Mitochondrial dysfunction and molecular pathways of disease

Resonance Raman spectral analysis of the heme site structure of cytochrome c oxidase with its positive regulator CHCHD2

Cytochrome c oxidase (CcO) reduces O2, pumps protons in the mitochondrial respiratory chain, and is essential for oxygen consumption in the cell. The coiled-coil-helix-coiled-coil-helix domain-containing 2 (CHCHD2; also known as mitochondrial nuclear retrograde regulator 1 [MNRR1], Parkinson's disease 22 [PARK22] and aging-associated gene 10 protein [AAG10]) is a protein that binds to CcO from the intermembrane space and positively regulates the activity of CcO. Despite the importance of CHCHD2 in mitochondrial function, the mechanism of action of CHCHD2 and structural information regarding its binding to CcO remain unknown. Here, we utilized visible resonance Raman spectroscopy to investigate the structural changes around the hemes in CcO in the reduced and CO-bound states upon CHCHD2 binding. We found that CHCHD2 has a significant impact on the structure of CcO in the reduced state. Mapping of the heme peripheries that result in Raman spectral changes in the structure of CcO highlighted helices IX and X near the hemes as sites where CHCHD2 takes action. Part of helix IX is exposed in the intermembrane space, whereas helix X, located between both hemes, may play a key role in proton uptake to a proton-loading site in the reduced state for proton pumping. Taken together, our results suggested that CHCHD2 binds near helix IX and induces a structural change in helix X, accelerating proton uptake.

Endocrine disrupting effects on morphological synaptic plasticity

Neural regulation of the homeostasis depends on healthy synaptic function. Adaptation of synaptic functions to physiological needs manifests in various forms of synaptic plasticity (SP), regulated by the normal hormonal regulatory circuits. During the past several decades, the hormonal regulation of animal and human organisms have become targets of thousands of chemicals that have the potential to act as agonists or antagonists of the endogenous hormones. As the action mechanism of these endocrine disrupting chemicals (EDCs) came into the focus of research, a growing number of studies suggest that one of the regulatory avenues of hormones, the morphological form of SP, may well be a neural mechanism affected by EDCs. The present review discusses known and potential effects of some of the best known EDCs on morphological synaptic plasticity (MSP). We highlight molecular mechanisms altered by EDCs and indicate the growing need for more research in this area of neuroendocrinology.

Perturbations in mitochondrial metabolism associated with defective cardiolipin biosynthesis: An in-organello real-time NMR study

Mitochondria are central to cellular metabolism; hence, their dysfunction contributes to a wide array of human diseases. Cardiolipin, the signature phospholipid of the mitochondrion, affects proper cristae morphology, bioenergetic functions, and metabolic reactions carried out in mitochondrial membranes. To match tissue-specific metabolic demands, cardiolipin typically undergoes an acyl tail remodeling process with the final step carried out by the phospholipid-lysophospholipid transacylase tafazzin. Mutations in tafazzin are the primary cause of Barth syndrome. Here, we investigated how defects in cardiolipin biosynthesis and remodeling impacts metabolic flux through the TCA cycle and associated yeast pathways. Nuclear magnetic resonance was used to monitor in real-time the metabolic fate of 13C3-pyruvate in isolated mitochondria from three isogenic yeast strains. We compared mitochondria from a WT strain to mitochondria from a Δtaz1 strain that lacks tafazzin and contains lower amounts of unremodeled cardiolipin and mitochondria from a Δcrd1 strain that lacks cardiolipin synthase and cannot synthesize cardiolipin. We found that the 13C-label from the pyruvate substrate was distributed through twelve metabolites. Several of the metabolites were specific to yeast pathways including branched chain amino acids and fusel alcohol synthesis. While most metabolites showed similar kinetics among the different strains, mevalonate concentrations were significantly increased in Δtaz1 mitochondria. Additionally, the kinetic profiles of α-ketoglutarate, as well as NAD+ and NADH measured in separate experiments, displayed significantly lower concentrations for Δtaz1 and Δcrd1 mitochondria at most time points. Taken together, the results show how cardiolipin remodeling influences pyruvate metabolism, tricarboxylic acid cycle flux, and the levels of mitochondrial nucleotides.

Benign prostatic hyperplasia nodules in patients treated with celecoxib and/or finasteride have reduced levels of NADH dehydrogenase [ubiquinone] iron-sulfur protein 3, a mitochondrial protein essential for efficient function of the electron transport chain

BACKGROUND

Benign prostatic hyperplasia (BPH) is a condition generally associated with advanced age in men that can be accompanied by bothersome lower urinary tract symptoms (LUTS) including intermittency, weak stream, straining, urgency, frequency, and incomplete bladder voiding. Pharmacotherapies for LUTS/BPH include alpha-blockers, which relax prostatic and urethral smooth muscle and 5ɑ-reductase inhibitors such as finasteride, which can block conversion of testosterone to dihydrotestosterone thereby reducing prostate volume. Celecoxib is a cyclooxygenase-2 inhibitor that reduces inflammation and has shown some promise in reducing prostatic inflammation and alleviating LUTS for some men with histological BPH. However, finasteride and celecoxib can reduce mitochondrial function in some contexts, potentially impacting their efficacy for alleviating BPH-associated LUTS.

METHODS

To determine the impact of these pharmacotherapies on mitochondrial function in prostate tissues, we performed immunostaining of mitochondrial Complex I (CI) protein NADH dehydrogenase [ubiquinone] iron-sulfur protein 3 (NDUFS3) and inflammatory cells on BPH specimens from patients naïve to treatment, or who were treated with celecoxib and/or finasteride for 28 days, as well as prostate tissues from male mice treated with celecoxib or vehicle control for 28 days. Quantification and statistical correlation analyses of immunostaining were performed.

RESULTS

NDUFS3 immunostaining was decreased in BPH compared to normal adjacent prostate. Patients treated with celecoxib and/or finasteride had significantly decreased NDUFS3 in both BPH and normal tissues, and no change in inflammatory cell infiltration compared to untreated patients. Mice treated with celecoxib also displayed a significant decrease in NDUFS3 immunostaining and no change in inflammatory cell infiltration.

CONCLUSIONS

These findings suggest that celecoxib and/or finasteride are associated with an overall decrease in NDUFS3 levels in prostate tissues but do not impact the presence of inflammatory cells, suggesting a decline in mitochondrial CI function in the absence of enhanced inflammation. Given that BPH has recently been associated with increased prostatic mitochondrial dysfunction, celecoxib and/or finasteride may exacerbate existing mitochondrial dysfunction in some BPH patients thereby potentially limiting their overall efficacy in providing metabolic stability and symptom relief.

Targeting Mitochondrial Dysfunction for the Prevention and Treatment of Metabolic Disease by Bioactive Food Components

Dysfunctional mitochondria have been linked to the pathogenesis of obesity-associated metabolic diseases. Excessive energy intake impairs mitochondrial biogenesis and function, decreasing adenosine-5'-triphosphate production and negatively impacting metabolically active tissues such as adipose tissue, skeletal muscle, and the liver. Compromised mitochondrial function disturbs lipid metabolism and increases reactive oxygen species production in these tissues, contributing to the development of insulin resistance, type 2 diabetes, and non-alcoholic fatty liver disease. Recent studies have demonstrated the therapeutic potential of bioactive food components, such as resveratrol, quercetin, coenzyme Q10, curcumin, and astaxanthin, by enhancing mitochondrial function. This review provides an overview of the current understanding of how these bioactive compounds ameliorate mitochondrial dysfunction to mitigate obesity-associated metabolic diseases.

Mitochondrial Dysfunctions: Genetic and Cellular Implications Revealed by Various Model Organisms

Mitochondria play a crucial role in maintaining the energy status and redox homeostasis of eukaryotic cells. They are responsible for the metabolic efficiency of cells, providing both ATP and intermediate metabolic products. They also regulate cell survival and death under stress conditions by controlling the cell response or activating the apoptosis process. This functional diversity of mitochondria indicates their great importance for cellular metabolism. Hence, dysfunctions of these structures are increasingly recognized as an element of the etiology of many human diseases and, therefore, an extremely promising therapeutic target. Mitochondrial dysfunctions can be caused by mutations in both nuclear and mitochondrial DNA, as well as by stress factors or replication errors. Progress in knowledge about the biology of mitochondria, as well as the consequences for the efficiency of the entire organism resulting from the dysfunction of these structures, is achieved through the use of model organisms. They are an invaluable tool for analyzing complex cellular processes, leading to a better understanding of diseases caused by mitochondrial dysfunction. In this work, we review the most commonly used model organisms, discussing both their advantages and limitations in modeling fundamental mitochondrial processes or mitochondrial diseases.

Contribution of inwardly rectifying potassium channel 4.1 in orofacial neuropathic pain: Regulation of pannexin 3 via the reactive oxygen species-activated P38 MAPK signal pathway

The involvement of inwardly rectifying potassium channel 4.1 (Kir4.1) in neuropathic pain has been established. However, there is limited understanding of the downstream mechanism through which Kir4.1 contributes to orofacial neuropathic pain. The objective of this study was to examine the regulation of Kir4.1 on the expression of pannexin 3 (Panx3) in the trigeminal ganglion (TG) and the underlying mechanism in the context of orofacial neuropathic pain caused by chronic constriction injury of the infraorbital nerve (CCI-ION). The study observed a significant increase in Panx3 expression in the TG of mice with CCI-ION. Inhibition of Panx3 in the TG of CCI-ION mice resulted in alleviation of orofacial mechanical allodynia. Furthermore, conditional knockdown (CKD) of Kir4.1 in the TG of both male and female mice led to mechanical allodynia and upregulation of Panx3 expression. Conversely, overexpression of Kir4.1 decreased Panx3 levels in the TG and relieved mechanical allodynia in CCI-ION mice. In addition, silencing Kir4.1 in satellite glial cells (SGCs) decreased Panx3 expression and increased the phosphorylation of P38 MAPK. Moreover, silencing Kir4.1 in SGCs increased the levels of reactive oxygen species (ROS). The elevated phosphorylation of P38 MAPK resulting from Kir4.1 silencing was inhibited by using a superoxide scavenger known as the tempol. Silencing Panx3 in the TG in vivo attenuated the mechanical allodynia caused by Kir4.1 CKD. In conclusion, these findings suggest that the reduction of Kir4.1 promotes the expression of Panx3 by activating the ROS-P38 MAPK signalling pathway, thus contributing to the development of orofacial neuropathic pain.

