Covalent functionalization of G protein-coupled receptors by small molecular probes

Roughly one-third of all marketed drugs act by binding to one or more of the >800 human GPCRs, primarily through activation or inhibition via the orthosteric binding site. In addition, novel strategies to alter GPCR functioning are being developed, including allosteric, biased and covalently binding ligands. Molecular probes play an important role in verifying such drug molecules with new modes of action and providing information on all factors involved in GPCR signalling. Various types of molecular probes have been developed, ranging from small molecules to antibodies, each bearing its own advantages and disadvantages. In this mini-review, a closer look is taken at small molecular probes that functionalize GPCRs in a covalent manner, such as through the conjugation of reporter groups like fluorophores or biotin. Covalently bound reporter groups allow the investigation of GPCRs across an increasing range of biochemical assay types, yielding new insights into GPCR signalling pathways. Here, a broad range of recently developed 'functionalized covalent probes' is summarized. Furthermore, the use of these probes in biochemical assays and their applications in the field of GPCR research are discussed. Lastly, a view on possible future applications of these types of small molecular probes is provided.

Research mapping of cannabinoids and endocannabinoid system in cancer over the past three decades: insights from bibliometric analysis

Background

The cannabinoids and endocannabinoid system are thought to play critical roles in multiple signaling pathways in organisms, and extensive evidence from preclinical studies indicated that cannabinoids and endocannabinoids displayed anticancer potential. This study aimed to summarize the research of cannabinoids and endocannabinoid system in cancer through bibliometric analysis.

Methods

Relevant literature in the field of cannabinoids and endocannabinoid system in cancer published during 1995-2024 were collected from the Web of Science Core Collection database. VOSviewer and SCImago Graphica were applied to perform bibliometric analysis of countries, institutions, authors, journals, documents, and keywords.

Results

A total of 3,052 publications were identified, and the global output exhibited a generally upward trend over the past 3 decades. The USA had the greatest number of publications and citations in this research field. Italian National Research Council led in terms of publication, while Complutense University of Madrid had the highest total citations. Vincenzo Di Marzo was the leading author in this field with the greatest number of publications and citations. The co-occurrence of keywords revealed that the research frontiers mainly included "cannabinoids", "endocannabinoid system", "cancer", "anandamide", "cannabidiol", "cannabinoid receptor", "apoptosis", and "proliferation".

Conclusion

Our results revealed that the research of cannabinoids and endocannabinoid system in cancer would receive continuous attention. The USA and Italy have made remarkable contributions to this field, supported by their influential institutions and prolific scholars. The research emphasis has evolved from basic functional characterization to mechanistic exploration of disease pathways and translational applications within multidisciplinary framework.

Plin5: A potential therapeutic target for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a kind of metabolic disease characterized by aberrant insulin secretion as a result of -cell loss or injury, or by impaired insulin sensitivity of peripheral tissues, which finally results in insulin resistance and a disturbance of glucose and lipid metabolism. Among them, lipid metabolism disorders lead to lipotoxicity through oxidative stress and inflammatory response, destroying the structure and function of tissues and cells. Abnormal lipid metabolism can lead to abnormal insulin signaling and disrupt glucose metabolism through a variety of pathways. Therefore, emphasizing lipid metabolism may be a crucial step in the prevention and treatment of T2DM. Plin5 is a lipid droplet surface protein, which can bi-directionally regulate lipid metabolism and plays an important role in lipolysis and fat synthesis. Plin5 can simultaneously decrease the buildup of free fatty acids in the cytoplasm, improve mitochondrial uptake of free fatty acids, speed up fatty acid oxidation through lipid drops-mitochondria interaction, and lessen lipotoxicity. In oxidative tissues like the heart, liver, and skeletal muscle, Plin5 is extensively expressed. And Plin5 is widely involved in β-cell apoptosis, insulin resistance, oxidative stress, inflammatory response and other pathological processes, which has important implications for exploring the pathogenesis of T2DM. In addition, recent studies have found that Plin5 is also closely related to T2DM and cancer, which provides a new perspective for exploring the relationship between T2DM and cancer.

RvD2 mitigates TNFɑ-Induced mitochondrial reactive oxygen species through NRF2 signaling in placental trophoblasts

Introduction

Hypertensive disorders of pregnancy (HDP) are marked by elevated levels of TNFα, which increases reactive oxygen species (ROS) and disrupts metabolism of trophoblasts. Resolvin D2 (RvD2), an omega-3 fatty acid-derived lipid mediator, is known to resolve inflammation, but its role in protecting trophoblasts by promoting antioxidant responses to alleviate ROS remains unclear. Nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2) controls cellular defense mechanisms against oxidative stress and helps with the maintenance of cellular redox homeostasis. Upon translocation to nucleus, NRF2 activates the antioxidant response element (ARE), inducing the expression of genes that can mitigate ROS. Hence, we hypothesized that RvD2 activates NRF2 and prevents TNFα-induced mitochondrial dysfunction in trophoblasts.

Methods

We investigated RvD2's potential protective mechanisms against TNFα-induced oxidative stress in trophoblasts by pretreating JEG cells with 100 nM RvD2, followed by exposure to 50 or 100 ng/mL TNFα.

Results

We also observed that placental TNFα levels were elevated, while NRF2 protein levels were reduced in human HDP placental tissues compared to normotensive placentas. We demonstrate that RvD2 alone enhances NRF2 nuclear translocation, increases glutathione levels and mitochondrial function, and reduces mitochondrial ROS. In contrast, TNFα alone decreases nuclear NRF2 levels, increases mitochondrial ROS and oxygen consumption rates, and impairs migration. Notably, pretreatment of RvD2 before TNFα exposure protects against mitochondrial ROS, increases NRF2 levels, and restores mitochondrial oxygen consumption rates in trophoblasts.

Discussion

These findings demonstrate that RvD2 functions as a positive regulator of endogenous antioxidant properties by enhancing NRF2 levels and mitigating mitochondrial ROS in placental trophoblasts.

NADPH Oxidases in Cancer Therapy-Induced Cardiotoxicity: Mechanisms and Therapeutic Approaches

Cancer therapy-induced cardiotoxicity remains a significant clinical challenge, limiting the efficacy of cancer treatments and impacting long-term survival and quality of life. NADPH oxidases, a family of enzymes that are able to generate reactive oxygen species (ROS), have emerged as key players in the pathogenesis of cardiotoxicity associated with various cancer therapies. This review comprehensively examines the role of NADPH oxidases in cancer therapy-induced cardiotoxicity, elucidating the underlying mechanisms and exploring potential therapeutic approaches. We discuss the structure and function of NADPH oxidases in the cardiovascular system and their involvement in cardiotoxicity induced by anthracyclines and ionizing radiation. The molecular mechanisms by which NADPH oxidase-derived ROS contribute to cardiac injury are explored, including direct oxidative damage, activation of pro-apoptotic pathways, mitochondrial dysfunction, vascular damage, inflammation, fibrosis, and others. Furthermore, we evaluate therapeutic strategies targeting NADPH oxidases, such as specific inhibitors, antioxidant therapies, natural products, and other cardioprotectors. The review also addresses current challenges in the field, including the need for isoform-specific targeting and the identification of reliable biomarkers. Finally, we highlight future research directions aimed at mitigating NADPH oxidase-mediated cardiotoxicity and alleviating cardiovascular side effects in cancer survivors. By synthesizing current knowledge and identifying knowledge gaps, this review provides a rationale for future studies and the development of novel cardioprotective strategies in cancer therapy.

Neutrophil extracellular traps (NETs) and NETosis in alcohol-associated diseases: A systematic review

Heavy alcohol consumption is implicated in the alteration of the antimicrobial function of neutrophils, such as phagocytosis, chemotaxis, the formation of neutrophil extracellular traps (NETs), and the occurrence of NETosis. NETosis is an endogenous process of elimination of invading microbes, autoantibodies, and inflammatory elements such as danger-associated molecular patterns (DAMPs) and pathogen-associated patterns (PAMPs). However, both exaggeration and suppression of NETosis modulate normal physiological and metabolic processes by influencing events at the molecular and cellular levels. Recent research shows that binge alcohol consumption induces NETosis, leading to tissue damage and inflammation. Binge alcohol consumption, chronic alcohol intake, and alcohol use disorder (AUD) can affect immunity and often lead to alcohol-associated liver disease (ALD) and/or other organ damage. Alcohol can lead to detrimental consequences in multiple organs, including the brain, liver, pancreas, and gut. Gut-derived microbial substances, such as endotoxins in the circulation, induce systemic inflammation. Sterile danger signals from damaged cells, cytokines, and prostaglandins act as proinflammatory stimuli and are involved in multiple signaling pathways. The alcohol-induced proinflammatory cytokines chemoattract neutrophils, which interact and coordinate with other immune cells to exaggerate or suppress inflammation within the inflammatory milieu, depending on the alcohol effects. Several proteins, including different receptors, play important roles in the activation and formation of NETs as well as the initiation and execution of NETosis. This review article specifically gathers the current information on NETosis, its biological components, and signaling pathways relating to the formation of NETs and the occurrence of NETosis associated with ALD and AUD in multiorgans, specifically in the brain, liver, and gut. We also briefly describe various therapeutic strategies against AUD-associated NETosis in experimental models and human disease states.

