Cobalt Chloride Upregulates Impaired HIF-1α Expression to Restore Sevoflurane Post-conditioning-Dependent Myocardial Protection in Diabetic Rats

Interactive Effects of Obesity and Hypertension on Patterns of Hair Essential Trace Element and Mineral Content in Adult Women

The objective of the present study was to evaluate potential similar patterns and interactive effects of obesity and hypertension on hair essential trace element and mineral content in adult women. In this cross-sectional study, a total of 607 adult women divided into controls (n = 101), groups with obesity without hypertension (n = 199), hypertension without obesity (n = 143), and both obesity and hypertension (n = 164) were included in the study. Assessment of hair mineral and trace element levels was performed by inductively-coupled plasma mass-spectrometry. Hair Ca, Mg, Co, and Mn levels in women with obesity, hypertension, and both diseases were significantly lower, compared to controls. Hair Mg levels in women with obesity and hypertension were significantly lower, whereas hair Na and K were found to be higher when compared to other groups. Hair Fe and V content in obese patients was lower than in other groups. Obesity was associated with lower hair Cu levels, whereas patients with hypertension had higher hair Cu content. Hypertension was also associated with higher hair Cr and Se content irrespective of body weight. Hair Zn levels in obese women with and without hypertension were significantly lower than those in healthy controls and normal-weight women with hypertension. In multiple regression models hair Mg was considered as a significant negative predictor of both systolic and diastolic blood pressure values. The observed alterations in hair trace element and mineral content provide an additional link between obesity and hypertension, although further detailed studies are required.

Cobalt-containing borate bioactive glass fibers for treatment of diabetic wound

Impaired angiogenesis is one of the predominant reasons for non-healing diabetic wounds. Cobalt is well known for its capacity to induce angiogenesis by stabilizing hypoxia-inducible factor-1α (HIF-1α) and subsequently inducing the production of vascular endothelial growth factor (VEGF). In this study, Co-containing borate bioactive glasses and their derived fibers were fabricated by partially replacing CaO in 1393B3 borate glass with CoO. Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) analyses were performed to characterize the effect of Co incorporation on the glass structure, and the results showed that the substitution promoted the transformation of [BO3] into [BO4] units, which endow the glass with higher chemical durability and lower reaction rate with the simulated body fluid (SBF), thereby achieving sustained and controlled Co2+ ion release. In vitro biological assays were performed to assess the angiogenic potential of the Co-containing borate glass fibers. It was found that the released Co2+ ion significantly enhanced the proliferation, migration and tube formation of the Human Umbilical Vein Endothelial Cells (HUVECs) by upregulating the expression of angiogenesis-related proteins such as HIF-1α and VEGF. Finally. In vivo results demonstrated that the Co-containing fibers accelerated full-thickness skin wound healing in streptozotocin (STZ)-induced diabetic rat model by promoting angiogenesis and re-epithelialization.

The Intriguing Role of Hypoxia-Inducible Factor in Myocardial Ischemia and Reperfusion: A Comprehensive Review

Hypoxia-inducible factors (HIFs) play a crucial role in cellular responses to low oxygen levels during myocardial ischemia and reperfusion injury. HIF stabilizers, originally developed for treating renal anemia, may offer cardiac protection in this context. This narrative review examines the molecular mechanisms governing HIF activation and function, as well as the pathways involved in cell protection. Furthermore, we analyze the distinct cellular roles of HIFs in myocardial ischemia and reperfusion. We also explore potential therapies targeting HIFs, emphasizing their possible benefits and limitations. Finally, we discuss the challenges and opportunities in this research area, underscoring the need for continued investigation to fully realize the therapeutic potential of HIF modulation in managing this complex condition.

