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Ischemia-reperfusion (I-R) injury is damage caused by restoring blood flow into ischemic tissues or organs. This complex and characteristic lesion accelerates cell death induced by signaling pathways such as apoptosis, necrosis, and even ferroptosis. In addition to the direct association between I-R and the release of reactive oxygen species and reactive nitrogen species, it is involved in developing mitochondrial oxidative damage. Thus, its mechanism plays a critical role via reactive species scavenging, calcium overload modulation, electron transport chain blocking, mitochondrial permeability transition pore activation, or noncoding RNA transcription. Other receptors and molecules reduce tissue and organ damage caused by this pathology and other related diseases. These molecular targets have been gradually discovered and have essential roles in I-R resolution. Therefore, the current study is aimed at highlighting the importance of these discoveries. In this review, we inquire about the oxidative damage receptors that are relevant to reducing the damage induced by oxidative stress associated with I-R. Several complications on surgical techniques and pathology interventions do not mitigate the damage caused by I-R. Nevertheless, these therapies developed using alternative targets could work as coadjuvants in tissue transplants or I-R-related pathologies

Since the discovery of mitochondrial-derived peptides (MDP), their participation in cellular metabolism is no longer considered as the sole function of the mitochondria, but importance was also attached to its role as a source of protective factors of metabolic stress. These peptides are encoded in the mitochondrial genome and translated into the mitochondria or cytoplasm, to signal within the cell or be released and bind to membrane receptors. The objective of this work was explored and compare the frequency of MT-RNR1 and MT-RNR2 variants in sequences obtained from T2D individuals and control population. 213 different mitochondrial polymorphisms previously reported in the literature associated with T2D and cardiovascular diseases were analyzed. We can found three variants in the MT-RNR1 not related with MOTS-c coding sequence: m.1189T>C (rs28358571), m.1420T>C (rs111033356), and m.1438A>G (rs2001030); and secondly, three polymorphisms associated to MT-RNR2 m.2667T>C (rs878870626) related to humanin, m.1811A>G (rs28358576) in SHPL3 and m.3027T>C (rs199838004) in SHPL6 associated with statistical differences between the T2D and control group. All these findings were previously related to cardiovascular complications in literature and, as far as we know, relating for the first time in diabetic patients.

Breast cancer has an important incidence in the worldwide female population. Although alterations in the mitochondrial genome probably play an important role in carcinogenesis, the actual evidence is ambiguous and inconclusive. The purpose of the present work was to explore mitochondrial sequences of clinical cases with breast cancer from different origins and determine the polymorphisms associated. The search for complete and partial mtDNA sequences obtained from breast cancer patients and controls was performed in NCBI Genbank database. We identified 124 mtDNA sequences associated to breast cancer cases of which 86 were complete and 38 partial sequences. Of these 86 complete sequences, 52 belong to patients with a confirmed diagnosis of breast cancer and 34 sequences were obtained from healthy mammary tissue of the same patients used as controls. From mtDNA analysis, two polymorphisms with significative statistical differences were found in D130 in sequences analyzed: m.310del (rs869289246) in 34.6% (27/78) breast cancer cases and 61.7% (21/34) of controls; and m.315dup (rs369786048) in 60.2% (47/78) of breast cancer cases and 38.2% (13/34) of controls. Also, the variant m.16519T>C (rs3937033) was found in 59% of control sequences and 52% of breast cancer sequences with a significant statistical difference. Polymorphic changes are evolutionarily related to haplogroup H of Indo-European and Euro Asiatic origins, however, were found in all non-European sequences with breast cancer.

Glioblastoma is the most frequent primary tumor in the human brain. Glioblastoma cells express aromatase and the classic estrogen receptors ERα and ERβ and can produce estrogens that promote tumor growth. The membrane G protein-coupled estrogen receptor (GPER) also plays a significant role in numerous types of cancer; its participation in glioblastoma tumor development is not entirely known. The present study investigated the effect of the agonists [17β-estradiol (E2) and G1] and antagonist (G15) of GPER on proliferation and apoptosis of C6 glioblastoma cells. GPER expression was evaluated by immunofluorescence, western blotting and reverse transcription-quantitative PCR. Cell proliferation was determined using Ki67 immunopositivity. Cell viability was examined using the MTT assay and apoptosis using caspase-3 immunostaining and ELISA. C6 cells express GPER, and the immunopositivity increased after exposure to E2, G1, or their combination. GPER protein expression increased after treatment with E2 combined with G1. However, GPER mRNA expression decreased in treated cells compared with control. The percentage of Ki67 immunopositive C6 cells increased under the effect of E2 in combination with G1 or G1 alone. G15 significantly reduced Ki67 immunopositivity. Pearson's correlation analysis revealed a positive relationship between GPER and Ki67 immunopositivity across the study conditions. Additionally, the MTT assay showed a significant reduction in C6 cell viability after G15 treatment, alone or in combination with G1. The exposure to G15 increased the percentage of caspase-3 immunopositivity cells and caspase-3 levels. Pearson's correlation analysis demonstrated a negative correlation between GPER and caspase-3 immunopositivity across the study conditions. Glioblastoma C6 cells express GPER, and this receptor modulates cell proliferation and apoptosis. The GPER agonists E2 and G1 favored cell proliferation; meanwhile, the antagonist G15 reduced cell proliferation, viability and favored apoptosis. Therefore, GPER may be used as a biomarker of glioblastoma and as a target to develop new therapeutic strategies for glioblastoma treatment.

