scholarly journals BKCa (Slo) Channel Regulates Mitochondrial Function and Lifespan in Drosophila melanogaster

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 945 ◽  
Author(s):  
Shubha Gururaja Rao ◽  
Piotr Bednarczyk ◽  
Atif Towheed ◽  
Kajol Shah ◽  
Priyanka Karekar ◽  
...  

BKCa channels, originally discovered in Drosophila melanogaster as slowpoke (slo), are recognized for their roles in cellular and organ physiology. Pharmacological approaches implicated BKCa channels in cellular and organ protection possibly for their ability to modulate mitochondrial function. However, the direct role of BKCa channels in regulating mitochondrial structure and function is not deciphered. Here, we demonstrate that BKCa channels are present in fly mitochondria, and slo mutants show structural and functional defects in mitochondria. slo mutants display an increase in reactive oxygen species and the modulation of ROS affected their survival. We also found that the absence of BKCa channels reduced the lifespan of Drosophila, and overexpression of human BKCa channels in flies extends life span in males. Our study establishes the presence of BKCa channels in mitochondria of Drosophila and ascertains its novel physiological role in regulating mitochondrial structural and functional integrity, and lifespan.

2020 ◽  
Author(s):  
Elizabeth Soria-Castro ◽  
María Elena Soto ◽  
Verónica ◽  
Gustavo Rojas ◽  
Mario Perezpeña-Diazconti ◽  
...  

Abstract Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection leads to multiorganic failure associated with a cytokine storm and septic shock. The virus evades the mitochondrial production of interferons through its N protein. From that moment on, SARS-CoV-2 hijacks the functions of this organelle. The aim of this study was to show how the virus kidnaps the mitochondrial machinery for its benefit and survival, altering serum parameters and leading to nitrosative stress (NSS). In a prospective cohort of 15 postmortem patients who died from COVID-19, six markers of mitochondrial function; COX II, COX IV, MnSOD, nitrotyrosine, Bcl-2 and caspase-9 were analyzed by the immune colloidal gold technique in samples from the lung, heart, kidney and liver. Biometric laboratory results from these patients showed alterations in hemoglobin, platelets, creatinine, urea nitrogen, glucose, C-reactive protein, albumin, D-dimer, ferritin, fibrinogen, Ca2+, K+, lactate and troponin. These changes were associated with alterations of the mitochondrial structure and function. The multiorganic dysfunction present in COVID-19 patients may be caused in part by damage to the mitochondria that results in an inflammatory state that contributes to the elevation of NSS. NSS activates the sepsis cascade and contributes to the increased mortality in COVID-19 patients.


Life Sciences ◽  
1981 ◽  
Vol 28 (13) ◽  
pp. 1425-1438 ◽  
Author(s):  
William J. Bettger ◽  
Boyd L. O'Dell

2020 ◽  
Vol 176 (2) ◽  
pp. 433-445 ◽  
Author(s):  
Abhishek Jauhari ◽  
Tanisha Singh ◽  
Saumya Mishra ◽  
Jai Shankar ◽  
Sanjay Yadav

Abstract Mitochondrial dysfunction is a common cause in pathophysiology of different neurodegenerative diseases. Elimination of dysfunctional and damaged mitochondria is a key requirement for maintaining homeostasis and bioenergetics of degenerating neurons. Using global microRNA (miRNA) profiling in a systemic rotenone model of Parkinson’s disease, we have identified miR-146a as upmost-regulated miRNA, which is known as inflammation regulatory miRNA. Here, we report the role of activated nuclear factor kappa beta (NF-kβ) in miR-146a-mediated downregulation of Parkin protein, which inhibits clearance of damaged mitochondria and induces neurodegeneration. Our studies have shown that 4-week rotenone exposure (2.5 mg/kg b.wt) induced oxidative imbalance-mediated NF-kβ activation in 1-year-old rat’s brain. Activated NF-kβ binds in promoter region of miR-146a gene and induces its transcription, which downregulates levels of Parkin protein. Decreased amount of Parkin protein results in accumulation of damaged and dysfunctional mitochondria, which further promotes the generation of reactive oxygen species in degenerating neurons. In conclusion, our studies have identified direct role of NF-kβ-mediated upregulation of miR-146a in regulating mitophagy through inhibition of the Parkin gene.


Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2621
Author(s):  
Yun Kyung Lee ◽  
Yu Seong Chung ◽  
Ji Hye Lee ◽  
Jin Mi Chun ◽  
Jun Hong Park

For more than three decades, numerous studies have demonstrated the function of p53 in cell cycle, cellular senescence, autophagy, apoptosis, and metabolism. Among diverse functions, the essential role of p53 is to maintain cellular homeostatic response to stress by regulating proliferation and apoptosis. Recently, adipocytes have been studied with increasing intensity owing to the increased prevalence of metabolic diseases posing a serious public health concern and because metabolic dysfunction can directly induce tumorigenesis. The prevalence of metabolic diseases has steadily increased worldwide, and a growing interest in these diseases has led to the focus on the role of p53 in metabolism and adipocyte differentiation with or without metabolic stress. However, our collective understanding of the direct role of p53 in adipocyte differentiation and function remains insufficient. Therefore, this review focuses on the newly discovered roles of p53 in adipocyte differentiation and function.


2010 ◽  
Vol 26 (5) ◽  
pp. 265-272 ◽  
Author(s):  
Sohini Singh ◽  
Suresh Vir Singh Rana

Arsenic is an ubiquitous and well-documented carcinogenic metalloid. The most common source of arsenic is drinking water. The mechanism of arsenic toxicity in a cell has historically been centered around its inhibitory effects on cellular respiration and mitochondrial injury. Ascorbic acid, a low molecular weight, water-soluble antioxidant, improves the reduced glutathione (GSH) status by recycling oxidized glutathione. Ascorbic acid can improve mitochondrial function by improving the thiol status; thereby preventing reactive oxygen species— mediated damage to liver as well as kidney. Ascorbic acid has been shown to protect membrane and other cellular compartments by regenerating vitamin E. Therefore, ascorbic acid seems to be a suitable protective factor against arsenic toxicity. Present reports describe the effect of ascorbic acid on oxidative phosphorylation, adenosine triphosphatase (ATPase), succinic dehydrogenase, caspase-3 and apoptosis in the liver of rats treated with arsenic trioxide (AsIII). Ultrastructural changes in the mitochondria have also been reported. We show that cotreatments with ascorbic acid and AsIII improve mitochondrial structure and function. We attribute these improvements mainly to antioxidative role of ascorbic acid. Apoptosis was restricted due to caspase-3 inhibition. Ascorbic acid could protect DNA from the attack of reactive oxygen species generated by AsIII. Consequently its events led to improved ADP:O ratio, normalized ATPase activity and restored the activity of succinic dehydrogenase. Overall, results support the protective role of ascorbic acid against As III-induced liver injury.


Zygote ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 251-260 ◽  
Author(s):  
João Diego de Agostini Losano ◽  
Daniel de Souza Ramos Angrimani ◽  
Roberta Ferreira Leite ◽  
Bárbara do Carmo Simões da Silva ◽  
Valquíria Hyppolito Barnabe ◽  
...  

SummaryDespite sperm mitochondrial relevance to the fertilization capacity, the processes involved in the production of ATP and functional dynamics of sperm mitochondria are not fully understood. One of these processes is the paradox involved between function and formation of reactive oxygen species performed by the organelle. Therefore, this review aimed to provide data on the role of sperm mitochondria in oxidative homeostasis and functionality as well the tools to assess sperm mitochondrial function.


Reproduction ◽  
2018 ◽  
Vol 155 (3) ◽  
pp. 307-319 ◽  
Author(s):  
Yan Cao ◽  
Ming Shen ◽  
Yi Jiang ◽  
Shao-chen Sun ◽  
Honglin Liu

