Lipotoxicity Impairs Granulosa Cell Function Through Activated Endoplasmic Reticulum Stress Pathway

Obesity is closely related to reproductive disorders, which may eventually lead to infertility in both males and females. Ovarian granulosa cells play a critical role during the maintenance of oocyte development through the generation of sex steroids (mainly estradiol and progesterone) and different kinds of growth factors. However, the molecular mechanism of obesity-induced granulosa cell dysfunction remains poorly investigated. In our current study, we observed that high-fat diet feeding significantly increased the level of glucose-regulated protein 78 kDa (GRP78) protein expression in mouse granulosa cells; testosterone-induced estradiol generation was impaired accordingly. To further evaluate the precise mechanism of lipotoxicity-induced granulosa cell dysfunction, mouse primary granulosa cells were treated with palmitate, and the expression levels of ER stress markers were evaluated by real-time PCR and western blot. Lipotoxicity significantly increased ER stress but impaired the mRNA expression of granulosa cell function-related makers, including androgen receptor (Ar), cytochrome P450 family 19 subfamily A member 1 (Cyp19a1), hydroxysteroid 17-beta dehydrogenase 1 (Hsd17b1), and insulin receptor substrate 1 (Irs1). Impaired testosterone-induced estradiol generation was also observed in cultured mouse granulosa cells after palmitate treatment. Insulin augmented testosterone induced estradiol generation through activation of the AKT pathway. However, palmitate treatment abolished insulin-promoted aromatase expression and estradiol generation by the stimulation of ER stress. Overexpression of IRS1 significantly ameliorated palmitate- or tunicamycin-induced impairment of aromatase expression and estradiol generation. Taken together, our current study demonstrated that lipotoxicity impaired insulin-stimulated estradiol generation through activated ER stress and inhibited IRS1 pathway.

Noncoding RNAs in Diabetic Nephropathy: Pathogenesis, Biomarkers, and Therapy

The correlation between diabetes and systematic well-being on human life has long established. As a common complication of diabetes, the prevalence of diabetic nephropathy (DN) has been increasing globally. DN is known to be a major cause of end-stage kidney disease (ESKD). Till now, the molecular mechanisms for DN have not been fully explored and the effective therapies are still lacking. Noncoding RNAs are a class of RNAs produced by genome transcription that cannot be translated into proteins. It has been documented that ncRNAs participate in the pathogenesis of DN by regulating inflammation, apoptosis, autophagy, cell proliferation, and other pathological processes. In this review, the pathological roles and diagnostic and therapeutic potential of three types of ncRNAs (microRNA, long noncoding RNA, and circular RNA) in the progression of DN are summarized and illustrated.

Objective Short Sleep Duration is Related to the Peripheral Inflammasome Dysregulation in Patients with Chronic Insomnia

OBJECTIVE

Insomnia with objective short sleep duration (IOSSD) is associated with an increased risk of cardiovascular morbidity, diabetes, neurocognitive impairment, and mortality. Inflammation is believed to be one of the main links between IOSSD and these diseases. The role of nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome in inducing activation of inflammatory signaling in IOSSD is not clear. In this study, we investigated the expression of NLRP3 inflammasome in patients with IOSSD to clarify this issue.

METHODS

Thirty-six patients with insomnia and 20 age- and sex-matched healthy controls were sequentially recruited. Subjects were categorized into three groups: IOSSD (sleep duration < 6h, n=20), insomnia with objective normal sleep duration (IONSD, sleep duration ≥ 6h, n=16) and healthy controls (n=20). Objective sleep parameters were measured by overnight polysomnography. Peripheral NLRP3 inflammasome protein levels [NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspase l] and cytokines [interleukin (IL)-1β and IL-18] were assessed by Western blotting and ELISA, respectively.

RESULTS

IOSSD group showed significantly increased protein expressions of ASC and caspase-1 compared to IONSD and healthy controls and significantly increased IL-18 levels compared to healthy controls. On correlation analysis, total sleep time showed an inverse correlation with NLRP3, ASC, IL-18, and IL-1β levels. Wake after sleep onset (WASO) showed a positive correlation with NLRP3, ASC, caspase-1, and IL-1β levels. N3 sleep ratio showed a significant negative correlation with NLRP3, ASC, and IL-18 levels.

CONCLUSION

The current study demonstrated upregulation of NLRP3 inflammasome in IOSSD. Short sleep duration, decreased slow wave sleep, and sleep fragmentation may contribute to dysregulation of NLRP3 inflammasome.

The Causal Role of Mitochondrial Dynamics in Regulating Innate Immunity in Diabetes

Background: Plenty of evidence suggested that chronic low-grade inflammation triggered by innate immunity activation contributes to the pathogenesis of type 2 diabetes (T2D). Using the trans-mitochondrial cybrid cell model, we have demonstrated that mitochondria independently take part in the pathological process of insulin resistance (IR) and pro-inflammatory phenotype in cybrid cells harboring mitochondrial haplogroup B4, which are more likely to develop T2D. The mitochondrial network is more fragmented, and the expression of fusion-related proteins is low in Cybrid B4. We also discovered the causal role of mitochondrial dynamics (mtDYN) proteins in regulating IR in this cybrid model, and the bidirectional interaction between mtDYN and mitochondrial oxidative stress is considered etiologically important. In this study, we further investigated whether mtDYN bridges the gap between nutrient excess and chronic inflammation in T2D. Methods: Trans-mitochondrial cybrid cells derived from the 143B human osteosarcoma cell line were cultured in a medium containing glucose (25 mM) with or without saturated fatty acid (0.25 mM BSA-conjugated palmitate), and the expression of innate immunity/inflammasome molecules was compared between cybrid B4 (the major T2D-susceptible haplogroup among the Chinese population) and cybrid D4 (the major T2D-resistant haplogroup among the Chinese population). We investigated the causal relationship between mtDYN and nutrient excess-induced inflammation in cybrid B4 by genetic manipulation of mtDYN and by pharmacologically inhibiting mitochondrial fission using the Drp1 inhibitor, mdivi-1, and metformin. Results: Under nutrient excess with high fatty acid, cybrid B4 presented increased mitochondrial pro-fission profiles and enhanced chronic inflammation markers (RIG-I, MDA5, MAVS) and inflammasome (NLRP3, Caspase-1, IL-1β), whereas the levels in cybrid D4 were not or less significantly altered. In cybrid B4 under nutrient excess, overexpression of fusion proteins (Mfn1 or Mfn2) significantly repressed the expression of innate immunity/inflammasome-related molecules, while knockdown had a less significant effect. On the contrary, knockdown of fission proteins (Drp1 or Fis1) significantly repressed the expression of innate immunity/inflammasome-related molecules, while overexpression had a less significant effect. In addition, Drp1 inhibitor mdivi-1 and metformin inhibited mitochondrial fission and attenuated the pro-inflammation expression as well. Conclusion: Our results discovered the causal relationship between mtDYN and nutrient excess-induced chronic inflammation in a diabetes-susceptible cell model. Targeting mtDYN by direct interfering pro-fission can be a therapeutic intervention for chronic inflammation in T2D.

3β-Hydroxysteroid-Δ24 Reductase (DHCR24) Protects Pancreatic β Cells from Endoplasmic Reticulum Stress-Induced Apoptosis by Scavenging Excessive Intracellular Reactive Oxygen Species

There is accumulating evidence showing that apoptosis induced by endoplasmic reticulum (ER) stress plays a key role in pancreatic β cell dysfunction and insulin resistance. 3β-Hydroxysteroid-Δ24 Reductase (DHCR24) is a multifunctional enzyme located in the endoplasmic reticulum (ER), which has been previously shown to protect neuronal cells from ER stress-induced apoptosis. However, the role of DHCR24 in type 2 diabetes is only incompletely understood so far. In the present study, we induced ER stress by tunicamycin (TM) treatment and showed that infection of MIN6 cells with Ad-DHCR24-myc rendered these cells resistant to caspase-3-mediated apoptosis induced by TM, while cells transfected with siRNAs targeting DHCR24 were more sensitive to TM. Western blot analysis showed that TM treatment induced upregulation of Bip protein levels in both cells infected with Ad-LacZ (the control group) and Ad-DHCR24-myc, indicating substantial ER stress. Cells infected with Ad-LacZ exhibited a rapid and strong activation of ATF6 and p38, peaking at 3 h after TM exposure. Conversely, cells infected with Ad-DHCR24-myc showed a higher and more sustained activation of ATF6 and Bip than control cells. DHCR24 overexpression also inhibited the generation of intracellular reactive oxygen species (ROS) induced by ER stress and protected cells from apoptosis caused by treatment with both cholesterol and hydrogen peroxide. In summary, these data demonstrate, for the first time, that DHCR24 protects pancreatic β cells from apoptosis induced by ER stress.

Androgen Therapy in Male Patients Suffering from Type 2 Diabetes: A Review of Benefits and Risks

BACKGROUND

The current estimated numbers of patients with Type 2 Diabetes (T2D) is believed to be close to 10% of the whole populations of many geographical regions, causing serious concerns over the resulting elevated morbidity and mortality as well as the impact on health care systems around the world. In addition to negatively affecting the quality of life, diabetes is associated with cardiovascular and cerebrovascular complications, indicating that appropriate drug therapy should not only deal with metabolic dysfunction but also protect the vascular system, kidney function and skeletal muscle mass from the effects of the epigenetic changes induced by hyperglycaemia.

OBJECTIVE

To provide an insight into the management of hypogonadism associated with T2D, this review focuses on clinical observations related to androgen therapy in qualified diabetic patients, and discusses the lines of evidence for its benefits and risks. The potential interactions of testosterone with medicines used by patients with T2D will also be discussed.

CONCLUSION

From recent clinical findings, it became evident that a considerable percentage of patients suffering from T2D manifested low serum testosterone and experienced diminished sexual activity, as well as reduced skeletal muscle mass and lower bone density. Although there are some controversies, Testosterone Replacement Therapy (TRT) for this particular population of patients appears to be beneficial overall only if it is implemented carefully and monitored regularly.