Heightened Serum Mitochondrial Biomarkers; FGF21 and NOS in Pediatric Anemia and a Negative Correlation between GDF15 and Serum Ferritin

Objective: Mitochondrial dysfunction is closely linked to chronic disorders. This study aims to explore the correlation between pediatric anemia and mitochondrial markers, specifically fibroblast growth factor 21 (FGF21), growth/differentiation factor 15 (GDF-15), and nitric oxide synthase (eNOS). Method: This study included 66 children, with 34 diagnosed with anemia and 32 in the healthy control group. Statistically significant biomarkers were determined through cutoff levels. Results: Among the participants, 34 children were classified as anemic, while 32 were categorized as healthy. The study revealed that FGF21 levels ≥ 0.745 pg/mL and eNOS levels ≥ 1.265 µg/mL predicted anemia. Hemoglobin levels exhibited a negative correlation with FGF21 (r = -0.381; p = 0.002) and eNOS levels (r = -0.462; p < 0.001). Furthermore, a significant negative correlation was observed between GDF-15 and ferritin (r = -0.311; p = 0.019), while eNOS levels correlated positively with folate (r = 0.313; p = 0.019). Conclusions: Anemia induced elevated mitochondrial biomarkers; FGF21 and eNOS levels. The findings suggest that the long-term ramifications of anemia in childhood may be associated with mitochondrial dysfunction.

Neutral rhodol-based dyes expressing localization in mitochondria

Neutral rhodol-based red emitters are shown to efficiently localize in mitochondria, as demonstrated by confocal microscopy and co-localization studies. A simple model is proposed to explain the localization mechanism of neutral molecules. The model takes into account the strong coupling between the molecular dipole moment and the electric field of the inner mitochondrial membrane.

Perturbations in mitochondrial metabolism associated with defective cardiolipin biosynthesis: An in-organello real-time NMR study

Mitochondria are central to cellular metabolism; hence, their dysfunction contributes to a wide array of human diseases including cancer, cardiopathy, neurodegeneration, and heritable pathologies such as Barth syndrome. Cardiolipin, the signature phospholipid of the mitochondrion promotes proper cristae morphology, bioenergetic functions, and directly affects metabolic reactions carried out in mitochondrial membranes. To match tissue-specific metabolic demands, cardiolipin typically undergoes an acyl tail remodeling process with the final step carried out by the phospholipid-lysophospholipid transacylase tafazzin. Mutations in the tafazzin gene are the primary cause of Barth syndrome. Here, we investigated how defects in cardiolipin biosynthesis and remodeling impact metabolic flux through the tricarboxylic acid cycle and associated pathways in yeast. Nuclear magnetic resonance was used to monitor in real-time the metabolic fate of 13C3-pyruvate in isolated mitochondria from three isogenic yeast strains. We compared mitochondria from a wild-type strain to mitochondria from a Δtaz1 strain that lacks tafazzin and contains lower amounts of unremodeled cardiolipin, and mitochondria from a Δcrd1 strain that lacks cardiolipin synthase and cannot synthesize cardiolipin. We found that the 13C-label from the pyruvate substrate was distributed through about twelve metabolites. Several of the identified metabolites were specific to yeast pathways, including branched chain amino acids and fusel alcohol synthesis. Most metabolites showed similar kinetics amongst the different strains but mevalonate and α-ketoglutarate, as well as the NAD+/NADH couple measured in separate nuclear magnetic resonance experiments, showed pronounced differences. Taken together, the results show that cardiolipin remodeling influences pyruvate metabolism, tricarboxylic acid cycle flux, and the levels of mitochondrial nucleotides.

Cinnamaldehyde hydrazone derivatives as potential cathepsin B inhibitors: parallel in-vitro investigation in liver and cerebrospinal fluid

The emergence of cathepsins as a potential target for anticancer drugs has led to extensive research in the development of their inhibitors. In the present study, we designed, synthesized, and characterized several cinnamaldehyde schiff bases employing diverse hydrazines, as potential cathepsin B inhibitors. The parallel studies on cathepsin B isolated from liver and cerebrospinal fluid unveiled the significance of the synthesized compounds as cathepsin B inhibitors at nanomolar concentrations. The compound, 7 exhibited the highest inhibition of 83.48 % and 82.96 % with an IC50 value of 0.06 nM and 0.09 nM for liver and cerebrospinal fluid respectively. The inhibitory potential of synthesized compounds has been extremely effective in comparison to previous reports. With the help of molecular docking studies using iGEMDOCK software, we found that the active site -CH2SH group is involved in the case of α-N-benzoyl-D, l-arginine-b-naphthylamide (BANA), curcumin 2, 3, 6, and 7. For toxicity prediction, ADMET studies were conducted and the synthesized compounds emerged to be non-toxic. The results obtained from the in vitro studies were supported with in silico studies. The synthesized cinnamaldehyde schiff bases can be considered promising drug candidates in conditions with elevated cathepsin B levels.

Associations between regional adipose tissue distribution and skeletal muscle bioenergetics in older men and women

OBJECTIVE

The aim of this study was to examine associations of ectopic adipose tissue (AT) with skeletal muscle (SM) mitochondrial bioenergetics in older adults.

METHODS

Cross-sectional data from 829 adults ≥70 years of age were used. Abdominal, subcutaneous, and visceral AT and thigh muscle fat infiltration (MFI) were quantified by magnetic resonance imaging. SM mitochondrial energetics were characterized in vivo (31P-magnetic resonance spectroscopy; ATPmax) and ex vivo (high-resolution respirometry maximal oxidative phosphorylation [OXPHOS]). ActivPal was used to measure physical activity ([PA]; step count). Linear regression adjusted for covariates was applied, with sequential adjustment for BMI and PA.

RESULTS

Independent of BMI, total abdominal AT (standardized [Std.] β = -0.21; R2 = 0.09) and visceral AT (Std. β = -0.16; R2 = 0.09) were associated with ATPmax (p < 0.01; n = 770) but not following adjustment for PA (p ≥ 0.05; n = 658). Visceral AT (Std. β = -0.16; R2 = 0.25) and thigh MFI (Std. β = -0.11; R2 = 0.24) were associated with carbohydrate-supported maximal OXPHOS independent of BMI and PA (p < 0.05; n = 609). Total abdominal AT (Std. β = -0.19; R2 = 0.24) and visceral AT (Std. β = -0.17; R2 = 0.24) were associated with fatty acid-supported maximal OXPHOS independent of BMI and PA (p < 0.05; n = 447).

CONCLUSIONS

Skeletal MFI and abdominal visceral, but not subcutaneous, AT are inversely associated with SM mitochondrial bioenergetics in older adults independent of BMI. Associations between ectopic AT and in vivo mitochondrial bioenergetics are attenuated by PA.

Proteomic characterization of human LMNA-related congenital muscular dystrophy muscle cells

LMNA-related congenital muscular dystrophy (L-CMD) is caused by mutations in the LMNA gene, encoding lamin A/C. To further understand the molecular mechanisms of L-CMD, proteomic profiling using DIA mass spectrometry was conducted on immortalized myoblasts and myotubes from controls and L-CMD donors each harbouring a different LMNA mutation (R249W, del.32 K and L380S). Compared to controls, 124 and 228 differentially abundant proteins were detected in L-CMD myoblasts and myotubes, respectively, and were associated with enriched canonical pathways including synaptogenesis and necroptosis in myoblasts, and Huntington's disease and insulin secretion in myotubes. Abnormal nuclear morphology and reduced lamin A/C and emerin abundance was evident in all L-CMD cell lines compared to controls, while nucleoplasmic aggregation of lamin A/C was restricted to del.32 K cells, and mislocalization of emerin was restricted to R249W cells. Abnormal nuclear morphology indicates loss of nuclear lamina integrity as a common feature of L-CMD, likely rendering muscle cells vulnerable to mechanically induced stress, while differences between L-CMD cell lines in emerin and lamin A localization suggests that some molecular alterations in L-CMD are mutation specific. Nonetheless, identifying common proteomic alterations and molecular pathways across all three L-CMD lines has highlighted potential targets for the development of non-mutation specific therapies.

Metabolomics and proteomics insights into subacute ruminal acidosis etiology and inhibition of proliferation of yak rumen epithelial cells in vitro

BACKGROUND

Untargeted metabolomics and proteomics were employed to investigate the intracellular response of yak rumen epithelial cells (YRECs) to conditions mimicking subacute rumen acidosis (SARA) etiology, including exposure to short-chain fatty acids (SCFA), low pH5.5 (Acid), and lipopolysaccharide (LPS) exposure for 24 h.

