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Background and Purpose: We hypothesized that an in vitro, stretch-based model of neural injury may be useful to identify compounds that decrease the cellular damage in neurotrauma., Experimental Approach: We screened three neural cell lines (B35, RN33B and SH-SY5Y) subjected to two differentiation methods and selected all-trans-retinoic acid-differentiated B35 rat neuroblastoma cells subjected to rapid stretch injury, coupled with a subthreshold concentration of H 2 O 2 , for the screen. The model induced marked alterations in gene expression and proteomic signature of the cells and culminated in delayed cell death (LDH release) and mitochondrial dysfunction [reduced 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) conversion]. Follow-up studies utilized human stem cell-derived neurons subjected to rapid stretch injury., Key Results: From screening of a composite library of 3500 drugs, five drugs (when applied in a post-treatment regimen relative to stretch injury) improved both LDH and MTT responses. The effects of rifampicin were investigated in further detail. Rifampicin reduced cell necrosis and apoptosis and improved cellular bioenergetics. In a second model (stretch injury in human stem cell-derived neurons), rifampicin pretreatment attenuated LDH release, protected against the loss of neurite length and maintained neuron-specific class III β-tubulin immunoreactivity., Conclusions and Implications: We conclude that the current model is suitable for medium-throughput screening to identify compounds with neuroprotective potential. Rifampicin, when applied either in pre- or post-treatment, improves the viability of neurons subjected to stretch injury and protects against neurite loss. Rifampicin may be a candidate for repurposing for the therapy of traumatic brain injury., Linked Articles: This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc., (© 2016 The British Pharmacological Society.)

Background: Although TGF-ß and the transcription factor Egr-1 play an important role in both kidney fibrosis and in response to acute changes of renal medullary osmolarity, their role under sustained hypo- or hyperosmolar conditions has not been elucidated. We investigated the effects of chronic hypertonicity and hypotonicity on the renal medullary TGF-ß and Egr-1 expression., Methods: Male adult Sprague Dawley rats (n = 6/group) were treated with 15 mg/day furosemide, or the rats were water restricted to 15 ml/200 g body weight per day. Control rats had free access to water and rodent chow. Kidneys were harvested after 5 days of treament. In cultured inner medullary collecting duct (IMCD) cells, osmolarity was increased from 330 mOsm to 900 mOsm over 6 days. Analyses were performed at 330, 600 and 900 mOsm., Results: Urine osmolarity has not changed due to furosemide treatment but increased 2-fold after water restriction (p < 0.05). Gene expression of TGF-ß and Egr-1 increased by 1.9-fold and 7-fold in the hypertonic medulla, respectively (p < 0.05), accompanied by 6-fold and 2-fold increased c-Fos and TIMP-1 expression, respectively (p < 0.05) and positive immunostaining for TGF-ß and Egr-1 (p < 0.05). Similarly, hyperosmolarity led to overexpression of TGF-ß and Egr-1 mRNA in IMCD cells (2.5-fold and 3.5-fold increase from 330 to 900 mOsm, respectively (p < 0.05)) accompanied by significant c-Fos and c-Jun overexpressions (p < 0.01), and increased Col3a1 and Col4a1 mRNA expression., Conclusion: We conclude that both TGF-ß and Egr-1 are upregulated by sustained hyperosmolarity in the rat renal medulla, and it favors the expression of extracellular matrix components.

Cystathionine-β-synthase (CBS) has been recently identified as a drug target for several forms of cancer. Currently no potent and selective CBS inhibitors are available. Using a composite collection of 8871 clinically used drugs and well-annotated pharmacological compounds (including the LOPAC library, the FDA Approved Drug Library, the NIH Clinical Collection, the New Prestwick Chemical Library, the US Drug Collection, the International Drug Collection, the 'Killer Plates' collection and a small custom collection of PLP-dependent enzyme inhibitors), we conducted an in vitro screen in order to identify inhibitors for CBS using a primary 7-azido-4-methylcoumarin (AzMc) screen to detect CBS-derived hydrogen sulfide (H 2 S) production. Initial hits were subjected to counterscreens using the methylene blue assay (a secondary assay to measure H 2 S production) and were assessed for their ability to quench the H 2 S signal produced by the H 2 S donor compound GYY4137. Four compounds, hexachlorophene, tannic acid, aurintricarboxylic acid and benserazide showed concentration-dependent CBS inhibitory actions without scavenging H 2 S released from GYY4137, identifying them as direct CBS inhibitors. Hexachlorophene (IC 50 : ∼60μM), tannic acid (IC 50 : ∼40μM) and benserazide (IC 50 : ∼30μM) were less potent CBS inhibitors than the two reference compounds AOAA (IC 50 : ∼3μM) and NSC67078 (IC 50 : ∼1μM), while aurintricarboxylic acid (IC 50 : ∼3μM) was equipotent with AOAA. The second reference compound NSC67078 not only inhibited the CBS-induced AzMC fluorescence signal (IC 50 : ∼1μM), but also inhibited with the GYY4137-induced AzMC fluorescence signal with (IC 50 of ∼6μM) indicative of scavenging/non-specific effects. Hexachlorophene (IC 50 : ∼6μM), tannic acid (IC 50 : ∼20μM), benserazide (IC 50 : ∼20μM), and NSC67078 (IC 50 : ∼0.3μM) inhibited HCT116 colon cancer cells proliferation with greater potency than AOAA (IC 50 : ∼300μM). In contrast, although a CBS inhibitor in the cell-free assay, aurintricarboxylic acid failed to inhibit HCT116 proliferation at lower concentrations, and stimulated cell proliferation at 300μM. Copper-containing compounds present in the libraries, were also found to be potent inhibitors of recombinant CBS; however this activity was due to the CBS inhibitory effect of copper ions themselves. However, copper ions, up to 300μM, did not inhibit HCT116 cell proliferation. Benserazide was only a weak inhibitor of the activity of the other H 2 S-generating enzymes CSE and 3-MST activity (16% and 35% inhibition at 100μM, respectively) in vitro. Benserazide suppressed HCT116 mitochondrial function and inhibited proliferation of the high CBS-expressing colon cancer cell line HT29, but not the low CBS-expressing line, LoVo. The major benserazide metabolite 2,3,4-trihydroxybenzylhydrazine also inhibited CBS activity and suppressed HCT116 cell proliferation in vitro. In an in vivo study of nude mice bearing human colon cancer cell xenografts, benserazide (50mg/kg/days.q.) prevented tumor growth. In silico docking simulations showed that benserazide binds in the active site of the enzyme and reacts with the PLP cofactor by forming reversible but kinetically stable Schiff base-like adducts with the formyl moiety of pyridoxal. We conclude that benserazide inhibits CBS activity and suppresses colon cancer cell proliferation and bioenergetics in vitro, and tumor growth in vivo. Further pharmacokinetic, pharmacodynamic and preclinical animal studies are necessary to evaluate the potential of repurposing benserazide for the treatment of colorectal cancers., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