IMproving Preclinical Assessment of Cardioprotective Therapies (IMPACT): a small animal acute myocardial infarction randomized-controlled multicenter study on the effect of ischemic preconditioning

Although many cardioprotective interventions have been shown to limit infarct size (IS), in preclinical animal studies of acute myocardial ischemia/reperfusion injury (IRI), their clinical translation to patient benefit has been largely disappointing. A major factor is the lack of rigor and reproducibility in the preclinical studies. To address this, we have established the IMproving Preclinical Assessment of Cardioprotective Therapies (IMPACT) small animal multisite acute myocardial infarction (AMI) network, with centralized randomization and blinded core laboratory IS analysis, and have validated the network using ischemic preconditioning (IPC). Eight sites from the COST Innovators Grant (IG16225) network participated in the IMPACT AMI study. Mice and rats were randomly allocated into Sham, Control, or IPC groups. The IRI group underwent 45 min (mice) or 30 min (rats) of left coronary artery occlusion followed by 24 h reperfusion. IPC comprised three cycles of 5 min occlusion/reperfusion before IRI. IS was determined by a blinded core lab. The majority of site showed significant cardioprotection with IPC. In pooled mouse data, IPC (N = 42) reduced IS/AAR by 35% compared to control (N = 48) (30 ± 16% versus 46 ± 13%; p < 0.005), and in rat data, IPC (N = 36) reduced IS/AAR by 29% when compared to control (N = 39) (32 ± 19% versus 45 ± 14%; p < 0.01). The IMPACT multisite mouse and rat AMI networks, with centralized randomization and blinded core IS analysis, were established to improve the reproducibility of cardioprotective interventions in preclinical studies and to facilitate the translation of these therapies for patient benefit.

The clinical relevance of the new criteria for cirrhotic cardiomyopathy and future directions

Cardiac dysfunction in patients with liver disease has been recognized since the 1950s. Initially attributed to shared risk factors, it is now evident that cardiac dysfunction in patients with cirrhosis can occur in the absence of known cardiac, that is, coronary artery and valvular heart disease, and across all etiologies for cirrhosis. In 1996, this myocardial dysfunction was termed cirrhotic cardiomyopathy (CCM). The pathophysiologic mechanisms underlying CCM include impaired beta-adrenergic membrane function and circulating proinflammatory and cardiotoxic substances. In 2005, the first diagnostic criteria for CCM were introduced enabling greater sensitivity and accuracy of diagnosis. Since 2005, advancements in echocardiographic methods and a better understanding of the pathophysiology of cardiac dysfunction in patients with cirrhosis necessitated a revision of CCM criteria. Changes in CCM criteria included the removal of blunted contractile or heart rate response on stress testing and the addition of global longitudinal systolic strain. The refinement of criteria for diastolic dysfunction was also incorporated into the new diagnostic approach. Since 2020, the prevalence of the disorder and clinical considerations for pretransplant, peritransplant, and posttransplant patients with cirrhosis have been further evaluated, and CCM was found to adversely impact clinical outcomes during all 3 phases of care. Future research considerations should address the timing of universal echocardiographic screening for patients with cirrhosis, the utility of biomarkers in aiding CCM diagnosis, the impact of CCM on right heart function, and the role of anti-remodeling agents after liver transplant.

In Situ 3D SERS Imaging of CO2 Reduction in Living Cells

The advancement of catalytic processes for therapeutic applications is pivotal to the development of next-generation medical technologies. One of the major challenges in this field lies in elucidating the intracellular generation of small molecules, such as carbon monoxide (CO), nitric oxide (NO), and others, which possess significant therapeutic potential. In this study, in situ surface-enhanced Raman spectroscopy (SERS) is employed to visualize and monitor the carbon dioxide (CO2) reduction process mediated by a rhenium coated gold nanoflower (Re@Au) catalyst within living cells. The findings provide direct spectroscopic evidence of CO2 reduction under intracellular conditions, demonstrating that CO can be catalytically generated from CO2 in the cellular environment. These results position SERS as an indispensable tool for investigating catalytic processes in biological systems, providing molecular-level insights through the analysis of molecular fingerprint spectra that are typically beyond the capabilities of conventional microscopy techniques.

Serum miR-365b-5p/miR-222-5p as a potential diagnostic biomarker for long-term weight loss in patients with morbid obesity after bariatric surgery

BACKGROUND

The successful weight loss following bariatric surgery is not achieved in all patients with morbid obesity (MO). This study aims to determine whether a serum miRNA profile can predict this outcome.

DESIGN

Thirty-three patients with MO were classified in "Good Responders" (GR, percentage of excess weight loss (%EWL) ≥ 50 %) or "Non-Responders" (NR, %EWL < 50 %) according to the %EWL 5-8 year following bariatric surgery. Baseline serum miRNA sequencing was performed to find predictor biomarkers and human adipocyte culture were performed to determine their effect.

RESULTS

Fifty-six differentially expressed miRNAs were found between GR and NR. Logistic regression models showed two miRNAs, hsa-miR-365b-5p (upregulated in GR) and hsa-miR-222-5p (upregulated in NR) associated to %EWL. Receiver operating characteristic curves showed that the combination of these miRNAs was the best serum miRNAs profile that distinguished between GR and NR. The experimentally validated target genes of these miRNAs were involved in processes related to the response to stress, cell cycle, transduction, and development and proliferation processes. The in vitro expression of six genes involved in adipogenesis and adipocyte differentiation (STAT3, ILR7, PARP1, SOD2, FGF2 and TMEM18) was downregulated in lipogenic and upregulated in lipolitic conditions in human adipocytes incubated with the combination of a hsa-miR-365b-5p mimic and a hsa-miR-222-5p inhibitor.

CONCLUSIONS

Baseline serum hsa-miR-365b-5p and hsa-miR-222-5p were able to predict %EWL 5-8 years following bariatric surgery. The combination of these potential predictive biomarkers was involved in regulating the expression levels of genes associated with obesity. However, these effects could be modified depending of other stimuli.

Identification of purinergic system components in the venom of Bothrops mattogrossensis and the inhibitory effect of specioside extracted from Tabebuia aurea

Snake bites are a severe problem in the countryside of Brazil and are usually attributed to snakes of the genera Bothrops, Crotalus, and Lachesis. Snake venom can release ectoenzymes and nucleotidases that modulate the purinergic system. In addition to serum therapy against snake poisoning, medicinal plants with anti-inflammatory activities, such as Tabebuia aurea, is empirically applied in accidents that occur in difficult-to-access areas. This study aimed was to verify the presence and activity of nucleotidases in the crude venom of Bothrops mattogrossensis (BmtV) in vitro and characterize the modulation of purinergic components, myeloid differentiation, and inflammatory/oxidative stress markers by BmtV in vivo and in vitro. Moreover, our study assessed the inhibitory activities of specioside, an iridoid isolated from Tabebuia aurea, against the effects of BmtV. Proteomic analysis of venom content and nucleotidase activity confirm the presence of ectonucleotidase-like enzymes in BmtV. In in vivo experiments, BmtV altered purinergic component expression (P2X7 receptor, CD39 and CD73), increased neutrophil numbers in peripheral blood, and elevated oxidative stress/inflammatory parameters such as lipid peroxidation and myeloperoxidase activity. BmtV also decreased viability and increased spreading index and phagocytic activity on macrophages. Specioside inhibited nucleotidase activity, restored neutrophil numbers, and mediate the oxidative/inflammatory effects produced by BmtV. We highlight the effects produced by BmtV in purinergic system components, myeloid differentiation, and inflammatory/oxidative stress parameters, while specioside reduced the main BmtV-dependent effects.

Polymorphonuclear neutrophil depletion in ileal tissues reduces the immunopathology induced by Clostridioides difficile toxins

INTRODUCTION

Clostridioides difficile, a leading cause of healthcare-associated infections, causes significant morbidity and mortality. Its pathogenesis centers on TcdA and TcdB toxins, which disrupt intestinal integrity, trigger inflammation, and promote extensive neutrophil infiltration.

OBJECTIVE

The main objective of this study was to evaluate the role of PMNs in CDI using neutrophil depletion in a murine-ileal-ligated loop.

METHODS

Mice were treated with C. difficile toxins TcdA, TcdB, and TcdBv, with PMN depletion achieved via intraperitoneal injections of Ly6G/Ly6C antibody. Histopathological analysis, cytokine quantification, and MPO activity assays were performed to assess the inflammatory and tissue damage responses.

RESULTS

PMN depletion significantly reduced histopathological damage and proinflammatory responses. TcdA induced the highest inflammation and epithelial damage, while TcdB showed lower activity, except for MPO. TcdBvNAP1's activity was comparable to that of TcdBNAP1 but less than TcdA. The findings indicate that TcdA's enterotoxin effects are more damaging than TcdBs from different strains and confirm the critical role of PMNs in CDI pathogenesis.

CONCLUSION

Our results show that PMN depletion reduced inflammatory responses and tissue damage, highlighting potential therapeutic strategies targeting PMN regulation. Further research on PMN extracellular traps (NETs) and their role in CDI is necessary to develop comprehensive treatments. Future studies should focus on combined in vivo and in vitro approaches to fully understand the pathological mechanisms and identify effective biomarkers for CDI therapy.

The Duality of Astrocyte Neuromodulation: Astrocytes Sense Neuromodulators and Are Neuromodulators

Neuromodulation encompasses different processes that regulate neuronal and network function. Classical neuromodulators originating from long-range nuclei, such as acetylcholine, norepinephrine, or dopamine, act with a slower time course and wider spatial range than fast synaptic transmission and action potential firing. Accumulating evidence in vivo indicates that astrocytes, which are known to actively participate in synaptic function at tripartite synapses, are also involved in neuromodulatory processes. The present article reviews recent findings obtained in vivo indicating that astrocytes express receptors for neuromodulators that elevate their internal calcium and stimulate the release of gliotransmitters, which regulate synaptic and network function, and hence mediate, at least partially, the effects of neuromodulators. In addition, we propose that astrocytes act in local support of neuromodulators by spatially and temporally integrating neuronal and neuromodulatory signals to regulate neural network function. The presence of astrocyte-neuron hysteresis loops suggests astrocyte-neuron interaction at tripartite synapses scales up to astrocyte-neuronal networks that modulate neural network function. We finally propose that astrocytes sense the environmental conditions, including neuromodulators and network function states, and provide homeostatic control that maximizes the dynamic range of neural network activity. In summary, we propose that astrocytes are critical in mediating the effects of neuromodulators, and they also act as neuromodulators to provide neural network homeostasis thus optimizing information processing in the brain. Hence, astrocytes sense ongoing neuronal activity along with neuromodulators and, acting as neuromodulators, inform the neurons about the state of the internal system and the external world.

