scholarly journals Key Role of Cytochrome C for Apoptosis Detection Using Raman Microimaging in an Animal Model of Brain Ischemia with Insulin Treatment

2019 ◽  
Vol 73 (10) ◽  
pp. 1208-1217 ◽  
Author(s):  
Vanessa Russo ◽  
Patrizio Candeloro ◽  
Natalia Malara ◽  
Gerardo Perozziello ◽  
Michelangelo Iannone ◽  
...  

Brain ischemia represents a leading cause of death and disability in industrialized countries. To date, therapeutic intervention is largely unsatisfactory and novel strategies are required for getting better protection of neurons injured by cerebral blood flow restriction. Recent evidence suggests that brain insulin leads to protection of neuronal population undergoing apoptotic cell death via modulation of oxidative stress and mitochondrial cytochrome c (CytC), an effect to be better clarified. In this work, we investigate on the effect of insulin given intracerebroventricular (ICV) before inducing a transient global ischemia by bilateral occlusion of the common carotid arteries (BCCO) in Mongolian gerbils (MG). The transient (3 min) global ischemia in MG is observed to produce neurodegenerative effect mainly into CA3 hippocampal region, 72 h after cerebral blood restriction. Intracerebroventricular microinfusion of insulin significantly prevents the apoptosis of CA3 hippocampal neurons. Histological observation, after hematoxylin and eosin staining, puts in evidence the neuroprotective role of insulin, but Raman microimaging provides a clearer insight in the CytC mechanism underlying the apoptotic process. Above all, CytC has been revealed to be an outstanding, innate Raman marker for monitoring the cells status, thanks to its resonant scattering at 530 nm of incident wavelength and to its crucial role in the early stages of cells apoptosis. These data support the hypothesis of an insulin-dependent neuroprotection and antiapoptotic mechanism occurring in the brain of MG undergoing transient brain ischemia. The observed effects occurred without any peripheral change on serum glucose levels, suggesting an alternative mechanism of insulin-induced neuroprotection.

1996 ◽  
Vol 16 (6) ◽  
pp. 1137-1142 ◽  
Author(s):  
Toshiho Ohtsuki ◽  
Christi A. Ruetzler ◽  
Kaoru Tasaki ◽  
John M. Hallenbeck

A series of experiments was performed to determine the role of interleukin (IL)-1 in the induction of tolerance to global ischemia in Mongolian gerbils. In Group I, a 2-min “preconditioning” ischemia protected CA1 hippocampal neurons in gerbils subjected to 3.5 min ischemia 3 days later. CA1 neuronal density was: sham, 171 ± 3/mm; 3.5 min ischemia, 30 ± 30/mm; 2 and 3.5 min ischemia 162 ± 6/mm. Experiments in Group II addressed the role of IL-1 in the induction of tolerance by sublethal ischemia. Arterial IL-1α and IL-Iβ became elevated between 1 and 3 days after a 2-min ischemic exposure. IL-1α was: sham, 6.4 ± 0.6 ng/ml; and 2-day, 10.2 ± 1.2 ng/ml. IL-1β was: sham, 6.4 ± 0.5 ng/ml; and 2-day, 17.3 ± 2 ng/ml. Recombinant human IL-1 receptor antagonist (IL-1ra) i.p. blocked ischemic tolerance induction by 2-min preconditioning ischemia: 2-min ischemia + vehicle, 162 ± 6/mm; and 2-min ischemia + IL-1ra, 67 ± 17/mm. Experiments in Group III assessed the capacity of IL-1 to induce tolerance to brain ischemia. IL-1α i.p. (0, 10, 20 μg/kg) for 3 days prior to 3.5-min forebrain ischemia provided significant CA1 neuroprotection in a dose-dependent manner: 2 ± 2, 68 ± 83, and 129 ± 42/mm, respectively. IL-1β (15 μg/kg) in combination with either IL-1ra (100 mg/kg) or IL-1ra vehicle i.p. on the same schedule demonstrated a significant CA1 neuroprotection that could be nullified by IL-1ra: IL-1β + IL-1ra vehicle, 153 ± 16/mm; and IL-1β + IL-1ra, 67 ± 36/mm. Recognition that tolerance arises from stimulation of a known receptor (IL-1RI) permits molecular analysis of the intracellular signaling that is critical for production of that state.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1231 ◽  
Author(s):  
Kinga Rusinek ◽  
Przemysław Sołek ◽  
Anna Tabęcka-Łonczyńska ◽  
Marek Koziorowski ◽  
Jennifer Mytych

Neuroinflammation is defined as the activation of the brain’s innate immune system in response to an inflammatory challenge and is considered to be a prominent feature of neurodegenerative diseases. The contribution of overactivated neuroglial cells to neuroinflammation and neurodegenerative disorders is well documented, however, the role of hippocampal neurons in the neuroinflammatory process remains fragmentary. In this study, we show for the first time, that klotho acts as a signal transducer between pro-survival and pro-apoptotic crosstalk mediated by ER stress in HT-22 hippocampal neuronal cells during LPS challenge. In control HT-22 cells, LPS treatment results in activation of the IRE1α-p38 MAPK pathway leading to increased secretion of anti-inflammatory IL-10, and thus, providing adaptation mechanism. On the other hand, in klotho-deficient HT-22 cells, LPS induces oxi-nitrosative stress and genomic instability associated with telomere dysfunctions leading to p53/p21-mediated cell cycle arrest and, in consequence, to ER stress, inflammation as well as of apoptotic cell death. Therefore, these results indicate that klotho serves as a part of the cellular defense mechanism engaged in the protection of neuronal cells against LPS-mediated neuroinflammation, emerging issues linked with neurodegenerative disorders.