High Mobility Group Box 1 (HMGB1) is a highly conserved non-histone chromatin-associated protein across species, primarily recognized for its regulatory impact on vital cellular processes, like autophagy, cell survival, and apoptosis. HMGB1 exhibits dual functionality based on its localization: both as a non-histone protein in the nucleus and as an inducer of inflammatory cytokines upon extracellular release. Pathophysiological insights reveal that HMGB1 plays a significant role in the onset and progression of a vast array of diseases, viz., atherosclerosis, kidney damage, cancer, and neurodegeneration. However, a clear mechanistic understanding of HMGB1 release, translocation, and associated signaling cascades in mediating such physiological dysfunctions remains obscure. This review presents a detailed outline of HMGB1 structure–function relationship and its regulatory role in disease onset and progression from a signaling perspective. This review also presents an insight into the status of HMGB1 druggability, potential limitations in understanding HMGB1 pathophysiology, and future perspective of studies that can be undertaken to address the existing scientific gap. Based on existing paradigm of various studies, HMGB1 is a critical regulator of inflammatory cascades and drives the onset and progression of a broad spectrum of dysfunctions. Studies focusing on HMGB1 druggability have enabled the development of biologics with potential clinical benefits. However, deeper understanding of post-translational modifications, redox states, translocation mechanisms, and mitochondrial interactions can potentially enable the development of better courses of therapy against HMGB1-mediated physiological dysfunctions. [ABSTRACT FROM AUTHOR]

Citrus fruits contain several bioactive components. Among them, one of the major components is 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), which has previously shown protective effects in the brain in some disease models; moreover, HMF has been shown to penetrate the brain. In recent years, inflammation has been identified as a defense response in the body; however, a chronic inflammatory response may trigger several diseases. Inflammation in the peripheral tissues spreads to the brain and is suggested to be closely associated with diseases of the central nervous system. HMF has shown anti-inflammatory effects in the hippocampus following global cerebral ischemia; however, its effects on acute and chronic inflammation in the brain remain unclear. Therefore, in the present study, we examined the effects of HMF in a mouse model of systemic inflammation induced by lipopolysaccharide (LPS) administration. In this study, HMF suppressed LPS-induced microglial activation in the brains of acute inflammation model mice two days after LPS administration. In addition, 24 days after the administration of LPS in a chronic inflammation model, HMF promoted BDNF production and neurogenesis in the brain, which also tended to suppress tau protein phosphorylation at Ser396. These results suggest that HMF has anti-inflammatory and neurotrophic effects in the brains of model mice with lipopolysaccharide-induced systemic inflammation. [ABSTRACT FROM AUTHOR]

It is unknown when inosine was first employed as a renoprotective agent in the context of kidney transplantation procedures. However, there is no clinical evidence to support a protective role of inosine. The aim of this study was to investigate the effect of inosine on graft recovery. Data related to donors and recipients were retrieved from relevant records between 2015 and 2023. A total of 1138 kidney transplant cases were identified, including 1005 recipients who received a bolus of 1000 mg inosine and 133 recipients who did not receive inosine during transplantation surgery. The endpoints of the analysis included recipient recovery after transplantation as assessed by delayed graft function (DGF), peak estimated glomerular filtration rate (eGFR) after transplantation, and unfavorable graft function recovery. Given the high dimensionality of the donor and recipient variables, propensity score weighting analyses were conducted. No significant differences in the risk of DGF (OR = 0.80 [0.52, 1.22], p = 0.301), unfavorable graft function recovery (OR = 0.95 [0.61, 1.51], p = 0.842) or peak eGFR after transplantation (β = 1.61 [−4.33, 7.56], p = 0.594) were observed between the inosine and no-inosine groups via overlap weighting analysis. Intraoperative infusion of 1000 mg of inosine has no effect on graft recovery after kidney transplantation. Therefore, the practice of using inosine during kidney transplantation surgery is not supported by evidence. [ABSTRACT FROM AUTHOR]

High mobility group box 1 (HMGB1), a highly conserved, ubiquitous protein, is released into the circulation during sterile inflammation (e.g. arthritis, trauma) and circulatory shock. It participates in the pathogenesis of delayed inflammatory responses and organ dysfunction. While several molecules have been identified that modulate the release of HMGB1, less attention has been paid to identify pharmacological inhibitors of the downstream inflammatory processes elicited by HMGB1 (C23-C45 disulfide C106 thiol form). In the current study, a cell-based medium-throughput screening of a 5000+ compound focused library of clinical drugs and drug-like compounds was performed in murine RAW264.7 macrophages, in order to identify modulators of HMGB1-induced tumor-necrosis factor alpha (TNFα) production. Clinically used drugs that suppressed HMGB1-induced TNFα production included glucocorticoids, beta agonists, and the anti-HIV compound indinavir. A re-screen of the NIH clinical compound library identified beta-agonists and various intracellular cAMP enhancers as compounds that potentiate the inhibitory effect of glucocorticoids on HMGB1-induced TNFα production. The molecular pathways involved in this synergistic anti-inflammatory effect are related, at least in part, to inhibition of TNFα mRNA synthesis via a synergistic suppression of ERK/IκB activation. Inhibition of TNFα production by prednisolone+salbutamol pretreatment was also confirmed in vivo in mice subjected to HMGB1 injection; this effect was more pronounced than the effect of either of the agents administered separately. The current study unveils several drug-like modulators of HMGB1-mediated inflammatory responses and offers pharmacological directions for the therapeutic suppression of inflammatory responses in HMGB1-dependent diseases.

We have conducted a phenotypic screening in endothelial cells exposed to elevated extracellular glucose (an in vitro model of hyperglycemia) to identify compounds that prevent hyperglycemia-induced reactive oxygen species (ROS) formation without adversely affecting cell viability. From a focused library of >6,000 clinically used drug-like and pharmacologically active compounds, several classes of active compounds emerged, with a confirmed hit rate of <0.5%. Follow-up studies focused on paroxetine, a clinically used antidepressant compound that has not been previously implicated in the context of hyperglycemia or diabetes. Paroxetine reduced hyperglycemia-induced mitochondrial ROS formation, mitochondrial protein oxidation, and mitochondrial and nuclear DNA damage, without interfering with mitochondrial electron transport or cellular bioenergetics. The ability of paroxetine to improve hyperglycemic endothelial cell injury was unique among serotonin reuptake blockers and can be attributed to its antioxidant effect, which primarily resides within its sesamol moiety. Paroxetine maintained the ability of vascular rings to respond to the endothelium-dependent relaxant acetylcholine, both during in vitro hyperglycemia and ex vivo, in a rat model of streptozotocin-induced diabetes. Thus, the current work identifies a novel pharmacological action of paroxetine as a protector of endothelial cells against hyperglycemic injury and raises the potential of repurposing of this drug for the experimental therapy of diabetic cardiovascular complications.