Association of Periodontal Disease and Polycystic Ovarian Syndrome: A Systematic Review and Meta-analysis with Trial Sequential Analysis

Introduction:

Several articles have suggested a potential synergistic relationship between periodontal disease and systemic inflammatory diseases, such as Polycystic Ovarian Syndrome (PCOS) and diabetes mellitus. However, the associations between periodontal disease and PCOS population remain unclear in the literature.

Objective:

The primary aim of this review is to examine the associations between periodontal disease and PCOS with different scoring methods, namely clinical attachment loss, probing depth, gingival index, percentage of bleeding on probing and plaque index.

Methods:

MEDLINE, EMBASE and CENTRAL were systematically searched for observational studies and case-control studies from its inception until 2nd June, 2019. Case reports, case series, non-systematic reviews and trials published as abstracts were excluded.

Results:

Four articles (614 subjects) were included for analysis. Out of 614 subjects, 329 PCOS patients were compared to 285 healthy subjects. In comparison to healthy cohort, women with PCOS had a statistically significant increase in clinical attachment loss (MD: 0.34, 95% CI: 0.13-0.55, ρ=0.002), probing depth (MD: 0.35, 95%CI: 0.21-0.48, ρ<0.001), gingival index (MD: 0.70, 95% CI: 0.70-1.11, ρ<0.001) and percentage of bleeding on probing (MD: 34.41, 95% CI: 20.23-48.59, ρ<0.001). No difference was demonstrated in plaque index (MD: 0.42, 95% CI: -0.29-1.12, ρ=0.24) for both PCOS and healthy cohort.

Conclusion:

PCOS is significantly associated with a higher severity of the periodontal disease. This association should be emphasized during the management of PCOS patients, by including referral to dentists or periodontists for regular mechanical debridement of plaque and periodontal maintenance.

The relationship between glutathione levels in leukocytes and ocular clinical parameters in glaucoma

PURPOSE

To investigate the effect of mitochondrial dysfunction on the autoregulation of blood flow, by measuring levels of glutathione, an indicator of mitochondrial dysfunction, in glaucoma patients.

METHODS

Fifty-six OAG patients and 21 age-matched controls underwent a blood assay. Mitochondrial function was measured according to the levels of total glutathione (t-GSH), reduced GSH (GSH), and oxidized GSH (GSSG, glutathione disulfide) in peripheral blood mononuclear cells. Ocular blood flow in the optic nerve head was assessed with laser speckle flowgraphy parameters, including acceleration time index (ATI). We determined correlations between these measurements and other clinical parameters. Furthermore, we investigated the association between glutathione levels and glaucoma with a logistic regression analysis. Finally, we calculated the area under the receiver operating characteristic (ROC) curve in order to determine the power of redox index (the log GSH/GSSG ratio) to distinguish the groups.

RESULTS

OAG patients demonstrated significantly higher GSSG levels and a lower redox index than the controls (p = 0.01, p = 0.01, respectively), but total GSH and reduced GSH levels were similar in the OAG subjects and controls (p = 0.80, p = 0.94, respectively). Additionally, redox index was significantly correlated with mean deviation (MD) of the visual field (r = 0.29, p = 0.03) and ATI (r = -0.30, p = 0.03). Multiple linear regression analysis showed that redox index contributed to MD (p = 0.02) and ATI (p = 0.04). The receiver operating characteristic curve (AUC) analysis suggested that redox index could differentiate between control eyes and eyes with glaucoma (AUC; 0.70: 95% interval; 0.57-0.84). The cutoff point for redox index to maximize its sensitivity and specificity was 2.0 (sensitivity: 91.1%, specificity: 42.9%).

CONCLUSIONS

These results suggest that redox index is lower in OAG patients than in controls. Thus, it is possible that mitochondrial dysfunction contributes to glaucoma pathogenesis by causing vascular alterations.

Parkin and Nrf2 prevent oxidative stress-induced apoptosis in intervertebral endplate chondrocytes via inducing mitophagy and anti-oxidant defenses

AIMS

Endplate chondrocyte apoptosis is an important contributor to the pathogenesis of cartilaginous endplate (CEP) degeneration that leads to the initiation and development of intervertebral disc degeneration (IDD). In this study, we hypothesized that Parkin-mediated mitophagy and nuclear factor E2-related factor 2 (Nrf2)-mediated antioxidant system played an important role in endplate chondrocyte survival under pathological conditions.

MATERIALS AND METHODS

Human endplate chondrocytes were stimulated with H₂O₂ to mimic pathological conditions. Western blotting, immunofluorescence staining, and flow cytometry were applied to detect the indicators related to mitochondrial dynamics, mitophagy, Nrf2 signaling, and apoptosis. The puncture-induced rat models were established to evaluate the changes in vivo.

KEY FINDINGS

Our results showed that H₂O₂ induced oxidative stress, mitochondrial dysfunction, and apoptosis in endplate chondrocytes. These H₂O₂-induced detrimental effects were inhibited by pretreatment with the mitochondria-targeted antioxidant Mito-TEMPO. In addition, mitochondrial dynamics, Parkin-mediated elimination of dysfunctional mitochondria, and Nrf2-mediated antioxidant system were promoted by H₂O₂. Knockdown of Parkin or Nrf2 increased H₂O₂-induced detrimental effects. Moreover, upregulation of Parkin and Nrf2 by polydatin protected endplate chondrocytes against H₂O₂-induced mitochondrial dysfunction, oxidative stress, and apoptosis. Finally, puncture-induced rat models showed that polydatin exerted a protective effect on CEP and disc degeneration.

SIGNIFICANCE

Targeting Parkin and Nrf2 to improve mitochondrial homeostasis, redox balance and endplate chondrocyte survival may represent a potential therapeutic strategy for preventing IDD.

Malnutrition impairs mitochondrial function and leukocyte activation

BACKGROUND

The aim of this study was to evaluate markers of inflammation, oxidative stress and endothelial function in a disease-related malnutrition (DRM) outpatient population.

METHODS

For this cross-sectional study, a total of 83 subjects were included and clustered in 3 groups: 34 with normonutrition (NN), 21 with DRM without inflammation (DRM-I) and 28 with DRM and inflammation (DRM + I). Nutritional diagnosis was conducted for all subjects according to ASPEN. Biochemical parameters, proinflammatory cytokines, reactive oxygen species production, glutathione, mitochondrial membrane potential, oxygen consumption, adhesion molecules and leukocyte-endothelium interactions were evaluated.

RESULTS

DRM + I patients showed lower albumin, prealbumin, transferrin, and retinol-binding protein levels with respect to the NN group (p < 0.05), differences that were less noticeable in the DRM-I group. DRM + I was associated with a significant increase in hsCRP and IL6 vs the NN and DRM-I groups, and TNFα was increased in both DRM vs NN. DRM was characterised by increased oxidative stress, which was marked by a significant increase in ROS levels and a decrease in mitochondrial membrane potential in the DRM + I group. An evident reduction in mitochondrial oxygen consumption and glutathione concentration was observed in both DRM groups, and was accompanied by increased leukocyte adhesion and adhesion molecules and decreased rolling velocity in the DRM + I group. Furthermore, percentage of weight loss was negatively correlated with albumin, prealbumin, transferrin, O₂ consumption, glutathione and leukocyte rolling velocity, and positively correlated with hsCRP, IL6, TNFα, ROS, leukocyte adhesion, and VCAM-1.

CONCLUSIONS

Our results show that DRM is associated with oxidative stress and an inflammatory state, with a deterioration of endothelial dysfunction in the DRM + I population.

Malaysian propolis and metformin mitigate subfertility in streptozotocin-induced diabetic male rats by targeting steroidogenesis, testicular lactate transport, spermatogenesis and mating behaviour

BACKGROUND

Diabetes mellitus is one of the risk factors for male subfertility/infertility. Malaysian propolis is reported to decrease hyperglycaemia in diabetic state.

OBJECTIVES

The present study investigated the protective effect of Malaysian propolis on diabetes-induced subfertility/infertility. Additionally, its combined beneficial effects with metformin were investigated.

MATERIALS AND METHODS

Forty adult male Sprague Dawley rats were randomly assigned into five groups, namely normal control, diabetic control, diabetic + Malaysian propolis (300 mg/k.g. b.w.), diabetic + metformin (300 mg/kg b.w.) and diabetic + Malaysian propolis + metformin. Diabetes was induced using a single intraperitoneal injection of streptozotocin (60 mg/kg b.w.) and treatment lasted for 4 weeks. During the 4th week, mating behavioural experiments were performed using sexually receptive female rats. Thereafter, fertility parameters were assessed in the female rats.

RESULTS

Malaysian propolis increased serum and intratesticular free testosterone levels, up-regulated the mRNA levels of AR and luteinizing hormone receptor, up-regulated the mRNA and protein levels of StAR, CYP11A1, CYP17A1, 3β-HSD and 17β-HSD in the testes of diabetic rats. Furthermore, Malaysian propolis up-regulated testicular MCT2, MCT4 and lactate dehydrogenase type C mRNA levels, in addition to improving sperm parameters (count, motility, viability and normal morphology) and decreasing sperm nDNA fragmentation in diabetic rats. Malaysian propolis improved mating behaviour by increasing penile guanosine monophosphate levels. Malaysian propolis also improved fertility outcome as seen with decreases in pre- and post-implantation losses, increases in gravid uterine weight, litter size per dam and foetal weight. Malaysian propolis's effects were comparable to metformin. However, their combination yielded better results relative to the monotherapeutic interventions.

CONCLUSION

Malaysian propolis improves fertility potential in diabetic state by targeting steroidogenesis, testicular lactate metabolism, spermatogenesis and mating behaviour, with better effects when co-administered with metformin. Therefore, Malaysian propolis shows a promising complementary effect with metformin in mitigating Diabetes mellitus-induced subfertility/infertility.

