Lipidomics Provides New Insight into Pathogenesis and Therapeutic Targets of the Ischemia-Reperfusion Injury

Cardiolipin in myocardial ischaemia-reperfusion injury: From molecular mechanisms to clinical strategies

Myocardial reperfusion injury occurs when blood flow is restored after ischemia, an essential process to salvage ischemic tissue. However, this phenomenon is intricate, characterized by various harmful effects. Tissue damage in ischemia-reperfusion injury arises from various factors, including the production of reactive oxygen species, the sequestration of proinflammatory immune cells in ischemic tissues, the induction of endoplasmic reticulum stress, and the occurrence of postischemic capillary no-reflow. Secretory phospholipase A2 (sPLA2) plays a crucial role in the eicosanoid pathway by releasing free arachidonic acid from membrane phospholipids' sn-2 position. This liberated arachidonic acid serves as a substrate for various eicosanoid biosynthetic enzymes, including cyclooxygenases, lipoxygenases, and cytochromes P450, ultimately resulting in inflammation and an elevated risk of reperfusion injury. Therefore, the activation of sPLA2 directly correlates with the heightened and accelerated damage observed in myocardial ischemia-reperfusion injury (MIRI). Presently, clinical trials are in progress for medications aimed at sPLA2, presenting promising avenues for intervention. Cardiolipin (CL) plays a crucial role in maintaining mitochondrial function, and its alteration is closely linked to mitochondrial dysfunction observed in MIRI. This paper provides a critical analysis of CL modifications concerning mitochondrial dysfunction in MIRI, along with its associated molecular mechanisms. Additionally, it delves into various pharmacological approaches to prevent or alleviate MIRI, whether by directly targeting mitochondrial CL or through indirect means.

The ability of microRNAs to regulate the immune response in ischemia/reperfusion inflammatory pathways

MicroRNAs play a crucial role in regulating the immune responses induced by ischemia/reperfusion injury. Through their ability to modulate gene expression, microRNAs adjust immune responses by targeting specific genes and signaling pathways. This review focuses on the impact of microRNAs on the inflammatory pathways triggered during ischemia/reperfusion injury and highlights their ability to modulate inflammation, playing a critical role in the pathophysiology of ischemia/reperfusion injury. Dysregulated expression of microRNAs contributes to the pathogenesis of ischemia/reperfusion injury, therefore targeting specific microRNAs offers an opportunity to restore immune homeostasis and improve patient outcomes. Understanding the complex network of immunoregulatory microRNAs could provide novel therapeutic interventions aimed at attenuating excessive inflammation and preserving tissue integrity.

Lipid droplets, autophagy, and ER stress as key (survival) pathways during ischemia-reperfusion of transplanted grafts

Ischemia-reperfusion injury is an event concerning any organ under a procedure of transplantation. The early result of ischemia is hypoxia, which causes malfunction of mitochondria and decrease in cellular ATP. This leads to disruption of cellular metabolism. Reperfusion also results in cell damage due to reoxygenation and increased production of reactive oxygen species, and later by induced inflammation. In damaged and hypoxic cells, the endoplasmic reticulum (ER) stress pathway is activated by increased amount of damaged or misfolded proteins, accumulation of free fatty acids and other lipids due to inability of their oxidation (lipotoxicity). ER stress is an adaptive response and a survival pathway, however, its prolonged activity eventually lead to induction of apoptosis. Sustaining cell functionality in stress conditions is a great challenge for transplant surgeons as it is crucial for maintaining a desired level of graft vitality. Pathways counteracting negative consequences of ischemia-reperfusion are autophagy and lipid droplets (LD) metabolism. Autophagy remove damaged organelles and molecules driving them to lysosomes, digested simpler compounds are energy source for the cell. Mitophagy and ER-phagy results in improvement of cell energetic balance and alleviation of ER stress. This is important in sustaining metabolic homeostasis and thus cell survival. LD metabolism is connected with autophagy as LD are degraded by lipophagy, a source of free fatty acids and glycerol-thus autophagy and LD can readily remove lipotoxic compounds in the cell. In conclusion, monitoring and pharmaceutic regulation of those pathways during transplantation procedure might result in increased/improved vitality of transplanted organ.