2003 ◽  
Vol 106 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Andrea B. Page ◽  
Cheri R. Owen ◽  
Rita Kumar ◽  
Janet M. Miller ◽  
José A. Rafols ◽  
...  

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.


2020 ◽  
Author(s):  
Yu-Chien Hung ◽  
Kuan-Lin Huang ◽  
Po-Lin Chen ◽  
Han-Yi Lin ◽  
Huei-An Lu ◽  
...  

2020 ◽  
Vol 25 (40) ◽  
pp. 4310-4317 ◽  
Author(s):  
Lichao Sun ◽  
Shouqin Ji ◽  
Jihong Xing

Background/Aims: Central pro-inflammatory cytokine (PIC) signal is involved in neurological deficits after transient global ischemia induced by cardiac arrest (CA). The present study was to examine the role of microRNA- 155 (miR-155) in regulating IL-1β, IL-6 and TNF-α in the hippocampus of rats with induction of CA. We further examined the levels of products of oxidative stress 8-isoprostaglandin F2α (8-iso PGF2α, indication of oxidative stress); and 8-hydroxy-2’-deoxyguanosine (8-OHdG, indication of protein oxidation) after cerebral inhibition of miR-155. Methods: CA was induced by asphyxia and followed by cardiopulmonary resuscitation in rats. ELISA and western blot analysis were used to determine the levels of PICs and products of oxidative stress; and the protein expression of NADPH oxidase (NOXs) in the hippocampus. In addition, neurological severity score and brain edema were examined to assess neurological functions. Results: We observed amplification of IL-1β, IL-6 and TNF-α along with 8-iso PGF2α and 8-OHdG in the hippocampus of CA rats. Cerebral administration of miR-155 inhibitor diminished upregulation of PICs in the hippocampus. This also attenuated products of oxidative stress and upregulation of NOX4. Notably, inhibition of miR-155 improved neurological severity score and brain edema and this was linked to signal pathways of PIC and oxidative stress. Conclusion: We showed the significant role of blocking miR-155 signal in improving the neurological function in CA rats likely via inhibition of signal pathways of neuroinflammation and oxidative stress, suggesting that miR-155 may be a target in preventing and/or alleviating development of the impaired neurological functions during CA-evoked global cerebral ischemia.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 639
Author(s):  
Domenico Ribatti ◽  
Francesco Pezzella

Angiogenesis is a crucial event in the physiological processes of embryogenesis and wound healing. During malignant transformation, dysregulation of angiogenesis leads to the formation of a vascular network of tumor-associated capillaries promoting survival and proliferation of the tumor cells. Starting with the hypothesis formulated by Judah Folkman that tumor growth is angiogenesis-dependent, this area of research has a solid scientific foundation and inhibition of angiogenesis is a major area of therapeutic development for the treatment of cancer. Over this period numerous authors published data of vascularization of tumors, which attributed the cause of neo-vascularization to various factors including inflammation, release of angiogenic cytokines, vasodilatation, and increased tumor metabolism. More recently, it has been demonstrated that tumor vasculature is not necessarily derived by endothelial cell proliferation and sprouting of new capillaries, but alternative vascularization mechanisms have been described, namely vascular co-option and vasculogenic mimicry. In this article, we have analyzed the mechanisms involved in tumor vascularization in association with classical angiogenesis, including post-natal vasculogenesis, intussusceptive microvascular growth, vascular co-option, and vasculogenic mimicry. We have also discussed the role of these alternative mechanism in resistance to anti-angiogenic therapy and potential therapeutic approaches to overcome resistance.


Pharmacology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Zhongyuan Piao ◽  
Lin Song ◽  
Lifen Yao ◽  
Limei Zhang ◽  
Yichan Lu

Introduction: Schisandrin which is derived from Schisandra chinensis has shown multiple pharmacological effects on various diseases including Alzheimer’s disease (AD). It is demonstrated that mitochondrial dysfunction plays an essential role in the pathogenesis of neurodegenerative disorders. Objective: Our study aims to investigate the effects of schisandrin on mitochondrial functions and metabolisms in primary hippocampal neurons. Methods: In our study, rat primary hippocampal neurons were isolated and treated with indicated dose of amyloid β1–42 (Aβ1–42) oligomer to establish a cell model of AD in vitro. Schisandrin (2 μg/mL) was further subjected to test its effects on mitochondrial function, energy metabolism, mitochondrial biogenesis, and dynamics in the Aβ1–42 oligomer-treated neurons. Results and Conclusions: Our findings indicated that schisandrin significantly alleviated the Aβ1–42 oligomer-induced loss of mitochondrial membrane potential and impaired cytochrome c oxidase activity. Additionally, the opening of mitochondrial permeability transition pore and release of cytochrome c were highly restricted with schisandrin treatment. Alterations in cell viability, ATP production, citrate synthase activity, and the expressions of glycolysis-related enzymes demonstrated the relief of defective energy metabolism in Aβ-treated neurons after the treatment of schisandrin. For mitochondrial biogenesis, elevated expression of peroxisome proliferator-activated receptor γ coactivator along with promoted mitochondrial mass was found in schisandrin-treated cells. The imbalance in the cycle of fusion and fission was also remarkably restored by schisandrin. In summary, this study provides novel mechanisms for the protective effect of schisandrin on mitochondria-related functions.


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