Hormones and oxidative stress: an overview

In aerobes, oxygen is essential for maintenance of life. However, incomplete reduction of oxygen leads to generation of reactive oxygen species. These oxidants oxidise biological macromolecules present in their vicinity and thereby impair cellular functions causing oxidative stress (OS). Aerobes have evolved both enzymatic and nonenzymatic antioxidant defences to protect themselves from OS. Although hormones as means of biological coordination involve in regulation of physiological activities of tissues by regulating metabolism, any change in their normal titre leads to pathophysiological states. While, hormones such as melatonin, insulin, oestrogen, progesterone display antioxidant features, thyroid hormone, corticosteroids and catecholamines elicit free radical generation and OS, and the role of testosterone in inducing OS is debateable. This review is an attempt to understand the impact of free radical generation and cross talk between the hormones modulating antioxidant defence system under various pathophysiological conditions.

Endoplasmic reticulum stress-induced cellular dysfunction and cell death in insulin-producing cells results in diabetes-like phenotypes in Drosophila

The destruction of pancreatic β cells leads to reduced insulin secretion and eventually causes diabetes. Various types of cellular stress are thought to be involved in destruction and/or malfunction of these cells. We show that endoplasmic reticulum (ER) stress accumulation in insulin-producing cells (IPCs) generated diabetes-like phenotypes in Drosophila To promote the accumulation of extra ER stress, we induced a dominant-negative form of a Drosophila ER chaperone protein (Hsc70-3DN) and demonstrate that it causes the unfolded-protein response (UPR) in various tissues. The numbers of IPCs decreased owing to apoptosis induction mediated by caspases. The apoptosis was driven by activation of Dronc, and subsequently by Drice and Dcp-1. Accordingly, the relative mRNA-expression levels of Drosophila insulin-like peptides significantly decreased. Consistent with these results, we demonstrate that glucose levels in larval haemolymph were significantly higher than those of controls. Accumulation of ER stress induced by continuous Hsc70-3DN expression in IPCs resulted in the production of undersized flies. Ectopic expression of Hsc70-3DN can induce more efficient ER stress responses and more severe phenotypes. We propose that ER stress is responsible for IPC loss and dysfunction, which results in diabetes-related pathogenesis in this Drosophila diabetes model. Moreover, inhibiting apoptosis partially prevents the ER stress-induced diabetes-like phenotypes.

The effect of endurance training with crocin consumption on the levels of MFN2 and DRP1 gene expression and glucose and insulin indices in the muscle tissue of diabetic rats

This study aimed to investigate the effect of crocin consumption, high-intensity interval training (HIIT), and low-intensity continuous training (LICT) and their interactive effect on the gene expression of Mfn2 and Drp1 in the skeletal muscle and serum glucose and insulin indices in high-fat diet (HFD) and streptozotocin (STZ)-induced diabetic rats. Fifty-six adult rats were divided into eight groups of seven subjects: crocin consumption, HIIT, LICT, HIIT with crocin, LICT with crocin, diabetic control, healthy control, and sham (placebo). At the end of the course (5 months), metabolic indices were measured. Moreover, the Mfn2 and Drp1 gene expression levels in all groups were measured using RT-PCR. The statistical analysis showed that in the exercise training (HIIT and LICT) and the crocin consumption groups, the glucose and insulin indices significantly improved (p = .005). Moreover, in these groups, the levels of gene expression of Mfn2 and Drp1 significantly increased and decreased, respectively (p = .001). Exercise training and crocin consumption appear to, either in combination or individually, have a beneficial effect on mitochondrial dynamics and diabetes by improving the mitochondrial fusion and fission indices (Mfn2 and Drp1), and by modifying the insulin resistance index and glucose homeostasis. PRACTICAL APPLICATIONS: Mfn2 and Drp1, as the main regulators of the mitochondrial fusion and fission, play an important role in maintaining mitochondrial dynamics and type 2 diabetes. Thus, the regulation of mitochondrial dynamics is an intricate process that retains the balance between mitochondrial fission and fusion, and any disturbance in this balance can lead to mitochondrial-associated diseases including insulin resistance and T2D. There is evidence that herbal antioxidants Including crocin and exercise training help improve the mitochondrial activity and insulin sensitivity in T2D. Considering the importance of the two Drp1 and Mfn1 genes in the mitochondrial dynamic pathway and coding the proteins that play a key role in relation to T2D, this study primarily examined the interactive effects of endurance training (HIIT and LICT) along with crocin consumption on the expression the genes mentioned above; the results obtained in this study can provide a new approach to the treatment of HFD + STZ-induced diabetic rats.

Genomic profiling of mitochondrial DNA reveals novel complex gene mutations in familial type 2 diabetes mellitus individuals from Mizo ethnic population, Northeast India

The variants reported for mitochondrial DNA (mtDNA) and type 2 diabetes (T2D) may not be accountable for the disease in certain other populations and the risk depends upon numerous factors which may include genetics, environment as well as ethnicity. This leads to a challenge in identifying, exploring and comparing the variants between diabetic cases and healthy controls in a remote unexplored tribal population. To study the possible contribution of mtDNA variants, we sequenced the entire mitochondrial genomes and the frequencies of mtSNPs, their association with familial T2D and the potential impact of non-synonymous substitutions on protein functions were determined. The mtSNP 8584 G > A (ATP6: A20T) was detected in 14.28% of the diabetic patients and none in the control groups. The mitochondrial ND3 variant 10398A > G was found to be significantly associated with the risk of T2D (OR = 9.489, 95% CI = 1.161-77.54, P value = 0.036). A novel Frame-shift substitution ND5: 81_81ins A at position 12,417 was observed in 53.57% of diabetic individuals. Majority of the variants lie in tRNA-Phe in the non-protein coding region of mtDNA for both diabetic cases and common cases. We concluded that mutations in the coding (synonymous or non-synonymous) and noncoding regions of the mitochondria might have contribution towards the development of T2D. Our study is the first to report the distinct mitochondrial variants which may be attributed to the susceptibility as well as development of type 2 diabetes in an ethnic tribe from northeast India.

Quercetin improves endothelial insulin sensitivity in obese mice by inhibiting Drp1 phosphorylation at serine 616 and mitochondrial fragmentation

Studies have shown that endothelial insulin resistance induced by oxidative stress contributes to vascular dysfunction in metabolic disorders. Quercetin, a natural antioxidant, has been recently shown to exert protective effects on endothelial function. However, the effects of quercetin on endothelial insulin resistance and its underlying mechanism are unclear. Here, we found that chronic oral treatment of obese mice with quercetin increased vascular endothelial insulin sensitivity, accompanied by alleviated mitochondrial fragmentation as revealed by confocal imaging. In addition, western blot analysis showed that quercetin treatment suppressed the levels of dynamin-related protein 1 (Drp1) and phosphorylation at serine 616 in endothelial cells of obese mice. Mechanistically, quercetin specifically suppressed Drp1 phosphorylation at serine 616, whereas it showed little effects on the Drp1 level and its phosphorylation at serine 637 in cultured endothelial cells under oxidative stress. Furthermore, our results also showed that quercetin suppressed Drp1 phosphorylation at serine 616 by inhibiting PKCδ as revealed by western blot analysis. Knockdown of PKCδ with siRNA alleviated the protective effects of quercetin on endothelial-mitochondrial dynamics and insulin sensitivity. These results suggest that chronic oral treatment with quercetin exerts endothelial protective effects through inhibition of PKCδ and the resultant mitochondrial fragmentation.

Roles of Oxidative Stress in Policystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) represent a common endocrine disorder that affects nearly 4 to 12 percents of reproductive age women in general population studies (1). PCOS is caracterized by the oligoovulation or anovulation, hyperandrogenisam and multiple small ovarian cysts. The etiology of PCOS is steel unclear. Patophysiology of PCOS represents the complex mehanism. There is a wide spectar of signs and symptoms of the PCOS, which vary in severity over the time and within individuals. Major symptoms are: the amenhorhea, oligomenorhea combined with of episodes of menometrorhagia. Some signs of hiperandrogenism are: acne, hirsutism and alopecia. Other important symptoms of the PCOS are: the obesity, dyslpedemia, insuline resistance, metabolic syndrome, infertility, endometrial neoplasia, pregnancy loss. Diagnosis is achieved by exclusion of other factors that lead to anovulation, and laboratory assay of sex hormones and gonadotropines. One of the novel approaches in evaluation of etiology and pathogenesis of the PCOS recognizes oxidative stress as an important factor in genesis of this syndrome. For investigation of the oxidative stress role in the pathogenesis of diseases, some biochemical markers have been used including the MDA and NO also anti-oxidative biomarkers such as Total Antioxidative Capacity, Superoxide Dismutase, Glutation Peroxidase, and glutathione. Most of recent studies compared the oxidative stress biomarker level or antioxidative biomarkers levels in the PCOS patients and healthy controls. Patients with the PCOS in those studies were often subdivided in groups by the presence of insulin resistance (HOMA index) or infertility or not. One of the main problems in this field of research is inconsistency in precise definition of the PCOS, as well as different expression of various symptoms within individuals over the time. In that manner it is very difficult to follow up these patients and to establish criteria that could be compared in studies.

DNA-PKcs promotes alcohol-related liver disease by activating Drp1-related mitochondrial fission and repressing FUNDC1-required mitophagy

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a novel housekeeper of hepatic mitochondrial homeostasis outside the DNA repair process. In this study, DNA-PKcs was upregulated in the livers of mice that were exposed to alcohol; the expression of DNA-PKcs positively correlated with hepatic steatosis, fibrosis, apoptosis, and mitochondrial damage. Functional studies revealed that liver-specific DNA-PKcs knockout (DNA-PKcs LKO ) mice were protected from chronic ethanol-induced liver injury and mitochondrial damage. Mechanistic investigations established that DNA-PKcs promoted p53 activation, which elevated dynamin-related protein 1 (Drp1)-related mitochondrial fission but repressed FUN14 domain containing 1 (FUNDC1)-required mitophagy. Excessive fission and defective mitophagy triggered mtDNA damage, mitochondrial respiratory inhibition, mROS overproduction, cardiolipin oxidation, redox imbalance, calcium overload, and hepatic mitochondrial apoptosis. In contrast, the deletion of DNA-PKcs rescued these phenotypic alterations, which alleviated the susceptibility of hepatocytes to alcohol-induced cytotoxicity. Additionally, we also showed that orphan nuclear receptor subfamily 4 group A member 1 (NR4A1) was the upstream signal for DNA-PKcs activation and that the genetic ablation of NR4A1 ameliorated the progression of alcohol-related liver disease (ARLD); these results were similar to those obtained in DNA-PKcs knockout mice. Collectively, our results identified the NR4A1/DNA-PKcs/p53 axis as a novel signaling pathway responsible for ARLD pathogenesis that acts by activating Drp1-related mitochondrial fission and restricting FUNDC1-required mitophagy. The findings have potential implications for new approaches for ARLD therapy.

