Background: Excessive production of mitochondrial reactive oxygen species (ROS) is a central mechanism for the development of diabetes complications. Recently, hypoxia has been identified to play an additional pathogenic role in diabetes. In this study, we hypothesized that ROS overproduction was secondary to the impaired responses to hypoxia due to the inhibition of hypoxia-inducible factor-1 (HIF-1) by hyperglycemia.Methods: The ROS levels were analyzed in the blood of healthy subjects and individuals with type 1 diabetes after exposure to hypoxia. The relation between HIF-1, glucose levels, ROS production and its functional consequences were analyzed in renal mIMCD-3 cells and in kidneys of mouse models of diabetes.Results: Exposure to hypoxia increased circulating ROS in subjects with diabetes, but not in subjects without diabetes. High glucose concentrations repressed HIF-1 both in hypoxic cells and in kidneys of animals with diabetes, through a HIF prolyl-hydroxylase (PHD)-dependent mechanism. The impaired HIF-1 signaling contributed to excess production of mitochondrial ROS through increased mitochondrial respiration that was mediated by Pyruvate dehydrogenase kinase 1 (PDK1). The restoration of HIF-1 function attenuated ROS overproduction despite persistent hyperglycemia, and conferred protection against apoptosis and renal injury in diabetes.Conclusions: We conclude that the repression of HIF-1 plays a central role in mitochondrial ROS overproduction in diabetes and is a potential therapeutic target for diabetic complications. These findings are timely since the first PHD inhibitor that can activate HIF-1 has been newly approved for clinical use.Funding: This work was supported by grants from the Swedish Research Council, Stockholm County Research Council, Stockholm Regional Research Foundation, Bert von Kantzows Foundation, Swedish Society of Medicine, Kung Gustaf V:s och Drottning Victorias Frimurarestifelse, Karolinska Institute’s Research Foundations, Strategic Research Programme in Diabetes, and Erling-Persson Family Foundation for S-B.C.; grants from the Swedish Research Council and Swedish Heart and Lung Foundation for T.A.S.; and ERC consolidator grant for M.M.

Polycystic ovary syndrome (PCOS) is associated with a low‐grade inflammation, but it is unknown how hyperandrogenism, the hallmark of PCOS, affects the immune system. Using a PCOS‐like mouse model, it is demonstrated that hyperandrogenism affects immune cell populations in reproductive, metabolic, and immunological tissues differently in a site‐specific manner. Co‐treatment with an androgen receptor antagonist prevents most of these alterations, demonstrating that these effects are mediated through androgen receptor activation. Dihydrotestosterone (DHT)‐exposed mice displayed a drastically reduced eosinophil population in the uterus and visceral adipose tissue (VAT). A higher frequency of natural killer (NK) cells and elevated levels of IFN‐γ and TNF‐α are seen in uteri of androgen‐exposed mice, while NK cells in VAT and spleen displayed a higher expression level of CD69, a marker of activation or tissue residency. Distinct alterations of macrophages in the uterus, ovaries, and VAT are also found in DHT‐exposed mice and can potentially be linked to PCOS‐like traits of the model. Indeed, androgen‐exposed mice are insulin‐resistant, albeit unaltered fat mass. Collectively, it is demonstrated that hyperandrogenism causes tissue‐specific alterations of immune cells in reproductive organs and VAT, which can have considerable implications on tissue function and contribute to the reduced fertility and metabolic comorbidities associated with PCOS.

Mitochondrial dysfunction in type 2 diabetes leads to oxidative stress, which drives disease progression and diabetes complications. L-carnosine, an endogenous dipeptide, improves metabolic control, wound healing and kidney function in animal models of type 2 diabetes. Coenzyme Q (CoQ), a component of the mitochondrial electron transport chain, possesses similar protective effects on diabetes complications. We aimed to study the effect of carnosine on CoQ, and assess any synergistic effects of carnosine and CoQ on improved mitochondrial function in a mouse model of type 2 diabetes. Carnosine enhanced CoQ gene expression and increased hepatic CoQ biosynthesis in db/db mice, a type 2 diabetes model. Co-administration of Carnosine and CoQ improved mitochondrial function, lowered ROS formation and reduced signs of oxidative stress. Our work suggests that carnosine exerts beneficial effects on hepatic CoQ synthesis and when combined with CoQ, improves mitochondrial function and cellular redox balance in the liver of diabetic mice. (4) Conclusions: L-carnosine has beneficial effects on oxidative stress both alone and in combination with CoQ on hepatic mitochondrial function in an obese type 2 diabetes mouse model.