A2B adenosine receptor signaling and regulation

The A2B adenosine receptor (A2BR) is one of the four adenosine-activated G protein-coupled receptors. In addition to adenosine, protein kinase C (PKC) was recently found to activate the A2BR. The A2BR is coupled to both Gs and Gi, as well as Gq proteins in some cell types. Many primary cells and cell lines, such as bladder and breast cancer, bronchial smooth muscle, skeletal muscle, and fat cells, express the A2BR endogenously at high levels, suggesting its potentially important role in asthma, cancer, diabetes, and other conditions. The A2BR has been characterized as both pro- and anti-inflammatory, inducing cell type-dependent secretion of IL-6, IL-8, and IL-10. Theophylline and enprofylline have long been used for asthma treatment, although it is still not entirely clear if their A2BR antagonism contributes to their therapeutic effects or side effects. The A2BR is required in ischemic cardiac preconditioning by adenosine. Both A2BR and protein kinase C (PKC) contribute to cardioprotection, and both modes of A2BR signaling can be blocked by A2BR antagonists. Inhibitors of PKC and A2BR are in clinical cancer trials. Sulforaphane and other isothiocyanates from cruciferous vegetables such as broccoli and cauliflower have been reported to inhibit A2BR signaling via reaction with an intracellular A2BR cysteine residue (C210). A full, A2BR-selective agonist, critical to elucidate many controversial roles of the A2BR, is still not available, although agonist-bound A2BR structures have recently been reported.

Unraveling GPCRs Allosteric Modulation. Cannabinoid 1 Receptor as a Case Study

G-protein-coupled receptors (GPCRs) constitute one of the most prominent families of integral membrane receptor proteins that mediate most transmembrane signaling processes. Malfunction of these signal transduction processes is one of the underlying causes of many human pathologies (Parkinson's, Huntington's, heart diseases, etc), provoking that GPCRs are the largest family of druggable proteins. However, these receptors have been targeted traditionally by orthosteric ligands, which usually causes side effects due to the simultaneous targeting of homologous receptor subtypes. Allosteric modulation offers a promising alternative approach to circumvent this problematic and, thus, comprehending its details is a most important task. Here we use the Cannabinoid type-1 receptor (CB1R) in trying to shed light on this issue, focusing on positive allosteric modulation. This is done by using the protein-dipole Langevin-dipole (PDLD) within the linear response approximation (LRA) framework (PDLD/S-2000) along with our coarse-grained (CG) model of membrane proteins to evaluate the dissociation constants (K Bs) and cooperativity factors (αs) for a diverse series of CB1R positive allosteric modulators belonging to the 2-phenylindole structural class, considering CP55940 as an agonist. The agreement with the experimental data evinces that significantly populated allosteric modulator:CB1R and allosteric modulator:CP55940:CB1R complexes have been identified and characterized successfully. Analyzing them, it has been determined that CB1R positive allosteric modulation lies in an outwards displacement of transmembrane α helix (TM) 4 extracellular end and in the regulation of the range of motion of a compound TM7 movement for binary and ternary complexes, respectively. In this respect, we achieved a better comprehension of the molecular architecture of CB1R positive allosteric site, identifying Lys1923.28 and Gly1943.30 as key residues regarding electrostatic interactions inside this cavity, and to rationalize (at both structural and molecular level) the exhibited stereoselectivity in relation to positive allosteric modulation activity by considered CB1R allosteric modulators. Additionally, putative/postulated allosteric binding sites have been screened successfully, identifying the real CB1R positive allosteric site, and most structure-activity relationship (SAR) studies of CB1R 2-phenylindole allosteric modulators have been rationalized. All these findings point out towards the predictive value of the methodology used in the current work, which can be applied to other biophysical systems of interest. The results presented in this study contribute significantly to understand GPCRs allosteric modulation and, hopefully, will encourage a more thorough exploration of the topic.

Cannabidiol Enhances the Anticancer Activity of Etoposide on Prostate Cancer Cells

Introduction: Cannabis sativa extract has been used as an herbal medicine since ancient times. It is one of the most researched extracts, especially among supportive treatments against cancer. Prostate cancer is one of the most frequently diagnosed cancer types in men worldwide and an estimated 288,300 new cases were diagnosed in 2023. Today, many advanced therapeutic approaches are used for prostate cancer, such as immunotherapy and chemotherapy, but acquired drug resistance, long-term drug usage and differentiation of cancer cells mostly restricted the efficiency of therapies. Therefore, it is thought that the use of natural products to overcome these limitations and improve the effectiveness of existing therapies may offer promising approaches. The present study focused on the investigation of the possible enhancer role of cannabidiol (CBD), which is a potent ingredient compound of Cannabis, on the chemotherapeutic agent etoposide in prostate cancer cells. Methods: Herein, we tested the potentiator role of CBD on etoposide in prostate cancer cells by testing the cytotoxic effect, morphological alterations, apoptotic effects, autophagy, unfolded protein response (UPR) signaling, endoplasmic reticulum-associated degradation mechanism (ERAD), angiogenic and androgenic factors, and epithelial-mesenchymal transition (EMT). In addition, we examined the combined treatment of CBD and etoposide on colonial growth, migrative, invasive capability, 3D tumor formation, and cellular senescence. Results: Our findings demonstrated that cotreatment of etoposide with CBD importantly suppressed autophagic flux and induced ERAD and UPR signaling in LNCaP cells. Also, CBD strongly enhanced the etoposide-mediated suppression of androgenic signaling, angiogenic factor VEGF-A, protooncogene c-Myc, EMT, and also induced apoptosis through activation caspase-3 and PARP-1. Moreover, coadministration markedly decreased tumorigenic properties, such as proliferative capacity, colonial growth, migration, and 3D tumor formation and also induced senescence. Altogether, our data revealed that CBD has a potent enhancer effect on etoposide-associated anticancer activities. Conclusion: The present study suggests that the use of CBD as a supportive therapy in existing chemotherapeutic approaches may be a promising option, but this effectiveness needs to be investigated on a large scale.

PCSK9 exacerbates sevoflurane-induced neuroinflammatory response and apoptosis by up-regulating cGAS-STING signal

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a postoperative complication that can be induced by anaesthesia. PCSK9 has been shown to have a role in neuronal development and apoptosis. However, PCSK9 has not been studied in sevoflurane-induced POCD-related disorders.

OBJECTIVE

To explore whether PCSK9 can exacerbate sevoflurane-induced neuroinflammatory response and apoptosis by up-regulating cGAS-STING signalling.

METHODS

A POCD model was constructed by stimulating BV2 microglia with Sevoflurane. CCK8 was used to detect the cell viability, and immunofluorescence was used to observe the expression of microglial activation markers (Iba-1, CD11b) and BDNF to determine the activation of BV2 microglia. Cell proliferation was measured by EDU staining, and apoptosis was analyzed by flow cytometry and western blot. The levels of inflammatory cytokines, ROS, MDA, SOD and CAT were respectively detected by ELISA, DCFH-DA staining, and kits to determine the neuroinflammation and oxidative stress of cells. Mitochondrial ROS, mitochondrial membrane potential, mtDNA and ATP levels were measured to evaluate cellular mitochondrial function.

RESULTS

Transfection of si-PCSK9 inhibited Sevoflurane-induced microglial activation and restored cellular viability, promoted cell proliferation, inhibited apoptosis and neuroinflammation, decreased ROS and MDA levels in the cells while up-regulating the levels of SOD and CAT, thus inhibiting oxidative stress, restored the mitochondrial membrane potential to normal and decreased mitochondrial ROS and mtDNA levels and increased ATP production, thereby alleviating mitochondrial dysfunction. Moreover, PCSK9 depletion also down-regulated the expression of cGAS and STING to inactivate cGAS-STING signaling. However, cGAS overexpression partially reversed the effects of si-PCSK9.

CONCLUSION

PCSK9 exacerbates sevoflurane-induced neuroinflammatory response and apoptosis by upregulating cGAS-STING signaling.

Maladaptive Peripheral Ketogenesis in Schwann Cells Mediated by CB1R Contributes to Diabetic Neuropathy

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes. Although studies have previously investigated metabolic disruptions in the peripheral nervous system (PNS), the exact metabolic mechanisms underlying DPN remain largely unknown. Herein, a specific form of metabolic remodeling involving aberrant ketogenesis within Schwann cells (SCs) in streptozotocin (STZ)-induced type I diabetes mellitus is identified. The PNS adapts poorly to such aberrant ketogenesis, resulting in disrupted energy metabolism, mitochondrial damage, and homeostatic decompensation, ultimately contributing to DPN. Additionally, the maladaptive peripheral ketogenesis is highly dependent on the cannabinoid type-1 receptor (CB1R)-Hmgcs2 axis. Silencing CB1R reprogrammed the metabolism of SCs by blocking maladaptive ketogenesis, resulting in rebalanced energy metabolism, reduced histopathological changes, and improved neuropathic symptoms. Moreover, this metabolic reprogramming can be induced pharmacologically using JD5037, a peripheral CB1R blocker. These findings revealed a new metabolic mechanism underlying DPN, and promoted CB1R as a promising therapeutic target for DPN.

Mitochondrial hyperactivity and reactive oxygen species drive innate immunity to the yellow fever virus-17D live-attenuated vaccine

The yellow fever virus 17D (YFV-17D) live attenuated vaccine is considered one of the most successful vaccines ever generated associated with high antiviral immunity, yet the signaling mechanisms that drive the response in infected cells are not understood. Here, we provide a molecular understanding of how metabolic stress and innate immune responses are linked to drive type I IFN expression in response to YFV-17D infection. Comparison of YFV-17D replication with its parental virus, YFV-Asibi, and a related dengue virus revealed that IFN expression requires RIG-I-Like Receptor signaling through MAVS, as expected. However, YFV-17D uniquely induces mitochondrial respiration and major metabolic perturbations, including hyperactivation of electron transport to fuel ATP synthase. Mitochondrial hyperactivity generates reactive oxygen species (ROS) including peroxynitrite, blocking of which abrogated MAVS oligomerization and IFN expression in non-immune cells without reducing YFV-17D replication. Scavenging ROS in YFV-17D-infected human dendritic cells increased cell viability yet globally prevented expression of IFN signaling pathways. Thus, adaptation of YFV-17D for high growth imparts mitochondrial hyperactivity to meet energy demands, resulting in generation of ROS as the critical messengers that convert a blunted IFN response into maximal activation of innate immunity essential for vaccine effectiveness.