Oxidative stress-induced granulosa cell (GCs) injury is believed to be a common trigger for follicular atresia. Emerging evidence indicates that excessive autophagy occurs in mammalian cells with oxidative damage. N-acetyl-5-methoxytrypamine (melatonin) has been shown to prevent GCs from oxidative injury, although the exact mechanism remains to be elucidated. Here, we first demonstrated that the suppression of autophagy through the JNK/BCL-2/BECN1 signaling is engaged in melatonin-mediated GCs protection against oxidative damage. Melatonin inhibited the loss of GCs viability, formation of GFP-MAP1LC3B puncta, accumulation of MAP1LC3B-II blots, degradation of SQSTM1 and the expression of BECN1, which was correlated with impaired activation of JNK during oxidative stress. On the other hand, blocking of autophagy and/or JNK also reduced the level of H2O2-induced GCs death, but failed to further restore GCs viability in the presence of melatonin. Particularly, the suppression of autophagy provided no additional protective effects when GCs were pretreated with JNK inhibitor and/or melatonin. Importantly, we found that the enhanced interaction between BCL-2 and BECN1 might be a responsive mechanism for autophagy suppression via the melatonin/JNK pathway. Moreover, blocking the downstream antioxidant system of melatonin using specific inhibitors further confirmed a direct role of melatonin/JNK/autophagy axis in preserving GCs survival without scavenging reactive oxygen species (ROS). Taken together, our findings uncover a novel function of melatonin in preventing GCs from oxidative damage by targeting JNK-mediated autophagy, which might contribute to develop therapeutic strategies for patients with ovulation failure-related disorders.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
O Horvath ◽  
L Deres ◽  
K Ordog ◽  
K Bruszt ◽  
B Sumegi ◽  
...  

Abstract Introduction The deterioration of mitochondrial quality control greatly contributes to the hypertension induced cardiac remodeling and progression of heart failure. Our previous in vitro results demonstrated the mitochondrial protective effect of antioxidant BGP-15 compound in the presence of cellular stress. Purpose In our recent study we investigated the effect of BGP-15 on cardiac remodeling in spontaneously hypertensive rats (SHR) with manifested heart failure and on mitochondrial dynamics and function in cell culture model. Methods 15-month-old male SHR received 25 mg/kg/day BGP-15 (SHR-B) or placebo (SHR-C) for 18 weeks. Age matched Wistar rats (WKY) were used as normotensive control. The heart function was monitored by echocardiography. Histological preparations were made from cardiac tissue. Neonatal rat cardiomyocytes (NRCMs) were used as in vitro model. 150 μM H2O2 stress and 50 μM BGP-15 treatment was applied. Mitochondrial network was stained with MitoTracker Red. Mitochondrial membrane potential was detected using JC-1 dye, while mitochondrial function was monitored by the Agilent Seahorse XFp, Cell Mito Stress Test. In both model the cellular levels of mitochondrial dynamics proteins were measured in Western blot. To study the ultrastructure we used electron microscopy in our in vivo and in vitro model. Results Left ventricular (LV) mass and LV wall thickness were increased significantly in SHR-C group compared to the initial values (p<0.05). These parameters were decreased considerably in the SHR-B group. Ejection fraction (EF%) decreased in both SHR group although this downturn was minimal because of the treatment. Chronic high blood pressure caused higher collagen deposition in SHR-C rats that was significantly diminished in the SHR-B group. Regarding the mitochondrial function decrease in the levels of fusion proteins OPA1 and MFN2 was observed in the SHR-C group. These differences were significantly reduced by BGP-15 treatment (p<0.05). Mitigation of the level of fission protein DRP1 was however reduced by BGP-15 (p<0.05). In our cellular model, we observed that the H2O2-induced mitochondrial fragmentation was decreased by BGP-15 treatment (p<0.05). BGP-15 treatment prevented mitochondrial membrane potential fall in H2O2 stress (p<0.05). There was no significant difference in basal respiration among groups by monitoring the mitochondrial function. The maximal respiration capacity and ATP production were significantly higher in the BGP-15 treated group in comparison to the stressed group (p<0.05). Conclusion BGP-15 treatment has beneficial effects on mitochondrial dynamics and structure by promoting fusion processes. It also supports the maintenance of mitochondrial function through the preservation of the mitochondrial structure. The mitigation of remodeling processes and the preserved EF in the treated group are results at least partly of the comprehensible effects of BGP-15 on mitochondrial structure and function. Acknowledgement/Funding GINOP-2.3.2-15-2016-00049; GINOP-2.3.2-15-2016-00048; GINOP-2.3.3-15-2016-00025


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