Energy sensor AMPK gamma regulates translation via phosphatase PPP6C independent of AMPK alpha.

Maintenance of energy level to drive movements and material exchange with the environment is a basic principle of life. AMP-activated protein kinase (AMPK) senses energy level and is a major regulator of cellular energy responses. The gamma subunit of AMPK senses elevated ratio of AMP to ATP and allosterically activates the alpha catalytic subunit to phosphorylate downstream effectors. Here, we report that knockout of AMPKγ, but not AMPKα, suppressed phosphorylation of eukaryotic translation elongation factor 2 (eEF2) induced by energy starvation. We identified PPP6C as an AMPKγ-regulated phosphatase of eEF2. AMP-bound AMPKγ sequesters PPP6C, thereby blocking dephosphorylation of eEF2 and thus inhibiting translation elongation to preserve energy and to promote cell survival. Further phosphoproteomic analysis identified additional targets of PPP6C regulated by energy stress in an AMPKγ-dependent manner. Thus, AMPKγ senses cellular energy availability to regulate not only AMPKα kinase, but also PPP6C phosphatase and possibly other effectors.

Inhibition of Syk promotes chemical reprogramming of fibroblasts via metabolic rewiring and H2 S production.

Chemical compounds have recently been introduced as alternative and non-integrating inducers of pluripotent stem cell fate. However, chemical reprogramming is hampered by low efficiency and the molecular mechanisms remain poorly characterized. Here, we show that inhibition of spleen tyrosine kinase (Syk) by R406 significantly promotes mouse chemical reprogramming. Mechanistically, R406 alleviates Syk / calcineurin (Cn) / nuclear factor of activated T cells (NFAT) signaling-mediated suppression of glycine, serine, and threonine metabolic genes and dependent metabolites. Syk inhibition upregulates glycine level and downstream transsulfuration cysteine biosynthesis, promoting cysteine metabolism and cellular hydrogen sulfide (H2 S) production. This metabolic rewiring decreased oxidative phosphorylation and ROS levels, enhancing chemical reprogramming. In sum, our study identifies Syk-Cn-NFAT signaling axis as a new barrier of chemical reprogramming and suggests metabolic rewiring and redox homeostasis as important opportunities for controlling cell fates.

Association of sleep duration and sleep quality with gestational diabetes mellitus in pregnant women after treatment with assisted reproductive technology: A birth cohort study.

Maternal sleep is closely related to subsequent gestational diabetes mellitus (GDM) in natural pregnancies. However, whether this connection exists in pregnant women conceiving with the help of assisted reproductive technology (ART) has not been confirmed. Hence, in this study, we evaluated whether early pregnancy sleep duration or sleep quality is associated with gestational diabetes mellitus in ART-pregnant women, as well as the influence of maternal age on this association. This prospective birth cohort study included 856 pregnant women who successfully conceived with the help of ART treatment. The sleep parameters of ART-pregnant women were assessed using the Pittsburgh Sleep Quality Index (PSQI) in early pregnancy. We explored the association between sleep and the risk of gestational diabetes mellitus using an unconditional binary logistic regression model. Different models were constructed to examine the robustness of the estimation by incorporating different confounding factors. Multivariable logistic regression revealed that sleep duration of more than 10 h among ART-pregnant women was significantly associated with the risk of GDM, and the association between sleep duration and gestational diabetes mellitus varied by maternal age. We found an increased risk of subsequent gestational diabetes mellitus with increasing sleep duration only in pregnant women aged <35 years. Additionally, no statistically significant association between sleep quality and gestational diabetes mellitus was found in this study. In conclusion, excessive sleep duration (≥10 h) is associated with a high risk of gestational diabetes mellitus in pregnant women who conceived with the help of assisted reproductive technology, and maternal age may modify this effect.

Inverse association between maternal serum concentrations of trace elements and risk of spontaneous preterm birth: a nested case-control study in China.