RESULTS

These treatments significantly altered the cellular morphology of YRECs. Metabolomic analysis identified significant perturbations with SCFA, Acid and LPS treatment affecting 259, 245 and 196 metabolites (VIP > 1, P < 0.05, and fold change (FC) ≥ 1.5 or FC ≤ 0.667). Proteomic analysis revealed that treatment with SCFA, Acid, and LPS resulted in differential expression of 1251, 1396, and 242 proteins, respectively (FC ≥ 1.2 or ≤ 0.83, P < 0.05, FDR < 1%). Treatment with SCFA induced elevated levels of metabolites involved in purine metabolism, glutathione metabolism, and arginine biosynthesis, and dysregulated proteins associated with actin cytoskeleton organization and ribosome pathways. Furthermore, SCFA reduced the number, morphology, and functionality of mitochondria, leading to oxidative damage and inhibition of cell survival. Gene expression analysis revealed a decrease the genes expression of the cytoskeleton and cell cycle, while the genes expression associated with inflammation and autophagy increased (P < 0.05). Acid exposure altered metabolites related to purine metabolism, and affected proteins associated with complement and coagulation cascades and RNA degradation. Acid also leads to mitochondrial dysfunction, alterations in mitochondrial integrity, and reduced ATP generation. It also causes actin filaments to change from filamentous to punctate, affecting cellular cytoskeletal function, and increases inflammation-related molecules, indicating the promotion of inflammatory responses and cellular damage (P < 0.05). LPS treatment induced differential expression of proteins involved in the TNF signaling pathway and cytokine-cytokine receptor interaction, accompanied by alterations in metabolites associated with arachidonic acid metabolism and MAPK signaling (P < 0.05). The inflammatory response and activation of signaling pathways induced by LPS treatment were also confirmed through protein interaction network analysis. The integrated analysis reveals co-enrichment of proteins and metabolites in cellular signaling and metabolic pathways.

CONCLUSIONS

In summary, this study contributes to a comprehensive understanding of the detrimental effects of SARA-associated factors on YRECs, elucidating their molecular mechanisms and providing potential therapeutic targets for mitigating SARA.

SIRT1-dependent PGC-1α deacetylation by SRT1720 rescues progression of atherosclerosis by enhancing mitochondrial function

Vascular smooth muscle cell (VSMC) senescence promotes atherosclerosis via lipid-mediated mitochondrial dysfunction and oxidative stress. However, the mechanisms of mitochondrial dysfunction and VSMC senescence in atherosclerosis have not been established. Here, we investigated the mechanisms whereby signaling pathways regulated by SRT1720 enhance or regulate mitochondrial functions in atherosclerotic VSMCs to suppress atherosclerosis. Initially, we examined the effect of SRT1720 on oleic acid (OA)-induced atherosclerosis. Atherosclerotic VSMCs exhibited elevated expressions of BODIPY and ADRP (adipose differentiation-related protein) and associated intracellular lipid droplet markers. In addition, the expression of collagen I was upregulated by OA, while the expressions of elastin and α-SMA were downregulated. mtDNA copy numbers, an ATP detection assay, transmission electron microscopy (TEM) imaging of mitochondria, mitochondria membrane potentials (assessed using JC-1 probe), and levels of mitochondrial oxidative phosphorylation (OXPHOS) were used to examine the effects of SRT1720 on OA-induced mitochondrial dysfunction. SRT1720 reduced mtDNA damage and accelerated mitochondria repair in VSMCs with OA-induced mitochondria dysfunction. In addition, mitochondrial reactive oxygen species (mtROS) levels were downregulated by SRT1720 in OA-treated VSMCs. Importantly, SRT1720 significantly increased SIRT1 and PGC-1α expression levels, but VSMCs senescence, inflammatory response, and atherosclerosis phenotypes were not recovered by treating cells with EX527 and SR-18292 before SRT1720. Mechanistically, the upregulations of SIRT1 and PGC-1α deacetylation by SRT1720 restored mitochondrial function, and consequently suppressed VSMC senescence and atherosclerosis-associated proteins and phenotypes. Collectively, this study indicates that SRT1720 can attenuate OA-induced atherosclerosis associated with VSMC senescence and mitochondrial dysfunction via SIRT1-mediated deacetylation of the PGC-1α pathway.

Phosphorylations and Acetylations of Cytochrome c Control Mitochondrial Respiration, Mitochondrial Membrane Potential, Energy, ROS, and Apoptosis

Cytochrome c (Cytc) has both life-sustaining and cellular death-related functions, depending on subcellular localization. Within mitochondria, Cytc acts as a single electron carrier as part of the electron transport chain (ETC). When released into the cytosol after cellular insult, Cytc triggers the assembly of the apoptosome, committing the cell to intrinsic apoptosis. Due to these dual natures, Cytc requires strong regulation by the cell, including post-translational modifications, such as phosphorylation and acetylation. Six phosphorylation sites and three acetylation sites have been detected on Cytc in vivo. Phosphorylations at T28, S47, Y48, T49, T58, and Y97 tend to be present under basal conditions in a tissue-specific manner. In contrast, the acetylations at K8, K39, and K53 tend to be present in specific pathophysiological conditions. All of the phosphorylation sites and two of the three acetylation sites partially inhibit respiration, which we propose serves to maintain an optimal, intermediate mitochondrial membrane potential (ΔΨm) to minimize reactive oxygen species (ROS) production. Cytc phosphorylations are lost during ischemia, which drives ETC hyperactivity and ΔΨm hyperpolarization, resulting in exponential ROS production thus causing reperfusion injury following ischemia. One of the acetylation sites, K39, shows a unique behavior in that it is gained during ischemia, stimulating respiration while blocking apoptosis, demonstrating that skeletal muscle, which is particularly resilient to ischemia-reperfusion injury compared to other organs, possesses a different metabolic strategy to handle ischemic stress. The regulation of Cytc by these post-translational modifications underscores the importance of Cytc for the ETC, ΔΨm, ROS production, apoptosis, and the cell as a whole.

Design and discovery of a highly potent ultralong-acting GLP-1 and glucagon co-agonist for attenuating renal fibrosis

The role of co-agonists of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) in chronic kidney disease (CKD) remains unclear. Herein we found that GLP-1R and GCGR expression levels were lower in the kidneys of mice with CKD compared to healthy mice and were correlated with disease severity. Interestingly, GLP-1R or GCGR knockdown aggravated the progression of kidney injury in both diabetic db/db mice and non-diabetic mice undergoing unilateral ureteral obstruction (UUO). Based on the importance of GLP-1R and GCGR in CKD, we reported a novel monomeric peptide, 1907-B, with dual-agonism on both GLP-1R and GCGR. The data confirmed that 1907-B had a longer half-life than long-acting semaglutide in rats or cynomolgus monkeys (∼2-3 fold) and exhibited better therapeutic contribution to CKD than best-in-class monoagonists, semaglutide, or glucagon, in db/db mice and UUO mice. Various lock-of-function models, including selective pharmacological activation and genetic knockdown, confirmed that 1907-B's effects on ameliorating diabetic nephropathy in db/db mice, as well as inhibiting kidney fibrosis in UUO mice, were mediated through GLP-1 and glucagon signaling. These findings highlight that 1907-B, a novel GLP-1R and GCGR co-agonist, exerts multifactorial improvement in kidney injuries and is an effective and promising therapeutic option for CKD treatment.

Emerging and multifaceted potential contributions of polyphenols in the management of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is recognized as a serious public health concern with a considerable impact on human life, long-term health expenditures, and substantial health losses. In this context, the use of dietary polyphenols to prevent and manage T2DM is widely documented. These dietary compounds exert their beneficial effects through several actions, including the protection of pancreatic islet β-cell, the antioxidant capacities of these molecules, their effects on insulin secretion and actions, the regulation of intestinal microbiota, and their contribution to ameliorate diabetic complications, particularly those of vascular origin. In the present review, we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type 2 diabetes patients.

LncRNA H19 inhibition impairs endoplasmic reticulum-mitochondria contact in hepatic cells and augments gluconeogenesis by increasing VDAC1 levels

Inspite of exerting independent cellular functions, the endoplasmic-reticulum (ER) and the mitochondria also physically connect at specific sites termed mitochondria-associated ER membranes (MAMs) and these sites consist of several tethering proteins that play varied roles in diverse cellular processes. However, the regulation of these tethering proteins within the cell is relatively less studied. Here, we show that several MAM proteins are significantly altered in the liver during diabetes and among these, the lncRNA, H19 regulates the levels of VDAC1. Inhibition of H19 expression using H19 specific siRNA altered VDAC1, mitochondrial Ca2+ and oxygen consumption rate, ATP and ROS levels and enhanced ER and mitochondria coupling in Hepa 1-6 cells. While H19 inhibition did not impact lipid accumulation, levels of gluconeogenic genes were significantly increased. JNK-phosphorylation and IRS1-Ser307-phosphorylation were increased by H19 inhibition and this was associated with abrogation of insulin-stimulated AKT (Ser-473) phosphorylation and glucose uptake in Hepa 1-6 cells. While inhibition of VDAC1 expression using siRNAs and with metformin significantly rescued the effects of H19 inhibition, VDAC1 overexpression alone exerted effects similar to H19 inhibition, suggesting that VDAC1 increase mediates the adverse effects of H19. In-vivo H19 inhibition using specific siRNAs increased hepatic VDAC1, pJNK and pIRS1 (Ser307) levels and decreased AKT (Ser-473) phosphorylation in mice. These suggest an important role of the H19-VDAC1 axis in ER-mitochondria coupling and regulation of gluconeogenesis in the liver during diabetes.