Liver ischemia represents a common clinical problem. In the present study, using an in vitro model of hepatic ischemia-reperfusion injury, we evaluated the potential cytoprotective effect of the purine metabolites, such as adenosine and inosine, and studied the mode of their pharmacological actions. The human hepatocellular carcinoma-derived cell line HepG2 was subjected to combined oxygen-glucose deprivation (COGD; 0-14-24 h), followed by re-oxygenation (0-4-24 h). Adenosine or inosine (300-1,000 µM) were applied in pretreatment. Cell viability and cytotoxicity were measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and lactate dehydrogenase methods, respectively. The results showed that both adenosine and inosine exerted cytoprotective effects, and these effects were not related to receptor-mediated actions, since they were not prevented by selective adenosine receptor antagonists. On the other hand, the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride (EHNA, 10 µM) markedly and almost fully reversed the protective effect of adenosine during COGD, while it did not influence the cytoprotective effect of inosine in the same assay conditions. These results suggest that the cytoprotective effects are related to intracellular actions, and, in the case of adenosine also involve intracellular conversion to inosine. The likely interpretation of these findings is that inosine serves as an alternative source of energy to produce ATP during hypoxic conditions. The protective effects are also partially dependent on adenosine kinase, as the inhibitor 4-amino-5-(3-bromophenyl)-7-(6‑morpholino-pyridin-3-yl)pyrido[2,3-d]pyrimidine, 2HCl (ABT 702, 30 µM) significantly reversed the protective effect of both adenosine and inosine during hypoxia and re-oxygenation. Collectively, the current results support the view that during hypoxia, adenosine and inosine exert cytoprotective effects via receptor-independent, intracellular modes of action, which, in part, depend on the restoration of cellular bioenergetics. The present study supports the view that testing of inosine for protection against various forms of warm and cold liver ischemia is relevant.

Background and Objectives: The effect and mechanism of the extract of Camellia japonica L. (ECJ) on brain injury following cerebral ischemia/reperfusion (I/R) were demonstrated in the present study. Materials and Methods: We detected mice's brain damage after cerebral I/R and tested neuronal injury following oxygen-glucose deprivation/re-oxygenation (OGD/R) to evaluate the neuroprotection of ECJ. Besides, we tested the expressions of hydrogen sulfide (H2S) synthase cystathionine-β-synthase (CBS) and α subunit of large-conductance Ca2+-activated K+ channels (BKα) both in brain tissues and culture neurons. Importantly, the roles of iberiotoxin (IbTX), BKCa channel inhibitor, and CBS inhibitor aminooxyacetic acid (AOAA) on ECJ-mediated neuroprotection were assessed to explore the neuroprotective mechanism of ECJ. Results: ECJ treatment could alleviate the mice's brain injury following cerebral I/R and reduce the neuronal damage caused by OGD/R in vitro, which was inhibited by IbTX and AOAA. In addition, ECJ could increase the expression of CBS and the α subunit of BKCa channel (BKα) in mice brain tissues and the culture neurons, as well as improve the H2S production. Furthermore, exogenous H2S donor NaHS also improved the BKα expression in OGD/R neurons. Importantly, NaHS alleviated the neuronal injury in vitro, which was inhibited by IbTX as well. Conclusion: ECJ can protect against mouse cerebral I/R injury, the mechanism of which is correlated with promoting the CBS/H2S-BKCa pathway. [ABSTRACT FROM AUTHOR]

Purpose: The goal of the current studies was to elucidate the role of the principal poly(ADP-ribose)polymerase isoform, PARP1 in the regulation of cellular energetics in endothelial cells under resting conditions and during oxidative stress., Methods: We utilized bEnd.3 endothelial cells and A549 human transformed epithelial cells. PARP1 was inhibited either by pharmacological inhibitors or by siRNA silencing. The Seahorse XF24 Extracellular Flux Analyzer was used to measure indices of mitochondrial respiration (oxygen consumption rate) and of glycolysis (extracellular acidification rate). Cell viability, cellular and mitochondrial NAD(+) levels and mitochondrial biogenesis were also measured., Results: Silencing of PARP1 increased basal cellular parameters of oxidative phosphorylation, providing direct evidence that PARP1 is a regulator of mitochondrial function in resting cells. Pharmacological inhibitors of PARP1 and siRNA silencing of PARP1 protected against the development of mitochondrial dysfunction and elevated the respiratory reserve capacity in endothelial and epithelial cells exposed to oxidative stress. The observed effects were unrelated to an effect on mitochondrial biogenesis. Isolated mitochondria of A549 human transformed epithelial cells exhibited an improved resting bioenergetic status after stable lentiviral silencing of PARP1; these effects were associated with elevated resting mitochondrial NAD+ levels in PARP1 silenced cells., Conclusions: PARP1 is a regulator of basal cellular energetics in resting endothelial and epithelial cells. Furthermore, endothelial cells respond with a decrease in their mitochondrial reserve capacity during low-level oxidative stress, an effect, which is attenuated by PARP1 inhibition. While PARP1 is a regulator of oxidative phosphorylation in resting and oxidatively stressed cells, it only exerts a minor effect on glycolysis., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Acute tubular necrosis is a clinical problem that lacks specific therapy and is characterized by high mortality rate. The ischemic renal injury affects the proximal tubule cells causing dysfunction and cell death after severe hypoperfusion. We utilized a cell-based screening approach in a hypoxia-reoxygenation model of tubular injury to search for cytoprotective action using a library of pharmacologically active compounds. Oxygen-glucose deprivation (OGD) induced ATP depletion, suppressed aerobic and anaerobic metabolism, increased the permeability of the monolayer, caused poly(ADP-ribose) polymerase cleavage and caspase-dependent cell death. The only compound that proved cytoprotective either applied prior to the hypoxia induction or during the reoxygenation was adenosine. The protective effect of adenosine required the coordinated actions of adenosine deaminase and adenosine kinase, but did not requisite the purine receptors. Adenosine and inosine better preserved the cellular ATP content during ischemia than equimolar amount of glucose, and accelerated the restoration of the cellular ATP pool following the OGD. Our results suggest that radical changes occur in the cellular metabolism to respond to the energy demand during and following hypoxia, which include the use of nucleosides as an essential energy source. Thus purine nucleoside supplementation holds promise in the treatment of acute renal failure., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The goal of the present studies was to investigate the role of changes in hydrogen sulfide (H(2)S) homeostasis in the pathogenesis of hyperglycemic endothelial dysfunction. Exposure of bEnd3 microvascular endothelial cells to elevated extracellular glucose (in vitro "hyperglycemia") induced the mitochondrial formation of reactive oxygen species (ROS), which resulted in an increased consumption of endogenous and exogenous H(2)S. Replacement of H(2)S or overexpression of the H(2)S-producing enzyme cystathionine-γ-lyase (CSE) attenuated the hyperglycemia-induced enhancement of ROS formation, attenuated nuclear DNA injury, reduced the activation of the nuclear enzyme poly(ADP-ribose) polymerase, and improved cellular viability. In vitro hyperglycemia resulted in a switch from oxidative phosphorylation to glycolysis, an effect that was partially corrected by H(2)S supplementation. Exposure of isolated vascular rings to high glucose in vitro induced an impairment of endothelium-dependent relaxations, which was prevented by CSE overexpression or H(2)S supplementation. siRNA silencing of CSE exacerbated ROS production in hyperglycemic endothelial cells. Vascular rings from CSE(-/-) mice exhibited an accelerated impairment of endothelium-dependent relaxations in response to in vitro hyperglycemia, compared with wild-type controls. Streptozotocin-induced diabetes in rats resulted in a decrease in the circulating level of H(2)S; replacement of H(2)S protected from the development of endothelial dysfunction ex vivo. In conclusion, endogenously produced H(2)S protects against the development of hyperglycemia-induced endothelial dysfunction. We hypothesize that, in hyperglycemic endothelial cells, mitochondrial ROS production and increased H(2)S catabolism form a positive feed-forward cycle. H(2)S replacement protects against these alterations, resulting in reduced ROS formation, improved endothelial metabolic state, and maintenance of normal endothelial function.