Few studies have evaluated the joint effect of trace elements on spontaneous preterm birth (SPTB). This study aimed to examine the relationships between the individual or mixed maternal serum concentrations of Fe, Cu, Zn, Se, Sr and Mo during pregnancy, and risk of SPTB. Inductively coupled plasma MS was employed to determine maternal serum concentrations of the six trace elements in 192 cases with SPTB and 282 controls with full-term delivery. Multivariate logistic regression, weighted quantile sum regression (WQSR) and Bayesian kernel machine regression (BKMR) were used to evaluate the individual and joint effects of trace elements on SPTB. The median concentrations of Sr and Mo were significantly higher in controls than in SPTB group (P < 0·05). In multivariate logistic regression analysis, compared with the lowest quartile levels of individual trace elements, the third- and fourth-quartile Sr or Mo concentrations were significantly associated with reduced risk of SPTB with adjusted OR (aOR) of 0·432 (95 CI < 0·05). In multivariate logistic regression analysis, compared with the lowest quartile levels of individual trace elements, the third- and fourth-quartile Sr or Mo concentrations were significantly associated with reduced risk of SPTB with adjusted aOR of 0·432 (95 % CI 0·247, 0·756), 0·386 (95 % CI 0·213, 0·701), 0·512 (95 % CI 0·297, 0·883) and 0·559 (95 % CI 0·321, 0·972), respectively. WQSR revealed the inverse combined effect of the trace elements mixture on SPTB (aOR = 0·368, 95 % CI 0·228, 0·593). BKMR analysis confirmed the overall mixture of the trace elements was inversely associated with the risk of SPTB, and the independent effect of Sr and Mo was significant. Our findings suggest that the risk of SPTB decreased with concentrations of the six trace elements, with Sr and Mo being the major contributors.

Maternal cardiovascular health in early pregnancy and the risk of congenital heart defects in offspring.

BACKGROUND: Congenital heart disease (CHD) is the predominant birth defect. This study aimed to explore the association between maternal cardiovascular health (CVH) and the CHD risk in offspring. METHODS: We used the prospective data from the Fujian Birth Cohort Study, collected from March 2019 to December 2022 on pregnant women within 14 weeks of gestation. Overall maternal CVH was assessed by seven CVH metrics (including physical activity, smoking, sleep duration, body mass index, blood pressure, total cholesterol, and fasting plasma glucose), with each metric classified as ideal, intermediate or poor with specific points. Participants were further allocated into high, moderate and low CVH categories based on the cumulative CVH score. The association with offspring CHD was determined with log-binominal regression models. RESULTS: A total of 19810 participants aged 29.7 (SD: 3.9) years were included, with 7846 (39.6%) classified as having high CVH, 10949 (55.3%) as having moderate CVH, and 1015 (5.1%) as having low CVH. The average offspring CHD rate was 2.52%, with rates of 2.35%, 2.52% and 3.84% across the high, moderate and low CVH categories, respectively (P = 0.02). Adjusted relative risks (RRs) of having offspring CHD were 0.64 (95% CI: 0.45-0.90, P = 0.001) for high CVH and 0.67 (95% CI: 0.48-0.93, P = 0.02) for moderate CVH compared to low CVH. For individual metrics, only ideal total cholesterol was significantly associated with lower offspring CHD (RR: 0.73, 95% CI: 0.59-0.83, P = 0.002). CONCLUSIONS: Pregnant women of high or moderate CVH categories in early pregnancy had reduced risks of CHD in offspring, compared to those of low CVH. It is important to monitor and improve CVH during pre-pregnancy counseling and early prenatal care.

The effects of different parity and delivery mode on wheezing disorders in the children-a retrospective cohort study in Fujian, China.

BACKGROUND: The relationship between childbirth delivery methods and the risk of wheezing in children remains controversial. Few studies have explored it under different maternal conditions. OBJECTIVE: To explore the influence of childbirth delivery method on the onset of wheezing in children of different parity. METHODS: A total of 21716 patients were included in this retrospective observational study. Multivariable logistic regression was used to analyze the relationship between childbirth delivery method and wheezing in children under 18 years of age in Fujian Province. RESULTS: Wheezing differed statistically based on the child's sex, age, season of onset, parity, jaundice history, and feeding patterns (P < 0.05). After adjusting for confounding factors, in cases of parity greater than two, the risk of wheezing in cesarean section deliveries was higher than that in vaginal deliveries (OR: 1.107; 95% CI 1.010-1.214). In girls with parity greater than two (OR: 1.179; 95% CI 1.003-1.387) and normal-weight infants with parity greater than two (OR: 1.106; 95% CI 1.003-1.220), the risk of wheezing in cesarean section deliveries was higher. The interaction term between the mode of childbirth and parity was significant in girls (P = 0.014). CONCLUSION: The method of childbirth delivery and parity are related to the risk of wheezing and may be relevant to gender and birth weight. Parity and gender have synergistic effects on wheezing.