Dexmedetomidine attenuates myocardial ischemia-reperfusion injury in hyperlipidemic rats by inhibiting inflammation, oxidative stress and NF-κB

The present study was conducted to determine the protective effect of Dexmedetomidine (DEX) in myocardial ischemia-reperfusion injury in hyperlipidemic rats. Towards this, the effect of DEX was first evaluated on the infarct size and the histopathology of cardiac tissues using TTC and H and E staining, and it was found that DEX significantly improved the infarct size and architecture of the myocardial tissues following the I/R injury. DEX also showed significant improvement in various examined hemodynamic parameters (e.g., LVSP, and ± dp/dtmax ) in a dose-dependent manner. The lipid profile (LDL, VLDL, TC, TG, and HDL level) of the rats were also found significantly improved in DEX-treated rats. The level of various pro-inflammatory cytokines (IL-1β, IL-6, IL-10, IL-17, and TNF-α), cardiac injury (CK, CK-MB, Troponin I AST, ALT, and LDH), and oxidative stress (MDA, SOD, and GSH) biomarkers were also found to be restored near to the normal in DEX-treated group. It has been found that DEX also significantly reduces apoptosis of rat cardiomyocytes. In western blot analysis, DEX showed a significant reduction in the activation of NF-κB. In conclusion, our study demonstrated the protective effect of Dexmedetomidine in myocardial ischemia-reperfusion injury in hyperlipidemic rats possibly via amelioration of oxidative stress, and inflammation apoptosis.

Altered Blood Molecular Markers of Cardiovascular Function in Rats after Intrauterine Hypoxia and Drug Therapy

Many children and adults who have suffered prenatal hypoxia at an early age develop many serious diseases. This disease is an actual problem of pediatric cardiology and little studied. The aim was to analyze the cardioprotective effect of L-arginine, Thiotriazoline, Angioline, and Mildronate on the cardiovascular system of rats after prenatal hypoxia. Methods: The experiments were carried out on 50 female white rats; intraperitoneal sodium nitrite solution was administered daily to pregnant female rats after 16 days at a dose of 50 mg/kg. Control pregnant rats received saline. The offspring were divided into groups: 1-intact; 2-the control group of rat pups after PH, treated daily with physiological saline; 3-six groups of rat pups after PH, treated daily from the 1st to the 30th day after birth. Heat shock protein HSP70 was determined by enzyme immunoassay, ST2 Nitrotyrosine, and eNOS was observed by ELISA. Results: Angiolin showed a high cardioprotective effect even a month after discontinuation of the drug, and after introduction, the highest decrease in ST2 nitrotyrosine was revealed. Thiotriazoline and L-arginine have an antioxidant effect and a positive effect on eNOS expression, increasing the concentration of HSP70. Mildronate increased the expression of eNOS and the concentration of HSP70 in the blood of experimental rats after a course of administration, but did not show an antioxidant effect and did not reduce the concentration of nitrotyrosine. The results obtained indicate the cardioprotective effect of modulators of the NO system with different mechanisms of action of drugs after prenatal hypoxia.

Mechanisms of Prostate Cancer Cells Survival and Their Therapeutic Targeting

Prostate cancer (PCa) is today the second most common cancer in the world, with almost 400,000 deaths annually. Multiple factors are involved in the etiology of PCa, such as older age, genetic mutations, ethnicity, diet, or inflammation. Modern treatment of PCa involves radical surgical treatment or radiation therapy in the stages when the tumor is limited to the prostate. When metastases develop, the standard procedure is androgen deprivation therapy, which aims to reduce the level of circulating testosterone, which is achieved by surgical or medical castration. However, when the level of testosterone decreases to the castration level, the tumor cells adapt to the new conditions through different mechanisms, which enable their unhindered growth and survival, despite the therapy. New knowledge about the biology of the so-called of castration-resistant PCa and the way it adapts to therapy will enable the development of new drugs, whose goal is to prolong the survival of patients with this stage of the disease, which will be discussed in this review.

Lipidomic changes in the liver of beagle dogs associated with Toxocara canis infection

A global lipidomic analysis using liquid chromatography–tandem mass spectrometry was performed on the liver of beagle dogs infected with Toxocara canis to profile hepatic lipid species at 12 h post-infection (hpi), 24 hpi, and 36 days post-infection (dpi). This analysis identified six categories and 42 subclasses of lipids, including 173, 64, and 116 differentially abundant lipid species at 12 hpi, 24 hpi, and 36 dpi, respectively. Many of the identified lysophospholipids, such as lysophosphatidylglycerol, lysophosphatidylserine, and lysophosphatidylcholine, may contribute to the migration and development of T. canis during the early infection stage. Pathway analysis revealed significant alterations of several immune-inflammatory pathways, such as the B-cell receptor signaling pathway, the NF-kappa B signaling pathway, and the C-type lectin receptor signaling pathway at 12 and 24 hpi. These findings demonstrate the value of lipidomic profiling in revealing the extent of changes in the composition and abundance of hepatic lipidome caused by T. canis infection and their relevance to the pathophysiology of toxocariasis in beagle dogs.