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

JOURNAL/nrgr/04.03/01300535-202504000-00027/figure1/v/2024-07-06T104127Z/r/image-tiff Cardiac arrest can lead to severe neurological impairment as a result of inflammation, mitochondrial dysfunction, and post-cardiopulmonary resuscitation neurological damage. Hypoxic preconditioning has been shown to improve migration and survival of bone marrow-derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest, but the specific mechanisms by which hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown. To this end, we established an in vitro co-culture model of bone marrow-derived mesenchymal stem cells and oxygen-glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis, possibly through inhibition of the MAPK and nuclear factor κB pathways. Subsequently, we transplanted hypoxia-preconditioned bone marrow-derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia. The results showed that hypoxia-preconditioned bone marrow-derived mesenchymal stem cells significantly reduced cardiac arrest-induced neuronal pyroptosis, oxidative stress, and mitochondrial damage, whereas knockdown of the liver isoform of phosphofructokinase in bone marrow-derived mesenchymal stem cells inhibited these effects. To conclude, hypoxia-preconditioned bone marrow-derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest, and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

Cannabidiol-Rich Cannabis sativa L. Extract Alleviates LPS-Induced Neuroinflammation Behavioral Alterations, and Astrocytic Bioenergetic Impairment in Male Mice

Neuroinflammation is a hallmark of various neurodegenerative disorders, yet effective treatments remain limited. This study investigates the neuroprotective potential of a cannabidiol (CBD)-Rich Cannabis sativa L. (CS) extract in a lipopolysaccharide (LPS)-induced neuroinflammation mouse model. The effects on anxiety-like behavior, cognitive function, and locomotor activity were assessed using behavioral tests (open field, elevated plus maze, novel object recognition, and Morris water maze). Antioxidant activity was measured by assaying glutathione (GSH) levels and lipid peroxidation by-products (TBARs). Anti-inflammatory properties were evaluated using quantitative reverse transcription polymerase chain reaction (QRt-PCR) for proinflammatory cytokines (IL-6 and TNF-α), glial fibrillary acidic protein (GFAP), and cannabinoid receptor 1 (CB1) mRNAs in the prefrontal cortex (PFC). Astrocytic bioenergetics were analyzed using extracellular flux assays. Additionally, computational inference with a deep learning approach was conducted to evaluate the synergistic interactions among CS phytocompounds on the CB1 receptors. Compared with synthetic CBD, the CS extract (20.0 mg/kg) demonstrated superior efficacy in mitigating LPS-induced anxiety-like behavior, cognitive deficits, and locomotor impairments. It also significantly mitigated oxidative stress (increased GSH, reduced TBARs) and suppressed proinflammatory cytokines and GFAP mRNAs, indicating potent anti-inflammatory properties. The extract modulated CB1 receptor expression and preserved metabolic homeostasis in cortical astrocytes, preventing their shift from glycolysis to oxidative phosphorylation under neuroinflammatory conditions. Computational modeling highlighted conformational changes in CB1 receptor residues induced by Delta-9-THC that enhanced CBD binding. These findings underscore the potential of CS extract as a therapeutic candidate for managing neuroinflammation and its associated neurodegenerative consequences, warranting further clinical exploration.

Cardioprotective effects of PARP inhibitors for platinum-agent induced cardiotoxicity

Poly(ADP-ribose) polymerase (PARP) inhibitors may have cardioprotective properties. This study aimed to evaluate the potential cardioprotective effects of PARP inhibitors in patients with epithelial ovarian cancer treated with platinum-based chemotherapeutic agents. A retrospective cohort study was conducted using the Health Insurance Review & Assessment Service claims database from January 2007 to July 2022. Eligible patients were those diagnosed with ovarian, primary peritoneal, or fallopian tube cancer who received platinum-based chemotherapy after 2017. Propensity score matching was employed to adjust for potential confounders, and logistic regression and Cox proportional hazards regression analyses were utilized to estimate the odds ratios, hazard ratios, and 95% confidence intervals (CIs) for the occurrence of cardiac adverse events, including myocardial infarction, cardiomyopathy, and heart failure. A total of 7,253 eligible patients were included in the study, of which 233 (3.2%) used PARP inhibitors. After propensity score matching, no significant cardioprotective effect was observed in the PARP inhibitor-exposed group compared to the non-exposed group (adjusted odds ratio, 0.753; 95% CI 0.275-2.059; adjusted hazard ratio, 0.601; 95% CI 0.228-1.584). Although no statistically significant cardioprotective effect of PARP inhibitors was found in this study, there was a directional trend suggesting that patients with gynecologic malignancies treated with platinum-based chemotherapy could potentially benefit from PARP inhibitors. Further research with larger sample sizes and longer follow-up periods is warranted to elucidate the role of PARP inhibitors in mitigating cardiac adverse events in this patient population.

A class of MicroRNAs as diagnostic biomarkers and therapeutic strategies in non-alcoholic fatty liver disease: A review

MicroRNAs (miRNAs), small and noncoding RNAs that regulate gene expression through hybridization to messenger RNA, play a crucial role in the prevention or progression of non-alcoholic fatty liver disease (NAFLD). There is an urgent demand for the improvement of diagnostic tools and effective pharmacotherapies for the treatment of NAFLD, which can advance to cirrhosis and liver cancer. MiRNAs act as regulatory factors and noninvasive diagnostic agents for NAFLD, enabling the staging of the disorder, prognosis, and identification of pharmaco-therapeutic targets. NAFLD causes alterations in the expression patterns of hepatocyte miRNAs, with some specific miRNAs related to the upgrade from NAFLD to non-alcoholic steatohepatitis (NASH). These miRNAs can activate certain signaling cascade and exacerbate or improve NAFLD, additionally, act as hepatocellular signals or second messengers that transmit information between the liver and other systems. This study provides a comprehensive review of the most important miRNAs and their involvement in the pathophysiology and cellular signaling pathways related to NAFLD.

The molecular determinants regulating redox signaling in diabetic endothelial cells

Oxidation and reduction are vital for keeping life through several prime mechanisms, including respiration, metabolism, and other energy supplies. Mitochondria are considered the cell's powerhouse and use nutrients to produce redox potential and generate ATP and H2O through the process of oxidative phosphorylation by operating electron transfer and proton pumping. Simultaneously, mitochondria also produce oxygen free radicals, called superoxide (O2 -), non-enzymatically, which interacts with other moieties and generate reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), peroxynitrite (ONOO-), and hydroxyl radical (OH-). These reactive oxygen species modify nucleic acids, proteins, and carbohydrates and ultimately cause damage to organs. The nutrient-sensing kinases, such as AMPK and mTOR, function as a key regulator of cellular ROS levels, as loss of AMPK or aberrant activation of mTOR signaling causes ROS production and compromises the cell's oxidant status, resulting in various cellular injuries. The increased ROS not only directly damages DNA, proteins, and lipids but also alters cellular signaling pathways, such as the activation of MAPK or PI3K, the accumulation of HIF-1α in the nucleus, and NFkB-mediated transcription of pro-inflammatory cytokines. These factors cause mesenchymal activation in renal endothelial cells. Here, we discuss the biology of redox signaling that underlies the pathophysiology of diabetic renal endothelial cells.

Sleep deprivation accelerates Parkinson's disease via modulating gut microbiota associated microglial activation and oxidative stress

The interplay between Parkinson's disease (PD) and sleep disturbances suggests that sleep problems constitute a risk factor for PD progression, but the underlying mechanisms remain unclear. Microglial activation and oxidative stress are considered to play an important role in the pathogenesis of aging and neurodegenerative diseases. We hypothesized that sleep deprivation (SD) could exacerbate PD progression via modulating microglial activation and oxidative stress. To test this hypothesis, we established a PD mouse model using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), then subjected the mice to SD. A battery of behavioral tests, including rotarod, pole, adhesive removal, and open field tests, were used to assess motor function. Our study showed that SD exacerbated motor deficits, loss of tyrosine hydroxylase (TH), microglial activation and oxidative stress damage in PD model mice. Fecal microbiota transplantation experiments revealed that SD mediated PD progression, microglial activation and oxidative stress via the gut microbiota. 16S rRNA sequencing analysis indicated that SD increased the abundances of bacteria such as Bacteroidaceae, while decreasing the abundances of bacteria including Lactobacillus. Non-targeted metabolomic analysis of gut microbiota-derived metabolites revealed that SD significantly increased the production of adenosine (ADO), a purine metabolite. Probiotic supplementation reversed the effects of SD on motor deficits, dopaminergic neuron loss, microglial activation and oxidative stress damage in PD mice; it also decreased SD-induced ADO production. Administration of Adenosine A2A receptor (A2AR) inhibitors, Istradefylline (Ist), attenuated the roles of SD and ADO in promoting microglial activation, oxidative stress and PD progression. Taken together, our findings indicate that SD accelerates PD progression via regulating microbiota associated microglial activation and oxidative stress, suggesting that efforts to improve sleep quality can be used to prevent and treat PD.