Cobalt chloride postconditioning as myoprotective therapy in cardiac ischemia-reperfusion

Since damage induced by ischemia-reperfusion (I/R) involves alterations in Ca²⁺ homeostasis and is reduced by ischemic postconditioning (IP) and that CoCl₂ can trigger changes resembling the response to a hypoxic event in normoxia and its blockade on Ca²⁺ current in heart muscle, our aim was to evaluate CoCl₂ as an IP therapeutic tool. Mechanic and energetic parameters of isolated and arterially perfused male Wistar rat heart ventricles were simultaneously analyzed in a model of I/R in which 0.23 mmol/L CoCl₂ was introduced upon reperfusion and kept or withdrawn after 20 min or introduced after 20 min of reperfusion. The presence of CoCl₂ did not affect diastolic pressure but increased post-ischemic contractile recovery, which peaked at 20 min and decreased at the end of reperfusion. This decrease was prevented when CoCl₂ was removed at 20 min of reperfusion. Total heat release increased throughout reperfusion, while economy increased between 15 and 25 min. No effect was observed when CoCl₂ was introduced at 20 min of reperfusion. In addition, both the area under the contracture curve evoked by 10 mmol/L caffeine-36 mmol/L Na⁺ and the contracture tension relaxation rate were higher with CoCl₂.Furthermore, CoCl₂ decreased the number of arrhythmias during reperfusion and the ventricular damaged area. The presence of CoCl₂ in reperfusion induces cardioprotection consistent with the improvement in cellular calcium handling. The use of CoCl₂ constitutes a potential cardioprotective tool of clinical relevance.

Sevoflurane prevents pulmonary vascular remodeling and right ventricular dysfunction in pulmonary arterial hypertension in rats

BACKGROUND

The cardioprotective properties of sevoflurane have been reported in studies of the left ventricle. However, whether this volatile anesthetic would also be beneficial for pulmonary vascular remodeling and associated right ventricular hypertrophy (RVH) remained to be explored. Here, we investigated the potential benefit of sevoflurane to right heart function in experimental pulmonary arterial hypertension (PAH).

METHODS

Adult Wistar rats received one dose peritoneal injection of monocrotaline (MCT, 60 mg/kg) or the equal volume of normal saline. Two weeks later, rats were treated with sevoflurane or sham exposure. PAH status and cardiac function were assessed by echocardiography weekly, and the body weight (BW) was monitored every week. After 6 weeks of exercise, Fulton's index calculation, histological observation, IL-6 and TNF-α immunohistochemical analyses, evaluation of MDA, SOD and GSH-Px levels and NF-κB and MAPK active determination were performed in lung and RV tissue samples.

RESULTS

MCT induced pulmonary vascular remodeling, RVH, increased Fulton's index (P<0.01), and right ventricular failure (RVF) in rats. Animals inhaled sevoflurane had an increased cardiac output (P<0.05) and lower incidence of RVF (P<0.05). Also, these animals had a reduced RVEDD, RVWTd and PAID (P<0.05), increased PV (P<0.05), reduced wall thickness and vascular wall area of pulmonary small vascular (vascular external diameter 50-150 um) (P<0.01), reduced RV fibrosis, and increased RV cardiomyocyte area (P<0.01). Furthermore, sevoflurane reduced IL-6 and TNF-α expression in lungs and heart (P<0.01), decreased level of MDA (P<0.01) and increased activity of SOD and GSH-Px (P<0.01). In addition, it decreased the activities of NF-κB and MAPK pathways (P<0.01).

CONCLUSION

Sevoflurane reduces pulmonary vascular remodeling and RVH in PAH induced by MCT in rats. This effect is likely due to down-regulation of inflammatory factors IL-6 and TNF-α, reduced level of oxidative stress and the inhibition of NF-κB and MAPK pathways.

Influence of cardiometabolic comorbidities on myocardial function, infarction, and cardioprotection: Role of cardiac redox signaling