Epidemiology of acute kidney injury in intensive care units in Beijing: the multi-center BAKIT study.

BACKGROUND: Acute kidney injury (AKI) commonly occurs in intensive care units (ICUs), leading to adverse clinical outcomes and increasing costs. However, there are limited epidemiological data of AKI in the critically ill in Beijing, China. METHODS: In this prospective cohort study in 30 ICUs, we screened the patients up to 10 days after ICU admission. Characteristics and outcomes were compared between AKI and non-AKI, renal replacement therapy (RRT) and non-RRT patients. Nomograms of logistic regression and Cox regression were performed to examine potential risk factors for AKI and mortality. RESULTS: A total of 3107 patients were included in the final analysis. The incidence of AKI was 51.0%; stages 1 to 3 accounted for 23.1, 11.8, and 15.7%, respectively. The majority (87.6%) of patients with AKI developed AKI on the first 4 days after admission to the ICU. A total of 281 patients were treated with RRT. Continuous RRT with predilution, citrate for anticoagulation and femoral vein for vascular access was the most common RRT pattern (29.9%, 84 of 281). Patients with AKI were associated with longer ICU-LOS and higher mortality and costs (P<0.001). In patients treated with RRT, 78.6 and 28.5% of RRTs were dependent on the 7th and 28th days, respectively. The 28 day mortalities of non-AKI, AKI stages 1-3, and septic shock patients were 6.83, 15.04, 27.99, 45.18 and 36.5%, respectively. CONCLUSIONS: Approximately half of our ICU patients experienced AKI. The majority of patients with AKI developed AKI during the first 4 days after admission to the ICU. Continuous RRT with predilution, citrate for anticoagulation and femoral vein for vascular access was the most common RRT pattern in our ICUs. AKI was associated with a higher mortality and costs, incomplete kidney recovery and s series of adverse outcomes.

Effects of air pollutants on occurrences of influenza-like illness and laboratory-confirmed influenza in Hefei, China.

Accumulating evidence suggests that air pollution is a risk factor for adverse respiratory and cardiovascular health outcomes. However, the different impacts of exposure to air pollutants on influenza virus activity and influenza-like illness (ILI) have not been well documented in epidemiological studies. We examined the association between air pollutants of particular matters < 2.5 µm (PM2.5), particular matters < 10 µm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and influenza occurrences in Hefei, China, from December 2013 to December 2015 by generalized Poisson additive regression models. The result suggested that PM2.5 and PM10 had similar effects on clinical ILI and influenza incidence. PM10 was negatively associated with clinical ILI (relative risk (RR) 0.980, 95% confidence interval (CI) 0.974-0.987), while PM2.5 were positively associated with clinical ILI (RR 1.040; 95% CI 1.032-1.049). RRs for the laboratory-confirmed cases of influenza were 0.813 (95% CI, 0.755-0.875) for PM10 and 1.216 (95% CI, 1.134-1.304) for PM2.5. Nevertheless, the impacts of SO2 and NO2 on ILI and influenza were distinct. SO2 had significant influence on laboratory-confirmed influenza and had no significant linear relationship with ILI. NO2 was negatively correlated with influenza but had no obvious effect on clinical ILI cases. The present study contributes novel evidence on understanding of the effects of various air pollutants on influenza activities, and these findings can be useful and important for the development of influenza surveillance and early warning systems.

Multiple MicroRNAs Ameliorate Hepatocyte Steatosis and Injury by Suppressing FABP1 Expression.