A new research hot spot: The role of NLRP3 inflammasome activation, a key step in pyroptosis, in diabetes and diabetic complications

Pyroptosis is a form of cell death mediated by gasdermin D (GSDMD); it is characterised by NLRP3 inflammasome activation, caspase activation, cell membrane pore formation, and the release of interleukin-1β and interleukin-18. NLRP3 inflammasome activation plays a central role in pyroptosis. Recent research has suggested that NLRP3 inflammasome activation may be involved in the occurrence and development of diabetes mellitus and its associated complications. This finding provided the impetus for us to clarify the significance of pyroptosis in diabetes. In this review, we summarise the current understanding of the molecular mechanisms involved in pyroptosis, as well as recent advances in the role of NLRP3 inflammasome activation and pyroptosis in the development of diabetes and diabetic complications.

Effect of the herbal medicines in obesity and metabolic syndrome: A systematic review and meta-analysis of clinical trials

Obesity is a medical situation in which excess body fat has gathered because of imbalance between energy intake and energy expenditure. In spite of the fact that the variety of studies are available for obesity treatment and management, its "globesity" still remains a big challenge all over the world. The current systematic review and meta-analysis aimed to evaluate the efficacy, safety, and mechanisms of effective herbal medicines in the management and treatment of obesity and metabolic syndrome in human. We systematically searched all relevant clinical trials via Web of Science, Scopus, PubMed, and the Cochrane database to assess the effects of raw or refined products derived from plants or parts of plants on obesity and metabolic syndrome in overweight and obesity adult subjects. All studies conducted by the end of May 2019 were considered in the systematic review. Data were extracted independently by two experts. The quality assessment was assessed using Consolidated Standards of Reporting Trials checklist. The main outcomes were anthropometric indices and metabolic syndrome components. Pooled effect of herbal medicines on obesity and metabolic syndrome were presented as standardized mean difference (SMD) and 95% confidence interval (CI). A total of 279 relevant clinical trials were included. Herbals containing green tea, Phaseolus vulgaris, Garcinia cambogia, Nigella sativa, puerh tea, Irvingia gabonensis, and Caralluma fimbriata and their active ingredients were found to be effective in the management of obesity and metabolic syndrome. In addition, C. fimbriata, flaxseed, spinach, and fenugreek were able to reduce appetite. Meta-analysis showed that intake of green tea resulted in a significant improvement in weight ([SMD]: -0.75 [-1.18, -0.319]), body mass index ([SMD]: -1.2 [-1.82, -0.57]), waist circumference ([SMD]: -1.71 [-2.66, -0.77]), hip circumference ([SMD]: -0.42 [-1.02, -0.19]), and total cholesterol, ([SMD]: -0.43 [-0.77, -0.09]). In addition, the intake of P. vulgaris and N. sativa resulted in a significant improvement in weight ([SMD]: -0.88, 95 % CI: [-1.13, -0.63]) and triglyceride ([SMD]: -1.67, 95 % CI: [-2.54, -0.79]), respectively. High quality trials are still needed to firmly establish the clinical efficacy of the plants in obesity and metabolic syndrome.

Clusterin ameliorates endothelial dysfunction in diabetes by suppressing mitochondrial fragmentation

Clusterin (CLU) is a stress-responding protein associated with cytoprotection in a broad range of pathological processes. However, clusterin's function in diabetes-induced endothelial dysfunction has not been defined. Herein, using two diabetes models, we investigated the role of clusterin in endothelial dysfunction triggered by diabetes and the molecular mechanisms involved. The results revealed that clusterin overexpression inhibited ICAM-1/VCAM-1 expression in aortas and improved endothelium-dependent vasodilatation in db/db diabetic mice and streptozotocin (STZ)-induced diabetes models. Consistently, in vitro, adenoviral clusterin overexpression reduced the expression of a range of pro-inflammatory cytokines and suppressed monocyte adhesion to endothelial cells subjected to high glucose and high palmitate. Further study indicated that clusterin overexpression mitigated mitochondrial excessive fission and reduced mitochondrial ROS production. Conversely, silencing clusterin aggravated mitochondrial fission and endothelial inflammatory activation in high glucose-exposed endothelial cells. Accumulating evidence indicates that impaired mitochondrial dynamics plays a considerable role in promoting endothelial dysfunction in diabetic subjects. Therefore, treatments targeting mitochondrial undue fission may be promising measures to prevent vascular complications of diabetes. Furthermore, AMP-activated protein kinase (AMPK) activation contributed to the modulation of mitochondrial dynamics executed by clusterin. Mechanistically, clusterin promoted the phosphorylation of AMPKα and its downstream target acetyl-CoA carboxylase (ACC), while the inhibition of AMPKα negated the improvement in mitochondrial dynamics provided by clusterin overexpression. Over all, these findings suggest that clusterin exerts beneficial effects in endothelial cells under diabetic conditions via inhibiting mitochondrial fragmentation mediated by AMPK.

Bergenin impedes the generation of extracellular matrix in glomerular mesangial cells and ameliorates diabetic nephropathy in mice by inhibiting oxidative stress via the mTOR/β-TrcP/Nrf2 pathway

Bergenin, a plant polyphenol, has been reported to lower the blood glucose level and ameliorate kidney function in streptozotocin (STZ)-induced diabetic rats. Herein, its protective effect on diabetic nephropathy (DN) was explored in view of extracellular matrix (ECM) generation in glomerular mesangial cells. Glomerular mesangial cells were treated with high glucose, and Q-PCR as well as western blot were used to determine the expression of ECM. To establish the participation and role of mammalian target of rapamycin (mTOR) and nuclear factor erythroid-derived 2-related factor 2 (Nrf2) in ECM generation, a combination of l-leucine (activator of mTOR) and Nrf2 shRNA transfection were performed, respectively. Moreover, a DN model was established in mice using high-glucose/high-fat diet and STZ. Bergenin impeded the generation of TGF-β1 and ECM, decreased the levels of intracellular superoxide anion and hydrogen peroxide, and increased the activity of antioxidant enzymes in the glomerular mesangial cells (HBZY-1 and HRMC cells) treated with high glucose. The inhibition of ECM generation by bergenin was dependent on the down-regulation of oxidative stress as confirmed via a superoxide overexpression system. The activation of Nrf2 was required for bergenin to inhibit the oxidative stress and ECM generation. Moreover, bergenin was found to inhibit the phosphorylation of mTOR, which is located at the upstream of Nrf2. Bergenin did not interfere with the expression of Nrf2 mRNA and Keap1 (the classic degradation control factor of Nrf2), but markedly inhibited the protein expression of the β-TrcP, an effect which could be abolished by l-leucine. In DN model mice, l-leucine diminished the ability of bergenin to reduce the levels of superoxide anion, hydrogen peroxide and ECM, which contributed to the eradication of the ameliorative effect of bergenin on nephropathy. Bergenin can inhibit glucose-induced ECM production in glomerular mesangial cells through the down-regulation of oxidative stress via the mTOR/β-TrcP/Nrf2 pathway, and it might be a candidate drug for the prevention and treatment of DN.

Graph cluster approach in identifying novel proteins and significant pathways involved in polycystic ovary syndrome

RESEARCH QUESTION

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder with diverse clinical implications, such as infertility, metabolic disorders, cardiovascular diseases and psychological problems among others. The heterogeneity of conditions found in PCOS contribute to its various phenotypes, leading to difficulties in identifying proteins involved in this abnormality. Several studies, however, have shown the feasibility in identifying molecular evidence underlying other diseases using graph cluster analysis. Therefore, is it possible to identify proteins and pathways related to PCOS using the same approach?

METHODS

Known PCOS-related proteins (PCOSrp) from PCOSBase and DisGeNET were integrated with protein-protein interactions (PPI) information from Human Integrated Protein-Protein Interaction reference to construct a PCOS PPI network. The network was clustered with DPClusO algorithm to generate clusters, which were evaluated using Fisher's exact test. Pathway enrichment analysis using gProfileR was conducted to identify significant pathways.

RESULTS

The statistical significance of the identified clusters has successfully predicted 138 novel PCOSrp with 61.5% reliability and, based on Cronbach's alpha, this prediction is acceptable. Androgen signalling pathway and leptin signalling pathway were among the significant PCOS-related pathways corroborating the information obtained from the clinical observation, where androgen signalling pathway is responsible in producing male hormones in women with PCOS, whereas leptin signalling pathway is involved in insulin sensitivity.

CONCLUSIONS

These results show that graph cluster analysis can provide additional insight into the pathobiology of PCOS, as the pathways identified as statistically significant correspond to earlier biological studies. Therefore, integrative analysis can reveal unknown mechanisms, which may enable the development of accurate diagnosis and effective treatment in PCOS.

Shikonin improve sepsis-induced lung injury via regulation of miRNA-140-5p/TLR4-a vitro and vivo study

Shikonin is an anti-inflammatory agent extracted from natural herbs. The aim of this study is to explain the treatment effects and mechanism of Shikonin in acute lung injury induced by sepsis. In this study, first, we evaluate different Shikonin concentrations for the anti-inflammation of acute lung injury induced by sepsis in an in vivo study. On the basis of the results, we confirm that 50.0 mg/kg was the best therapeutic Shikonin concentration. As a second step, we discuss the mechanism of Shikonin by a vitro cell experiment. Finaly, we validate that Shikonin has effective treatment effects on acute lung injury via regulation of microRNA-140-5p/toll-like receptor 4 (miRNA-140-5p/TLR4) in the in vivo study. The results of vitro and vivo study showed that Shikonin could improve acute lung injury induced by sepsis. The mechanism might be correlation miRNA-140-5p expression increasing, and regulated targeted gene TLR4, with TLR4 expression depressing, the downstream myeloid differentiation protein 88 and nuclear factor κB proteins expression were suppressed. In conclusion, Shikonin improved sepsis induced lung injury by regulation miRNA-140-5p/TLR4.