Mitochonic Acid 5 Increases Ram Sperm Quality by Improving Mitochondrial Function during Storage at 4 °C

Semen preservation involves lengthening sperm's fertile lifespan without any detrimental effects on its biochemical, functional, and ultrastructural properties. Liquid storage at 4 °C is a ram sperm preservation method. However, this method of storage causes irreversible damage due to cold shocks, osmotic stresses, oxidative stresses, and reductions in sperm metabolism. The present study aims to investigate whether the supplementation of mitochonic acid 5 (MA-5) in a sperm extender could improve chilled ram sperm quality and elucidate its mechanism of action. Ram sperm were diluted with a tris-citrate-glucose extender containing different concentrations of MA-5 (0, 0.1, 1, 10, and 100 nM) and stored at 4 °C for up to 48 h. Sperm motility, membrane integrity, acrosome integrity, mitochondrial membrane potential, reactive oxygen species (ROS) level, ATP content, and the expression of NADPH dehydrogenase subunits 1 (MT-ND1) and NADPH dehydrogenase subunits 6 (MT-ND6) were evaluated. It was observed that compared to the control, the 10 nM MA-5 treatment significantly (p < 0.05) increased total motility (82 ± 3.5% vs. 76 ± 5.9%), progressive motility (67.6 ± 8.2% vs. 51 ± 8.3%), and other parameters (straight-line velocity (VSL), average path velocity (VAP), and curvilinear velocity (VCL)). In addition, 10 nM MA-5 supplementation also improved ram sperm membrane integrity and acrosomal integrity as well increased mitochondrial membrane potential (51.1 ± 0.7% vs. 37.7 ± 1.3%), reduced ROS levels, and elevated adenosine triphosphate (ATP) contents. Furthermore, a Western blot analysis demonstrated that the addition of MA-5 significantly (p < 0.05) increased the expression of MT-ND1 and MT-ND6 proteins in ram sperm, with the 10 nM MA-5 treatment resulting in the highest expression level. These results suggest that MA-5 improves ram sperm quality by maintaining high sperm mitochondrial function during liquid storage at 4 °C.

Skin Bioimpedance Analysis to Determine Cellular Integrity by Phase Angle in Women with Fibromyalgia: A Cross-Sectional Study

Oxidative stress has been proposed as a significant part of the pathogenesis of fibromyalgia, and the phase angle in bioelectrical impedance analysis has been explored as a potential technique to screen oxidative abnormalities. This study recruited 35 women with fibromyalgia and 35 healthy women, who underwent bioelectrical impedance analysis and maximum isometric handgrip strength tests. Women with fibromyalgia showed lower bilateral handgrip strength (right hand: 16.39 ± 5.87 vs. 27.53 ± 4.09, p < 0.001; left hand: 16.31 ± 5.51 vs. 27.61 ± 4.14, p < 0.001), as well as higher body fat mass (27.14 ± 10.21 vs. 19.94 ± 7.25, p = 0.002), body fat percentage (37.80 ± 8.32 vs. 30.63 ± 7.77, p < 0.001), and visceral fat area (136.76 ± 55.31 vs. 91.65 ± 42.04, p < 0.01) compared with healthy women. There was no statistically significant difference in muscle mass between groups, but women with fibromyalgia showed lower phase angles in all body regions when compared with healthy control women (right arm: 4.42 ± 0.51 vs. 4.97 ± 0.48, p < 0.01; left arm: 4.23 ± 0.48 vs. 4.78 ± 0.50, p < 0.001; trunk: 5.62 ± 0.77 vs. 6.78 ± 0.84, p < 0.001; right leg: 5.28 ± 0.56 vs. 5.81 ± 0.60, p < 0.001; left leg: 5.07 ± 0.51 vs. 5.69 ± 0.58, p < 0.001; whole body: 4.81 ± 0.47 vs. 5.39 ± 0.49, p < 0.001). Moreover, whole-body phase-angle reduction was only predicted by the presence of fibromyalgia (R2 = 0.264; β = 0.639; F(1,68) = 24.411; p < 0.001). Our study revealed significantly lower phase angle values, lower handgrip strength, and higher fat levels in women with fibromyalgia compared to healthy controls, which are data of clinical relevance when dealing with such patients.

Traditional herbs: mechanisms to combat cellular senescence

Cellular senescence plays a very important role in the ageing of organisms and age-related diseases that increase with age, a process that involves physiological, structural, biochemical and molecular changes in cells. In recent years, it has been found that the active ingredients of herbs and their natural products can prevent and control cellular senescence by affecting telomerase activity, oxidative stress response, autophagy, mitochondrial disorders, DNA damage, inflammatory response, metabolism, intestinal flora, and other factors. In this paper, we review the research information on the prevention and control of cellular senescence in Chinese herbal medicine through computer searches of PubMed, Web of Science, Science Direct and CNKI databases.

Multitargeted inhibition of key enzymes associated with diabetes and Alzheimer's disease by 1,3,4-oxadiazole derivatives: Synthesis, in vitro screening, and computational studies

A library of 22 derivatives of 1,3,4-oxadiazole-2-thiol was synthesized, structurally characterized, and assessed for its potential to inhibit α-amylase, α-glucosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and antioxidant activities. Most of the tested compounds demonstrated good to moderate inhibition potential; however, their activity was lower than that of the standard acarbose. Significantly, compound 3f exhibited the highest inhibition potential against α-glucosidase and α-amylase enzymes, with IC50 values of 18.52 ± 0.09 and 20.25 ± 1.05 µM, respectively, in comparison to the standard acarbose (12.29 ± 0.26; 15.98 ± 0.14 µM). Compounds also demonstrated varying degrees of inhibitory potential against AChE (IC50  = 9.25 ± 0.19 to 36.15 ± 0.12 µM) and BChE (IC50  = 10.06 ± 0.43 to 35.13 ± 0.12 µM) enzymes compared to the standard donepezil (IC50  = 2.01 ± 0.12; 3.12 ± 0.06 µM), as well as DPPH (IC50  = 20.98 ± 0.06 to 52.83 ± 0.12 µM) and ABTS radical scavenging activities (IC50  = 22.29 ± 0.18 to 47.98 ± 0.03 µM) in comparison to the standard ascorbic acid (IC50  = 18.12 ± 0.15; 19.19 ± 0.72). The kinetic investigations have demonstrated that the compounds exhibit competitive-type inhibition for α-amylase, noncompetitive-type inhibition for α-glucosidase and AChE, and mixed-type inhibition for BChE. Additionally, a molecular docking study was performed on all synthetic oxadiazoles to explore the interaction details of these compounds with the active sites of the enzymes.

Associations between regional adipose tissue distribution and skeletal muscle bioenergetics in older men and women

Objective

Examine the association of ectopic adipose tissue (AT) with skeletal muscle (SM) mitochondrial bioenergetics in older adults.

Methods

Cross-sectional data from 829 older adults ≥70 years was used. Total abdominal, subcutaneous, and visceral AT; and thigh muscle fat infiltration (MFI) was quantified by MRI. SM mitochondrial energetics were characterized using in vivo 31 P-MRS (ATP max ) and ex vivo high-resolution respirometry (maximal oxidative phosphorylation (OXPHOS)). ActivPal was used to measure PA (step count). Linear regression models adjusted for covariates were applied, with sequential adjustment for BMI and PA.

Results

Independent of BMI, total abdominal (standardized (Std.) β=-0.21; R 2 =0.09) and visceral AT (Std. β=-0.16; R 2 =0.09) were associated with ATP max ( p <0.01), but not after further adjustment for PA (p≥0.05). Visceral AT (Std. β=-0.16; R 2 =0.25) and thigh MFI (Std. β=-0.11; R 2 =0.24) were negatively associated with carbohydrate-supported maximal OXPHOS independent of BMI and PA ( p <0.05). Total abdominal AT (Std. β=-0.19; R 2 =0.24) and visceral AT (Std. β=-0.17; R 2 =0.24) were associated with fatty acid-supported maximal OXPHOS independent of BMI and PA (p<0.05).

Conclusions

Skeletal MFI and abdominal visceral, but not subcutaneous AT, are inversely associated with SM mitochondrial bioenergetics in older adults independent of BMI. Associations between ectopic AT and in vivo mitochondrial bioenergetics are attenuated by PA.

The Host-specific Microbiota is Required for Diet-Specific Metabolic Homeostasis

In complex mammals, the importance and host-specificity of microbial communities have been demonstrated through their positive effects on host immune fitness or performance. However, whether host metabolic physiology homeostasis depends on a specific bacterial community exclusive to the host remains unclear. Here, we show that the coevolved host-specific microbiota is required to maintain diet-specific flexible and sufficient metabolic homeostasis through a high colonization rate, modulating gut metabolites, and related targets. Using germ-free (GF) mice, we tested whether the fitness benefiting the host metabolic phenotype of microbiota was host-specific. We demonstrated that GF mice associated with exogenous microbiota (human microbiota (HM)), which exhibited different and reduced gut microbial species diversity, significantly elevated metabolic rate, and exhibited metabolic insufficiency, all characteristics of GF mice. Strikingly, the absence of the host-specific microbiome attenuated high-fat diet-specific metabolism features. Different diets caused different metabolic changes in only host-specific microbiota-associated mice, not the host-microbiota mismatched mice. While RNA sequencing revealed subtle changes in the expression of genes in the liver, GF mice and HM mice showed considerably altered expression of genes associated with metabolic physiology compared to GF mice associated with host-specific microbiota. The effect of diet outweighed microbiota in the liver transcriptome. These changes occurred in the setting of decreased luminal short-chain fatty acids (SCFAs) and the secondary bile acid (BAs) pool and downstream gut signaling targets in HM and GF mice, which affects whole-body metabolism. These data indicate that a foreign microbial community provides little metabolic benefit to the host when compared to a host-specific microbiome, due to the colonization selection pressure and microbiota-derived metabolites dysfunction. Overall, microbiome fitness effects on the host metabolic phenotype were host-specific. Understanding the impact of the host-specificity of the microbiome on metabolic homeostasis may provide important insights for building a better probiotic.

Highlights

Microbiome fitness effects on the host metabolic phenotype were host-specific in mammals.Human microbiota-associated mice exhibited lower host metabolic fitness or performance, and similar functional costs in GF mice.Different diets cause different metabolic changes only in host-specific microbiota-associated mice, not the host-microbiota mismatched mice.The defective gut microbiota in host-specific microbiota, microbial metabolites and related targets likely drive the metabolic homeostasis.