The morbidity and mortality from cardiovascular diseases (CVD) remain high. Metabolic diseases such as obesity, hyperlipidemia, diabetes mellitus (DM), non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) as well as hypertension are the most common comorbidities in patients with CVD. These comorbidities result in increased myocardial oxidative stress, mainly from increased activity of nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, mitochondria as well as downregulation of antioxidant defense systems. Oxidative and nitrosative stress play an important role in ischemia/reperfusion injury and may account for increased susceptibility of the myocardium to infarction and myocardial dysfunction in the presence of the comorbidities. Thus, while early reperfusion represents the most favorable therapeutic strategy to prevent ischemia/reperfusion injury, redox therapeutic strategies may provide additive benefits, especially in patients with heart failure. While oxidative and nitrosative stress are harmful, controlled release of reactive oxygen species is however important for cardioprotective signaling. In this review we summarize the current data on the effect of hypertension and major cardiometabolic comorbidities such as obesity, hyperlipidemia, DM, NAFLD/NASH on cardiac redox homeostasis as well as on ischemia/reperfusion injury and cardioprotection. We also review and discuss the therapeutic interventions that may restore the redox imbalance in the diseased myocardium in the presence of these comorbidities.

Pharmacological postconditioning: a molecular aspect in ischemic injury

OBJECTIVE

Ischaemia/reperfusion (I/R) injury is defined as the damage to the tissue which is caused when blood supply returns to tissue after ischaemia. To protect the ischaemic tissue from irreversible injury, various protective agents have been studied but the benefits have not been clinically applicable due to monotargeting, low potency, late delivery or poor tolerability.

KEY FINDINGS

Strategies involving preconditioning or postconditioning can address the issues related to the failure of protective therapies. In principle, postconditioning (PoCo) is clinically more applicable in the conditions in which there is unannounced ischaemic event. Moreover, PoCo is an attractive beneficial strategy as it can be induced rapidly at the onset of reperfusion via series of brief I/R cycles following a major ischaemic event or it can be induced in a delayed manner. Various pharmacological postconditioning (pPoCo) mechanisms have been investigated systematically. Using different animal models, most of the studies on pPoCo have been carried out preclinically.

SUMMARY

However, there is a need for the optimization of the clinical protocols to quicken pPoCo clinical translation for future studies. This review summarizes the involvement of various receptors and signalling pathways in the protective mechanisms of pPoCo.

Deferoxamine Treatment Combined With Sevoflurane Postconditioning Attenuates Myocardial Ischemia-Reperfusion Injury by Restoring HIF-1/BNIP3-Mediated Mitochondrial Autophagy in GK Rats

Mitochondrial autophagy is involved in myocardial protection of sevoflurane postconditioning (SPostC) and in diabetic state this protective effect is weakened due to impaired HIF-1 signaling pathway. Previous studies have proved that deferoxamine (DFO) could activate impaired HIF-1α in diabetic state to restore the cardioprotective of sevoflurane, while the specific mechanism is unclear. This study aims to investigate whether HIF-1/BNIP3-mediated mitochondrial autophagy is involved in the restoration of sevoflurane postconditioning cardioprotection in diabetic state. Ischemia/reperfusion (I/R) model was established by ligating the anterior descending coronary artery and sevoflurane was administered at the first 15 min of reperfusion. Myocardial infarct size, mitochondrial ultrastructure and autophagosome, ATP content, mitochondrial membrane potential, ROS production, HIF-1α, BNIP3, LC3B-II, Beclin-1, P62, LAMP2 protein expression were detected 2 h after reperfusion, and cardiac function was evaluated by ultrasound at 24 h after reperfusion. Our results showed that with DFO treatment, SPostC up-regulated the expression of HIF-1α and BNIP3, thus reduced the expression of key autophagy proteins LC3B-II, Beclin-1, p62, and increased the expression of LAMP2. Furthermore, it reduced the accumulation of autophagosomes and ROS production, increased the content of ATP, and stabilized the membrane potential. Finally, the myocardial infarction size was reduced and cardiac function was improved. Taken together, DFO treatment combined with SPostC could alleviate myocardial ischemia reperfusion injury in diabetic rats by restoring and promoting HIF-1/BNIP3-mediated mitochondrial autophagy.

Carbon monoxide-releasing molecule-3 protects against cortical pyroptosis induced by hemorrhagic shock and resuscitation via mitochondrial regulation

OBJECTIVE

Carbon monoxide (CO) releasing molecule (CORM)-3, a water-soluble CORM, has protective effects against inflammatory and ischemia/reperfusion injury. We determined the effect of CORM-3 against neuronal pyroptosis in a model of hemorrhagic shock and resuscitation (HSR) in rats via mitochondrial regulation.