Adenosine metabolism and receptors in aging of the skin, musculoskeletal, immune and cardiovascular systems

Aging populations worldwide face an increasing burden of age-related chronic conditions, necessitating a deeper understanding of the underlying mechanisms. Purine metabolism has emerged as a crucial player in the pathophysiology of aging, affecting various tissues and organs. Dysregulation of purine metabolism, particularly alterations in extracellular adenosine levels and adenosine receptor signaling, contributes to age-related musculoskeletal problems, cardiovascular diseases, inflammation, and impaired immune responses. Changes in purine metabolism are associated with diminished tissue repair and regeneration, altered bone density, and impaired muscle regeneration. Mechanistically, age-related alterations in purine metabolism involve reductions in extracellular adenosine production, impaired autocrine signaling, and dysregulated expression of CD73 and CD39. Targeting adenosine receptors, such as A2A and A2B receptors, emerges as a promising therapeutic approach to mitigate age-related conditions, including sarcopenia, obesity, osteoarthritis, and impaired wound healing. Since we cannot reverse time, understanding the intricate molecular interplay between purine metabolism and aging-related pathologies holds significant potential for developing novel therapeutic strategies to improve the health and quality of life of aging populations. In this review, we compile the findings related to purine metabolism during aging in several tissues and organs and provide insights into how these signals can be manipulated to circumvent the deleterious effects of the passage of time on our body.

Deep learning-based design and screening of benzimidazole-pyrazine derivatives as adenosine A2B receptor antagonists

The Adenosine A2B receptor (A2BAR) is considered a novel potential target for the immunotherapy of cancer, and A2BAR antagonists have an inhibitory effect on tumor growth, proliferation, and metastasis. In our previous studies, we identified a class of benzimidazole-pyrazine scaffolds whose derivatives exhibited the antagonistic effect but lacked subtype selectivity towards A2BAR. In this work, we developed a scaffold-based protocol that incorporates a deep generative model and multilayer virtual screening to design benzimidazole-pyrazine derivatives as potential selective A2BAR antagonists. By utilizing a generative model with reported A2BAR antagonists as the training set, we built up a scaffold-focused library of benzimidazole-pyrazine derivatives and processed a virtual screening protocol to discover potential A2BAR antagonists. Finally, five molecules with different Bemis-Murcko scaffolds were identified and exhibited higher binding free energies than the reference molecule 12o. Further computational analysis revealed that the 3-benzyl derivative ABA-1266 presented high selectivity toward A2BAR and showed preferred draggability, providing future potent development of selective A2BAR antagonists.

Considering Long-Acting Synthetic Cannabidiol for Chronic Pain: A Narrative Review

Chronic pain is prevalent and challenging to treat. Cannabinoids, in particular cannabidiol (CBD), have been evaluated as analgesics without the issues of tolerance or dependence. Side effects tend to be mild and infrequent. These products have multiple routes of administration and composition, and some are available over the counter, allowing pain patients to self-medicate. Most self-medicated CBD are plant-derived extracts administered as either oils, pills, or by inhalation. During the early 1960s, CBD was chemically synthesized for the first time, but it was not yet approved for medical use; synthetic CBD has been and continues to be studied in clinical trials for numerous indications, including chronic pain, neuropathic pain, and pain in cancer. However, studies are often small, populations heterogeneous, and some results are equivocal. Research is lively, with over 60 studies reported on ClinicalTrials.gov. Multimodal CBD therapy may hold promise, particularly in combination with palmitoylethanolamide. Greater patient education and training for physicians and other healthcare providers are needed along with more comprehensive studies. Considering the problem of chronic pain, further intensive study of synthetic CBD for pain control is warranted to meet this unmet clinical need. This is particularly important in the context of long-lasting administration methods that enable easy dosing and support long-term use for patients dealing with persistent and often debilitating symptoms.

Ectonucleotidase inhibitors: targeting signaling pathways for therapeutic advancement-an in-depth review

Ectonucleotidase inhibitors are a family of pharmacological drugs that, by selectively targeting ectonucleotidases, are essential in altering purinergic signaling pathways. The hydrolysis of extracellular nucleotides and nucleosides is carried out by these enzymes, which include ectonucleoside triphosphate diphosphohydrolases (NTPDases) and ecto-5'-nucleotidase (CD73). Ectonucleotidase inhibitors can prevent the conversion of ATP and ADP into adenosine by blocking these enzymes and reduce extracellular adenosine. These molecules are essential for purinergic signaling, which is associated with a variability of physiological and pathological processes. By modifying extracellular nucleotide metabolism and improving purinergic signaling regulation, ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) inhibitors have the potential to improve cancer treatment, inflammatory management, and immune response modulation. Purinergic signaling is affected by CD73 inhibitors because they prevent AMP from being converted to adenosine. These inhibitors are useful in cancer therapy and immunotherapy because they may improve chemotherapy effectiveness and alter immune responses. Purinergic signaling is controlled by NTPDase inhibitors, which specifically target enzymes involved in extracellular nucleotide breakdown. These inhibitors show promise in reducing immunological responses, thrombosis, and inflammation, perhaps assisting in the treatment of cardiovascular and autoimmune illnesses. Alkaline phosphatase (ALP) inhibitors alter the function of enzymes involved in dephosphorylation reactions, which has an impact on a variety of biological processes. By altering the body's phosphate levels, these inhibitors may be used to treat diseases including hyperphosphatemia and certain bone problems. This article provides a guide for researchers and clinicians looking to leverage the remedial capability of ectonucleotidase inhibitors in a variety of illness scenarios by illuminating their processes, advantages, and difficulties.

In-silico screening to identify phytochemical inhibitor for hP2X7: A crucial inflammatory cell death mediator in Parkinson's disease

The second most prevalent neurological disease among the elderly is Parkinson's disease, where neuroinflammation plays a significant role in its pathology. Purinergic signaling mediated by P2X7 plays a significant role in neuroinflammation and pyroptotic cell death pathways through mediators like NLRP3, Caspase-1, and Caspase-3, instigating pyroptotic cell death. No synthetic agent advanced in late-stage clinical trials due to their inefficacy and toxicity. Hence, in this study, we aimed to identify a phytoconstituent inhibitor against the hP2X7 receptor to ameliorate the inflammatory processes involved. To achieve this aim, we performed homology modeling of the receptor and screened phytoconstituents from a library of over 3500 commercially available phytoconstituents. Molecular docking through the Maestro program of the Schrödinger suite was performed considering evaluation parameters like docking score, docking pose and spatial arrangement, and MMGBSA binding free energy. Predictive pharmacokinetic and toxicity profiling was done using tools like QikProp, ADMETLab 2.0, SwissADME, and Protox-II. Molecular dynamic simulation was performed using Schrödinger's Desmond tool for the top 10 phytoconstituents. The complex stability was evaluated based on the ligand- and protein-RMSD, protein-ligand contact stability over a simulation period of 100 ns, protein RMSF, and ligand properties like RMSF, radius of gyration, intramolecular hydrogen bonding, and SASA. Based on the studies' results, silychristin, silybin, rosmarinic acid, nordihydroguaiaretic acid, and aurantiamide were shortlisted as the top 5 phytoconstituents against hP2X7. Further in-vitro and in-vivo studies would offer better clarity on the mechanism of action of these agents specifically related to pyroptotic cell death in various disease models.

Acute Cannabis Administration Transiently Reduces Mitochondrial DNA in Young Adults: Findings from a Secondary Analysis of a Double-Blind, Placebo-Controlled, Randomized Clinical Trial

Background: Cannabis is one of the world's most commonly used substances; however, many questions remain unanswered as to how cannabis impacts the body. Recently, there has been a resurgence of research into the effects of plant-derived cannabinoids on mitochondrial health. In particular, a number of studies implicate mitochondrial-Δ9-tetrahydrocannabinol (Δ9-THC) interactions with altered memory, metabolism, and catalepsy in mice. Although the research in this field is expanding rapidly, there is little known about the effects of cannabis on mitochondria health in human subjects either in acute or chronic term use. Methods: Blood samples were obtained from a double-blind, placebo-controlled, parallel-group randomized clinical trial in which adults who regularly use cannabis (1-4 days/week) aged 19-25 years were randomized 2:1 to receive either an active (12.5% Δ9-THC) cigarette or placebo (<0.01% Δ9-THC) cigarette containing 750 mg of cannabis before driving simulator testing. DNA was extracted from whole blood using commercial spin columns, followed by measurement of mt-ND1, mt-ND4, and β2M using quantitative polymerase chain reaction. One-way repeated measures analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test was used to observe changes in mitochondrial DNA (mtDNA) copy number over time. A two-tailed Pearsons R test was used to assess correlations between mtDNA copy number and cannabinoid levels (Δ9-THC and metabolites) in blood. Results: We found that exposure to active cannabis containing Δ9-THC, as opposed to placebo, was associated with an acute reduction in mitochondrial DNA copy number in whole blood at 15 min and 1 h after smoking. The observed decrease in mtDNA copy number negatively correlated with blood concentrations of 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), the two primary metabolites of Δ9-THC, but not Δ9-THC itself. Further, the negative correlation between 11-OH THC and THC-COOH concentrations and mtDNA copy number was found in only a subgroup of participants who use cannabis infrequently, suggesting a tolerance effect. Conclusions: These results illuminate mitochondrial alterations attributed to Δ9-THC consumption, which may be mediated by metabolites. These results appear to suggest stronger effects in individuals who consume cannabis less frequently, suggesting some form of tolerance to the effects of Δ9-THC and its metabolites on mtDNA content in whole blood. Keywords: Mitochondria; mtDNA; cannabis; THC; THC metabolites; blood; THC-COOH; 11-OH-THC.

Uric Acid Stroke Cerebroprotection Transcended Sex, Age, and Comorbidities in a Multicenter Preclinical Trial

BACKGROUND

Past failures in translating stroke cerebroprotection provoked calls for a more rigorous methodological approach, leading to the stroke preclinical assessment network SPAN (Stroke Preclinical Assessment Network), where uric acid (UA) treatment exceeded a prespecified efficacy boundary for the primary functional outcome. Still, successful translation to humans requires confirmation of the effect of UA across key biological variables relevant to patients with stroke.

METHODS

We measured the effects of intravenous UA treatment (16 mg/kg) versus intravenous saline in groups of animals enrolled in the SPAN network with diverse comorbidities, sex, and age. The masked study drug or placebo was administered during reperfusion in rodents undergoing a transient middle cerebral artery filament occlusion. The primary outcome was the modified corner test index at day 30 poststroke, and numerous secondary outcomes were collected. A modified intention-to-treat population was used in the analysis. We tested for any interactions with sex, age, and comorbidities (obesity-induced hyperglycemia and hypertension).