Oxidative Stress Indexes for Diagnosis of Health or Disease in Humans

Oxidative stress (OS) is the imbalance between oxidant and antioxidant molecules, in favor of oxidants, that causes aging and disease. Many studies have been published that demonstrate the relationship between OS and human health and disease; however, the following questions arise: (i) how are we sure that the OS is present in a biological process? (ii) Is the OS reported in the different investigations equivalent? (iii) What are the best oxidant and antioxidant markers for OS diagnosis? (iv) Can we establish the types and the intensity of the OS? (v) Does OS index could be useful for research and/or application in clinical medicine? In this regard, several indexes have been proposed to measure OS in humans relative to the state of health and disease, among which the following can be highlighted: Oxidative Stress Index (OSI), Tiol Ratios (-SH/TT, -SS/-SH, and-SS/TT), Glutathione Ratio (GSSG/GSH), Oxidative Stress Score (OSS), and OXY-index. Therefore, the aim of this review is to present the state of the art of knowledge about OS indexes for diagnosis of health or disease in humans. We searched for articles in English or Spanish in the PubMed/MEDLINE and Scopus electronic databases published up until May 2019. The keywords used were “oxidative stress,” “index,” and “oxidative stress index.” It was identified 11479 records in both databases, and 490 articles were analyzed. Our review suggests that all indexes analyzed allow diagnose and differentiate the OS related to human health and disease. Also, the studies on OSI, Oxy-score, and OSS indexes have proven to be reliable, practical, and with clinical utility. However, it is necessary to continue with longitudinal studies, especially assess the usefulness of the indexes in the clinical prognosis, and make comparative studies between the different indexes.

MicroRNA-223-3p modulates dendritic cell function and ameliorates experimental autoimmune myocarditis by targeting the NLRP3 inflammasome

Autoimmune myocarditis is a cause of dilated cardiomyopathy and heart failure. MicroRNAs regulate many immune processes, but their role in aberrant inflammation during autoimmune myocarditis remains unclear. In this study, we investigated the role of miR-223-3p in experimental autoimmune myocarditis (EAM). We found that miR-223-3p expression was significantly lower in EAM mice than that in normal mice. miR-223-3p inhibited NLRP3 inflammasome expression, promoting the polarization of dendritic cells (DCs) towards a tolerogenic DC phenotype. miR-223-3p effectively induced regulatory T cell (Treg) generation by inhibiting the function of antigen-presenting DCs. Transfer of miR-223-3p-overexpressing DCs protected mice against the development of EAM. Our findings suggest that miR-223-3p is involved in the induction of the tolerogenic DC phenotype and regulates tolerance in autoimmune myocarditis.

FDG uptake tracks the oxidative damage in diabetic skeletal muscle: An experimental study

OBJECTIVES

The present study aims to verify the relationship between glucose consumption and uptake of ¹⁸F-2-deoxy-glucose (FDG) in the skeletal muscle (SM) of experimental models of streptozotocin-induced diabetes mellitus (STZ-DM).

METHODS

The study included 36 Balb/c mice. Two weeks after intraperitoneal administration of saline (control group, n = 18) or 150 mg streptozotocin (STZ-DM group, n = 18), the two cohorts were submitted to an oral glucose tolerance test and were further subdivided into three groups (n = 6 each): untreated and treated with metformin (MTF) at low or high doses (10 or 750 mg/kg daily, respectively). Two weeks thereafter, all mice were submitted to dynamic micro-positron emission tomography (PET) imaging after prolonged fasting. After sacrifice, enzymatic pathways and response to oxidative stress were evaluated in harvested SM.

RESULTS

On PET imaging, the FDG uptake rate in hindlimb SM was significantly lower in nondiabetic mice as compared with STZ-DM-untreated mice. MTF had no significant effect on SM FDG uptake in untreated mice; however, its high dose induced a significant decrease in STZ-DM animals. Upon conventional analysis, the SM standard uptake value was higher in STZ-DM mice, while MTF was virtually ineffective in either control or STZ-DM models. This metabolic reprogramming was not explained by any change in cytosolic glucose metabolism. By contrast, it closely agreed with the catalytic function of hexose-6P-dehydrogenase (H6PD; i.e., the trigger of a specific pentose phosphate pathway selectively located within the endoplasmic reticulum). In agreement with this role, the H6PD enzymatic response to both STZ-DM and MTF matched the activation of the NADPH-dependent antioxidant responses to the increased generation of reactive oxygen species caused by chronic hyperglycemia. Ex vivo analysis of tracer kinetics confirmed that the enhanced SM avidity for FDG occurred despite a significant reduction in glucose consumption, while it was associated with increased radioactivity transfer to the endoplasmic reticulum.

CONCLUSIONS

These data challenge the current dogma linking FDG uptake to the glycolytic rate. They instead introduce a new model considering a strict link between the uptake of this glucose analog, H6PD reticular activity, and oxidative damage in diabetes, at least under fasting condition.

The Effects of L-Carnitine Supplementation on Serum Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background:

The findings of trials investigating the effects of L-carnitine administration on serum lipids are inconsistent. This meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effects of L-carnitine intake on serum lipids in patients and healthy individuals.

Methods:

Two authors independently searched electronic databases including MEDLINE, EMBASE, Cochrane Library, Web of Science, PubMed and Google Scholar from 1990 until August 1, 2019, in order to find relevant RCTs. The quality of selected RCTs was evaluated using the Cochrane Collaboration risk of bias tool. Cochrane’s Q test and I-square (I2) statistic were used to determine the heterogeneity across included trials. Weight mean difference (SMD) and 95% CI between the two intervention groups were used to determine pooled effect sizes. Subgroup analyses were performed to evaluate the source of heterogeneity based on suspected variables such as, participant’s health conditions, age, dosage of L-carnitine, duration of study, sample size, and study location between primary RCTs.

Results:

Out of 3460 potential papers selected based on keywords search, 67 studies met the inclusion criteria and were eligible for the meta-analysis. The pooled results indicated that L-carnitine administration led to a significant decrease in triglycerides (WMD: -10.35; 95% CI: -16.43, -4.27), total cholesterol (WMD: -9.47; 95% CI: - 13.23, -5.70) and LDL-cholesterol (LDL-C) concentrations (WMD: -6.25; 95% CI: -9.30, -3.21), and a significant increase in HDL-cholesterol (HDL-C) levels (WMD: 1.39; 95% CI: 0.21, 2.57). L-carnitine supplementation did not influence VLDL-cholesterol concentrations. When we stratified studies for the predefined factors such as dosage, and age, no significant effects of the intervention on triglycerides, LDL-C, and HDL-C levels were found.

Conclusion:

This meta-analysis demonstrated that L-carnitine administration significantly reduced triglycerides, total cholesterol and LDL-cholesterol levels, and significantly increased HDL-cholesterol levels in the pooled analyses, but did not affect VLDL-cholesterol levels; however, these findings were not confirmed in our subgroup analyses by participant’s health conditions, age, dosage of L-carnitine, duration of study, sample size, and study location.

Mitophagy: A crucial modulator in the pathogenesis of chronic diseases

Mitophagy is an autophagic process through which damaged or dysfunctional mitochondria are specifically degraded to maintain cellular homeostasis. It is highly regulated by various signaling pathways such as the PTEN-induced putative kinase 1 (PINK1)/Parkin and NIP3-like protein X (NIX)/BNIP3 pathways. Additionally, it plays a crucial role in inducing some pathological processes. Notably, some evidence suggesting the association of mitophagy with the occurrence of chronic diseases such as Parkinson's disease (PD), cancer, diabetes, atherosclerosis (AS), and myocardial ischemia reperfusion (MIR) injury is available. Particularly, it has been reported that mitophagy could hinder the development of PD by activating the PINK1/Parkin pathway and acting as a defense mechanism against the induction of diabetes. Conversely, the induction of mitophagy plays dual roles in driving the process of cancer, AS, and MIR injury. In this review, we have explained the role and regulatory mechanisms through which mitophagy plays a role in these chronic pathologies. Importantly, the pharmacological targeting of mitophagy might prove to be a potential alternative for the treatment of these chronic diseases.

Evolutionary genomics analysis of human nucleus-encoded mitochondrial genes: implications for the roles of energy production and metabolic pathways in the pathogenesis and pathophysiology of demyelinating diseases

The myelin sheath is a plasma membrane extension that lines nerve fibers to protect, support and insulate neurons. The myelination of axons in vertebrates enables fast, saltatory impulse propagation, and this process relies on organelles, especially on mitochondria to supply energy. Approximately 99% of mitochondrial proteins are encoded in the nucleus. Since mitochondria play a central role in the energy production and metabolic pathways, which are essential for myelinogenesis, studying these nucleus-encoded genes (nMGs) may provide new insights into the roles of energy metabolism in demyelinating diseases. In this work, a multiomics-based approach was employed to 1) construct a 1,740 human nMG subset with mitochondrial localization evidence obtained from the Integrated Mitochondrial Protein Index (IMPI) and MitoCarta databases, 2) conduct an evolutionary genomics analysis across mouse, rat, monkey, chimp, and human models, 3) examine dysmyelination phenotype-related genes (nMG subset genes with oligodendrocyte- ​and myelin-related ​phenotypes, OMP-nMGs) in MGI mouse lines and human patients, 4) determine the expression discrepancy of OMP-nMGs in brain tissues of cuprizone-treated mice, multiple sclerosis patients, and normal controls, and 5) conduct literature data mining to explore OMP-nMG-associated disease impacts. By contrasting OMP-nMGs with other genes, OMP-nMGs were found to be more ubiquitously expressed (59.1% vs. 16.1%), disease-associated (67.3% vs. 20.2%), and evolutionarily conserved within the human populations. Our multiomics-based analysis identified 110 OMP-nMGs implicated in energy production and lipid and glycan biosynthesis in the pathogenesis and pathophysiology of demyelinating disorders. Future targeted characterization of OMP-nMGs in abnormal myelination conditions may allow the discovery of novel nMG mediated mechanisms underlying myelinogenesis and related diseases.