Women with polycystic ovary syndrome (PCOS) exhibit sustained elevation in circulating androgens during pregnancy, an independent risk factor linked to pregnancy complications and adverse outcomes in offspring. Yet, further studies are required to understand the effects of elevated androgens on cell type‐specific placental dysfunction and fetal development. Therefore, a PCOS‐like mouse model induced by continuous androgen exposure is examined. The PCOS‐mice exhibited impaired placental and embryonic development, resulting in mid‐gestation lethality. Co‐treatment with the androgen receptor blocker, flutamide, prevents these phenotypes including germ cell specification. Comprehensive profiling of the placenta by whole‐genome bisulfite and RNA sequencing shows a reduced proportion of trophoblast precursors, possibly due to the downregulation of Cdx2 expression. Reduced expression of Gcm1 , Synb , and Prl3b1 is associated with reduced syncytiotrophoblasts and sinusoidal trophoblast giant cells, impairs placental labyrinth formation. Importantly, human trophoblast organoids exposed to androgens exhibit analogous changes, showing impaired trophoblast differentiation as a key feature in PCOS‐related pregnancy complications. These findings provide new insights into the potential cellular targets for future treatments.

Background Isofraxidin is a coumarin compound mainly isolated from several traditional and functional edible plants beneficial for neurodegenerative diseases, including Sarcandra glabra and Apium graveolens, and Siberian Ginseng. Objective This study aimed to assess effects of isofraxidin against memory impairments and cognition deficits in a scopolamine-induced mouse model. Materials & methods Animals were randomly divided into 6 groups, control, vehicle, donepezil (10 mg/kg, p.o.), and isofraxidin (3, 10, and 30 mg/kg, p.o.). Isofraxidin or donepezil was administered for 44 days, once per day. The scopolamine insults (1 mg/kg, i.p.) was given from the 21st day, once per day. Morris water maze test and Y-maze test were used for the behavioral test. After that, brain samples were collected for analysis. Results Firstly, isofraxidin significantly improved scopolamine-induced behavioral impairments and cognition deficits in Morris water maze and Y-maze test. Then, isofraxidin facilitated cholinergic activity via inhibiting acetylcholinesterase (AChE) activity. Besides, isofraxidin decreased lipid peroxidation level but enhanced levels of glutathione, glutathione peroxidase, and superoxide dismutase. Moreover, isofraxidin suppressed the expression of inflammatory mediators and cytokines. Further investigations showed that isofraxidin up-regulated expression of brain-derived neurotrophic factor (BDNF), and promoted phosphorylation of tropomyosin-related kinase B (TrkB), cyclic AMP-response element-binding protein (CREB), and extracellular signal-regulated kinase (ERK). Discussion & Conclusions These results suggested that isofraxidin ameliorated scopolamine-induced cognitive and memory impairments, possibly through regulating AChE activity, suppressing oxidative stress and inflammatory response, and modulating BDNF-CREB-ERK pathways.

Introduction: Available data on severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and pregnancy outcomes mostly refer to women contracting the infection during advanced pregnancy or close to delivery. There is limited information on the association between SARS‐CoV‐2 infection in early pregnancy and outcomes thereof.Material and methods: We aimed to systematically review the maternal, fetal and neonatal outcomes following SARS‐CoV‐2 infection in early pregnancy, defined as <20 weeks of gestation (PROSPERO Registration 2020 CRD42020177673). Searches were carried out in PubMed, Medline, EMBASE, and Scopus databases from January 2020 until April 2023 and the WHO database of publications on coronavirus disease 2019 (COVID‐19) from December 2019 to April 2023. Cohort and case–control studies on COVID‐19 occurring in early pregnancy that reported data on maternal, fetal, and neonatal outcomes were included. Case reports and studies reporting only exposure to SARS‐CoV‐2 or not stratifying outcomes based on gestational age were excluded. Data were extracted in duplicate. Meta‐analyses were conducted when appropriate, using R meta (R version 4.0.5).Results: A total of 18 studies, 12 retrospective and six prospective, were included in this review, reporting on 10 147 SARS‐CoV‐2‐positive women infected in early pregnancy, 9533 neonates, and 180 882 SARS‐CoV‐2 negative women. The studies had low to moderate risk of bias according to the Newcastle–Ottawa quality assessment Scale. The studies showed significant clinical and methodological heterogeneity. A meta‐analysis could be performed only on the outcome miscarriage rate, with a pooled random effect odds ratio of 1.44 (95% confidence interval 0.96–2.18), showing no statistical difference in miscarriage in SARS‐CoV‐2‐infected women. Individual studies reported increased incidences of stillbirth, low birthweight and preterm birth among neonates born to mothers affected by COVID‐19 in early pregnancy; however, these results were not consistent among all studies.Conclusions: In this comprehensive systematic review of available evidence, we identified no statistically significant adverse association between SARS‐CoV‐2 infection in early pregnancy (before 20 weeks of gestation) and fetal, neonatal, or maternal outcomes. However, a 44% increase in miscarriage rate is concerning and further studies of larger sample size are needed to confirm or refute our findings.