RESULTS

In total, 710 animals were randomized to receive either intravenous UA or saline. After accounting for procedural dropouts and exclusions from treatment, a total of 687 animals were qualified and analyzed, including 458 assigned to UA and 229 to intravenous saline control. UA-treated animals exhibited a better primary functional outcome at day 30 (probability, 0.56 [95% CI, 0.52-0.60]; P=0.006). UA-treated animals also had a better corner test index at day 7 (probability, 0.55 [95% CI, 0.5-0.59]; P=0.035) and a higher survival rate at day 30 (hazard ratio, 1.41 [95% CI, 1.08-1.83]; P=0.011). Brain morphometry at day 2 and 30 was comparable between the treatment groups. The improved functional outcome and survival in UA-treated animals were preserved across different species, sexes, ages, and comorbidities.

CONCLUSIONS

UA provides ischemic stroke cerebroprotection across key relevant biological variables, making it a promising intervention to be further tested in human clinical trials.

Andrographolide and its Derivatives in Cardiovascular Disease: A Comprehensive Review

Cardiovascular disease is one of the main causes of mortality worldwide. Andrographolide represents an important category of natural phytochemicals that has significant therapeutic potential in various conditions such as acute lung injury, heart disease, and viral infections due to its anti-oxidative, anti-inflammatory, and anti-apoptotic properties. This compound plays a protective role in human pathophysiology. This review provides a comprehensive overview of the effects of andrographolide on cardiovascular disease and examines its essential roles and mechanisms in cardiovascular disease and other vascular dysfunctions. The data collected in this review serve as a comprehensive reference for the role of andrographolide in cardiovascular disease and provide valuable insights for further research and the development of andrographolide as a novel therapeutic approach for cardiovascular disease.

CardiLect: A combined cross-species lectin histochemistry protocol for the automated analysis of cardiac remodelling

BACKGROUND

Cardiac remodelling, a crucial aspect of heart failure, is commonly investigated in preclinical models by quantifying cardiomyocyte cross-sectional area (CSA) and microvascular density (MVD) via histological methods, such as immunohistochemistry. To achieve this, optimized protocols are needed, and the species specificity is dependent on the antibody used. Lectin histochemistry offers several advantages compared to antibody-based immunohistochemistry, including as cost-effectiveness and cross-species applicability. Direct comparisons between the two methods are lacking from the literature.

METHODS AND RESULTS

In this study, we compared antibody- and lectin-based methods for the histological assessment of cardiomyocyte CSA (with the use of anti-laminin and wheat germ agglutinin [WGA]) and microvascular density (utilizing anti-CD31 and isolectin B4 [ILB4]) using different embedding and antigen/carbohydrate retrieval techniques. Here, we describe a detailed, easy-to-use combined lectin histochemistry protocol (WGA and ILB4, 'CardiLect' protocol) for the histological assessment of cardiac remodelling. The lectin-based approach has been evaluated on a cross-species basis, and its efficacy has been demonstrated in zebrafish, rodents, large animals and human samples. We provide an ImageJ script ('CardiLect Analyser') for automated image analysis, validated in a preclinical heart failure model by correlating histological parameters with echocardiographic findings. CSA showed a significant positive correlation with left ventricular (LV) mass (P = 0.0098, rS = 0.7545) and significant negative correlation with markers of systolic function, such as ejection fraction (EF) (P = 0.0402, rS = -0.6364). Microvascular density showed significant negative correlation with LV mass (P = 0.0055, rS = -0.7622) and significant positive correlation with EF (P = 0.0106, rS = 0.7203).

CONCLUSIONS

The described combined lectin histochemistry protocol with the provided ImageJ script is an easy-to-use, cost-effective, cross-species approach for the histological assessment of cardiac remodelling.

Hepatoprotective Effect of Cannabidiol on the Progression of Experimental Hepatic Cirrhosis in Rats

Introduction: Liver cirrhosis is a condition characterized by the gradual replacement of normal liver tissue with scar tissue, ultimately leading to liver failure. This slow and progressive disease begins with a chronic inflammatory process induced by a noxious agent. In its advanced stages, the disease lacks effective therapies. Research has demonstrated the significant involvement of the endocannabinoid system in the pathogenesis of this disease. This study evaluated the hepatoprotective effect of cannabidiol (CBD) in the progression of experimental hepatic cirrhosis induced by thioacetamide (TAA) in rats. Methods: A randomized experimental design was employed using Holtzman rats. Hepatic cirrhosis was induced by intraperitoneal administration of TAA at a dose of 150 mg/kg for 6 weeks, with treatment initiated additionally. The groups were as follows: Group 1: TAA + vehicle; Group 2: TAA + CBD 2 mg/kg; Group 3: TAA + CBD 9 mg/kg; Group 4: TAA + CBD 18 mg/kg; Group 5: TAA + silymarin 50 mg/kg; and Group 6: Healthy control. Serum biochemical analysis (total bilirubin, direct bilirubin, ALT, AST, alkaline phosphatase, and albumin) and hepatic histopathological study were performed. The Knodell histological activity index (HAI) was determined, considering periportal necrosis, intralobular degeneration, portal inflammation, fibrosis, and focal necrosis. Results: All groups receiving TAA exhibited an elevation in AST levels; however, only those treated with CBD at doses of 2 mg/kg and 18 mg/kg did not experience significant changes compared to their baseline values (152.8 and 135.7 IU/L, respectively). Moreover, ALT levels in animals treated with CBD showed no significant variation compared to baseline. The HAI of hepatic tissue was notably lower in animals treated with CBD at doses of 9 and 18 mg/kg, scoring 3.0 and 3.25, respectively, in contrast to the TAA + vehicle group, which recorded a score of 7.00. Animals treated with CBD at 18 mg/kg showed a reduced degree of fibrosis and necrosis compared to those receiving TAA alone (p ≤ 0.05). Conclusion: Our findings demonstrate that cannabidiol exerts a hepatoprotective effect in the development of experimental hepatic cirrhosis induced in rats.

Overexpressed CD73 attenuates GSDMD-mediated astrocyte pyroptosis induced by cerebral ischemia-reperfusion injury through the A2B/NF-κB pathway

Ischemic stroke, resulting from the blockage or narrowing of cerebral vessels, causes brain tissue damage due to ischemia and hypoxia. Although reperfusion therapy is essential to restore blood flow, it may also result in reperfusion injury, causing secondary damage through mechanisms like oxidative stress, inflammation, and excitotoxicity. These effects significantly impact astrocytes, neurons, and endothelial cells, aggravating brain injury and disrupting the blood-brain barrier. CD73, an ectoenzyme that regulates adenosine production through ATP hydrolysis, plays a critical role in purinergic signaling and neuroprotection. During ischemic stroke, CD73 expression is dynamically regulated in response to ischemia and inflammation. It catalyzes the conversion of AMP to adenosine, which activates adenosine receptors to exert neuroprotective effects. Targeting the CD73-adenosine pathway presents a potential therapeutic strategy for mitigating ischemic stroke damage. Pyroptosis, a highly inflammatory form of programmed cell death mediated by inflammasomes like NLRP3 and caspases, plays a significant role in cerebral ischemia-reperfusion injury. Astrocytes, the most abundant CNS cells, contribute to both neuroprotection and injury, with pyroptosis exacerbating inflammation and brain damage. Regulating astrocyte pyroptosis is a promising therapeutic target. Our study investigates CD73's role in regulating astrocyte pyroptosis during ischemia-reperfusion injury. Using CD73 knockout mice and overexpression models, along with in vitro oxygen-glucose deprivation/reperfusion experiments, we found that CD73 overexpression reduces GSDMD-mediated astrocyte pyroptosis via the A2B/NF-κB pathway. These findings offer a novel approach to reducing neuroinflammation, protecting astrocytes, and improving outcomes in ischemic stroke.

Exploring receptors for pro-resolving and non-pro-resolving mediators as therapeutic targets for sarcopenia

Sarcopenia is defined by a reduction in both muscle strength and mass. Sarcopenia may be an inevitable component of the aging process, but it may also be accelerated by comorbidities and metabolic derangements. The underlying mechanisms contributing to these pathological changes remain poorly understood. We propose that chronic inflammation-mediated networks and metabolic defects that exacerbate muscle dysfunction are critical factors in sarcopenia and related diseases. Consequently, utilizing specialized pro-resolving mediators (SPMs) that function through specific G-protein coupled receptors (GPCRs) may offer effective therapeutic options for these disorders. However, challenges such as a limited understanding of SPM/receptor signaling pathways, rapid inactivation of SPMs, and the complexities of SPM synthesis impede their practical application. In this context, stable small-molecule SPM mimetics and receptor agonists present promising alternatives. Moreover, the aged adipose-skeletal axis may contribute to this process. Activating non-SPM GPCRs on adipocytes, immune cells, and muscle cells under conditions of systemic, chronic, low-grade inflammation (SCLGI) could help alleviate inflammation and metabolic dysfunction. Recent preclinical studies indicate that both SPM GPCRs and non-SPM GPCRs can mitigate symptoms of aging-related diseases such as obesity and diabetes, which are driven by chronic inflammation and metabolic disturbances. These findings suggest that targeting these receptors could provide a novel strategy for addressing various chronic inflammatory conditions, including sarcopenia.

Non-coding RNA as a key regulator and novel target of apoptosis in diabetic cardiomyopathy: Current status and future prospects

The occurrence of diabetic cardiomyopathy (DCM) can be independent of several risk factors such as hypertension and myocardial ischemia, which can lead to heart failure, thus seriously threatening human health and life. Sustained hyperglycemic stimulation can induce cardiomyocyte apoptosis, which is recognized as the pathological basis of DCM. It has been demonstrated that dysregulation induced by apoptosis is closely associated to progression of DCM, but mechanisms behind it requires further clarification. Currently, increasing evidence has shown that non-coding RNA (ncRNA), especially microRNA, long-chain non-coding RNA (lncRNA), and circular RNA (circRNA), play a regulative role in apoptosis, thus affecting the progression of DCM. Notably, some ncRNAs have also exhibit potential significance as biomarkers and/or therapeutic targets for patients with DCM. In this review, recent findings regarding the potential mechanisms of ncRNA in regulating apoptosis and their role in the progression of DCM were systematically summarized in this research. The conclusion reveals that ncRNA abnormalities exert a crucial role in pathological changes of DCM, which offers potential therapeutic targets for the prevention of DCM.