Astaxanthin: A Potential Mitochondrial-Targeted Antioxidant Treatment in Diseases and with Aging

Oxidative stress is characterized by an imbalance between prooxidant and antioxidant species, leading to macromolecular damage and disruption of redox signaling and cellular control. It is a hallmark of various diseases including metabolic syndrome, chronic fatigue syndrome, neurodegenerative, cardiovascular, inflammatory, and age-related diseases. Several mitochondrial defects have been considered to contribute to the development of oxidative stress and known as the major mediators of the aging process and subsequent age-associated diseases. Thus, mitochondrial-targeted antioxidants should prevent or slow down these processes and prolong longevity. This is the reason why antioxidant treatments are extensively studied and newer and newer compounds with such an effect appear. Astaxanthin, a xanthophyll carotenoid, is the most abundant carotenoid in marine organisms and is one of the most powerful natural compounds with remarkable antioxidant activity. Here, we summarize its antioxidant targets, effects, and benefits in diseases and with aging.

Anorexia Nervosa and the Immune System-A Narrative Review

The pathogenesis of an increasing number of chronic diseases is being attributed to effects of the immune system. However, its role in the development and maintenance of anorexia nervosa is seemingly under-appreciated. Yet, in examining the available research on the immune system and genetic studies in anorexia nervosa, one becomes increasingly suspicious of the immune system’s potential role in the pathophysiology of anorexia nervosa. Specifically, research is suggestive of increased levels of various pro-inflammatory cytokines as well as the spontaneous production of tumor necrosis factor in anorexia nervosa; genetic studies further support a dysregulated immune system in this disorder. Potential contributors to this dysregulated immune system are discussed including increased oxidative stress, chronic physiological/psychological stress, changes in the intestinal microbiota, and an abnormal bone marrow microenvironment, all of which are present in anorexia nervosa.

Pretreatment of Diabetic Adipose-derived Stem Cells with mitoTEMPO Reverses their Defective Proangiogenic Function in Diabetic Mice with Critical Limb Ischemia

Adipose-derived stem cells (ADSCs) have the ability to migrate to injury sites and facilitate tissue repair by promoting angiogenesis. However, the therapeutic effect of ADSCs from patients with diabetes is impaired due to oxidative stress. Given that diabetes is a group of metabolic disorders and mitochondria are a major source of reactive oxygen species (ROS), it is possible that mitochondrial ROS plays an important role in the induction of diabetic ADSC (dADSC) dysfunction. ADSCs isolated from diabetic mice were treated with mitoTEMPO, a mitochondrial ROS scavenger, or TEMPO, a universal ROS scavenger, for three passages. The results showed that pretreatment with mitoTEMPO increased the proliferation, multidifferentiation potential, and the migration and proangiogenic capacities of dADSCs to levels similar to those of ADSCs from control mice, whereas pretreatment with TEMPO showed only minor effects. Mechanistically, mitoTEMPO pretreatment enhanced the mitochondrial antioxidant capacity of dADSCs, and knockdown of superoxide dismutase reduced the restored mitochondrial antioxidant capacity and attenuated the proangiogenic effects induced by mitoTEMPO pretreatment. In addition, mitoTEMPO pretreatment improved the survival of dADSCs in diabetic mice with critical limb ischemia, showing protective effects similar to those of control ADSCs. Pretreatment of dADSCs with mitoTEMPO decreased limb injury and improved angiogenesis in diabetic mice with critical limb ischemia. These findings suggested that short-term pretreatment of dADSCs with a mitochondrial ROS scavenger restored their normal functions, which may be an effective strategy for improving the therapeutic effects of ADSC-based therapies in patients with diabetes.

Metformin induces lipid changes on sphingolipid species and oxidized lipids in polycystic ovary syndrome women

Metformin is one of the treatments used for PCOS pathology decreasing body weight, plasma androgen, FSH and glucose levels. Unfortunately, there is little known about metformin's effects on lipid metabolism, a crucial process in PCOS pathology. We have employed a lipidomic approach to explore alterations in the plasma lipid profile of patients with PCOS following metformin treatment. The aim is to offer new insights about the effect of metformin in PCOS patients. Plasma samples were obtained from 27 subjects prior to and following 12 weeks of metformin treatment. A detailed biochemical characterization and lipidomic profile was performed. Metformin reduces BMI, HOMA-IR, FSH and androstenedione and increases DHEA-S but no changes were found in glucose levels after treatment. Multivariate statistics revealed a specific lipidomic signature due to the effect of 12 weeks of metformin treatment in PCOS patients. This signature includes changes in sphingolipid metabolism suggesting a crosstalk between these lipid species and the androgenic metabolism and a decrease in oxidized lipids reinforcing that metformin treatment improves oxidative stress status. Our study confirms the specific effect of metformin in lipid metabolism on women with PCOS after 12 weeks of treatment.

Bilateral multiple oncocytic cysts of the parotid gland in type 2 diabetes patients

AIMS

The hallmarks of type 2 diabetes (T2D) are hyperglycaemia and insulin resistance. These factors, at the cellular level, are associated with mitochondrial dysfunction and increased glucose uptake. Such events are poorly explored in the context of the salivary glands. In this study, we present a series of eight cases of a distinct salivary gland lesion characterised by multiple oncocytic cysts, and we provide new pathological insights regarding its pathogenesis.

METHODS AND RESULTS

Seven patients (87.5%) had confirmed T2D, and obesity was identified in five (62.5%) patients. Clinically, the patients showed bilateral parotid gland swelling with recurrent episodes of pain and enlargement. Imaging examination revealed multiple cystic lesions in both parotid glands. Microscopically, the parotid glands showed multiple cysts of different sizes, lined by oncocytic epithelial cells. Intraluminally, strongly eosinophilic glass-like crystalloid material was observed. Immunohistochemical studies were performed, and the most notable finding was glucose transporter 1 (GLUT1) overexpression in the oncocytic cysts which is not observed in any other oncocytic lesion of patients without T2D. In addition, high expressions of mitochondrial antigen, fission 1 protein and mitofusin-2 were observed in the oncocytic epithelium of the cysts. Furthermore, most of the oncocytic cysts showed a pattern of cytokeratin expression consistent with striated ducts.

CONCLUSIONS

These results strongly suggest that T2D is associated with alterations in GLUT1 expression in the cells of striated ducts with mitochondrial dysfunction, causing a hyperplastic process characterised by multiple oncocytic cysts. For this lesion, the designation of 'diabetes-associated-bilateral multiple oncocytic cysts of the parotid gland' is proposed.

Preclinical and clinical results regarding the effects of a plant-based antidiabetic formulation versus well established antidiabetic molecules

Diabetes mellitus (DM) is a complex syndrome with debilitating long-term complications, comprising alterations of carbohydrate, protein and lipid metabolisms, along increased oxidative stress and chronic low-grade inflammation. Diet management and plant-based formulations can improve the metabolic status of patients, being used as adjuvants of classic antidiabetic therapy. The purpose of our study was to evaluate the impact of a plant-based antidiabetic formulation (PBAF), containing Vaccinium myrtillus, Ribes nigrum, Rosa canina and Capsicum annuum, on the increased oxidative burden found in diabetes mellitus, comparing it with the effects of metformin and gliclazide. Firstly, we characterized the individual plant-derived components of this formulation and also assessed their in vitro radical scavenging capacity. We devised a preclinical study protocol to examine the impact of the PBAF, along metformin and gliclazide, on tissue histology as well as on the redox status of tissue, mitochondria, serum and serum lipoproteins of alloxan-induced diabetic Wistar rats. Subsequently, we assessed their long-term impact on the redox status of serum and isolated serum lipoproteins of type 2 DM (T2DM) patients, taking into consideration their cardiometabolic profile. In the preclinical stage, we found that PBAF was able to enhance total serum antioxidant defense, while metformin yielded the best results regarding the advanced glycation and protein/lipid oxidation of serum and of serum lipoproteins. The latter also improved overall serum redox status and HDL redox function. Also, antidiabetic treatment seemed to increase mitochondrial redox activity, without overturning overall tissue redox balance. Histologically, liver and brain tissues of treated diabetic rats were fairly similar to those of non-diabetic rats. In T2DM patients, the most striking results involved the effects on serum lipoproteins. The tested PBAF exerted protective antioxidant effects on low-density and, especially, on high density lipoproteins. We conclude that this formulation might constitute a good addition to the well-established pharmacological approach of DM, contributing to the reduction of overall oxidative burden.

Resveratrol treatment in patients with polycystic ovary syndrome decreased pro-inflammatory and endoplasmic reticulum stress markers

PROBLEM

Polycystic ovary syndrome (PCOS) is associated with endoplasmic reticulum (ER) stress and pro-inflammatory condition. The aim of the present study was to evaluate the effect of resveratrol treatment on pro-inflammatory and ER stress markers in patients with PCOS.

METHOD OF STUDY

Cumulus cells were obtained from 40 patients with PCOS who were divided into two groups: placebo and resveratrol treatment (receiving 800 mg/d for 40 days) groups. Blood samples were obtained from all patients before and after the procedure to evaluate interleukin (IL)-6, IL-1β, IL-18, TNF-α, NF-κB, and C-reactive protein (CRP). Total RNA was extracted from cumulus cells, and cDNA was synthesized by reverse transcription. Expressions of five genes in ER stress response pathway (ATF4, ATF6, CHOP, GRP78, and XBP1s) were assessed with quantitative real-time PCR. Statistical analysis was performed with Student's t test.

RESULTS

After treatment with resveratrol, it was found that serum levels of IL-6, IL-1β, TNF-α, IL-18, NF-κB, and CRP decreased in the treatment group. In addition, gene expression results showed that the expression levels of ATF4 (P < .05) and ATF6 (P < .001) significantly increased in the resveratrol treatment group, while the expression levels of CHOP, GRP78, and XBP1 (P < .001 for all) significantly decreased.

CONCLUSION

Results demonstrated that resveratrol has anti-inflammatory effects through the suppression of NF-κB and NF-κB-regulated gene products. On the other hand, resveratrol can modulate ER stress in granulosa cells (GCs) by altering the expression of genes involved in unfolding protein response (UPR) process. Our findings suggest that ER stress is a potential therapeutic target for patients with PCOS.