Background and Purpose: We have established an in vitro model of acute tubular necrosis in rat kidney tubular cells, using combined oxygen-glucose deprivation (COGD) and screened a library of 1280 pharmacologically active compounds for cytoprotective effects., Experimental Approach: We used in vitro cell-based, high throughput, screening, with cells subjected to COGD using hypoxia chambers, followed by re-oxygenation. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and the Alamar Blue assay measured mitochondrial respiration and the lactate dehydrogenase assay was used to indicate cell death. ATP levels were measured using a luminometric assay., Key Results: Adenosine markedly reduced cellular injury, with maximal cytoprotective effect at 100 microM and an EC(50) value of 14 microM. Inosine was also found to be cytoprotective. The selective A(3) adenosine receptor antagonist MRS 1523 attenuated the protective effects of adenosine and inosine, while an A(3) adenosine receptor agonist provided a partial protective effect. Adenosine deaminase inhibition attenuated the cytoprotective effect of adenosine but not of inosine during COGD. Inhibition of adenosine kinase reduced the protective effects of both adenosine and inosine during COGD. Pretreatment of the cells with adenosine or inosine markedly protected against the fall in cellular ATP content in the cells subjected to COGD., Conclusions and Implications: The cytoprotection elicited by adenosine and inosine in a model of renal ischaemia involved both interactions with cell surface adenosine receptors on renal tubular epithelial cells and intracellular metabolism and conversion of adenosine to ATP.

Myocyte injury due to myocardial reperfusion injury plays a crucial role in the pathogenesis of acute myocardial infarction even after successful coronary revascularization. Identification of compounds that reduce reperfusion-associated myocyte death is important. Therefore, we developed an in vitro model of myocardial reperfusion injury in H9c2 rat cardiomyocytes and applied a cell-based high-throughput approach to screen a standard library of pharmacologically active compounds (LOPAC) in order to identify drugs with cardioprotective effects. Oxidative stress was induced with hydrogen peroxide (H2O2) treatment, which resulted in approximately 50% reduction in cell viability. Test compounds were added at a 3-microM final concentration as a pretreatment or in a delayed fashion (30 min after the peroxide challenge in order to imitate pharmacological treatment following angioplasty). Cells were cultured for 3 or 24 h. Viability was quantitated with the methylthiazolyldiphenyl-tetrazolium bromide method. Cytotoxicity and cytoprotection were also evaluated by measuring the lactate dehydrogenase activity in the cell culture supernatant. The screening identified a number of compounds with cytoprotective action, including molecules that are known to interfere with components of DNA repair and cell cycle progression, e.g. poly(ADP-ribose) polymerase (PARP) inhibitors, topoisomerase inhibitors, and cyclin dependent kinase inhibitors, or reduce energy consumption by interfering with cardiac myofilament function. A number of dopamine D1 receptor agonists also provided significant cytoprotection at 3 h, but only three of them showed a similar effect at 24 h: chloro- and bromo-APB and chloro-PB hydrobromide. Chloro-APB hydrobromide significantly reduced peroxide-induced PARP activation in the myocytes independently of its action on dopamine D1 receptors, but lacked PARP inhibitor capacity in a cell-free PARP assay system. In conclusion, the pattern of cytoprotective drugs identified in the current assay supports the overall validity of our model system. The findings demonstrate that cytoprotective agents, including novel indirect inhibitors of cellular PARP activation can be identified with the method, chloro-APB hydrobromide being one such compound. The current experimental setting can be employed for cell-based high-throughput screening of various compound libraries.

Background: We have evidence that hydrogen sulfide (H2S)-releasing compounds can reduce intraocular pressure in normotensive and glaucomatous rabbits by increasing the aqueous humor (AH) outflow through the trabecular meshwork. Since H2S has been reported to possess neuroprotective actions, the prevention of retinal ganglion cell loss is an important strategy in the pharmacotherapy of glaucoma. Consequently, the present study aimed to investigate the neuroprotective actions of H2S-releasing compounds against hydrogen peroxide (H2O2)-induced oxidative stress in an isolated bovine retina. Materials and Methods: The isolated neural retinae were pretreated with a substrate for H2S biosynthesis called L-cysteine, with the fast H2S-releasing compound sodium hydrosulfide, and with a mitochondrial-targeting H2S-releasing compound, AP123, for thirty minutes before a 30-min oxidative insult with H2O2 (100 µM). Lipid peroxidation was assessed via an enzyme immunoassay by measuring the stable oxidative stress marker, 8-epi PGF2α (8-isoprostane), levels in the retinal tissues. To determine the role of endogenous H2S, studies were performed using the following biosynthesis enzyme inhibitors: aminooxyacetic acid (AOAA, 30 µM); a cystathione-β-synthase/cystathionine-γ-lyase (CBS/CSE) inhibitor, α–ketobutyric acid (KBA, 1 mM); and a 3-mercaptopyruvate-s-sulfurtransferase (3-MST) inhibitor, in the absence and presence of H2S-releasing compounds. Results: Exposure of the isolated retinas to H2O2 produced a time-dependent (10–40 min) and concentration-dependent (30–300 µM) increase in the 8-isoprostane levels when compared to the untreated tissues. L-cysteine (10 nM–1 µM) and NaHS (30 –100 µM) significantly (p < 0.001; n = 12) prevented H2O2-induced oxidative damage in a concentration-dependent manner. Furthermore, AP123 (100 nM–1 µM) attenuated oxidative H2O2 damage resulted in an approximated 60% reduction in 8-isoprostane levels compared to the tissues treated with H2O2 alone. While AOAA (30 µM) and KBA (1 mM) did not affect the L-cysteine evoked attenuation of H2O2-induced oxidative stress, KBA reversed the antioxidant responses caused by AP123. Conclusions: In conclusion, various forms of H2S-releasing compounds and the substrate, L-cysteine, can prevent H2O2-induced lipid peroxidation in an isolated bovine retina. [ABSTRACT FROM AUTHOR]

Background: Poly(ADP-ribose) polymerase-1 (PARP-1) is a pan nuclear protein that utilizes NAD+ as a substrate for poly(ADP-ribosyl)ation reaction (PARylation), resulting in both auto-modification and the modification of its accepter proteins. Earlier reports suggested that several nucleolar proteins interact and colocalize with PARP-1, leading to their PARylation. However, whether PARP-1 has any role in nucleolar biogenesis and the functional relevance of such a role is still obscure. Results: Using PARP-1 depleted cells, we investigated the function of PARP-1 in maintaining the nucleolar morphology and protein levels under normal physiological conditions. Our results revealed that several nucleolar proteins like nucleolin, fibrillarin, and nucleophosmin get up-regulated when PARP-1 is depleted. Additionally, in line with the higher accumulation of nucleolin, stably depleted PARP-1 cells show lower activation of caspase-3, lesser annexin-V staining, and reduced accumulation of AIF in the nucleus upon induction of oxidative stress. Concurrently, PARP-1 silenced cells showed higher mitochondrial oxidative phosphorylation and more fragmented and intermediate mitochondria than the parental counterpart, suggesting higher metabolic activity for better survival. Conclusion: Based on our findings, we demonstrate that PARP-1 may have a role in regulating nucleolar protein levels and mitochondrial activity, thus maintaining the homeostasis between cell protective and cell death pathways, and such cell-protective mechanism could be implicated as the priming state of a pre-cancerous condition or tumour dormancy. [ABSTRACT FROM AUTHOR]