Cannabidiol reverses myeloperoxidase hyperactivity in the prefrontal cortex and striatum, and reduces protein carbonyls in the hippocampus in a ketamine-induced schizophrenia rat model

BACKGROUND

Schizophrenia (SCZ) has limited treatment options, often with significant side effects. Cannabidiol (CBD), a non-euphoric phytocannabinoid, has shown potential as a novel therapeutic option in SCZ due to antipsychotic-like, anti-inflammatory, and antioxidant properties. We compared the therapeutic effects of CBD and risperidone (RISP) in a rat model of SCZ induced by sub-chronic ketamine (KET), focusing on inflammatory and oxidative stress, and behavioral phenotypes.

METHODS

Rats were pre-treated with KET or saline (SAL) for 10 days followed by CBD or RISP for 8 days. Locomotion, anxiety- and anhedonia-like behavior, and recognition memory were assessed. Oxidative damage as measured by protein carbonyls, thiobarbituric acid reactive substances, and catalase activity, and the inflammation markers myeloperoxidase (MPO) activity and nitrite/nitrate (N/N) concentration ratio were assessed in the prefrontal cortex (PFC), hypothalamus (HYP), hippocampus (HPC), and striatum, brain areas relevant to SCZ.

RESULTS

CBD restored the KET-induced decreased rearing behavior in the OFT, while RISP further decreased rearing. RISP treatment in control rats decreased rearing and elicited an anhedonic-like phenotype, while CBD did not. CBD, but not RISP restored the KET-induced increased levels of MPO activity in the PFC and the striatum, and protein carbonyls in the HPC. Post-KET treatment with RISP but not CBD decreased protein carbonyls in the PFC, and decreased the N/N concentration ratio in the HYP.

CONCLUSION

CBD restored the KET-induced decrease in rearing behavior without inducing an anhedonic-like phenotype as observed with RISP. CBD, and to a lesser extent RISP restored the oxidative stress and neuroinflammation elicited by KET in the striatum, HPC, and PFC. These findings support the possibility that the antipsychotic effects of CBD might be mediated by its antioxidant and anti-inflammatory effects.

Plastic chemicals disrupt molecular circadian rhythms via adenosine 1 receptor in vitro

The adenosine 1 receptor (A1R) is a G protein-coupled receptor that transduces signals to regulate sleep-wake cycles and circadian rhythms. Plastic products contain thousands of chemicals, known to disrupt physiological function. Recent research has demonstrated that some of these chemicals are also A1R agonists, however, the extent to which such activation propagates downstream and results in cellular alterations remains unknown. Thus, we investigate whether chemicals extracted from polyurethane (PUR) and polyvinyl chloride (PVC) plastics disrupt circadian rhythms via agonism of A1R. We confirm that plastic chemicals in both plastics activate A1R and inhibit intracellular cAMP in U2OS cells. Notably, this inhibition is comparable to that induced by the highly specific A1R agonist 2'-MeCCPA. To assess circadian disruption, we quantify temporal expression patterns of the clock genes PER2 and CRY2 at 4-h intervals over 48 h. Here, exposure to plastic chemicals shifts the phase in the oscillatory expression cycles of both clock genes by 9-17 min. Importantly, these effects are dose-dependent and reversible when A1R is inhibited by a pharmacological antagonist. This demonstrates that plastic chemicals can disrupt circadian processes by interfering with A1R signaling and suggests a novel mechanism by which these and other chemicals may contribute to non-communicable diseases.

Portal Fibrosis and the Ductular Reaction: Pathophysiological Role in the Progression of Liver Disease and Translational Opportunities

A consistent feature of chronic liver diseases and the hallmark of pathologic repair is the so-called "ductular reaction." This is a histologic abnormality characterized by an expansion of dysmorphic cholangiocytes inside and around portal spaces infiltrated by inflammatory, mesenchymal, and vascular cells. The ductular reaction is a highly regulated response based on the reactivation of morphogenetic signaling mechanisms and a complex crosstalk among a multitude of cell types. The nature and mechanism of these exchanges determine the difference between healthy regenerative liver repair and pathologic repair. An orchestrated signaling among cell types directs mesenchymal cells to deposit a specific extracellular matrix with distinct physical and biochemical properties defined as portal fibrosis. Progression of fibrosis leads to vast architectural and vascular changes known as "liver cirrhosis." The signals regulating the ecology of this microenvironment are just beginning to be addressed. Contrary to the tumor microenvironment, immune modulation inside this "benign" microenvironment is scarcely known. One of the reasons for this is that both the ductular reaction and portal fibrosis have been primarily considered a manifestation of cholestatic liver disease, whereas this phenomenon is also present, albeit with distinctive features, in all chronic human liver diseases. Novel human-derived cellular models and progress in "omics" technologies are increasing our knowledge at a fast pace. Most importantly, this knowledge is on the edge of generating new diagnostic and therapeutic advances. Here, we will critically review the latest advances, in terms of mechanisms, pathophysiology, and treatment prospects. In addition, we will delineate future avenues of research, including innovative translational opportunities.

Antioxidant and Anti-Inflammatory Benefits of Gymnema inodorum Leaf Extract in Human Umbilical Vein Endothelial Cells Under Peroxynitrite Stress

Endothelial dysfunction driven by oxidative and nitrosative stress is a critical factor in the pathogenesis of diabetes-related vascular complications. This study investigated the antioxidant and anti-inflammatory effects of Gymnema inodorum leaf (GiL) extract and its flavonoid constituents, kaempferol and quercetin, on human umbilical vein endothelial cells (HUVECs) exposed to peroxynitrite-induced stress. Peroxynitrite exposure significantly reduced the mRNA levels of antioxidant enzymes (e.g., catalase, glutathione peroxidase 1, superoxide dismutase 1, and superoxide dismutase 2) while increasing the expression of pro-inflammatory cytokines (e.g., tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, interleukin-10, and interleukin-12), ultimately leading to oxidative stress and cellular damage. Treatment with GiL extract reversed these effects by enhancing the defenses of antioxidants through the upregulation of enzymatic mRNA expression and suppressing inflammation via the downregulation of cytokine gene expression. The flavonoid constituents of the extract were identified as the active compounds responsible for these protective effects, with kaempferol and quercetin exhibiting significant free radical scavenging activity and the modulation of inflammatory signaling pathways. High doses of GiL extract showed greater efficacy in restoring cellular homeostasis and preventing oxidative damage. These findings underscore the potential of Gymnema inodorum as a source of bioactive compounds for preventing and managing endothelial dysfunction and other oxidative stress-related complications in diabetes.

Triclosan exposure induces liver fibrosis in mice: The heterogeneous nuclear ribonucleoprotein A1/pyruvate kinase M2 axis drives hepatic stellate cell activation

Triclosan (TCS) is an effective broad-spectrum antibacterial agent. TCS possesses a stable structure, can easily accumulate in the environment, and may have numerous negative impacts on human health. One organ particularly susceptible to TCS damage is the liver; however, the molecular mechanisms underlying TCS-induced liver damage remain unclear. A long-term TCS exposure model was established in C57BL/6 mice through maternal administration from gestation to postnatal 8-week-old. The offspring were randomly assigned to three groups (0, 50, and 100 mg/kg TCS) with six animals per group, ensuring an equal gender distribution (3 males and 3 females). The results showed that TCS-exposed mice exhibited serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase enzyme activities increased by 1.5-2 times when compared with vehicle-treated mice, along with features of liver fibrosis. In the LX-2 cell line, used as an in vitro model, TCS promoted proliferation and migration and induced the activation of hepatic stellate cells (HSCs). The level of pyruvate kinase M2 (PKM2) dimer increased by 200 % in LX-2 cells treated with TCS. PKM2 dimer overexpression stimulated HSC activation, whereas treatment with TEPP-46 (a PKM2 dimer inhibitor) significantly decreased the activation process. The expression of heterogeneous ribonucleoprotein particle A1 (hnRNPA1) was upregulated in the TCS treatment group and promoted the PKM2 expression. Moreover, disruption of the hnRNPA1/PKM2 axis reduced HSC proliferation and migration activated by TCS. Overall, our findings highlighted that TCS could cause liver fibrosis by stimulating the proliferation and migration of HSCs activated via the hnRNPA1/PKM2 axis, providing promising treatment options for TCS-related liver damage.

Reactivation of Oxidized Soluble Guanylate Cyclase as a Novel Treatment Strategy to Slow Progression of Calcific Aortic Valve Stenosis: Preclinical and Randomized Clinical Trials to Assess Safety and Efficacy

BACKGROUND

Pharmacological treatments for fibrocalcific aortic valve stenosis (FCAVS) have been elusive for >50 years. Here, we tested the hypothesis that reactivation of oxidized sGC (soluble guanylate cyclase), the primary receptor for nitric oxide, with ataciguat is a safe and efficacious strategy to slow progression of FCAVS.

METHODS

We used quantitative real-time reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry to characterize sGC signaling and the biological effects of ataciguat on signaling cascades related to nitric oxide, calcification, and fibrosis in excised human aortic valve tissue, aortic valve interstitial cells, and mouse aortic valves. We then conducted randomized, placebo-controlled phase I (14-day safety/tolerance) and phase II (6-month efficacy) trials in patients with moderate aortic valve stenosis.

