scholarly journals The calcilytic drug Calhex-231 ameliorates vascular hyporesponsiveness in traumatic hemorrhagic shock by inhibiting oxidative stress and mitochondrial fission

2020 ◽  
Author(s):  
Yan Lei ◽  
Xiaoyong Peng ◽  
Tao Li ◽  
Liangming Liu ◽  
Guangming Yang
Keyword(s):  
Oxidative Stress ◽  
Hemorrhagic Shock ◽  
Vascular Reactivity ◽  
Mitochondrial Fission ◽  
Blood Perfusion ◽  
Mitochondrial Fusion ◽  
Vital Organ ◽  
Animal Survival ◽  
Traumatic Hemorrhagic Shock ◽  
Mlc Phosphorylation

Abstract Background The calcium-sensing receptor (CaSR) plays a fundamental role in extracellular calcium homeostasis in humans. Surprisingly, CaSR is also expressed in non-homeostatic tissues and is involved in regulating diverse cellular functions. The objective of this study was to determine if Calhex-231 (Cal), a negative modulator of CaSR, may be beneficial in the treatment of traumatic hemorrhagic shock (THS) by improving cardiovascular function, and investigated its relationship to oxidative stress and the mitochondrial fusion-fission pathway. Methods Rats that had been subjected to traumatic hemorrhagic shock were used as models in this study. Hypoxia-treated vascular smooth muscle cells (VSMCs) were also used. The effects of Cal on cardiovascular function, animal survival, hemodynamic parameters, and vital organ function in THS rats were observed, and the relationship to oxidative stress and mitochondrial fusion-fission was investigated. Results Cal significantly improved hemodynamics, elevated blood pressure, increased vital organ blood perfusion and local oxygen supply, and markedly improved the survival outcomes of THS rats. Furthermore, Cal significantly improved vascular reactivity after THS, including the pressor response of THS rats to norepinephrine (NE), and also the contractile response of superior mesenteric arteries, mesenteric arterioles, and isolated VSMCs to NE. Cal also restored the THS-induced decrease in myosin light chain (MLC) phosphorylation, which is the principal mechanism responsible for VSMC contraction and vascular reactivity. Inhibition of MLC phosphorylation antagonized the Cal-induced restoration of vascular reactivity following THS. Cal decreased oxidative stress indexes and increased antioxidant enzyme levels in THS rats, and also reduced reactive oxygen species levels in hypoxic VSMCs. In addition, THS induced expression of mitochondrial fission proteins Drp1 and Fis1, and decreased expression of mitochondrial fusion protein Mfn1 in vascular tissues. Cal reduced expression of Drp1 and Fis1, but did not affect Mfn1 expression. In hypoxic VSMCs, Cal inhibited hypoxia-induced mitochondrial fragmentation and preserved mitochondrial morphology. Conclusions Calhex-231 exhibits outstanding potential for effective therapy of traumatic hemorrhagic shock, due to its ability to improve hemodynamics, increase vital organ blood perfusion, and markedly prolong animal survival. These beneficial effects result from its protection of vascular function via inhibition of oxidative stress and mitochondrial fission.

scholarly journals The Calcilytic Drug Calhex-231 Ameliorates Vascular Hyporesponsiveness in Traumatic Hemorrhagic Shock by Inhibiting Oxidative Stress and miR-208a-Mediated Mitochondrial Fission

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yan Lei ◽  
Xiaoyong Peng ◽  
Yi Hu ◽  
Mingying Xue ◽  
Tao Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hemorrhagic Shock ◽  
Vascular Reactivity ◽  
Mitochondrial Fission ◽  
Cardiovascular Function ◽  
Mitochondrial Fusion ◽  
Mitochondrial Morphology ◽  
Vital Organ ◽  
Traumatic Hemorrhagic Shock ◽  
Mlc Phosphorylation