POMC Neurons Dysfunction in Diet-induced Metabolic Disease: Hallmark or Mechanism of Disease?

One important lesson from the last decade of studies in the field of systemic energy metabolism is that obesity is first and foremost a brain disease. Hypothalamic neurons dysfunction observed in response to chronic metabolic stress is a key pathogenic node linking consumption of hypercaloric diets with body weight gain and associated metabolic sequelae. A key hypothalamic neuronal population expressing the neuropeptide Pro-opio-melanocortin (POMC) displays altered electrical activity and dysregulated neuropeptides production capacity after long-term feeding with hypercaloric diets. However, whether such neuronal dysfunction represents a consequence or a mechanism of disease, remains a subject of debate. Here, we will review and highlight emerging pathogenic mechanisms that explain why POMC neurons undergo dysfunctional activity in response to caloric overload, and critically address whether these mechanisms may be causally implicated in the physiopathology of obesity and of its associated co-morbidities.

The endothelial mineralocorticoid receptor: Contributions to sex differences in cardiovascular disease

Cardiovascular disease remains the leading cause of death for both men and women. The observation that premenopausal women are protected from cardiovascular disease relative to age-matched men, and that this protection is lost with menopause, has led to extensive study of the role of sex steroid hormones in the pathogenesis of cardiovascular disease. However, the molecular basis for sex differences in cardiovascular disease is still not fully understood, limiting the ability to tailor therapies to male and female patients. Therefore, there is a growing need to investigate molecular pathways outside of traditional sex hormone signaling to fully understand sex differences in cardiovascular disease. Emerging evidence points to the mineralocorticoid receptor (MR), a steroid hormone receptor activated by the adrenal hormone aldosterone, as one such mediator of cardiovascular disease risk, potentially serving as a sex-dependent link between cardiovascular risk factors and disease. Enhanced activation of the MR by aldosterone is associated with increased risk of cardiovascular disease. Emerging evidence implicates the MR specifically within the endothelial cells lining the blood vessels in mediating some of the sex differences observed in cardiovascular pathology. This review summarizes the available clinical and preclinical literature concerning the role of the MR in the pathophysiology of endothelial dysfunction, hypertension, atherosclerosis, and heart failure, with a special emphasis on sex differences in the role of endothelial-specific MR in these pathologies. The available data regarding the molecular mechanisms by which endothelial-specific MR may contribute to sex differences in cardiovascular disease is also summarized. A paradigm emerges from synthesis of the literature in which endothelial-specific MR regulates vascular function in a sex-dependent manner in response to cardiovascular risk factors to contribute to disease. Limitations in this field include the relative paucity of women in clinical trials and, until recently, the nearly exclusive use of male animals in preclinical investigations. Enhanced understanding of the sex-specific roles of endothelial MR could lead to novel mechanistic insights underlying sex differences in cardiovascular disease incidence and outcomes and could identify additional therapeutic targets to effectively treat cardiovascular disease in men and women.

The SGLT2 Inhibitor Empagliflozin Ameliorates the Inflammatory Profile in Type 2 Diabetic Patients and Promotes an Antioxidant Response in Leukocytes

Sodium-glucose co-transporter 2 inhibitors (iSGLT2) have been linked to a considerable reduction in cardiovascular risk in patients with type 2 diabetes (T2D), but the precise molecular mechanisms are still elusive. We aimed to evaluate the effects of the iSGLT2 empagliflozin on systemic inflammation and its potential antioxidant properties. This is an observational, prospective follow-up study of a cohort of fifteen patients with T2D who received 10 mg/day of empagliflozin according to standard clinical care. Measures at baseline, 12 and 24 weeks were taken. Metabolic and anthropometric parameters were evaluated. Production of mitochondrial superoxide, glutathione content, and glutathione s-reductase and catalase mRNA levels were measured in leukocytes. Serum levels of myeloperoxidase, hs-CRP and IL-10 were determined. In addition to decreased body weight and reduced glucose and HbA1c levels, we observed a reduction in superoxide production in leukocytes of diabetic patients and increased glutathione content, prominently after 24 weeks of empagliflozin treatment. Leukocyte expression of glutathione s-reductase and catalase, and serum levels of IL-10 were enhanced at 24 weeks of empagliflozin treatment. Concomitantly, reduced hs-CRP and myeloperoxidase levels were seen. This study provides evidence of the antioxidant and anti-inflammatory properties of empagliflozin treatment in humans, which may contribute to its beneficial cardiovascular effects.

The metabolic underpinning of eating disorders: A systematic review and meta-analysis of insulin sensitivity

BACKGROUND

A recent study reported a positive genetic correlation between anorexia nervosa and insulin sensitivity using data from genome-wide association studies. Epidemiological studies have, on the other hand, suggested that bulimia nervosa and binge-eating disorder are associated with decreased insulin sensitivity. The aim of this study was to conduct a systematic review and meta-analysis of insulin sensitivity across the spectrum of eating disorders.

METHODS

EMBASE, Medline, and PsycINFO were searched for all relevant studies published until January 2017, and retrieved studies were assessed for eligibility by two independent reviewers as per predefined inclusion criteria. The associations between eating disorder subtypes and insulin sensitivity were analysed separately. Individual effect sizes were standardized, and a meta-analysis was performed to calculate a pooled effect size using random effects.

RESULTS

Of 296 citations retrieved, 22 studies met the inclusion criteria, and 12 studies had appropriate data for meta-analysis. Using the random effects model, the pooled effect size (95% confidence interval) was 1.66 (0.79, 2.54) in people with anorexia nervosa (n = 340) and -0.57 (-0.80, -0.34) in people with bulimia nervosa (n = 120) and binge-eating disorders (n = 3241).

INTERPRETATION

Anorexia nervosa is associated with increased insulin sensitivity whilst bulimia nervosa and binge-eating disorders are associated with decreased insulin sensitivity. The possible mechanism underpinning these findings needs to be determined.

MicroRNAs as biomarkers of diabetic retinopathy and disease progression

Diabetes mellitus, together with its complications, has been increasing in prevalence worldwide. Its complications include cardiovascular disease (e.g., myocardial infarction, stroke), neuropathy, nephropathy, and eye complications (e.g., glaucoma, cataracts, retinopathy, and macular edema). In patients with either type 1 or type 2 diabetes mellitus, diabetic retinopathy is the leading cause of visual impairment or blindness. It is characterized by progressive changes in the retinal microvasculature. The progression from nonproliferative diabetic retinopathy to a more advanced stage of moderate to severe nonproliferative diabetic retinopathy and proliferative diabetic retinopathy occurs very quickly after diagnosis of mild nonproliferative diabetic retinopathy. The etiology of diabetic retinopathy is unclear, and present treatments have limited effectiveness. Currently diabetic retinopathy can only be diagnosed by a trained specialist, which reduces the population that can be examined. A screening biomarker of diabetic retinopathy with high sensitivity and specificity would aid considerably in identifying those individuals in need of clinical assessment and treatment. The majority of the studies reviewed identified specific microRNAs in blood serum/plasma able to distinguish diabetic patients with retinopathy from those without retinopathy and for the progresion of the disease from nonproliferative diabetic retinopathy to proliferative diabetic retinopathy. In addition, certain microRNAs in vitreous humor were dysregulated in proliferative diabetic retinopathy compared to controls. A very high percentage of patients with diabetic retinopathy develop Alzheimer's disease. Thus, identifying diabetic retinopathy by measurement of suitable biomarkers would also enable better screening and treatment of those individuals at risk of Alzheimer's disease.

Autophagy protects peripheral blood mononuclear cells against inflammation, oxidative and nitrosative stress in diabetic dyslipidemia

BACKGROUND

Type 2 diabetes mellitus (T2DM) results in severe oxidative and nitrosative stress and inflammation when associated with hyperlipidemia. In this study, we have attempted to explore the role of autophagy in T2DM subjects with or without dyslipidemia.

METHODS

Experiments were carried out in isolated Peripheral blood mononuclear cells (PBMC) from study subjects and insulin resistant HepG2 cells utilizing flow cytometry, confocal microscopy and molecular biology techniques like western blotting, immunofluorescence and real time PCR.

RESULTS

In case of T2DM with dyslipidemia, higher population of autophagy positive cell was detected compared to T2DM which may have been originated due to higher stress. Flow cytometric data indicated autophagy to be triggered by both oxidative and nitrosative stress in PBMC of diabetic dyslipidemic patients, which is a novel finding of our work. Expression of LC3 puncta, a hallmark of autophagy was observed at periphery of PBMC and Hep G2 cells in case of diabetic dyslipidemic condition. Increased expression of ATG5, LC3B and Beclin1 supports the autophagic pathway in both PBMC and Hep G2 cells. Upon blocking autophagy by 3-methyl adenine (3MA), the apoptotic cell population increased significantly. Autophagy was also been evidenced to control oxidative stress mediated up-regulation of inflammatory markers like IL-6, TNF-α.

CONCLUSION

Induction of autophagy emerged to be a protective mechanism for the diabetic cells coupled with dyslipidemia. Not only Reactive oxygen species, but also reactive nitrogen species was involved in autophagy induction process. Moreover inhibition study documented autophagy to have a protective role in pro-inflammatory responses. Thus, enhancing autophagic activity may be an efficient mechanism leading to new therapeutic strategy to restore the glycemic regulation.