BACKGROUND/AIMS: Liver fatty acid-binding protein (FABP1) is a key regulator of hepatic lipid metabolism. MicroRNAs (miRNAs) are thought to be involved in nonalcoholic fatty liver disease (NAFLD), and the underlying mechanism is largely unclear. We investigated whether miRNAs influence hepatocyte steatosis by regulating the FABP1 gene. METHODS: Candidate FABP1-targeting miRNAs were evaluated using luciferase reporter assay. FABP1 expression was measured using western blotting and quantitative reverse transcription-PCR. Intracellular lipid accumulation was measured based on Oil Red O staining and intracellular triglyceride content. Hepatocyte injury was evaluated based on culture supernatant levels of alanine aminotransferase, aspartate aminotransferase, and intracellular adenosine triphosphate, and mitochondrial membrane potential. RESULTS: Dicer1 knockdown significantly elevated FABP1 expression. In total, 68 miRNAs potentially targeting FABP1 were selected; of these, miR-3941, miR-4517, and miR-4672 directly targeted the FABP1 3' untranslated region. Mimics of the three miRNAs substantially repressed FABP1 expression at translational level and led to HepG2 cell resistance to steatosis and cell injury induced by free fatty acids mixture, which rescue of FABP1 overexpression reversed. CONCLUSION: Our findings identify a novel mechanism by which miRNAs protect against hepatocyte steatosis and injury by downregulating FABP1 expression.

Hepatitis B Virus X Protein Induces Hepatic Steatosis by Enhancing the Expression of Liver Fatty Acid Binding Protein.

UNLABELLED: Hepatitis B virus (HBV) has been implicated as a potential trigger of hepatic steatosis although molecular mechanisms involved in the pathogenesis of HBV-associated hepatic steatosis still remain elusive. Our prior work has revealed that the expression level of liver fatty acid binding protein 1 (FABP1), a key regulator of hepatic lipid metabolism, was elevated in HBV-producing hepatoma cells. In this study, the effects of HBV X protein (HBx) mediated FABP1 regulation on hepatic steatosis and the underlying mechanism were determined. mRNA and protein levels of FABP1 were measured by quantitative RT-PCR (qPCR) and Western blotting. HBx-mediated FABP1 regulation was evaluated by luciferase assay, coimmunoprecipitation, and chromatin immunoprecipitation. Hepatic lipid accumulation was measured by using Oil-Red-O staining and the triglyceride level. It was found that expression of FABP1 was increased in HBV-producing hepatoma cells, the sera of HBV-infected patients, and the sera and liver tissues of HBV-transgenic mice. Ectopic overexpression of HBx resulted in upregulation of FABP1 in HBx-expressing hepatoma cells, whereas HBx abolishment reduced FABP1 expression. Mechanistically, HBx activated the FABP1 promoter in an HNF3ß-, C/EBPα-, and PPARα-dependent manner, in which HBx increased the gene expression of HNF3ß and physically interacted with C/EBPα and PPARα. On the other hand, knockdown of FABP1 remarkably blocked lipid accumulation both in long-chain free fatty acids treated HBx-expressing HepG2 cells and in a high-fat diet-fed HBx-transgenic mice. Therefore, FABP1 is a key driver gene in HBx-induced hepatic lipid accumulation via regulation of HNF3ß, C/EBPα, and PPARα. FABP1 may represent a novel target for treatment of HBV-associated hepatic steatosis. IMPORTANCE: Accumulating evidence from epidemiological and experimental studies has indicated that chronic HBV infection is associated with hepatic steatosis. However, the molecular mechanism underlying HBV-induced pathogenesis of hepatic steatosis still remains to be elucidated. In this study, we found that expression of liver fatty acid binding protein (FABP1) was dramatically increased in the sera of HBV-infected patients and in both sera and liver tissues of HBV-transgenic mice. Forced expression of HBx led to FABP1 upregulation, whereas knockdown of FABP1 remarkably diminished lipid accumulation in both in vitro and in vivo models. It is possible that HBx promotes hepatic lipid accumulation through upregulating FABP1 in the development of HBV-induced nonalcoholic fatty liver disease. Therefore, inhibition of FABP1 might have therapeutic value in steatosis-associated chronic HBV infection.

Could remifentanil reduce duration of mechanical ventilation in comparison with other opioids for mechanically ventilated patients? A systematic review and meta-analysis.