Chronic exposure to environmental hazards causes airway epithelial dysfunction, primarily impaired physical barriers, immune dysfunction, and repair or regeneration. Impairment of airway epithelial function subsequently leads to exaggerated airway inflammation and remodeling, the main features of chronic obstructive pulmonary disease (COPD). Mitochondrial damage has been identified as one of the mechanisms of airway abnormalities in COPD, which is closely related to airway inflammation and airflow limitation. In this review, we evaluate updated evidence for airway epithelial mitochondrial damage in COPD and focus on the role of mitochondrial damage in airway epithelial dysfunction. In addition, the possible mechanism of airway epithelial dysfunction mediated by mitochondrial damage is discussed in detail, and recent strategies related to airway epithelial-targeted mitochondrial therapy are summarized. Results have shown that dysregulation of mitochondrial quality and oxidative stress may lead to airway epithelial dysfunction in COPD. This may result from mitochondrial damage as a central organelle mediating abnormalities in cellular metabolism. Mitochondrial damage mediates procellular senescence effects due to mitochondrial reactive oxygen species, which effectively exacerbate different types of programmed cell death, participate in lipid metabolism abnormalities, and ultimately promote airway epithelial dysfunction and trigger COPD airway abnormalities. These can be prevented by targeting mitochondrial damage factors and mitochondrial transfer. Thus, because mitochondrial damage is involved in COPD progression as a central factor of homeostatic imbalance in airway epithelial cells, it may be a novel target for therapeutic intervention to restore airway epithelial integrity and function in COPD. [ABSTRACT FROM AUTHOR]

Irisin is a myokine secreted under the influence of physical activity and exposure to low temperatures and through different exogenous stimuli by the cleavage of its precursor, fibronectin type III domain-containing protein 5 (FNDC5). It is mainly known for maintaining of metabolic homeostasis, promoting the browning of white adipose tissue, the thermogenesis process, and glucose homeostasis. Growing experimental evidence suggests the possible central role of irisin in the regulation of cardiometabolic pathophysiological processes. On the other side, hydrogen sulfide (H2S) is well recognized as a pleiotropic gasotransmitter that regulates several homeostatic balances and physiological functions and takes part in the pathogenesis of cardiometabolic diseases. Through the S-persulfidation of cysteine protein residues, H2S is capable of interacting with crucial signaling pathways, exerting beneficial effects in regulating glucose and lipid homeostasis as well. H2S and irisin seem to be intertwined; indeed, recently, H2S was found to regulate irisin secretion by activating the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)/FNDC5/irisin signaling pathway, and they share several mechanisms of action. Their involvement in metabolic diseases is confirmed by the detection of their lower circulating levels in obese and diabetic subjects. Along with the importance of metabolic disorders, these modulators exert favorable effects against cardiovascular diseases, preventing incidents of hypertension, atherosclerosis, heart failure, myocardial infarction, and ischemia–reperfusion injury. This review, for the first time, aims to explore the role of H2S and irisin and their possible crosstalk in cardiovascular diseases, pointing out the main effects exerted through the common molecular pathways involved. [ABSTRACT FROM AUTHOR]

Background: Odontogenic cysts/tumor can cause severe bone destruction, which affects maxillofacial function and aesthetics. Meanwhile, metabolic reprogramming is an important hallmark of diseases. Changes in metabolic flow affect all aspects of disease, especially bone-related diseases. At present, the researches on pathogenesis of odontogenic cysts/tumor are mainly focused on the level of gene regulation, but the effects of metabolic alterations on odontogenic cysts/tumor have still underexplored. Materials and methods: Imaging analysis was used to evaluate the lesion size of different odontogenic lesions. Tartrate resistant acid phosphatase (TRAP) and immunohistochemistry (IHC) assays were utilized to detect the differences in bone destruction activity in odontogenic cysts and tumors. Furthermore, metabolomics and weighted gene co-expression network analysis (WGCNA) were conducted for the metabolomic features and key metabolite screening, respectively. The effect of ferroptosis inhibition on bone destruction was confirmed by IHC, immunofluorescence, and malondialdehyde colorimetric assay. Results: The bone destruction activity of ameloblastoma (AM) was the strongest and the weakest in odontogenic cysts (OC). High-throughput targeted metabolomics was used to map the metabolomic profiles of OC, odontogenic keratocyst (OKC) and AM. WGCNA and differential analysis identified L-cysteine in OKC and AM. Cystathionine γ-lyase (CTH) was further screened by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The functions of L-cysteine were further validated. Finally, we confirmed that CTH affected destructive activities by regulating the sensitivity of epithelial cells to ferroptosis. Conclusion: High-throughput targeted metabolomics performed on diseased tissue confirmed the unique alteration of metabolic profiles in OKC and AM. CTH and its metabolite L-cysteine are the key factors regulating destructive activities. [ABSTRACT FROM AUTHOR]