Bioenergetic function is decreased in peripheral blood mononuclear cells of veterans with Gulf War Illness

Gulf War Illness (GWI) is a major health problem for approximately 250,000 Gulf War (GW) veterans, but the etiology of GWI is unclear. We hypothesized that mitochondrial dysfunction is an important contributor to GWI, based on the similarity of some GWI symptoms to those occurring in some mitochondrial diseases; the plausibility that certain pollutants to which GW veterans were exposed affect mitochondria; mitochondrial effects observed in studies in laboratory models of GWI; and previous evidence of mitochondrial outcomes in studies in GW veterans. A primary role of mitochondria is generation of energy via oxidative phosphorylation. However, direct assessment of mitochondrial respiration, reflecting oxidative phosphorylation, has not been carried out in veterans with GWI. In this case-control observational study, we tested multiple measures of mitochondrial function and integrity in a cohort of 114 GW veterans, 80 with and 34 without GWI as assessed by the Kansas definition. In circulating white blood cells, we analyzed multiple measures of mitochondrial respiration and extracellular acidification, a proxy for non-aerobic energy generation; mitochondrial DNA (mtDNA) copy number; mtDNA damage; and nuclear DNA damage. We also collected detailed survey data on demographics; deployment; self-reported exposure to pesticides, pyridostigmine bromide, and chemical and biological warfare agents; and current biometrics, health and activity levels. We observed a 9% increase in mtDNA content in blood in veterans with GWI, but did not detect differences in DNA damage. Basal and ATP-linked oxygen consumption were respectively 42% and 47% higher in veterans without GWI, after adjustment for mtDNA amount. We did not find evidence for a compensatory increase in anaerobic energy generation: extracellular acidification was also lower in GWI (12% lower at baseline). A subset of 27 and 26 veterans returned for second and third visits, allowing us to measure stability of mitochondrial parameters over time. mtDNA CN, mtDNA damage, ATP-linked OCR, and spare respiratory capacity were moderately replicable over time, with intraclass correlation coefficients of 0.43, 0.44, 0.50, and 0.57, respectively. Other measures showed higher visit-to-visit variability. Many measurements showed lower replicability over time among veterans with GWI compared to veterans without GWI. Finally, we found a strong association between recalled exposure to pesticides, pyridostigmine bromide, and chemical and biological warfare agents and GWI (p < 0.01, p < 0.01, and p < 0.0001, respectively). Our results demonstrate decreased mitochondrial respiratory function as well as decreased glycolytic activity, both of which are consistent with decreased energy availability, in peripheral blood mononuclear cells in veterans with GWI.

The effects of pomegranate consumption on inflammatory and oxidative stress biomarkers in adults: a systematic review and meta-analysis

BACKGROUND

Several studies have shown the effects of pomegranate on oxidative stress and inflammation biomarkers, while some studies showed no effects of pomegranate on these biomarkers. Therefore, we aimed to evaluate the effects of pomegranate consumption on C-reactive protein (CRP), interlukin-6 (IL-6), tumor necrosis factor α (TNF-α), total antioxidant capacity (TAC), and malondialdehyde (MDA) in adults.

METHODS

A systematic literature search was performed using databases, including PubMed, Web of Science, and Scopus, up to May 2023 to identify eligible randomized controlled trials (RCTs). Heterogeneity tests of the included trials were performed using the I2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference with a 95% confidence interval.

RESULTS

Of 3811 records, 33 eligible RCTs were included in the current study. Our meta-analysis of the pooled findings showed that pomegranate consumption significantly reduced CRP (WMD: -0.50 mg/l; 95% CI -0.79 to -0.20; p = 0.001), IL-6 (WMD: -1.24 ng/L 95% CI -1.95 to -0.54; p = 0.001), TNF-α (WMD: -1.96 pg/ml 95%CI -2.75 to -1.18; p < 0.001), and MDA (WMD: -0.34 nmol/ml 95%CI -0.42 to -0.25; p < 0.001). Pooled analysis of 13 trials revealed that pomegranate consumption led to a significant increase in TAC (WMD: 0.26 mmol/L 95%CI 0.03 to 0.49; p = 0.025).

CONCLUSION

Overall, the results demonstrated that pomegranate consumption has beneficial effects on oxidative stress and inflammatory biomarkers in adults. Therefore, pomegranate can be consumed as an effective dietary approach to attenuate oxidative stress and inflammation in patients with cardiovascular diseases.

PROSPERO REGISTRATION CODE

CRD42023406684.

Mitochondrial Neurodegenerative Diseases: Three Mitochondrial Ribosomal Proteins as Intermediate Stage in the Pathway That Associates Damaged Genes with Alzheimer's and Parkinson's

Currently, numerous research endeavors are dedicated to unraveling the intricate nature of neurodegenerative diseases. These conditions are characterized by the gradual and progressive impairment of specific neuronal systems that exhibit anatomical or physiological connections. In particular, in the last twenty years, remarkable efforts have been made to elucidate neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, despite extensive research endeavors, no cure or effective treatment has been discovered thus far. With the emergence of studies shedding light on the contribution of mitochondria to the onset and advancement of mitochondrial neurodegenerative disorders, researchers are now directing their investigations toward the development of therapies. These therapies include molecules designed to protect mitochondria and neurons from the detrimental effects of aging, as well as mutant proteins. Our objective is to discuss and evaluate the recent discovery of three mitochondrial ribosomal proteins linked to Alzheimer's and Parkinson's diseases. These proteins represent an intermediate stage in the pathway connecting damaged genes to the two mitochondrial neurological pathologies. This discovery potentially could open new avenues for the production of medicinal substances with curative potential for the treatment of these diseases.

A Review on Pathophysiology, and Molecular Mechanisms of Bacterial Chondronecrosis and Osteomyelitis in Commercial Broilers

Modern day broilers have a great genetic potential to gain heavy bodyweights with a huge metabolic demand prior to their fully mature ages. Moreover, this made the broilers prone to opportunistic pathogens which may enter the locomotory organs under stress causing bacterial chondronecrosis and osteomyelitis (BCO). Such pathogenic colonization is further accelerated by microfractures and clefts that are formed in the bones due to rapid growth rate of the broilers along with ischemia of blood vessels. Furthermore, there are several pathways which alter bone homeostasis like acute phase response, and intrinsic and extrinsic cell death pathways. In contrast, all the affected birds may not exhibit clinical lameness even with the presence of lameness associated factors causing infection. Although Staphylococcus, E. coli, and Enterococcus are considered as common bacterial pathogens involved in BCO, but there exist several other non-culturable bacteria. Any deviation from maintaining a homeostatic environment in the gut might lead to bacterial translocation through blood followed by proliferation of pathogenic bacteria in respective organs including bones. It is important to alleviate dysbiosis of the blood which is analogous to dysbiosis in the gut. This can be achieved by supplementing pro, pre, and synbiotics which helps in providing a eubiotic environment abating the bacterial translocation that was studied to the incidence of BCO. This review focused on potential and novel biomarkers, pathophysiological mechanism, the economic significance of BCO, immune mechanisms, and miscellaneous factors causing BCO. In addition, the role of gut microbiomes along with their diversity and cell culture models from compact bones of chicken in better understanding of BCO were explored.

Kalanchoe sp. Extracts-Phytochemistry, Cytotoxic, and Antimicrobial Activities

Kalanchoe species are succulents occurring in tropical regions. They have many biological and pharmacological properties. In this study, the cytotoxic and antimicrobial activities of water and dichloromethane Kalanchoe fractions obtained from ethanol extracts of three Kalanchoe species-K. daigremontiana, K. pinnata, and K. blossfeldiana were estimated. The cytotoxic effect was assessed on human cancer cell lines-ovarian SKOV-3, cervical HeLa, breast MCF-7, and melanoma A375-by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The antimicrobial activity was estimated on selected Gram-positive and Gram-negative bacteria strains and on Candida albicans. The phytochemical analysis of selected Kalanchoe extracts was conducted by LC-QTOF-MS. The obtained results showed that the water fraction of K. blossfeldiana was active both on the tested cancer cells (IC₅₀ values were 28.28 ± 2.76 and 32.51 ± 0.69 µg/mL on HeLa and SKOV-3, respectively) and bacteria strains (MIC values were 16 and 32 µg/mL on S. epidermidis and S. aureus, respectively). The water fraction of K. pinnata also had a significant effect on S. epidermidis and S. aureus, with MIC values of 32 and 64 µg/mL, respectively. The water fraction of K. blossfeldiana triggered a decrease in mitochondrial membrane potential (MMP) and induced cell cycle arrest in the G2/M phase in the SKOV-3 and HeLa cells. This fraction did not significantly increase cellular oxidative stress level. The DPPH and ABTS assays revealed that the water fraction of K. blossfeldiana had a strong antioxidant effect (IC₅₀ was 9.44 ± 0.06 and 3.17 ± 0.1 µg/mL, respectively). The phytochemical analysis of the extracts of K. blossfeldiana and K. pinnata revealed the presence of at least 218 main components. The most frequently occurring were flavonol glycosides (31 metabolites), phenylpropanoids (13 metabolites), gallic acid derivatives (13 compounds), benzoic acid derived compounds (14 metabolites), and acyclic alcohol glycosides (16 compounds). In addition, proanthocyanidins were detected mainly in K. blossfeldiana. The study indicates that the water fraction of K. blossfeldiana has significant biological potential and can be further investigated towards anticancer and antimicrobial application.