RESULTS

In excised human tissue, we found robust losses in sGC signaling despite upregulation of sGC subunits. In vitro, ataciguat increased sGC signaling and reduced BMP2 (bone morphogenetic protein 2) signaling in aortic valve interstitial cells. In mice with established FCAVS, treatment with ataciguat attenuated BMP signaling and slowed progression of valve calcification and dysfunction. In a phase I, randomized, placebo-controlled trial, treatment with ataciguat for 2 weeks was safe and well tolerated in patients with moderate FCAVS (https://www.clinicaltrials.gov; Unique identifier: NCT02049203). In a separate phase II, randomized, placebo-controlled trial, treatment with ataciguat for 6 months slowed the progression of aortic valve calcification and tended to slow the progression of valvular and ventricular dysfunction in patients with moderate FCAVS (https://www.clinicaltrials.gov; Unique identifier: NCT02481258).

CONCLUSIONS

Collectively, this study highlights the therapeutic potential of the targeted restoration of the diseased/inactive form of sGC for treatment of FCAVS.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02049203. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02481258.

Impact of Cannabis Use on Deep Inferior Epigastric Perforator Autologous Breast Reconstruction: analysis of 719 patients and 1148 flaps: Impact of Cannabis Use in DIEP Reconstruction

INTRODUCTION

Given recent efforts to legalize and decriminalize recreational marijuana, its use has become increasingly common in the plastic surgery patient population. Although cannabis use has generally been considered lower risk than use of other recreational substances, recent studies have suggested it may be associated with an increased surgical complication rate. The aims of our study were to (1) characterize the extent of cannabis use and (2) determine the clinical effects of cannabis use in our cohort of patients undergoing autologous breast reconstruction using deep inferior epigastric perforator (DIEP) flaps.

METHODS

A retrospective study was conducted in adult patients who underwent autologous breast reconstruction using DIEP flaps between January 2015 and December 2023 by 5 plastic surgeons at our institution. Patients were divided into 2 groups of cannabis users and nonusers. Univariate and multivariable analyses were performed to assess outcomes between the groups.

RESULTS

A total of 87 cannabis users (12.1%) and 632 nonusers were included. A 5-fold increase in the proportion of cannabis users from 2015 to 2023 was found. Cannabis users were significantly younger (47.5 vs 51.7, P < 0.001) and had a significantly higher body mass index (30.5 vs 28.9, P = 0.012). Postoperatively, cannabis users had a significantly higher readmission rate (8.0% vs 3.2%, P = 0.035) and longer time to last abdominal drain removal (21 vs 17 days, P < 0.001). After controlling for confounders, multivariable logistic regression revealed cannabis use as a significant risk factor for postoperative general hematoma (OR: 3.078, confidence interval [95% CI]: 1.265-7.491, P = 0.013), breast hematoma (OR: 3.098, 95% CI: 1.197-8.020, P = 0.020), and readmission (OR: 2.865, 95% CI: 1.098-7.475, P = 0.031).

CONCLUSION

To our knowledge, this is the largest study examining the effects of cannabis use in patients receiving DIEP breast reconstruction. Our findings suggest that cannabis users undergoing DIEP breast reconstruction may require greater postoperative care and attention.

Causes and consequences of DNA double-stranded breaks in cardiovascular disease

The genome, whose stability is essential for survival, is incessantly exposed to internal and external stressors, which introduce an estimated 104 to 105 lesions, such as oxidation, in the nuclear genome of each mammalian cell each day. A delicate homeostatic balance between the generation and repair of DNA lesions maintains genomic stability. To initiate transcription, DNA strands unwind to form a transcription bubble and provide a template for the RNA polymerase II (RNAPII) complex to synthesize nascent RNA. The process generates DNA supercoils and introduces torsional stress. To enable RNAPII processing, the supercoils are released by topoisomerases by introducing strand breaks, including double-stranded breaks (DSBs). Thus, DSBs are intrinsic genomic features of gene expression. The breaks are quickly repaired upon processing of the transcription. DNA lesions and damaged proteins involved in transcription could impede the integrity and efficiency of RNAPII processing. The impediment, which is referred to as transcription stress, not only could lead to the generation of aberrant RNA species but also the accumulation of DSBs. The latter is particularly the case when topoisomerase processing and/or the repair mechanisms are compromised. The DSBs activate the DNA damage response (DDR) pathways to repair the damaged DNA and/or impose cell cycle arrest and cell death. In addition, the release of DSBs into the cytosol activates the cytosolic DNA-sensing proteins (CDSPs), which along with the nuclear DDR pathways induce the expression of senescence-associated secretory phenotype (SASP), cell cycle arrest, senescence, cell death, inflammation, and aging. The primary stimulus in hereditary cardiomyopathies is a mutation(s) in genes encoding the protein constituents of cardiac myocytes; however, the phenotype is the consequence of intertwined complex interactions among numerous stressors and the causal mutation(s). Increased internal DNA stressors, such as oxidation, alkylation, and cross-linking, are expected to be common in pathological conditions, including in hereditary cardiomyopathies. In addition, dysregulation of gene expression also imposes transcriptional stress and collectively with other stressors provokes the generation of DSBs. In addition, the depletion of nicotinamide adenine dinucleotide (NAD), which occurs in pathological conditions, impairs the repair mechanism and further facilitates the accumulation of DSBs. Because DSBs activate the DDR pathways, they are expected to contribute to the pathogenesis of cardiomyopathies. Thus, interventions to reduce the generation of DSBs, enhance their repair, and block the deleterious DDR pathways would be expected to impart salubrious effects not only in pathological states, as in hereditary cardiomyopathies but also aging.

The isolated, perfused working heart preparation of the mouse-Advantages and pitfalls

Isolated, perfused hearts are viable for hours outside the body, and important research findings have been made using mouse hearts ex vivo. In the Langendorff perfusion mode, the coronary tree is perfused via retrograde flow of a perfusate down the ascending aorta. Although the Langendorff setup is generally simpler and quicker to establish, the working heart mode allows the heart to function in a more physiologically relevant manner, where the perfusate is directed into the left ventricle via the left atrium. The contracting, fluid-filled ventricle will eject the perfusate into the aorta in a more physiologically relevant manner, lifting the physiological relevance of the contractile and energetic data. The workload on the heart (preload, afterload and heart rate) can be precisely adjusted in the working, isolated heart, and the ventricular performance, for example, end-diastolic and end-systolic pressures, stroke volume, cardiac output, and oxygen consumption can be determined. Moreover, using pressure-volume catheters, ventricular performance can be assessed in great detail. With the present review, we highlight the benefits and drawbacks of the technique and indicate where particular attention must be put when building the working heart setup, designing experiments, executing the studies, and analyzing the obtained data.

Soluble guanylate cyclase stimulators and activators as potential antihypertensive drugs

Poor blood pressure control in treated patients with hypertension is an important topic in the field of hypertension, and an unmet need for new therapeutic drugs remains. Soluble guanylate cyclase (sGC), a key signal transduction enzyme responsible for vasodilation, has attracted increasing interest as a therapeutic target in various cardiovascular diseases. Two different sGC agonists, sGC stimulators and activators, can increase its enzymatic activity in reduced and oxidized/apo forms, respectively. With some sGC agonists being already in clinical use, drugs in this category are expected to become new therapeutic agents for various conditions, including hypertension. In this review, we summarize the current knowledge on the antihypertensive effects of sGC agonists in various preclinical studies involving animal models of spontaneous hypertension, salt-sensitive hypertension, nitric oxide-deficient hypertension, renin-angiotensin-aldosterone system-dependent hypertension, malignant hypertension, metabolic syndrome, renoprival hypertension, renovascular hypertension, drug-induced hypertension, pregnancy hypertension, and treatment-resistant hypertension. Our compilation provides a comprehensive rationale for advancing the clinical development of sGC agonists for the treatment of hypertension.

Mechanistic insight into the role of cardiac-enriched microRNAs in diabetic heart injury

Cardiovascular complications, particularly diabetic cardiomyopathy (DCM), are the primary causes of morbidity and mortality among individuals with diabetes. Hyperglycemia associated with diabetes leads to cardiomyocyte hypertrophy, apoptosis, and myocardial fibrosis, culminating in heart failure (HF). Patients with diabetes face a 2-4 times greater risk of developing HF compared with those without diabetes. Consequently, there is a growing interest in exploring the molecular mechanisms that contribute to the development of DCM. MicroRNAs (miRNAs) are short, single-stranded, noncoding RNA molecules that participate in the maintenance of physiological homeostasis through the regulation of essential processes such as metabolism, cell proliferation, and apoptosis. At the posttranscriptional level, miRNAs modulate gene expression by binding directly to genes' mRNAs. Multiple cardiac-enriched miRNAs were reported to be dysregulated under diabetic conditions. Different studies revealed the role of specific miRNAs in the pathogenesis of diabetes and related cardiovascular complications, including cardiomyocyte hypertrophy and fibrosis, mitochondrial dysfunction, metabolic impairment, inflammatory response, or cardiomyocyte death. Circulating miRNAs have been shown to represent the potential biomarkers for early detection of diabetic heart injury. A deeper understanding of miRNAs and their role in diabetes-related pathophysiological processes could lead to new therapeutic strategies for addressing cardiac complications associated with diabetes.

Five Years of Long COVID Syndrome: An Updated Review on Cardiometabolic and Psychiatric Aspects

Five years after the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, there is still a significant number of people who have survived COVID-19 but never fully recovered from the disease. They go through an odyssey of doctor visits and a multitude of diagnostic tests, which ultimately do not provide concrete correlations and answers to the question of how exactly long COVID (LC) affects both physical and mental health, and performance. Often, not even highly technical and highly specialized methods, such as cardiac magnetic resonance imaging (MRI), can provide further explanation. Various research efforts continue to investigate the causes, effects and possible treatments of LC, particularly its impact on cognition and mental health. Patients with LC may experience persistent symptoms, but new symptoms also occur. Based on available studies, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) does not only affect the pulmonary system, but nearly every major system and organ, from the brain and heart to the kidneys and immune system. What mechanisms could explain the persistent symptoms of LC and the inadequate recovery? How valuable is an early internal and neurological examination, particularly in the context of psychotherapy? In this review, we examined which factors could contribute to the persistence of LC symptoms and to what extent mitochondrial impairment by LC can explain the symptoms of LC.