Background: Gut microbiota is significantly influenced by altitude. However, the dynamics of gut microbiota in relation to altitude remains undisclosed. Methods: In this study, we investigated the microbiome profile of 610 healthy young men from three different places in China, grouped by altitude, duration of residence, and ethnicity. We conducted widely targeted metabolomic profiling and clinical testing to explore metabolic characteristics. Results: Our findings revealed that as the Han individuals migrated from low altitude to high latitude, the gut microbiota gradually converged towards that of the Tibetan populations but reversed upon returning to lower altitude. Across different cohorts, we identified 51 species specifically enriched during acclimatization and 57 species enriched during deacclimatization to high altitude. Notably, Prevotella copri was found to be the most enriched taxon in both Tibetan and Han populations after ascending to high altitude. Furthermore, significant variations in host plasma metabolome and clinical indices at high altitude could be largely explained by changes in gut microbiota composition. Similar to Tibetans, 41 plasma metabolites, such as lactic acid, sphingosine-1-phosphate, taurine, and inositol, were significantly elevated in Han populations after ascending to high altitude. Germ-free animal experiments demonstrated that certain species, such as Escherichia coli and Klebsiella pneumoniae, which exhibited altitude-dependent variations in human populations, might play crucial roles in host purine metabolism. Conclusions: This study provides insights into the dynamics of gut microbiota and host plasma metabolome with respect to altitude changes, indicating that their dynamics may have implications for host health at high altitude and contribute to host adaptation. 88DwbBo5LkUszxYCpXiUg_ Video Abstract [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) induces significant energy metabolic reprogramming in renal tubular epithelial cells (TECs), thereby altering lipid, glucose, and amino acid metabolism. The changes in lipid metabolism encompass not only the downregulation of fatty acid oxidation (FAO) but also changes in cell membrane lipids and triglycerides metabolism. Regarding glucose metabolism, AKI leads to increased glycolysis, activation of the pentose phosphate pathway (PPP), inhibition of gluconeogenesis, and upregulation of the polyol pathway. Research indicates that inhibiting glycolysis, promoting the PPP, and blocking the polyol pathway exhibit a protective effect on AKI-affected kidneys. Additionally, changes in amino acid metabolism, including branched-chain amino acids, glutamine, arginine, and tryptophan, play an important role in AKI progression. These metabolic changes are closely related to the programmed cell death of renal TECs, involving autophagy, apoptosis, necroptosis, pyroptosis, and ferroptosis. Notably, abnormal intracellular lipid accumulation can impede autophagic clearance, further exacerbating lipid accumulation and compromising autophagic function, forming a vicious cycle. Recent studies have demonstrated the potential of ameliorating AKI-induced kidney damage through calorie and dietary restriction. Consequently, modifying the energy metabolism of renal TECs and dietary patterns may be an effective strategy for AKI treatment. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the effects of garlic (Allium sativum Linn) and leek (Allium porrum L.) on biochemical parameters, lipid profile and gene expression in high fructose diet (HDF)- induced diabetes in rat. In this study, we used 80 males Wistar rats for 18 weeks, HDF was administered daily in diet to induce diabetes. A high and low dose of garlic oil and leek powder were given orally daily to HDF-diabetic rats. Compared to rats in the diabetic groups, the garlic oil and leek powder reduced serum cholesterol, triacylglycerol, low-density lipoprotein-cholesterol (LDL-c) and very low density lipoprotein-cholesterol (VLDL-c) levels. The garlic oil and leek powder also helped reduce hepatic destruction. A reduction was found in the gene expression in the hepatic homogenate of activating transcription factor 6 (ATF6) and X-Box Binding Protein1 (XBP1), Binding immunoglobulin protein (BIP), C/EBP homologous protein (CHOP), Jun N-terminal kinase (JNK), and peroxisome proliferator- activated receptor gamma (PPAR-γ). On the other hand, there was a significant upregulation in the mRNA expression of has been found in the promoter of glucose transporter 2 (Glut2), and miRNA 27a which is also a dose- and time-dependent manner. These results suggest that H2S donor as garlic oil and leek powder exhibits therapeutic potential for diabetes, which is most likely related to its protective effects against ER stress and regulating miRNA 27a and its target gene. [ABSTRACT FROM AUTHOR]

Obesity is a major source of morbidity worldwide with more than 2 billion adults being overweight or obese. The incidence of obesity has tripled in the last 50 years, leading to an increased risk for a variety of noncommunicable diseases. Previous studies have demonstrated the positive effects of green leafy vegetables on weight gain and obesity and have attributed these beneficial properties, at least in part, to nitrates and isothiocyanates. Nitrates are converted to nitric oxide (NO) and isothiocyanates are known to release hydrogen sulfide (H 2 S). Herein, we investigated the effect of extracts and fractions produced from Beta vulgaris and Eruca sativa for their ability to limit lipid accumulation, regulate glucose homeostasis, and reduce body weight. Extracts from the different vegetables were screened for their ability to limit lipid accumulation in adipocytes and hepatocytes and for their ability to promote glucose uptake in skeletal muscle cultures; the most effective extracts were next tested in vivo. Wild type mice were placed on high-fat diet for 8 weeks to promote weight gain; animals receiving the selected B. vulgaris and E. sativa extracts exhibited attenuated body weight. Treatment with extracts also led to reduced white adipose tissue depot mass, attenuated adipocyte size, reduced expression of Dgat2 and PPARγ expression, and improved liver steatosis. In contrast, the extracts failed to improve glucose tolerance in obese animals and did not affect blood pressure. Taken together, our data indicate that extracts produced from B. vulgaris and E. sativa exhibit anti-obesity effects, suggesting that dietary supplements containing nitrates and sulfide-releasing compounds might be useful in limiting weight gain., (© 2024 The Author(s). Phytotherapy Research published by John Wiley & Sons Ltd.)

Diabetes is a known risk factor for various cardiovascular complications, mediated by endothelial dysfunction. Despite the high prevalence of this metabolic disorder, there is a lack of in vitro models that recapitulate the complexity of genetic and environmental factors associated with diabetic endothelial dysfunction. Here, we utilized human induced pluripotent stem cell (iPSC)‐derived endothelial cells (ECs) to develop in vitro models of diabetic endothelial dysfunction. We found that the diabetic phenotype was recapitulated in diabetic patient‐derived iPSC‐ECs, even in the absence of a diabetogenic environment. Subsequent exposure to culture conditions that mimic the diabetic clinical chemistry induced a diabetic phenotype in healthy iPSC‐ECs but did not affect the already dysfunctional diabetic iPSC‐ECs. RNA‐seq analysis revealed extensive transcriptome‐wide differences between cells derived from healthy individuals and diabetic patients. The in vitro disease models were used as a screening platform which identified angiotensin receptor blockers (ARBs) that improved endothelial function in vitro for each patient. In summary, we present in vitro models of diabetic endothelial dysfunction using iPSC technology, taking into account the complexity of genetic and environmental factors in the metabolic disorder. Our study provides novel insights into the pathophysiology of diabetic endothelial dysfunction and highlights the potential of iPSC‐based models for drug discovery and personalized medicine. [ABSTRACT FROM AUTHOR]

Excessive renal TGF-β production and pro-fibrotic miRNAs are important drivers of kidney fibrosis that lack any efficient treatment. Dysfunctional autophagy might play an important role in the pathogenesis. We aimed to study the yet unknown effects of peroxisome proliferator-activated receptor-γ (PPARγ) agonist pioglitazone (Pio) on renal autophagy and miRNA dysregulation during fibrosis. Mouse primary tubular epithelial cells (PTEC) were isolated, pre-treated with 5 µM pioglitazone, and then stimulated with 10 ng/mL TGF-β1 for 24 h. Male 10-week-old C57Bl6 control (CTL) and TGF-β overexpressing mice were fed with regular chow (TGF) or Pio-containing chow (20 mg/kg/day) for 5 weeks (TGF + Pio). PTEC and kidneys were evaluated for mRNA and protein expression. In PTEC, pioglitazone attenuated (p < 0.05) the TGF-β-induced up-regulation of Col1a1 (1.4-fold), Tgfb1 (2.2-fold), Ctgf (1.5-fold), Egr2 (2.5-fold) mRNAs, miR-130a (1.6-fold), and miR-199a (1.5-fold), inhibited epithelial-to-mesenchymal transition, and rescued autophagy function. In TGF mice, pioglitazone greatly improved kidney fibrosis and related dysfunctional autophagy (increased LC3-II/I ratio and reduced SQSTM1 protein content (p < 0.05)). These were accompanied by 5-fold, 3-fold, 12-fold, and 2-fold suppression (p < 0.05) of renal Ccl2, Il6, C3, and Lgals3 mRNA expression, respectively. Our results implicate that pioglitazone counteracts multiple pro-fibrotic processes in the kidney, including autophagy dysfunction and miRNA dysregulation. [ABSTRACT FROM AUTHOR]