Pharmacological Modulation of Energy and Metabolic Pathways Protects Hearing in the Fus1/Tusc2 Knockout Model of Mitochondrial Dysfunction and Oxidative Stress

Tightly regulated and robust mitochondrial activities are critical for normal hearing. Previously, we demonstrated that Fus1/Tusc2 KO mice with mitochondrial dysfunction exhibit premature hearing loss. Molecular analysis of the cochlea revealed hyperactivation of the mTOR pathway, oxidative stress, and altered mitochondrial morphology and quantity, suggesting compromised energy sensing and production. Here, we investigated whether the pharmacological modulation of metabolic pathways using rapamycin (RAPA) or 2-deoxy-D-glucose (2-DG) supplementation can protect against hearing loss in female Fus1 KO mice. Additionally, we aimed to identify mitochondria- and Fus1/Tusc2-dependent molecular pathways and processes critical for hearing. We found that inhibiting mTOR or activating alternative mitochondrial energetic pathways to glycolysis protected hearing in the mice. Comparative gene expression analysis revealed the dysregulation of critical biological processes in the KO cochlea, including mitochondrial metabolism, neural and immune responses, and the cochlear hypothalamic-pituitary-adrenal axis signaling system. RAPA and 2-DG mostly normalized these processes, although some genes showed a drug-specific response or no response at all. Interestingly, both drugs resulted in a pronounced upregulation of critical hearing-related genes not altered in the non-treated KO cochlea, including cytoskeletal and motor proteins and calcium-linked transporters and voltage-gated channels. These findings suggest that the pharmacological modulation of mitochondrial metabolism and bioenergetics may restore and activate processes critical for hearing, thereby protecting against hearing loss.

Involvement of a flavoprotein, acetohydroxyacid synthase, in growth and riboflavin production in riboflavin-overproducing Ashbya gossypii mutant

BACKGROUND

Previously, we isolated a riboflavin-overproducing Ashbya gossypii mutant (MT strain) and discovered some mutations in genes encoding flavoproteins. Here, we analyzed the riboflavin production in the MT strain, in view of flavoproteins, which are localized in the mitochondria.

RESULTS

In the MT strain, mitochondrial membrane potential was decreased compared with that in the wild type (WT) strain, resulting in increased reactive oxygen species. Additionally, diphenyleneiodonium (DPI), a universal flavoprotein inhibitor, inhibited riboflavin production in the WT and MT strains at 50 µM, indicating that some flavoproteins may be involved in riboflavin production. The specific activities of NADH and succinate dehydrogenases were significantly reduced in the MT strain, but those of glutathione reductase and acetohydroxyacid synthase were increased by 4.9- and 25-fold, respectively. By contrast, the expression of AgGLR1 gene encoding glutathione reductase was increased by 32-fold in the MT strain. However, that of AgILV2 gene encoding the catalytic subunit of acetohydroxyacid synthase was increased by only 2.1-fold. These results suggest that in the MT strain, acetohydroxyacid synthase, which catalyzes the first reaction of branched-chain amino acid biosynthesis, is vital for riboflavin production. The addition of valine, which is a feedback inhibitor of acetohydroxyacid synthase, to a minimal medium inhibited the growth of the MT strain and its riboflavin production. In addition, the addition of branched-chain amino acids enhanced the growth and riboflavin production in the MT strain.

CONCLUSION

The significance of branched-chain amino acids for riboflavin production in A. gossypii is reported and this study opens a novel approach for the effective production of riboflavin in A. gossypii.

Role of mitochondrial dysfunction and oxidative stress in sensorineural hearing loss

Sensorineural hearing loss (SNHL) can either be genetically inherited or acquired as a result of aging, noise exposure, or ototoxic drugs. Although the precise pathophysiological mechanisms underlying SNHL remain unclear, an overwhelming body of evidence implicates mitochondrial dysfunction and oxidative stress playing a central etiological role. With its high metabolic demands, the cochlea, particularly the sensory hair cells, stria vascularis, and spiral ganglion neurons, is vulnerable to the damaging effects of mitochondrial reactive oxygen species (ROS). Mitochondrial dysfunction and consequent oxidative stress in cochlear cells can be caused by inherited mitochondrial DNA (mtDNA) mutations (hereditary hearing loss and aminoglycoside-induced ototoxicity), accumulation of acquired mtDNA mutations with age (age-related hearing loss), mitochondrial overdrive and calcium dysregulation (noise-induced hearing loss and cisplatin-induced ototoxicity), or accumulation of ototoxic drugs within hair cell mitochondria (drug-induced hearing loss). In this review, we provide an overview of our current knowledge on the role of mitochondrial dysfunction and oxidative stress in the development of SNHL caused by genetic mutations, aging, exposure to excessive noise, and ototoxic drugs. We also explore the advancements in antioxidant therapies for the different forms of acquired SNHL that are being evaluated in preclinical and clinical studies.

The Key Role of Mitochondrial Function in Health and Disease

The role of mitochondrial function in health and disease has become increasingly recognized, particularly in the last two decades. Mitochondrial dysfunction as well as disruptions of cellular bioenergetics have been shown to be ubiquitous in some of the most prevalent diseases in our society, such as type 2 diabetes, cardiovascular disease, metabolic syndrome, cancer, and Alzheimer's disease. However, the etiology and pathogenesis of mitochondrial dysfunction in multiple diseases have yet to be elucidated, making it one of the most significant medical challenges in our history. However, the rapid advances in our knowledge of cellular metabolism coupled with the novel understanding at the molecular and genetic levels show tremendous promise to one day elucidate the mysteries of this ancient organelle in order to treat it therapeutically when needed. Mitochondrial DNA mutations, infections, aging, and a lack of physical activity have been identified to be major players in mitochondrial dysfunction in multiple diseases. This review examines the complexities of mitochondrial function, whose ancient incorporation into eukaryotic cells for energy purposes was key for the survival and creation of new species. Among these complexities, the tightly intertwined bioenergetics derived from the combustion of alimentary substrates and oxygen are necessary for cellular homeostasis, including the production of reactive oxygen species. This review discusses different etiological mechanisms by which mitochondria could become dysregulated, determining the fate of multiple tissues and organs and being a protagonist in the pathogenesis of many non-communicable diseases. Finally, physical activity is a canonical evolutionary characteristic of humans that remains embedded in our genes. The normalization of a lack of physical activity in our modern society has led to the perception that exercise is an "intervention". However, physical activity remains the modus vivendi engrained in our genes and being sedentary has been the real intervention and collateral effect of modern societies. It is well known that a lack of physical activity leads to mitochondrial dysfunction and, hence, it probably becomes a major etiological factor of many non-communicable diseases affecting modern societies. Since physical activity remains the only stimulus we know that can improve and maintain mitochondrial function, a significant emphasis on exercise promotion should be imperative in order to prevent multiple diseases. Finally, in populations with chronic diseases where mitochondrial dysfunction is involved, an individualized exercise prescription should be crucial for the "metabolic rehabilitation" of many patients. From lessons learned from elite athletes (the perfect human machines), it is possible to translate and apply multiple concepts to the betterment of populations with chronic diseases.

Mitochondrial Dysfunction, Oxidative Stress, and Therapeutic Strategies in Diabetes, Obesity, and Cardiovascular Disease

Mitochondria are subcellular organelles involved in essential cellular functions, including cytosolic calcium regulation, cell apoptosis, and reactive oxygen species production. They are the site of important biochemical pathways, including the tricarboxylic acid cycle, parts of the ureagenesis cycle, or haem synthesis. Mitochondria are responsible for the majority of cellular ATP production through OXPHOS. Mitochondrial dysfunction has been associated with metabolic pathologies such as diabetes, obesity, hypertension, neurodegenerative diseases, cellular aging, and cancer. In this article, we describe the pathophysiological changes in, and mitochondrial role of, metabolic disorders (diabetes, obesity, and cardiovascular disease) and their correlation with oxidative stress. We highlight the genetic changes identified at the mtDNA level. Additionally, we selected several representative biomarkers involved in oxidative stress and summarize the progress of therapeutic strategies.

Nutrients, Physical Activity, and Mitochondrial Dysfunction in the Setting of Metabolic Syndrome

Metabolic syndrome (MetS) is a cluster of metabolic risk factors for diabetes, coronary heart disease, non-alcoholic fatty liver disease, and some tumors. It includes insulin resistance, visceral adiposity, hypertension, and dyslipidemia. MetS is primarily linked to lipotoxicity, with ectopic fat deposition from fat storage exhaustion, more than obesity per se. Excessive intake of long-chain saturated fatty acid and sugar closely relates to lipotoxicity and MetS through several pathways, including toll-like receptor 4 activation, peroxisome proliferator-activated receptor-gamma regulation (PPARγ), sphingolipids remodeling, and protein kinase C activation. These mechanisms prompt mitochondrial dysfunction, which plays a key role in disrupting the metabolism of fatty acids and proteins and in developing insulin resistance. By contrast, the intake of monounsaturated, polyunsaturated, and medium-chain saturated (low-dose) fatty acids, as well as plant-based proteins and whey protein, favors an improvement in sphingolipid composition and metabolic profile. Along with dietary modification, regular exercises including aerobic, resistance, or combined training can target sphingolipid metabolism and improve mitochondrial function and MetS components. This review aimed to summarize the main dietary and biochemical aspects related to the physiopathology of MetS and its implications for mitochondrial machinery while discussing the potential role of diet and exercise in counteracting this complex clustering of metabolic dysfunctions.