Background. The calcium-sensing receptor (CaSR) plays a fundamental role in extracellular calcium homeostasis in humans. Surprisingly, CaSR is also expressed in nonhomeostatic tissues and is involved in regulating diverse cellular functions. The objective of this study was to determine if Calhex-231 (Cal), a negative modulator of CaSR, may be beneficial in the treatment of traumatic hemorrhagic shock (THS) by improving cardiovascular function and investigated the mechanisms. Methods. Rats that had been subjected to THS and hypoxia-treated vascular smooth muscle cells (VSMCs) were used in this study. The effects of Cal on cardiovascular function, animal survival, hemodynamics, and vital organ function in THS rats and the relationship to oxidative stress, mitochondrial fusion-fission, and microRNA (miR-208a) were investigated. Results. Cal significantly improved hemodynamics, elevated blood pressure, increased vital organ blood perfusion and local oxygen supply, and markedly improved the survival outcomes of THS rats. Furthermore, Cal significantly improved vascular reactivity after THS in vivo and in vitro. Cal also restored the THS-induced decrease in myosin light chain (MLC) phosphorylation (the key element for VSMC contraction). Inhibition of MLC phosphorylation antagonized the Cal-induced restoration of vascular reactivity following THS. Cal suppressed oxidative stress in THS rats and hypoxic-VSMCs. Meanwhile, THS induced expression of mitochondrial fission proteins Drp1 and Fis1 and decreased expression of mitochondrial fusion protein Mfn1 in vascular tissues. Cal reduced expression of Drp1 and Fis1. In hypoxic-VSMCs, Cal inhibited mitochondrial fragmentation and preserved mitochondrial morphology. In addition, miR-208a mimic decreased Fis1 expression, and miR-208a inhibitor prevented Cal-induced Fis1 downregulation in hypoxic-VSMCs. Conclusion. Calhex-231 exhibits outstanding potential for effective therapy of traumatic hemorrhagic shock, and the beneficial effects result from its protection of vascular function via inhibition of oxidative stress and miR-208a-mediated mitochondrial fission.

scholarly journals NME3 Regulates Mitochondria to Reduce ROS-Mediated Genome Instability

2020 ◽  
Vol 21 (14) ◽  
pp. 5048
Author(s):  
Chih-Wei Chen ◽  
Ning Tsao ◽  
Wei Zhang ◽  
Zee-Fen Chang
Keyword(s):  
Oxidative Stress ◽  
Dna Repair ◽  
Genome Stability ◽  
Nuclear Dna ◽  
Genome Instability ◽  
Mitochondrial Fission ◽  
Nucleoside Diphosphate Kinase ◽  
Mitochondrial Fusion ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Oxidative Stress

NME3 is a member of the nucleoside diphosphate kinase (NDPK) family that binds to the mitochondrial outer membrane to stimulate mitochondrial fusion. In this study, we showed that NME3 knockdown delayed DNA repair without reducing the cellular levels of nucleotide triphosphates. Further analyses revealed that NME3 knockdown increased fragmentation of mitochondria, which in turn led to mitochondrial oxidative stress-mediated DNA single-strand breaks (SSBs) in nuclear DNA. Re-expression of wild-type NME3 or inhibition of mitochondrial fission markedly reduced SSBs and facilitated DNA repair in NME3 knockdown cells, while expression of N-terminal deleted mutant defective in mitochondrial binding had no rescue effect. We further showed that disruption of mitochondrial fusion by knockdown of NME4 or MFN1 also caused mitochondrial oxidative stress-mediated genome instability. In conclusion, the contribution of NME3 to redox-regulated genome stability lies in its function in mitochondrial fusion.

scholarly journals T-2 Toxin-Induced Oxidative Stress Leads to Imbalance of Mitochondrial Fission and Fusion to Activate Cellular Apoptosis in the Human Liver 7702 Cell Line

Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 43 ◽  
Author(s):  
Junhua Yang ◽  
Wenbo Guo ◽  
Jianhua Wang ◽  
Xianli Yang ◽  
Zhiqi Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Apoptosis ◽  
Human Liver ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Mitochondrial Fusion ◽  
Mitochondrial Dynamic ◽  
Normal Human Liver ◽  
Induced Apoptosis

T-2 toxin, as a highly toxic mycotoxin to humans and animals, induces oxidative stress and apoptosis in various cells and tissues. Apoptosis and mitochondrial fusion/fission are two tightly interconnected processes that are crucial for maintaining physiological homeostasis. However, the role of mitochondrial fusion/fission in apoptosis of T-2 toxin remains unknown. Hence, we aimed to explore the putative role of mitochondrial fusion/fission on T-2 toxin induced apoptosis in normal human liver (HL-7702) cells. T-2 toxin treatment (0, 0.1, 1.0, or 10 μg/L) for 24 h caused decreased cell viability and ATP concentration and increased production of (ROS), as seen by a loss of mitochondrial membrane potential (∆Ψm) and increase in mitochondrial fragmentation. Subsequently, the mitochondrial dynamic imbalance was activated, evidenced by a dose-dependent decrease and increase in the protein expression of mitochondrial fusion (OPA1, Mfn1, and Mfn2) and fission (Drp1 and Fis1), respectively. Furthermore, the T-2 toxin promoted the release of cytochrome c from mitochondria to cytoplasm and induced cell apoptosis triggered by upregulation of Bax and Bax/Bcl-2 ratios, and further activated the caspase pathways. Taken together, these results indicate that altered mitochondrial dynamics induced by oxidative stress with T-2 toxin exposure likely contribute to mitochondrial injury and HL-7702 cell apoptosis.