METHODS

Rats were treated with CORM-3 (4 mg/kg) in vitro after HSR. We measured cortical CO content 3-24 h after HSR; assessed neuronal pyroptosis, mitochondrial morphology, ROS production, and mitochondrial membrane potential at 12 h after HSR; and evaluated brain magnetic resonance imaging at 24 h after HSR and learning ability 30 days after HSR. We also measured soluble guanylate-cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signaling pathway activity using a blocker of sGC, NS2028, and ¹²⁵I-cGMP assay.

RESULTS

Among rats that underwent HSR, CORM-3-treated rats had more CO in the cortical tissue than sham- and iCORM-3-treated rats. CORM-3-treated rats had significantly less neuronal pyroptosis in the cortical tissue; higher sGC activity and cGMP content; lower ROS production; better mitochondrial morphology, function, and membrane potential; and enhanced learning/memory ability than HSR-treated rats. However, these neuroprotective effects of CORM-3 were partially inhibited by NS2028.

CONCLUSION

CORM-3 may alleviate neuronal pyroptosis and improve neurological recovery in HSR through mitochondrial regulation mediated by the sGC-cGMP pathway. Thus, CO administration could be a promising therapeutic strategy for hemorrhagic shock.

Infarct size-limiting effect of epoxyeicosatrienoic acid analog EET-B is mediated by hypoxia-inducible factor-1α via downregulation of prolyl hydroxylase 3

Epoxyeicosatrienoic acids (EETs) decrease cardiac ischemia-reperfusion injury; however, the mechanism of their protective effect remains elusive. Here, we investigated the cardioprotective action of a novel EET analog, EET-B, in reperfusion and the role of hypoxia-inducible factor (HIF)-1α in such action of EET-B. Adult male rats were subjected to 30 min of left coronary artery occlusion followed by 2 h of reperfusion. Administration of 14,15-EET (2.5 mg/kg) or EET-B (2.5 mg/kg) 5 min before reperfusion reduced infarct size expressed as a percentage of the area at risk from 64.3 ± 1.3% in control to 42.6 ± 1.9% and 46.0 ± 1.6%, respectively, and their coadministration did not provide any stronger effect. The 14,15-EET antagonist 14,15-epoxyeicosa-5( Z)-enoic acid (2.5 mg/kg) inhibited the infarct size-limiting effect of EET-B (62.5 ± 1.1%). Similarly, the HIF-1α inhibitors 2-methoxyestradiol (2.5 mg/kg) and acriflavine (2 mg/kg) completely abolished the cardioprotective effect of EET-B. In a separate set of experiments, the immunoreactivity of HIF-1α and its degrading enzyme prolyl hydroxylase domain protein 3 (PHD3) were analyzed in the ischemic areas and nonischemic septa. At the end of ischemia, the HIF-1α immunogenic signal markedly increased in the ischemic area compared with the septum (10.31 ± 0.78% vs. 0.34 ± 0.08%). After 20 min and 2 h of reperfusion, HIF-1α immunoreactivity decreased to 2.40 ± 0.48% and 1.85 ± 0.43%, respectively, in the controls. EET-B blunted the decrease of HIF-1α immunoreactivity (7.80 ± 0.69% and 6.44 ± 1.37%, respectively) and significantly reduced PHD3 immunogenic signal in ischemic tissue after reperfusion. In conclusion, EET-B provides an infarct size-limiting effect at reperfusion that is mediated by HIF-1α and downregulation of its degrading enzyme PHD3. NEW & NOTEWORTHY The present study shows that EET-B is an effective agonistic 14,15-epoxyeicosatrienoic acid analog, and its administration before reperfusion markedly reduced myocardial infarction in rats. Most importantly, we demonstrate that increased hypoxia-inducible factor-1α levels play a role in cardioprotection mediated by EET-B in reperfusion likely by mechanisms including downregulation of the hypoxia-inducible factor -1α-degrading enzyme prolyl hydroxylase domain protein 3.