Recent studies draw attention to how excessive salt (NaCl) intake induces fibrotic alterations in the peritoneum through sodium accumulation and osmotic events. The aim of our study was to better understand the underlying mechanisms. The effects of additional NaCl were investigated on human primary mesothelial cells (HPMC), human primary peritoneal fibroblasts (HPF), endothelial cells (HUVEC), immune cells (PBMC), as well as ex vivo on peritoneal tissue samples. Our results showed that a high-salt environment and the consequently increased osmolarity increase the production of inflammatory cytokines, profibrotic growth factors, and components of the renin–angiotensin–aldosterone system, including IL1B, IL6, MCP1, TGFB1, PDGFB, CTGF, Renin and Ace both in vitro and ex vivo. We also demonstrated that high salt induces mesenchymal transition by decreasing the expression of epithelial marker CDH1 and increasing the expression of mesenchymal marker ACTA2 and SNAIL1 in HPMCs, HUVECs and peritoneal samples. Furthermore, high salt increased extracellular matrix production in HPFs. We demonstrated that excess Na+ and the consequently increased osmolarity induce a comprehensive profibrotic response in the peritoneal cells, thereby facilitating the development of peritoneal fibrosis. [ABSTRACT FROM AUTHOR]

Simple Summary: This review article addresses the introduction and mechanism of action concerning the potential health effects of air-born microplastics on lung epithelial cell line A549. Micro- and nanoplastics are air-born pollutants, are inhaled, and cause lung toxicity by becoming internalized in cells, inducing genotoxicity, oxidative stress, immunomodulation, and morphological changes in A549 cells. These microplastics have the potential to accumulate in cells and trigger inflammation thereby contributing to the development of lung diseases. Numerous studies have investigated various aspects of micro- and nanoplastics on lung epithelial cells; however, the precise mechanism by which they initiate, or progress, lung toxicity is still subject to investigation. Nonetheless, the findings of previous studies strongly suggested that microplastics cannot be underestimated as insignificant air pollutants due to their potential to accumulate not only in the lungs but also in other organs such as the brain. This review article compiles studies on the effects of polystyrene microplastics on lung epithelial cells, highlighting existing research gaps, and providing suggestions for further research in this area. Airborne microplastics raise significant concerns due to their potential health impacts. Having a small size, larger surface area, and penetrative ability into the biological system, makes them hazardous to health. This review article compiles various studies investigating the mechanism of action of polystyrene micro- and nanoplastics affecting lung epithelial cells A549. These inhalable microplastics damage the respiratory system, by triggering a proinflammatory environment, genotoxicity, oxidative stress, morphological changes, and cytotoxic accumulation in A549 cells. PS-NP lung toxicity depends on various factors such as size, surface modifications, concentration, charge, and zeta potential. However, cellular uptake and cytotoxicity mechanisms depend on the cell type. For A549 cells, PS-NPs are responsible for energy imbalance by mitochondrial dysfunction, oxidative stress-mediated cytotoxicity, immunomodulation, and apoptosis. Additionally, PS-NPs have the ability to traverse the placental barrier, posing a risk to offspring. Despite the advancements, the precise mechanisms underlying how prolonged exposure to PS-NPs leads to the development and progression of lung diseases have unclear points, necessitating further investigations to unravel the root cause. This review also sheds light on data gaps, inconsistencies in PS-Nos research, and provides recommendations for further research in this field. [ABSTRACT FROM AUTHOR]

Background and Purpose: Excessive oxidative stress can induce PARP1-mediated programmed necrotic cell death, termed parthanatos. Inhibition of parthanatos may be therapeutically beneficial in a wide array of diseases associated with tissue injury and inflammation. Our goal was to identify novel molecules inhibiting parthanatos., Experimental Approach: A small library of 774 pharmacologically active compounds was screened in a Sytox Green uptake assay, which identified 20 hits that reduced hydrogen-peroxide-induced parthanatos with an efficiency comparable to the benchmark PARP inhibitor, PJ34., Key Results: Of these hits, two compounds, antifungal ciclopirox and dopamine receptor agonist apomorphine, inhibited PAR polymer synthesis. These two compounds prevented the binding of PARP1 to oxidatively damaged DNA but did not directly interfere with the interaction between DNA and PARP1. Both compounds inhibited mitochondrial superoxide and H 2 O 2 production and suppressed DNA breakage. Since H 2 O 2 -induced damage is dependent on Fe 2+ -catalysed hydroxyl radical production (Fenton chemistry), we determined the iron chelation activity of the two test compounds and found that ciclopirox and, to a lesser extent, apomorphine act as iron chelators. We also show that the Fe 2+ chelation and indirect PARP inhibitory effects of ciclopirox translate to anti-inflammatory actions as demonstrated in a mouse dermatitis model, where ciclopirox reduced ear swelling, inflammatory cell recruitment and poly(ADP-ribosyl)ation., Conclusion and Implications: Our findings indicate that the antimycotic drug, ciclopirox, acts as an iron chelator and thus targets an early event in hydrogen-peroxide-induced parthanatos. Ciclopirox has the potential to be repurposed as a cytoprotective and anti-inflammatory agent., (© 2020 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Background: The novel coronavirus disease 2019 (COVID-19) presents with complex pathophysiological effects in various organ systems. Following the COVID-19, there are shifts in biomarker and cytokine equilibrium associated with altered physiological processes arising from viral damage or aggressive immunological response. We hypothesized that high daily dose methylprednisolone improved the injury biomarkers and serum cytokine profiles in COVID-19 patients. Methods: Injury biomarker and cytokine analysis was performed on 50 SARS-Cov-2 negative controls and 101 hospitalized severe COVID-19 patients: 49 methylprednisolone-treated (MP group) and 52 placebo-treated serum samples. Samples from the treated groups collected on days D1 (pre-treatment) all the groups, D7 (2 days after ending therapy) and D14 were analyzed. Luminex assay quantified the biomarkers HMGB1, FABP3, myoglobin, troponin I and NTproBNP. Immune mediators (CXCL8, CCL2, CXCL9, CXCL10, TNF, IFN-γ, IL-17A, IL-12p70, IL-10, IL-6, IL-4, IL-2, and IL-1β) were quantified using cytometric bead array. Results: At pretreatment, the two treatment groups were comparable demographically. At pre-treatment (D1), injury biomarkers (HMGB1, TnI, myoglobin and FABP3) were distinctly elevated. At D7, HMGB1 was significantly higher in the MP group (p=0.0448) compared to the placebo group, while HMGB1 in the placebo group diminished significantly by D14 (p=0.0115). Compared to healthy control samples, several immune mediators (IL-17A, IL-6, IL-10, MIG, MCP-1, and IP-10) were considerably elevated at baseline (all p≤0.05). At D7, MIG and IP-10 of the MP-group were significantly lower than in the placebo-group (p=0.0431, p=0.0069, respectively). Longitudinally, IL-2 (MPgroup) and IL-17A (placebo-group) had increased significantly by D14. In placebo group, IL-2 and IL-17A continuously increased, as IL-12p70, IL-10 and IP-10 steadily decreased during follow-up. The MP treated group had IL-2, IFN-γ, IL-17A and IL-12p70 progressively increase while IL-1b and IL-10 gradually decreased towards D14. Moderate to strong positive correlations between chemokines and cytokines were observed on D7 and D14. Conclusion: These findings suggest MP treatment could ameliorate levels of myoglobin and FABP3, but appeared to have no impact on HMGB1, TnI and NTproBNP. In addition, methylprednisolone relieves the COVID-19 induced inflammatory response by diminishing MIG and IP-10 levels. Overall, corticosteroid (methylprednisolone) use in COVID-19 management influences the immunological molecule and injury biomarker profile in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Endothelial cells (ECs) angiogenesis is the process of sprouting new vessels from the existing ones, playing critical roles in physiological and pathological processes such as wound healing, placentation, ischemia/reperfusion, cardiovascular diseases and cancer metastasis. Although mitochondria are not the major sites of energy source in ECs, they function as important biosynthetic and signaling hubs to regulate ECs metabolism and adaptations to local environment, thus affecting ECs migration, proliferation and angiogenic process. The understanding of the importance and potential mechanisms of mitochondria in regulating ECs metabolism, function and the process of angiogenesis has developed in the past decades. Thus, in this review, we discuss the current understanding of mitochondrial proteins and signaling molecules in ECs metabolism, function and angiogeneic signaling, to provide new and therapeutic targets for treatment of diverse cardiovascular and angiogenesis-dependent diseases. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction is involved in the pathophysiology of psychiatric and neurodegenerative disorders and can be used as a modulator and/or predictor of treatment responsiveness. Understanding the mitochondrial effects of antidepressants is important to connect mitochondria with their therapeutic and/or adverse effects. Pig brain-isolated mitochondria were used to evaluate antidepressant-induced changes in the activity of electron transport chain (ETC) complexes, monoamine oxidase (MAO), mitochondrial respiratory rate, and ATP. Bupropion, escitalopram, fluvoxamine, sertraline, paroxetine, and trazodone were tested. All tested antidepressants showed significant inhibition of complex I and IV activities at high concentrations (50 and 100 µmol/L); complex II + III activity was reduced by all antidepressants except bupropion. Complex I-linked respiration was reduced by escitalopram >> trazodone >> sertraline. Complex II-linked respiration was reduced only by bupropion. Significant positive correlations were confirmed between complex I-linked respiration and the activities of individual ETC complexes. MAO activity was inhibited by all tested antidepressants, with SSRIs causing a greater effect than trazodone and bupropion. The results indicate a probable association between the adverse effects of high doses of antidepressants and drug-induced changes in the activity of ETC complexes and the respiratory rate of mitochondria. In contrast, MAO inhibition could be linked to the antidepressant, procognitive, and neuroprotective effects of the tested antidepressants. [ABSTRACT FROM AUTHOR]