BACKGROUND: Sedation and analgesia are commonly required to relieve anxiety and pain in mechanically ventilated patients. Fentanyl and morphine are the most frequently used opioids. Remifentanil is a selective µ-opioid receptor that is metabolized by unspecific esterases and eliminated independently of liver or renal function. Remifentanil has a rapid onset and offset and a short context-sensitive half-life regardless of the duration of infusion, which may lead to reductions in weaning and extubation. We aimed to compare the efficacy and safety of remifentanil to that of other opioids in mechanically ventilated patients. METHODS: We conducted a search to identify relevant randomized controlled studies (RCTs) in the PubMed, Embase, Cochrane Library and SinoMed databases that had been published up to 31 December 2016. The results were analysed using weighted mean differences (WMDs) and 95% confidence intervals (CIs). RESULTS: Twenty-three RCTs with 1905 patients were included. Remifentanil was associated with reductions in the duration of mechanical ventilation (mean difference -1.46; 95% CI -2.44 to -0.49), time to extubation after sedation cessation (mean difference -1.02; 95% CI -1.59 to -0.46), and ICU-LOS (mean difference -0.10; 95% CI -0.16 to -0.03). No significant differences were identified in hospital-LOS (mean difference -0.05; 95% CI -0.25 to 0.15), costs (mean difference -709.71; 95% CI -1590.98 to 171.55; I2 88%), mortality (mean difference -0.64; 95% CI -1.33 to 0.06; I2 87%) or agitation (mean difference -0.71; 95% CI -1.80 to 0.37; I2 93%). CONCLUSIONS: Remifentanil seems to be associated with reductions in the duration of mechanical ventilation, time to extubation after cessation of sedation, and ICU-LOS. No significant differences were identified between remifentanil and other opioids in terms of hospital-LOS, costs, mortality or agitation.

Association between lipid profile in early pregnancy and the risk of congenital heart disease in offspring: a prospective cohort study.

This study aimed to investigate the association of lipid profile in early pregnancy and the risk of congenital heart disease (CHD) in offspring. This study was a prospective cohort design based on the Fujian Birth Cohort Study in China. We recruited pregnant women at ≤ 14 weeks of gestation between 2019 and 2022, and all participants in this study filled out the questionnaire about periconceptional exposure. Simultaneously, we collected participants' fasting blood samples to measure their lipid profile by automatic biochemical analyzer. The outcome was defined as offspring with CHD. A multivariable logistic regression model was used to calculate adjusted odds ratio (AOR) risk estimates, which indicate the associations between maternal lipid profiles and CHD in offspring. Restricted cubic splines were used to estimate their nonlinear relationship. A total of 21,425 pregnant women with an average gestational age of 11.3 (± 1.40) weeks were included in the analysis. The higher triglyceride (AOR 1.201, 95% CI [1.036, 1.394]), low-density lipoprotein (AOR 1.216, 95% CI [1.048, 1.410]), apolipoprotein B (Apo B) (AOR 2.107, 95% CI [1.179, 3.763]) levels were correlated with increased odds of CHD in offspring, while high-density lipoprotein (OR 0.672, 95% CI [0.490, 0.920]) related with decreased odds of CHD in offspring. The restricted cubic spline suggested a nonlinear relationship between total cholesterol (TC) levels and the risk of CHD in offspring (P = 0.0048), but no significant nonlinear relationships were found in other lipid profile. Apolipoprotein A was not related to the risk of CHD in offspring as either a continuous variable or a hierarchical variable. Elevated lipid profile in early pregnancy levels are associated with an increased risk of CHD in offspring. Additionally, there is a non-linear relationship between TC levels and the risk of CHD in offspring.

Precursor-Led Grain Boundary Engineering for Superior Thermoelectric Performance in Niobium Strontium Titanate.

We present a novel method to significantly enhance the thermoelectric performance of ceramics in the model system SrTi0.85Nb0.15O3 through the use of the precursor ammonium tetrathiomolybdate (0.5-2% w/w additions). After sintering the precursor-infused green body at 1700 K for 24 h in 5% H2/Ar, single-crystal-like electron transport behavior developed with electrical conductivity reaching ∼3000 S/cm at ∼300 K, almost a magnitude higher than that in the control sample. During processing, the precursor transformed into MoS2, then into MoOx, and finally into Mo particles. This limited grain growth promoted secondary phase generation but importantly helped to reduce the grain boundary barriers. Samples prepared with additions of the precursor exhibited vastly increased electrical conductivity, without significant impact on Seebeck coefficients giving rise to high power factor values of 1760 µW/mK2 at ∼300 K and a maximum thermoelectric figure-of-merit zT of 0.24 at 823 K. This processing strategy provides a simple method to achieve high charge mobility in polycrystalline titanate and related materials and with the potential to create "phonon-glass-electron-crystal" oxide thermoelectric materials.