Pretreatment with vildagliptin boosts ischemic-postconditioning effects on cardioprotection and expression profile of genes regulating autophagy and mitochondrial fission/fusion in diabetic heart with reperfusion injury

The burden of myocardial ischemia/reperfusion (IR) injury is 2-3-folds higher in diabetic patients, so protecting diabetic hearts is clinically important. Here, we investigated the effect of combinational therapy with vildagliptin and ischemic postconditioning (IPostC) on cardioprotection and the expression of genes regulating autophagy and mitochondrial function in diabetic hearts with IR injury. Type 2 diabetes was induced through high-fat diet and streptozotocin protocol in Wistar rats. Vildagliptin was orally administered to diabetic rats 5 weeks before IR injury. Myocardial-IR injury was modeled by ligation of left the coronary artery for 30 min followed by 60-min reperfusion, on a Langendorff-perfusion system. IPostC was applied at early reperfusion as 6 alternative cycles of 10-s reperfusion/ischemia. Creatine-kinase levels were measured spectrometrically, and infarct size was evaluated by TTC staining method. Left ventricles were harvested for assessing the expression levels of autophagy and mitochondrial-related genes using real-time PCR. Induction of diabetes significantly increased creatine-kinase release in comparison to healthy rats, and all treatments significantly reduced the release of enzyme toward control levels (P < 0.05). Only the combination therapy (IPostC + vildagliptin) could significantly reduce the infarct size of diabetic hearts as compared to untreated diabetic-IR group (P < 0.01). The levels of autophagy genes LC3 and p62 were significantly higher in diabetic groups than healthy ones. Induction of IR injury in diabetic hearts enhanced mitochondrial fission (drp-1) and reduced mitochondrial fusion (mfn1 and mfn2) genes. IPostC alone had no significant effect on the gene expression and vildagliptin alone could only affect LC3-II and mfn2 expressions. Nevertheless, administration of combination therapy significantly reduced the expression of both autophagy genes and increased both LC3-II/I and mfn2/1 ratios as compared with diabetic-IR hearts (P < 0.01-0.05). Application of this combination therapy could overcome the diabetes-induced failure of cardioprotection by individual treatments and improve mitochondrial dynamic and autophagy flux.

Interleukins and miRNAs intervene in the early stages of diabetic kidney disease in Type 2 diabetes mellitus patients

Aim: The involvement of proinflammatory interleukins (IL) in diabetic kidney disease of Type 2 diabetes mellitus (DM) patients was studied in relation to a particular miRNA profile. Materials & methods: A total of 117 patients with Type 2 DM and 11 controls were enrolled in a case series study. Serum and urinary ILs and miRNAs were assessed. Results: IL-1α correlated with miRNA21, 124, estimated glomerular filtration rate (eGFR) and negatively with miRNA125a and 192; IL-8 with miRNA21, 124, eGFR and negatively with miRNA125a, 126 and 146a; IL-18 with miRNA21, 124 and negatively with miRNA146a, 192, eGFR. Conclusion: There is an association between specific serum and urinary ILs and serum and urinary miRNAs profiles in the inflammatory response in Type 2 DM patients with diabetic kidney disease.

miR-34b Alleviates High Glucose-Induced Inflammation and Apoptosis in Human HK-2 Cells via IL-6R/JAK2/STAT3 Signaling Pathway

Background

It is well established that inflammation and apoptosis of renal tubular epithelial cells caused by hyperglycemia contribute to the development of diabetic nephropathy (DN). Although microRNAs (miRNAs) are known to have roles in inflammation-related disorders, the exact role of miR-34b in DN has not been defined, and the regulatory mechanism has been unclear. This study aimed to clarify the role of miR-34b in DN pathogenesis.

Material/Methods

Expression of miR-34b, IL-6R, and other key factors of inflammation, apoptosis (TNF-α, IL-1β, IL-6, caspase-3) in high glucose (HG)-induced HK-2 cells were measured by real-time PCR, Western blot, and flow cytometric cell apoptosis assays. We used luciferase reporter assay to detect the target of miR-34b. Moreover, the targeting gene of miR-34b and its downstream JAK2/STAT3 signaling pathway were explored.

Results

It was demonstrated that miR-34b overexpression inhibited apoptosis and expression levels of TNF-α, IL-1β, IL-6, and caspase-3 in HG-treated HK-2 cells. We also found that IL-6R is a direct target of miR-34b, which could rescue inflammation and apoptosis in HG-treated HK-2 cells transfected with miR-34b mimic. Furthermore, we showed that overexpression of miR-34b inhibited the IL-6R/JAK2/STAT3 signaling pathway in HG-treated HK-2 cells.

Conclusions

Our data suggest that overexpression of miR-34b improves inflammation and ameliorates apoptosis in HG-induced HK-2 cells via the IL-6R/JAK2/STAT3 pathway, indicating that miR-34b could be a promising therapeutic target in DN.

The Pathogenesis of Sepsis and Potential Therapeutic Targets

Sepsis is defined as “a life-threatening organ dysfunction caused by a host’s dysfunctional response to infection”. Although the treatment of sepsis has developed rapidly in the past few years, sepsis incidence and mortality in clinical treatment is still climbing. Moreover, because of the diverse manifestations of sepsis, clinicians continue to face severe challenges in the diagnosis, treatment, and management of patients with sepsis. Here, we review the recent development in our understanding regarding the cellular pathogenesis and the target of clinical diagnosis of sepsis, with the goal of enhancing the current understanding of sepsis. The present state of research on targeted therapeutic drugs is also elaborated upon to provide information for the treatment of sepsis.

Nutrient Metabolism, Subcellular Redox State, and Oxidative Stress in Pancreatic Islets and β-Cells

Insulin-secreting pancreatic β-cells play a critical role in blood glucose homeostasis and the development of type 2 diabetes (T2D) in the context of insulin resistance. Based on data obtained at the whole cell level using poorly specific chemical probes, reactive oxygen species (ROS) such as superoxide and hydrogen peroxide have been proposed to contribute to the stimulation of insulin secretion by nutrients (positive role) and to the alterations of cell survival and secretory function in T2D (negative role). This raised the controversial hypothesis that any attempt to decrease β-cell oxidative stress and apoptosis in T2D would further impair insulin secretion. Over the last decade, the development of genetically-encoded redox probes that can be targeted to cellular compartments of interest and are specific of redox couples allowed the evaluation of short- and long-term effects of nutrients on β-cell redox changes at the subcellular level. The data indicated that the nutrient regulation of β-cell redox signaling and ROS toxicity is far more complex than previously thought and that the subcellular compartmentation of these processes cannot be neglected when evaluating the mechanisms of ROS production or the efficacy of antioxidant enzymes and antioxidant drugs under glucolipotoxic conditions and in T2D. In this review, we present what is currently known about the compartmentation of redox homeostatic systems and tools to investigate it. We then review data about the effects of nutrients on β-cell subcellular redox state under normal conditions and in the context of T2D and discuss challenges and opportunities in the field.

Dengue Virus M Protein Promotes NLRP3 Inflammasome Activation To Induce Vascular Leakage in Mice

Dengue virus (DENV) infection causes serious clinical symptoms, including dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Vascular permeability change is the main feature of the diseases, and the abnormal expression of proinflammatory cytokines is the important cause of vascular permeability change. However, the mechanism underlying vascular permeability induced by DENV has not been fully elucidated. Here, we reveal a distinct mechanism by which DENV infection promotes NLRP3 inflammasome activation and interleukin-1 beta (IL-1β) release to induce endothelial permeability and vascular leakage in mice. DENV M protein interacts with NLRP3 to facilitate NLRP3 inflammasome assembly and activation, which induce proinflammatory cytokine IL-1β activation and release. Notably, M can induce vascular leakage in mouse tissues by activating the NLRP3 inflammasome and IL-1β. More importantly, inflammatory cell infiltration and tissue injuries are induced by M in wild-type (WT) mouse tissues, but they are not affected by M in NLRP3 knockout (NLRP3^-/-) mouse tissues. Evans blue intensities in WT mouse tissues are significantly higher than in NLRP3^-/- mouse tissues, demonstrating an essential role of NLRP3 in M-induced vascular leakages in mice. Therefore, we propose that upon DENV infection, M interacts with NLRP3 to facilitate inflammasome activation and IL-1β secretion, which lead to the induction of endothelial permeability and vascular leakage in mouse tissues. The important role of the DENV-M-NLRP3-IL-1β axis in the induction of vascular leakage provides new insights into the mechanisms underlying DENV pathogenesis and DENV-associated DHF and DSS development.IMPORTANCE Dengue virus (DENV) is a mosquito-borne pathogen, and infections by this virus are prevalent in over 100 tropical and subtropical countries or regions, with approximately 2.5 billion people at risk. DENV infection induces a spectrum of clinical symptoms, ranging from classical dengue fever (DF) to severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Therefore, it is important to understand the mechanisms underlying DENV pathogenesis. In this study, we reveal that the DENV membrane protein (M) interacts with the host NLRP3 protein to promote NLRP3 inflammasome activation, which leads to the activation and release of a proinflammatory cytokine, interleukin-1 beta (IL-1β). More importantly, we demonstrate that M protein can induce vascular permeability and vascular leakage and that NLRP3 is required for M-induced vascular leakage in mouse tissues. Collectively, this study reveals a distinct mechanism underlying DENV pathogeneses and provides new insights into the development of therapeutic agents for DENV-associated diseases.

Mitophagy in Hepatic Insulin Resistance: Therapeutic Potential and Concerns

Metabolic syndrome, characterized by central obesity, hypertension, and hyperlipidemia, increases the morbidity and mortality of cardiovascular disease, type 2 diabetes, nonalcoholic fatty liver disease, and other metabolic diseases. It is well known that insulin resistance, especially hepatic insulin resistance, is a risk factor for metabolic syndrome. Current research has shown that hepatic fatty acid accumulation can cause hepatic insulin resistance through increased gluconeogenesis, lipogenesis, chronic inflammation, oxidative stress and endoplasmic reticulum stress, and impaired insulin signal pathway. Mitochondria are the major sites of fatty acid β-oxidation, which is the major degradation mechanism of fatty acids. Mitochondrial dysfunction has been shown to be involved in the development of hepatic fatty acid–induced hepatic insulin resistance. Mitochondrial autophagy (mitophagy), a catabolic process, selectively degrades damaged mitochondria to reverse mitochondrial dysfunction and preserve mitochondrial dynamics and function. Therefore, mitophagy can promote mitochondrial fatty acid oxidation to inhibit hepatic fatty acid accumulation and improve hepatic insulin resistance. Here, we review advances in our understanding of the relationship between mitophagy and hepatic insulin resistance. Additionally, we also highlight the potential value of mitophagy in the treatment of hepatic insulin resistance and metabolic syndrome.