REPERFUSION DOES NOT INDUCE OXIDATIVE STRESS BUT SUSTAINED ENDOPLASMIC RETICULUM STRESS IN LIVERS OF RATS SUBJECTED TO TRAUMATIC-HEMORRHAGIC SHOCK

Shock ◽  
2010 ◽  
Vol 33 (3) ◽  
pp. 289-298 ◽  
Author(s):  
Johanna Catharina Duvigneau ◽  
Andrey V. Kozlov ◽  
Clara Zifko ◽  
Astrid Postl ◽  
Romana T. Hartl ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Hemorrhagic Shock ◽  
Traumatic Hemorrhagic Shock

Exogenous Hydrogen Sulfide Protects Against Traumatic Hemorrhagic Shock Via Attenuation of Oxidative Stress

2012 ◽  
Vol 176 (1) ◽  
pp. 210-219 ◽  
Author(s):  
Wei Chai ◽  
Yan Wang ◽  
Jia-Yan Lin ◽  
Xu-De Sun ◽  
Li-Nong Yao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Sulfide ◽  
Hemorrhagic Shock ◽  
Traumatic Hemorrhagic Shock

scholarly journals Neuroprotective Effects of a Small Mitochondrially-Targeted Tetrapeptide Elamipretide in Neurodegeneration

2022 ◽  
Vol 15 ◽  
Author(s):  
Nguyen Thanh Nhu ◽  
Shu-Yun Xiao ◽  
Yijie Liu ◽  
V. Bharath Kumar ◽  
Zhen-Yang Cui ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Respiration ◽  
Mitochondrial Fission ◽  
Mitochondrial Fusion ◽  
Protein Accumulation ◽  
Therapeutic Effects ◽  
Neuroprotective Effects ◽  
Toxic Protein ◽  
Neural Apoptosis

Neural mitochondrial dysfunction, neural oxidative stress, chronic neuroinflammation, toxic protein accumulation, and neural apoptosis are common causes of neurodegeneration. Elamipretide, a small mitochondrially-targeted tetrapeptide, exhibits therapeutic effects and safety in several mitochondria-related diseases. In neurodegeneration, extensive studies have shown that elamipretide enhanced mitochondrial respiration, activated neural mitochondrial biogenesis via mitochondrial biogenesis regulators (PCG-1α and TFAM) and the translocate factors (TOM-20), enhanced mitochondrial fusion (MNF-1, MNF-2, and OPA1), inhibited mitochondrial fission (Fis-1 and Drp-1), as well as increased mitophagy (autophagy of mitochondria). In addition, elamipretide has been shown to attenuate neural oxidative stress (hydrogen peroxide, lipid peroxidation, and ROS), neuroinflammation (TNF, IL-6, COX-2, iNOS, NLRP3, cleaved caspase-1, IL-1β, and IL-18), and toxic protein accumulation (Aβ). Consequently, elamipretide could prevent neural apoptosis (cytochrome c, Bax, caspase 9, and caspase 3) and enhance neural pro-survival (Bcl2, BDNF, and TrkB) in neurodegeneration. These findings suggest that elamipretide may prevent the progressive development of neurodegenerative diseases via enhancing mitochondrial respiration, mitochondrial biogenesis, mitochondrial fusion, and neural pro-survival pathway, as well as inhibiting mitochondrial fission, oxidative stress, neuroinflammation, toxic protein accumulation, and neural apoptosis. Elamipretide or mitochondrially-targeted peptide might be a targeted agent to attenuate neurodegenerative progression.