Lipidomics: An excellent tool for chronic disease detection

It has been known as almost all the cells consists a lipid molecule which has a considerable impact in various biological processes. Lipids have been investigated with a potential role for the formation of cellular membrane and thereby maintaining the structural integrity. Omics has placed as a combined technologies utilized for an exploaration of mechanistic actions in several kinds of molecules that make up the cells of an organism. Lipidomics has been recognized as a newly emerged branch of omics technology. This technology has the captivating factors to classify and characterize almost all the cellular lipids with the help of various analytical techniques and computational biological plateform. In lipidomics studies, structural display of several lipid biomarkers could also be analyzed and considered for actual disease diagnosis procedures. This could also replace certain traditional diagnostics method at all over the globe. Our review focuses how important this lipidomics particularly in disease diagnosis and also covers various analytical techniques and computational methods or bioinformatics tools in for the diagnosis of disease. In addtion, we also pinponted the possible role of lipids in several kinds of cellular disorders including cancer, neurodegenerative diseases, cardiovascular diseases, diabetes and obesity in human population. .

Immunometabolic rewiring of tubular epithelial cells in kidney disease

Kidney tubular epithelial cells (TECs) have a crucial role in the damage and repair response to acute and chronic injury. To adequately respond to constant changes in the environment, TECs have considerable bioenergetic needs, which are supported by metabolic pathways. Although little is known about TEC metabolism, a number of ground-breaking studies have shown that defective glucose metabolism or fatty acid oxidation in the kidney has a key role in the response to kidney injury. Imbalanced use of these metabolic pathways can predispose TECs to apoptosis and dedifferentiation, and contribute to lipotoxicity and kidney injury. The accumulation of lipids and aberrant metabolic adaptations of TECs during kidney disease can also be driven by receptors of the innate immune system. Similar to their actions in innate immune cells, pattern recognition receptors regulate the metabolic rewiring of TECs, causing cellular dysfunction and lipid accumulation. TECs should therefore be considered a specialized cell type - like cells of the innate immune system - that is subject to regulation by immunometabolism. Targeting energy metabolism in TECs could represent a strategy for metabolically reprogramming the kidney and promoting kidney repair.

Transition of acute kidney injury to chronic kidney disease: role of metabolic reprogramming

Acute kidney injury (AKI) is a global public health concern associated with high morbidity and mortality. Although advances in medical management have improved the in-hospital mortality of severe AKI patients, the renal prognosis for AKI patients in the later period is not encouraging. Recent epidemiological investigations have indicated that AKI significantly increases the risk for the development of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the future, further contributing to the economic burden on health care systems. The transition of AKI to CKD is complex and often involves multiple mechanisms. Recent studies have suggested that renal tubular epithelial cells (TECs) are more prone to metabolic reprogramming during AKI, in which the metabolic process in the TECs shifts from fatty acid β-oxidation (FAO) to glycolysis due to hypoxia, mitochondrial dysfunction, and disordered nutrient-sensing pathways. This change is a double-edged role. On the one hand, enhanced glycolysis acts as a compensation pathway for ATP production; on the other hand, long-term shut down of FAO and enhanced glycolysis lead to inflammation, lipid accumulation, and fibrosis, contributing to the transition of AKI to CKD. This review discusses developments and therapies focused on the metabolic reprogramming of TECs during AKI, and the emerging questions in this evolving field.

NMMHC IIA triggered lipid metabolize reprogramming resulting in vascular endothelial cellular tight junction injury

BACKGROUND AND PURPOSE

Nonmuscle myosin heavy chain IIA, played an essential role in the promotion of tight junction injury in vascular endothelial cells under oxygen glucose deprivation condition. Rat microvascular endothelial cells had been confirmed to have the susceptibility to ox-LDL stimulation under OGD condition. We proposed the hypothesis that lipid metabolic reprogramming might be the root cause for damage to RBMCs tight junction.

METHODS

Untargeted shotgun and targeted lipid metabolomics mass spectrometry approaches combined with principal component analysis was applied to better define the lipids contributing to the variance observed between control and different OGD time. The protein expression of tight junction of RBMCs: occludin, claudin-5, and ZO-1 were detected with immunofluorescence staining and western blot. The proof of the interaction between NMMHC IIA and SREBP1 was investigated via GST-pull down, while their specific binding fragments were also confirmed. The regulation mechanism of NMMHC IIA on SREBP1 was investigated to explore downstream regulatory signaling pathways.

RESULTS

Untargeted and targeted shotgun lipidomics data revealed that OGD might be the conditional factor in reshaping lipid components. Mechanistic studies showed that with the increase of OGD time, PCA analysis of lipidomics obtained from RBMCs indicated their specificity in reshaping lipid components, while ≥80% major lipid components phospholipids and sphingolipids transferred from phospholipids, sphingolipids, and neutral lipids, of which neutral lipids taken the largest proportion with OGD time course. Perturbing reprogramming of lipid composition was less susceptible to OGD condition via knockdown of NMMHC IIA of vascular endothelial cells. Knockdown of NMMHC IIA could promote tight junction defense to OGD condition. NMMHC IIA could directly bind with SREBP1, then could affect sterol regulatory element binding protein-1 to adjust lipid metabolize reprogramming of RBMCs.

CONCLUSIONS

Mechanistic studies showed that perturbing reprogramming of lipid composition could enhance tight junction damage, which was mediated by the opposing effects of NMMHC IIA.