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by an abnormal CAG repeat expansion in the huntingtin gene coding for a protein with an elongated polyglutamine sequence. HD patients present choreiform movements, which are caused by the loss of neurons in the striatum and cerebral cortex. Previous reports indicate that the absence of the aryl hydrocarbon receptor (AhR) protects mice from excitotoxic insults and increases the transcription of neurotrophic factors. Based on these data, we evaluated the effects of the lack of the AhR on a mice model of HD, generating a double transgenic mouse, expressing human mutated huntingtin (R6/1 mice) and knockout for the AhR. Our results show that the body weight of 30-week-old double transgenic mice is similar to that of R6/1 mice; however, feet clasping, an indicative of neuronal damage in the R6/1 animals, was not observed. In addition, motor coordination and ambulatory behavior in double transgenic mice did not deteriorate over time as occur in the R6/1 mice. Moreover, the anxiety behavior of double transgenic mice was similar to wild type mice. Interestingly, astrogliosis is also reduced in the double transgenic mice. The present data demonstrate that the complete loss of the AhR reduces the motor and behavioral deterioration observed in R6/1 mice, suggesting that the pharmacological modulation of the AhR could be a therapeutic target in HD.

NMDA and AMPA receptors are thought to be responsible for Ca(++) influx during glutamate-induced excitotoxicity and, therefore, hippocampal neuronal death. We assessed whether excitotoxicity induced by neonatal treatment with monosodium glutamate in rats at postnatal age of 1, 3, 5, and 7 modifies the hippocampal expression of the NMDAR subunit NR1 and the AMPAR subunits GluR1/GluR2 at postnatal days 8, 10, 12, and 14. We also assessed the involvement of MAPK signaling by using the p38 inhibitor SB203580. Our results showed that monosodium glutamate induces neuronal death and alters the expression of the subunits evaluated in the hippocampus at all ages studied, which could be prevented by SB203580 treatment.Furthermore, expression of the NRSF gene silencing factor also increased in response to excitotoxicity, suggesting a relationship in suppressing GluR2-expression, which was regulated by the p38-MAPK pathway inhibitor SB203580. This result suggests that selectively blocking the pro-death signaling pathway may reduce neuronal death in some neurodegenerative diseases in which these neurotoxic processes are present and produce major clinical benefits in the treatment of these pathologies.

Erythropoietin in the nervous system is a potential neuroprotective factor for cerebral ischemic damage due to specific-binding to the erythropoietin receptor, which is associated with survival mechanisms. However, the role of its receptor is unclear. Thus, this work assessed whether a low dose (500 UI/Kg) of intranasal recombinant human erythropoietin administered 3 h after ischemia induced changes in the activation of its receptor at the Tyr456-phosphorylated site in ischemic hippocampi in rats. The results showed that recombinant human erythropoietin after injury maintained cell survival and was associated with an increase in receptor phosphorylation at the Tyr456 site as an initial signaling step, which correlated with a neuroprotective effect.

Epilepsy is a disorder characterised by recurrent seizures and molecular events, including the activation of early expression genes and the post-translational modifications of functional proteins. These events lead to changes in neurogenesis, mossy fibre sprouting, network reorganisation and neuronal death. The role of these events is currently a matter of great debate, especially as they relate to protection, repair, or further brain injury. In recent years, accumulating data have supported the idea that erythropoietin (EPO) regulates biological processes including neuroprotection and neurogenesis in several diseases, such as epilepsy. This review summarises the role of EPO in some of the molecular mechanisms involved in these events that could direct a more detailed approach for its use as a therapeutic alternative in reducing epileptic seizures.