Beneficial effects of platelet-derived growth factor on hemorrhagic shock in rats and the underlying mechanisms

2014 ◽  
Vol 307 (9) ◽  
pp. H1277-H1287 ◽  
Author(s):  
Liangming Liu ◽  
Jie Zhang ◽  
Yu Zhu ◽  
Xudong Xiao ◽  
Xiaoyong Peng ◽  
...  
Keyword(s):  
Growth Factor ◽  
Hemorrhagic Shock ◽  
Gap Junction ◽  
Vascular Reactivity ◽  
Rho Kinase ◽  
Mesenteric Arteries ◽  
Platelet Derived Growth Factor ◽  
Beneficial Effects ◽  
Animal Survival ◽  
Systemic Application

Studies have shown that local application of platelet-derived growth factor (PDGF) can be used for the treatment of acute and chronic wounds. We investigated if systemic application of PDGF has a protective effect on acute hemorrhagic shock in rats in the present study. Using hemorrhagic shock rats and isolated superior mesenteric arteries, the effects of PDGF-BB on hemodynamics, animal survival, and vascular reactivity as well as the roles of the gap junction proteins connexin (Cx)40 and Cx43, PKC, and Rho kinase were observed. PDGF-BB (1–15 μg/kg iv) significantly improved the hemodynamics and blood perfusion to vital organs (liver and kidney) as well as vascular reactivity and improved the animal survival in hemorrhagic shock rats. PDGF recovering shock-induced vascular hyporeactivity depended on the integrity of the endothelium and myoendothelial gap junction. Cx43 antisense oligodeoxynucleotide abolished these improving effects of PDGF, whereas Cx40 oligodeoxynucleotide did not. Further study indicated that PDGF increased the activity of Rho kinase and PKC as well as vascular Ca2+sensitivity, whereas it did not interfere with the intracellular Ca2+concentration in hypoxia-treated vascular smooth muscle cells. In conclusion, systemic application of PDGF-BB may exert beneficial effects on hemorrhagic shock, which are closely related to the improvement of vascular reactivity and hemodynamics. The improvement of PDGF-BB in vascular reactivity is vascular endothelium and myoendothelial gap junction dependent. Cx43, Rho kinase, and PKC play very important role in this process. These findings suggest that PDGF may be a potential measure to treat acute clinical critical diseases such as severe trauma, shock, and sepsis.

scholarly journals HO-1/PINK1 Regulated Mitochondrial Fusion/Fission to Inhibit Pyroptosis and Attenuate Septic Acute Kidney Injury

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hai-Bo Li ◽  
Xi-Zhe Zhang ◽  
Yi Sun ◽  
Qi Zhou ◽  
Jian-Nan Song ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Acute Kidney Injury ◽  
Renal Function ◽  
Inflammatory Response ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Endotoxic Shock ◽  
Kidney Injury ◽  
Treated Group ◽  
Mitochondrial Fusion

Background. Endotoxin-associated acute kidney injury (AKI), a disease characterized by marked oxidative stress and inflammation disease, is a major cause of mortality in critically ill patients. Mitochondrial fission and pyroptosis often occur in AKI. However, the underlying biological pathways involved in endotoxin AKI remain poorly understood, especially those related to mitochondrial dynamics equilibrium disregulation and pyroptosis. Previous studies suggest that heme oxygenase- (HO-) 1 confers cytoprotection against AKI during endotoxic shock, and PTEN-induced putative kinase 1 (PINK1) takes part in mitochondrial dysfunction. Thus, in this study, we examine the roles of HO-1/PINK1 in maintaining the dynamic process of mitochondrial fusion/fission to inhibit pyroptosis and mitigate acute kidney injury in rats exposed to endotoxin. Methods. An endotoxin-associated AKI model induced by lipopolysaccharide (LPS) was used in our study. Wild-type (WT) rats and PINK1 knockout (PINK1KO) rats, respectively, were divided into four groups: the control, LPS, Znpp+LPS, and Hemin+LPS groups. Rats were sacrificed 6 h after intraperitoneal injecting LPS to assess renal function, oxidative stress, and inflammation by plasma. Mitochondrial dynamics, morphology, and pyroptosis were evaluated by histological examinations. Results. In the rats with LPS-induced endotoxemia, the expression of HO-1 and PINK1 were upregulated at both mRNA and protein levels. These rats also exhibited inflammatory response, oxidative stress, mitochondrial fission, pyroptosis, and decreased renal function. After upregulating HO-1 in normal rats, pyroptosis was inhibited; mitochondrial fission and inflammatory response to oxidative stress were decreased; and the renal function was improved. The effects were reversed by adding Znpp (a type of HO-1 inhibitor). Finally, after PINK1 knockout, there is no statistical difference in the LPS-treated group and Hemin or Znpp pretreated group. Conclusions. HO-1 inhibits inflammation response and oxidative stress and regulates mitochondria fusion/fission to inhibit pyroptosis, which can alleviate endotoxin-induced AKI by PINK1.

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