Arteries and veins are lined by nonproliferating endothelial cells that play a critical role in regulating blood flow. Endothelial cells also regulate tissue perfusion, metabolite exchange, and thrombosis. It is thought that endothelial cells rely on ATP generated via glycolysis, rather than mitochondrial oxidative phosphorylation, to fuel each of these energy-demanding processes. However, endothelial metabolism has mainly been studied in the context of proliferative cells, and little is known about energy production in endothelial cells within the fully formed vascular wall. Using intact arteries isolated from rats and mice, we show that inhibiting mitochondrial respiration disrupts endothelial control of vascular tone. Basal, mechanically activated, and agonist-evoked calcium activity in intact artery endothelial cells are each prevented by inhibiting mitochondrial ATP synthesis. Agonist-evoked calcium activity was also inhibited by blocking the transport of pyruvate, the master fuel for mitochondrial energy production, through the mitochondrial pyruvate carrier. The role for mitochondria in endothelial cell energy production is independent of species, sex, or vascular bed. These data show that a mitochondrial ATP supply is necessary for calcium-dependent, nitric oxide-mediated endothelial control of vascular tone, and identifies the critical role of endothelial mitochondrial energy production in fueling perfused blood vessel function. [ABSTRACT FROM AUTHOR]

Cystathionine beta‐synthase (CBS)‐deficient homocystinuria (HCU) is the most common inborn error of sulfur amino acid metabolism. The pyridoxine non‐responsive form of the disease manifests itself by massively increasing plasma and tissue concentrations of homocysteine, a toxic intermediate of methionine metabolism that is thought to be the major cause of clinical complications including skeletal deformities, connective tissue defects, thromboembolism and cognitive impairment. The current standard of care involves significant dietary interventions that, despite being effective, often adversely affect quality of life of HCU patients, leading to poor adherence to therapy and inadequate biochemical control with clinical complications. In recent years, the unmet need for better therapeutic options has resulted in development of novel enzyme and gene therapies and exploration of pharmacological approaches to rescue CBS folding defects caused by missense pathogenic mutations. Here, we review scientific evidence and current state of affairs in development of recent approaches to treat HCU. [ABSTRACT FROM AUTHOR]

Over the last two decades, hydrogen sulfide (H2S) has emerged as an endogenous regulator of a broad range of physiological functions. H2S belongs to the class of molecules known as gasotransmitters, which typically include nitric oxide (NO) and carbon monoxide (CO). Three enzymes are recognized as endogenous sources of H2S in various cells and tissues: cystathionine c-lyase (CSE), cystathionine b-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST). The present article reviews the regulation of these enzymes as well as the pathways of their enzymatic and nonenzymatic degradation and elimination. The multiple interactions of H2S with other labile endogenous molecules (e.g., NO) and reactive oxygen species are also outlined. Next, the various biological targets and signaling pathways are outlined, with special reference to H2S or oxidative posttranscriptional modification (persulfidation or sulfhydration) of proteins and the effect of H2S on various channels and intracellular second messenger pathways, the regulation of gene transcription and translation, and the regulation of cellular bioenergetics and metabolism. The pharmacological and molecular tools currently available to study H2S physiology are also reviewed, including their utility and limitations. In subsequent sections, the role of H2S in the regulation of various physiological and cellular functions is reviewed, including the regulation of membrane potential, endo- and exocytosis, regulation of various cell organelles (endoplasmic reticulum, Golgi, mitochondria), regulation of cell movement, cell cycle, cell differentiation, and physiological aspects of regulated cell death. Next, the physiological roles of H2S in various cell types and organ systems are overviewed, including the role of H2S in red blood cells, immune cells, the central and peripheral nervous systems (with focus on neuronal transmission, learning, and memory formation), and regulation of vascular function (including angiogenesis as well as its specialized roles in the cerebrovascular, renal, and pulmonary vascular beds) and the role of H2S in the regulation of special senses, vision, hearing, taste and smell, and pain-sensing. Finally, the roles of H2S in the regulation of various organ functions (lung, heart, liver, kidney, urogenital organs, reproductive system, bone and cartilage, skeletal muscle, and endocrine organs) are presented, with a focus on physiology (including physiological aging) but also extending to some common pathophysiological conditions. From these data, a wide array of significant roles of H2S in the physiological regulation of all organ functions emerges and the characteristic bell-shaped biphasic effects of H2S are highlighted. In addition, key pathophysiological aspects, debated areas, and future research and translational areas are identified. [ABSTRACT FROM AUTHOR]