Summary Mitochondria provide chemical energy for endoergonic reactions in form of ATP. Their activity must meet cellular energy requirements, but mechanisms linking organelle performance to ATP levels are poorly understood. Here, we identify a mitochondria-localized protein complex that mediates ATP-dependent potassium currents, referred to as mitoK ATP . We show that similarly to their plasma membrane counterparts, mitoK ATP channels are composed of pore-forming (MITOK) and ATP-binding (MITOSUR) subunits. In vitro reconstitution of MITOK together with MITOSUR recapitulates the main properties of mitoK ATP . While MITOK overexpression triggers dramatic organelle swelling, its genetic ablation causes instability of mitochondrial membrane potential, widening of intracristal space and decreased oxidative phosphorylation. Most importantly, loss of Mitok suppresses cardioprotection elicited by diazoxide-induced pharmacological preconditioning. Our data indicate that mitoK ATP channels respond to the cellular energetic status by regulating organelle volume and function, thereby representing key players in mitochondrial physiology with potential impact on several pathological processes.

Graphical Abstract Highlights d An HTS identifies MCU-i4 and MCU-i11 as negative modulators of the MCU d MCU-i4 and MCU-i11 bind MICU1 d MICU1 is required for the activity of MCU-i4 and MCU-i11 d MCU-i4 and MCU-i11 impair muscle cell growth

Objective The timing of delivery for women affected by gestational diabetes (GDM) is still controversial. Good clinical practice often suggests offering induction of labor at term in order to reduce the complications associated with this condition, while recent evidence supports expectant management. Fetal Doppler parameters represent a validated tool for testing fetal well-being at term and can select pregnancies that need increased surveillance. The aim of the present study was to evaluate the role of fetal Doppler parameters at term for the prediction of pregnancy outcomes in patients affected by GDM. Methods Prospective cohort study in a single center. Evaluation of umbilical artery (UA) PI, middle cerebral artery (MCA) PI, cerebroplacental ratio (CPR) and umbilical-to-cerebral ratio (UCR) at > 37 weeks of gestation in singleton, morphologically normal pregnancies affected by GDM, was performed in order to estimate the association between ultrasound measurements at term and perinatal outcome. Regression linear analysis was used to estimate the association between fetal Doppler parameters and neonatal pH, neonatal Apgar score, neonatal weight and a composite adverse outcome. The receiver operating characteristic (ROC) curve was used to estimate the possible predictive value of the above association. Results Our results on 130 women showed MCA PI to be the best predictor of perinatal outcomes in terms of low Apgar score at the 1st minute (p = 0.00), pH (p = 0.02) and composite adverse outcome (p = 0.05). UCR showed a significant correlation with neonatal pH (p = 0.02). No significant correlations for UA PI and CPR MoMs have been demonstrated in our population. However, the small sample size is a limitation of the study. Conclusion Evaluation of MCA Doppler and eventually UCR at term can be a useful tool to discriminate pregnancies affected by GDM that can benefit from IOL before 41 weeks in order to reduce complications related to this condition.

Autophagy is responsible for the maintenance of skeletal muscle homeostasis, thanks to the removal of aberrant and dysfunctional macromolecules and organelles. During fasting, increased autophagy ensures the maintenance of the amino acid pool required for energy production. The activity of the mitochondrial Ca2+ uniporter (MCU), the highly selective channel responsible for mitochondrial Ca2+ uptake, controls skeletal muscle size, force, and nutrient utilization. Thus, both autophagy and mitochondrial Ca2+ accumulation play a pivotal role to maintain muscle homeostasis and to sustain muscle function. Here, we address whether, in skeletal muscle, mitochondrial Ca2+ uptake and autophagy are mutually related. Muscle-restricted MCU silencing partially inhibits the autophagy flux. Moreover, skeletal muscle-specific deletion of the essential autophagy gene Atg7, known to cause the accumulation of dysfunctional mitochondria, drastically reduces mitochondrial Ca2+ accumulation. Thus, a vicious cycle takes place, in which reduced MCU activity hampers the autophagic flux, and loss of autophagy further impairs mitochondrial Ca2+ signaling.

The aim of our study was to identify characteristics associated with postpartum hemorrhage (PPH defined as blood loss >1000 mL) in twin pregnancies in order to select patients at higher risk to be treated. This retrospective study includes multiple pregnancies between 2015 and 2020. The possible association between pregnancy characteristics and the primary endpoint (occurrence of PPH) was conducted using chi-square or Fisher exact test and Wilcoxon test. Then, univariate logistic models were performed considering as outcome the PPH, and the odds ratios with 95% CI were estimated. Finally, a multivariate logistic model was implemented, including all significant covariates. Seven hundred seven twin pregnancies giving birth beyond 32 weeks were included and of those, 120 (16.97%) had a PPH. The univariate analysis showed that factors significantly associated with PPH were: Preterm delivery, episiotomy, neonatal weight, and mode of delivery. The multivariate analysis showed that the most important factors were episiotomy and neonatal weight. The results show that the performance of episiotomy and the neonatal weight are the factors that most impact the risk of PPH in twin pregnancies. The correct identification of factors associated with PPH in twins could ideally allow to modify the clinical management and positively affect the rate of complications.