Two polyphenols isolated from Corallodiscus flabellata B. L. Burtt ameliorate amyloid β-protein induced Alzheimer's disease neuronal injury by improving mitochondrial homeostasis

Corallodiscus flabellata B. L. Burtt (CF) is a Chinese folk herb with reported potential for the treatment of Alzheimer's disease (AD). 3,4-Dihydroxyphenylethanol-8-O-[4-O-trans-caffeoyl-β-D-apiofuranosyl-(1→3)-β-D-glucopyranosyl (1→6)][1]-β-D-glucopyranoside (SDC-1-8) and hydroxytyrosol (HT) are two polyphenolic compounds isolated from CF. The aim of this study was to investigate the protective effects of SDC-1-8 and HT on an Aβ_25-35-induced AD model and to study the underlying mechanism. The AD mouse model was established using a brain injection of amyloid β-protein 25-35 (Aβ_25-35, 200 μM), followed by continuous administration of SDC-1-8 and HT for 4 weeks, and found that they improved cognitive dysfunction; ameliorated neuronal damage and apoptosis; decreased oxidative stress, and mitochondrial fission protein levels; and increased mitochondrial fusion protein levels in AD mice. Moreover, SDC-1-8 and HT inhibited mitochondrial membrane depolarization, reduced intracellular stored Ca²⁺ levels, enhanced mitochondrial respiration, increased mitochondrial fusion, and decreased mitochondrial division in Aβ_25-35-induced PC12 cells even in the presence of mdivi-1. Furthermore, molecular docking simulations showed that SDC-1-8 and HT interacted with dynamin-related protein 1 with higher affinity than mitofusin 1. Thus, it is summarized that SDC-1-8 and HT may have neuroprotective effects by balancing the abnormalities of mitochondrial fission and fusion, and SDC-1-8 and HT are the components providing the therapeutic basis of CF.

miR-494-5p mediates the antioxidant activity of EPA by targeting the mitochondrial elongation factor 1 gene MIEF1 in HepG2 cells

Eicosapentaenoic acid (EPA) shows antioxidant activity, which may be attributed to its regulatory effect on microRNA expression. Our preliminary study indicated that EPA upregulated miR-494-5p, which was possibly involved in the regulation of cellular stress responses. The current study aimed to address whether miR-494-5p was targeted by EPA to regulate cellular oxidative stress and its possible functional mechanism. The results showed that miR-494-5p mediated the antioxidant effect of EPA and miR-494-5p reduction deteriorated EPA-induced increase in the cellular antioxidant capacity of HepG2 cells. Moreover, the mitochondrial elongation factor 1 (MIEF1) gene was a target gene of miR-494-5p. Both miR-494-5p overexpression and MIEF1 knockdown significantly enhanced cellular antioxidant capacity, as indicated by a reduction in the reactive oxygen species level and an increase in the total cellular antioxidant capacity, along with enhancing antioxidant enzymes. Thus, miR-494-5p and MIEF1 had opposite effects on cellular antioxidant capacity. Furthermore, their regulatory effects on oxidative stress may have been attributed to modulation of mitochondrial function, biogenesis and homeostasis. Taken together, the findings indicated that miR-494-5p mediated EPA activity and promoted cellular antioxidant capacity by inhibiting the expression of MIEF1, which further modulated mitochondrial structure and activity. This study may provide novel insights into the post-translational regulation of antioxidation reactions, which involves the coordinated control of mitochondria.

Fatigue in older persons: the role of nutrition

Fatigue is defined as a symptom leading to the inability to continue functioning at the expected activity level. It is a highly prevalent symptom, challenging to frame into monodimensional pathophysiological mechanisms. As a result, fatigue is often underestimated in the clinical setting and is wrongly considered an unavoidable consequence of ageing. Several potential mechanisms responsible for fatigue have been proposed, including sleep patterns, autonomic nervous system abnormalities and biological complexity. Inflammation and mitochondrial dysfunction are among the most promising mechanisms through which malnutrition may cause fatigue. Not surprisingly, fatigue is highly prevalent in inflammatory conditions (e.g. COVID-19 infection). The nutritional status may also represent a critical factor in the development and presentation of fatigue, which may mimic the exhaustion of the individual's metabolic reserves. For example, the insufficient dietary intake of energy and proteins may determine the catabolism of body fat and muscles, disrupt the homeostatic balance and cause the onset of fatigue. It is necessary to conduct research on fatigue. By characterising its pathophysiological mechanisms, it will be possible to (1) support the design and development of targeted interventions, (2) improve the quality of life of many persons by acting on the symptom and (3) reduce the direct and indirect costs of a burdening condition typical of advancing age. In the present review, we provide an overview of the role that nutrition may play as a determinant of fatigue in older people, also in the context of the COVID-19 pandemic.

Mitochondrial Toxicant-Induced Neuronal Apoptosis in Parkinson's Disease: What We Know so Far

Parkinson's disease (PD) is one of the most common progressive neurodegenerative diseases caused by the loss of dopamine-producing neuronal cells in the region of substantia nigra pars compacta of the brain. During biological aging, neuronal cells slowly undergo degeneration, but the rate of cell death increases tremendously under some pathological conditions, leading to irreversible neurodegenerative diseases. By the time symptoms of PD usually appear, more than 50 to 60% of neuronal cells have already been destroyed. PD symptoms often start with tremors, followed by slow movement, stiffness, and postural imbalance. The etiology of PD is still unknown; however, besides genetics, several factors contribute to neurodegenerative disease, including exposure to pesticides, environmental chemicals, solvents, and heavy metals. Postmortem brain tissues of patients with PD show mitochondrial abnormalities, including dysfunction of the electron transport chain. Most chemicals present in our environment have been shown to target the mitochondria; remarkably, patients with PD show a mild deficiency in NADH dehydrogenase activity, signifying a possible link between PD and mitochondrial dysfunction. Inhibition of electron transport complexes generates free radicals that further attack the macromolecules leading to neuropathological conditions. Apart from that, oxidative stress also causes neuroinflammation-mediated neurodegeneration due to the activation of microglial cells. However, the mechanism that causes mitochondrial dysfunction, especially the electron transport chain, in the pathogenesis of PD remains unclear. This review discusses the recent updates and explains the possible mechanisms of mitochondrial toxicant-induced neuroinflammation and neurodegeneration in PD.

Oxidative Stress and Antioxidants in Chronic Rhinosinusitis with Nasal Polyps

Oxidative stress results from an imbalance between the production of reactive oxygen species and the body's antioxidant defense system. It plays an important role in the regulation of the immune response and can be a pathogenic factor in various diseases. Chronic rhinosinusitis (CRS) is a complex and heterogeneous disease with various phenotypes and endotypes. Recently, an increasing number of studies have proposed that oxidative stress (caused by both environmental and intrinsic stimuli) plays an important role in the pathogenesis and persistence of CRS. This has attracted the attention of several researchers. The relationship between the presence of reactive oxygen species composed of free radicals and nasal polyp pathology is a key topic receiving attention. This article reviews the role of oxidative stress in respiratory diseases, particularly CRS, and introduces potential therapeutic antioxidants that may offer targeted treatment for CRS.

Swietenine Alleviates Vascular Remodelling by Enhancing Mitophagy of Pulmonary Arterial Smooth Muscle Cells in Experimental Pulmonary Hypertension

BACKGROUND

Vascular remodelling during pulmonary hypertension (PH) is characterized by the phenotypic transformation of pulmonary arterial smooth muscle cells (PASMCs). Swietenine (Swi), extracted from the seeds of traditional medicine Swietenia mahagoni, has been used to treat cardiac remodelling, but the effect of Swi on PH is unknown. This study aims to evaluate the effect of Swi on hypoxia-induced phenotypic transformation of PASMCs in experimental PH.

METHODS

In our research, C57BL/6 mice were treated with SU5416 and exposed to hypoxia for 4 weeks to establish HySu-PH model. Mice in the Swi treatment group were subjected to HySu with daily administration of Swi. Hemodynamic parameters, echocardiography, and degree of vascular muscularization were measured to evaluate the PH model. Proliferation of PASMC was assessed by Ki67 and EdU assay. Cell migration was detected by wound-healing assay. Mitophagy levels were evaluated by mito-tracker and lyso-tracker, autophagic flux, and protein expression of Pink1 and Lc3Ⅱ. The molecular docking was used to validate the interaction of Swi with Nrf2. Immunofluorescence and immunohistochemical staining was applied to determine the subcellular localization of Nrf2.

RESULTS

The results showed that Swi attenuated hypoxia-induced increase of right ventricle systolic pressure, Fulton index, and vascular remodelling and decreased PASMC proliferation, migration, and enhanced mitophagy. Furthermore, the interaction of Swi with Nrf2 promoted the translocation of Nrf2 into the nucleus, resulting in the induction of Pink1.

CONCLUSIONS

This study demonstrates that Swi prevents vascular remodelling in experimental PH through inhibition of phenotypic transformation and hyperproliferation of PASMCs caused by reversing hypoxia-induced inhibition of mitophagy.

Interactive effect of carbendazim and imidacloprid on buffalo bone marrow derived mesenchymal stem cells: oxidative stress, cytotoxicity and genotoxicity

The effect of a combination of two pesticides, carbendazim (CBZ) and imidacloprid (IMI), was investigated on mesenchymal stem cells derived from the bone marrow of buffalo (bMSCs). The bMSCs were exposed to the CBZ (2.25 µM, 4.49 µM, and 8.98 µM) and IMI (0.81 mM, 1.61 mM, and 3.22 mM) alone as well as in combinations. The bMSCs were found to be positive for the stem cell markers, AP, CD73, and OCT4. The bMSCs showed a significant reduction (p ≤ 0.05) in cell viability, and status of anti-oxidants while a significant increase (p ≤ 0.05) in the level of LDH, ALP, and CK-MB in CBZ and IMI-treated groups. A significant increase (p ≤ 0.05) was noticed in LPO, O^2─ radical, total ROS, loss of ΔΨm, apoptotic index, and DNA damage in CBZ and IMI-treated groups. A low-dose combination group showed an elevated effect compared to the groups treated with the single pesticide. The interaction index was calculated for CBZ-IMI combined treatment groups on various parameters that showed the majority of antagonist effects. Present findings confirmed that CBZ and IMI-induced cytotoxicity in bMSCs was mediated via ROS production, altered ΔΨm and LPO along with depressed antioxidant status which was responsible for cell apoptosis and cell damage. This study suggested that CBZ and IMI had a dose-dependent toxic effect when the pesticides were used alone, while, co-exposure to both the pesticides simultaneously had an antagonist or non-additive effect on buffalo bMSCs at lower dose combinations and they induced a potentiating effect at high-dose combination.

