photobleaching (FRAP) to measure the dynamics of junctional populations of proteins in living tissue. Specifically, we describe how to perform FRAP in Drosophila pupal wings on fluorescently tagged core planar polarity proteins, which exhibit relatively slow junctional turnover. We provide a step-by-step practical guide to performing FRAP, and list a series of controls and optimizations to do before conducting a FRAP experiment. Finally, we describe how to present the FRAP data for publication.

Keywords:  Drosophila; FRAP; Fluorescence; In vivo imaging; Live-imaging; PCP; Photobleaching; Planar cell polarity; Planar polarity; Pupal wing

DOI:  https://doi.org/10.1007/978-1-0716-2035-9_1
Cell Death Dis. 2022 Feb 08. 13(2): 127

Inhibition of mitoNEET attenuates LPS-induced inflammation and oxidative stress.

Seunghee Lee, Byeong Geun Seok, Seon-Jin Lee, Su Wol Chung.

MitoNEET (mitochondrial protein containing Asn-Glu-Glu-Thr (NEET) sequence) is a 2Fe-2S cluster-containing integral membrane protein that resides in the mitochondrial outer membrane and participates in a redox-sensitive signaling and Fe-S cluster transfer. Thus, mitoNEET is a key regulator of mitochondrial oxidative capacity and iron homeostasis. Moreover, mitochondrial dysfunction and oxidative stress play critical roles in inflammatory diseases such as sepsis. Increased iron levels mediated by mitochondrial dysfunction lead to oxidative damage and generation of reactive oxygen species (ROS). Increasing evidence suggests that targeting mitoNEET to reverse mitochondrial dysfunction deserves further investigation. However, the role of mitoNEET in inflammatory diseases is unknown. Here, we investigated the mechanism of action and function of mitoNEET during lipopolysaccharide (LPS)-induced inflammatory responses in vitro and in vivo. Levels of mitoNEET protein increased during microbial or LPS-induced sepsis. Pharmacological inhibition of mitoNEET using mitoNEET ligand-1 (NL-1) decreased the levels of pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α in animal models of sepsis, as well as LPS-induced inflammatory responses by macrophages in vitro. Inhibition of mitoNEET using NL-1 or mitoNEET shRNA abrogated LPS-induced ROS formation and mitochondrial dysfunction. Furthermore, mitochondrial iron accumulation led to generation of LPS-induced ROS, a process blocked by NL-1 or shRNA. Taken together, these data suggest that mitoNEET could be a key therapeutic molecule that targets mitochondrial dysfunction during inflammatory diseases and sepsis.

DOI: https://doi.org/10.1038/s41419-022-04586-2