Role of Nrf2 and exercise in alleviating COPD-induced skeletal muscle dysfunction

Chronic obstructive pulmonary disease (COPD) is a complex chronic respiratory disease with cumulative impacts on multiple systems, exhibiting significant extrapulmonary impacts, and posing a serious public health problem. Skeletal muscle dysfunction is one of the most pronounced extrapulmonary effects in patients with COPD, which severely affects patient prognosis and mortality primarily through reduced productivity resulting from muscle structural and functional alterations. Although the detailed pathogenesis of COPD has not been fully determined, some researchers agree that oxidative stress plays a significant role. Oxidative stress not only catalyzes the progression of pulmonary symptoms but also drives the development of skeletal muscle dysfunction. Nuclear factor erythroid 2-related factor 2 (Nrf2), is a key transcription factor that regulates the antioxidant response and plays an enormous role in combating oxidative stress. In this review, we have summarized current research on oxidative stress damage to COPD skeletal muscle and analyzed the role of Nrf2 in improving skeletal muscle dysfunction in COPD through exercise. The results suggest that oxidative stress drives the occurrence and development of skeletal muscle dysfunction in COPD. Exercise may improve skeletal muscle dysfunction in patients with COPD by promoting the dissociation of Kelch-like ECH-associated protein 1 (Keap1) and Nrf2, inducing sequestosome1(p62) phosphorylation to bind with Keap1 competitively leading to Nrf2 stabilization and improving dynamin-related protein 1-dependent mitochondrial fission. Nrf2 may be a key target for exercise anti-oxidative stress to alleviate skeletal muscle dysfunction in COPD.

Ginsenoside Rg1 can reverse fatigue behavior in CFS rats by regulating EGFR and affecting Taurine and Mannose 6-phosphate metabolism

Background: Chronic fatigue syndrome (CFS) is characterized by significant and persistent fatigue. Ginseng is a traditional anti-fatigue Chinese medicine with a long history in Asia, as demonstrated by clinical and experimental studies. Ginsenoside Rg1 is mainly derived from ginseng, and its anti-fatigue metabolic mechanism has not been thoroughly explored. Methods: We performed non-targeted metabolomics of rat serum using LC-MS and multivariate data analysis to identify potential biomarkers and metabolic pathways. In addition, we implemented network pharmacological analysis to reveal the potential target of ginsenoside Rg1 in CFS rats. The expression levels of target proteins were measured by PCR and Western blotting. Results: Metabolomics analysis confirmed metabolic disorders in the serum of CFS rats. Ginsenoside Rg1 can regulate metabolic pathways to reverse metabolic biases in CFS rats. We found a total of 34 biomarkers, including key markers Taurine and Mannose 6-phosphate. AKT1, VEGFA and EGFR were identified as anti-fatigue targets of ginsenoside Rg1 using network pharmacological analysis. Finally, biological analysis showed that ginsenoside Rg1 was able to down-regulate the expression of EGFR. Conclusion: Our results suggest ginsenoside Rg1 has an anti-fatigue effect, impacting the metabolism of Taurine and Mannose 6-phosphate through EGFR regulation. This demonstrates ginsenoside Rg1 is a promising alternative treatment for patients presenting with chronic fatigue syndrome.

Obesity-associated cardiometabolic complications in polycystic ovary syndrome: The potential role of sodium-glucose cotransporter-2 inhibitors

Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive-age women. PCOS is characterized by androgen excess, oligo/anovulation, and polycystic appearance of the ovaries. Women with PCOS have an increased prevalence of multiple cardiovascular risk factors such as insulin resistance, hypertension, renal injury, and obesity. Unfortunately, there is a lack of effective, evidence-based pharmacotherapeutics to target these cardiometabolic complications. Sodium-glucose cotransporter-2 (SGLT2) inhibitors provide cardiovascular protection in patients with and without type 2 diabetes mellitus. Although the exact mechanisms of how SGLT2 inhibitors confer cardiovascular protection remains unclear, numerous mechanistic hypotheses for this protection include modulation of the renin-angiotensin system and/or the sympathetic nervous system and improvement in mitochondrial function. Data from recent clinical trials and basic research show a potential role for SGLT2 inhibitors in treating obesity-associated cardiometabolic complications in PCOS. This narrative review discusses the mechanisms of the beneficial effect of SGLT2 inhibitors in cardiometabolic diseases in PCOS.

Effects of Near-Infrared Light on Well-Being and Health in Human Subjects with Mild Sleep-Related Complaints: A Double-Blind, Randomized, Placebo-Controlled Study

Modern urban human activities are largely restricted to the indoors, deprived of direct sunlight containing visible and near-infrared (NIR) wavelengths at high irradiance levels. Therapeutic exposure to doses of red and NIR, known as photobiomodulation (PBM), has been effective for a broad range of conditions. In a double-blind, randomized, placebo-controlled study, we aimed to assess the effects of a PBM home set-up on various aspects of well-being, health, sleep, and circadian rhythms in healthy human subjects with mild sleep complaints. The effects of three NIR light (850 nm) doses (1, 4, or 6.5 J·cm^-2) were examined against the placebo. Exposure was presented five days per week between 9:30 am and 12:30 pm for four consecutive weeks. The study was conducted in both summer and winter to include seasonal variation. The results showed PBM treatment only at 6.5 J·cm^-2 to have consistent positive benefits on well-being and health, specifically improving mood, reducing drowsiness, reducing IFN-γ, and resting heart rate. This was only observed in winter. No significant effects on sleep or circadian rhythms were noted. This study provides further evidence that adequate exposure to NIR, especially during low sunlight conditions, such as in the winter, can be beneficial for human health and wellness.

Dysregulation in Multiple Transcriptomic Endometrial Pathways Is Associated with Recurrent Implantation Failure and Recurrent Early Pregnancy Loss

Overlapping disease aetiologies associated with multiple altered biological processes have been identified that change the endometrial function leading to recurrent implantation failure (RIF) and recurrent early pregnancy loss (REPL). We aimed to provide a detailed insight into the nature of the biological malfunction and related pathways of differentially expressed genes in RIF and REPL. Endometrial biopsies were obtained from 9 women experiencing RIF, REPL and control groups. Affymetrix microarray analysis was performed to measure the gene expression level of the endometrial biopsies. Unsupervised clustering of endometrial samples shows scattered distribution of gene expression between the RIF, REPL and control groups. 2556 and 1174 genes (p value < 0.05, Fold change > 1.2) were significantly altered in the endometria of RIF and REPL patients’ group, respectively compared to the control group. Downregulation in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the differentially expressed genes (DEGs) in RIF and REPL including ribosome and oxidative phosphorylation pathways. Gene Ontology (GO) analysis revealed ribosomes and mitochondria inner membrane as the most significantly downregulated cellular component (CC) affected in RIF and REPL. Determination of the dysregulated genes and related biological pathways in RIF and REPL will be key in understanding their molecular pathology and of major importance in addressing diagnosis, prognosis, and treatment issues

AMPK/Drp1 pathway mediates Streptococcus uberis-Induced mitochondrial dysfunction

Excessive production of reactive oxygen species (ROS) leads to oxidative stress in host cells and affects the progress of disease. Mitochondria are an important source of ROS and their dysfunction is closely related to ROS production. S. uberis is a common causative agent of mastitis. The expression of key enzymes of the mitochondrial apoptotic pathway is increased in mammary epithelial cells after S. uberis stimulation, while expression of proteins related to mitochondrial function is decreased. Drp1, a key protein associated with mitochondrial function, is activated upon infection. Accompanied by mitochondria-cytosol translocation of Drp1, Fis1 expression is significantly upregulated while Mfn1 expression is downregulated implying that the balance of mitochondrial dynamics is disrupted. This leads to mitochondrial fragmentation, decreased mitochondrial membrane potential, higher levels of mROS and oxidative injury. The AMPK activator AICAR inhibits the increased phosphorylation of Drp1 and the translocation of Drp1 to mitochondria by salvaging mitochondrial function in an AMPK/Drp1 dependent manner, which has a similar effect to Drp1 inhibitor Mdivi-1. These data show that AMPK, as an upstream negative regulator of Drp1, ameliorates mitochondrial dysfunction induced by S. uberis infection.

Hypomagnesemia and Cardiovascular Risk in Type 2 Diabetes

Hypomagnesemia is tenfold more common in individuals with type 2 diabetes (T2D), compared to the healthy population. Factors that are involved in this high prevalence are low Mg2+ intake, gut microbiome composition, medication use and presumably genetics. Hypomagnesemia is associated with insulin resistance, which subsequently increases the risk to develop T2D or deteriorates glycaemic control in existing diabetes. Mg2+ supplementation decreases T2D associated features like dyslipidaemia and inflammation; which are important risk factors for cardiovascular disease (CVD). Epidemiological studies have shown an inverse association between serum Mg2+ and the risk to develop heart failure (HF), atrial fibrillation (AF) and microvascular disease in T2D. The potential protective effect of Mg2+ on HF and AF may be explained by reduced oxidative stress, fibrosis and electrical remodeling in the heart. In microvascular disease, Mg2+ reduces the detrimental effects of hyperglycemia and improves endothelial dysfunction. Though, clinical studies assessing the effect of long-term Mg2+ supplementation on CVD incidents are lacking and gaps remain on how Mg2+ may reduce CVD risk in T2D. Despite the high prevalence of hypomagnesemia in people with T2D, routine screening of Mg2+ deficiency to provide Mg2+ supplementation when needed is not implemented in clinical care as sufficient clinical evidence is lacking. In conclusion, hypomagnesemia is common in people with T2D and is both involved as cause, probably through molecular mechanisms leading to insulin resistance, and consequence and is prospectively associated with development of HF, AF and microvascular complications. Whether long-term supplementation of Mg2+ is beneficial, however, remains to be determined.