Methionine restriction constrains lipoylation and activates mitochondria for nitrogenic synthesis of amino acids.

Methionine restriction (MR) provides metabolic benefits in many organisms. However, mechanisms underlying the MR-induced effect remain incompletely understood. Here, we show in the budding yeast S. cerevisiae that MR relays a signal of S-adenosylmethionine (SAM) deprivation to adapt bioenergetic mitochondria to nitrogenic anabolism. In particular, decreases in cellular SAM constrain lipoate metabolism and protein lipoylation required for the operation of the tricarboxylic acid (TCA) cycle in the mitochondria, leading to incomplete glucose oxidation with an exit of acetyl-CoA and α-ketoglutarate from the TCA cycle to the syntheses of amino acids, such as arginine and leucine. This mitochondrial response achieves a trade-off between energy metabolism and nitrogenic anabolism, which serves as an effector mechanism promoting cell survival under MR.

An analysis of risk factors associated with recurrent wheezing in the pediatric population.

BACKGROUND: Recurrent wheezing is a common clinical problem in early childhood, which is associated with significant morbidity. There is no international consensus on the management and prevention of recurrent wheezing; therefore, identifying the risk factors associated with recurrent wheezing is crucial to prevent episodes of wheezing in young children. METHODS: In this retrospective study, we collected the data of 24,737 patients who were admitted to our hospital between 27th April 2012 and 11th September 2019. After screening for patients with wheezing, we identified 8572 patients with a primary diagnosis of pneumonia with wheezing. Patients' clinical data were collected from the hospital medical records. Patients were stratified for age in the groups of < 6 months, 6-12 months, and > 12 months. RESULTS: Among the 8569 pediatric pneumonia patients with wheezing, there were 343 patients with recurrent wheezing. Most enrolled patients were under 6 months of age (45.17%) and had a normal birth weight (86.95%). Winter was the most common onset season for the first episode of wheezing, while spring was the most common season for the second episode of wheezing for those with recurrent wheezing. The univariate and multivariate logistic regression analysis for the risk factor associated with recurrent wheezing showed that male gender, past history of respiratory and cardiovascular diseases, low birth weight, development of severe pneumonia, and PICU admission were significantly associated with recurrent wheezing. CONCLUSION: Male gender, past history of respiratory and cardiovascular diseases, low birth weight, severe pneumonia, and PICU admission are independent risk factors of recurrent wheezing in the pediatric population.

Trajectories of maternal D-dimer are associated with the risk of developing adverse maternal and perinatal outcomes: A prospective birth cohort study.

OBJECTIVE: To assess the relationships of maternal D-dimer trajectories with the risk of developing adverse maternal and perinatal outcomes (AMPOs). METHODS: A prospective birth cohort study was conducted in China, and 7,095 women who had singleton birth were included. The latent class growth model was used to determine the maternal D-dimer trajectory. RESULTS: Three maternal D-dimer trajectories were identified: (1) slight increase (43.6%), (2) rapid rise (51.3%), (3) sustained high (5.1%). Compared to pregnant women with a slight increase in D-dimer trajectory, the risk of gestational diabetes mellitus, placenta previa, macrosomia, large for gestational age (LGA), and increased postpartum bleeding was significantly increased in those with a rapid rise trajectory (adjusted OR = 1.22, 2.00, 1.80, and 1.56, adjusted ß = 15.92 âˆ¼ 25.1 ml, respectively, P < 0.05), and women with a sustained high trajectory also demonstrated a relatively elevated risk of macrosomia and LGA (adjusted OR = 2.11 and 1.82, respectively, P < 0.05). While the odds of pregnancy-induced hypertension, low birth weight, and small for gestational age in pregnant women with the rapid rise D-dimer trajectory and fetal distress in those with sustained high trajectory exhibited a reduction (adjusted OR = 0.62, 0.38, 0.54, and 0.64, respectively, P < 0.05). CONCLUSION: This study highlights the influence of inappropriate maternal D-dimer trajectories on the risk of AMPOs.

Increased axonal mitochondrial mobility does not slow amyotrophic lateral sclerosis (ALS)-like disease in mutant SOD1 mice.

Reduced axonal mitochondrial transport has been observed in major neurodegenerative diseases, including fALS patients and SOD1(G93A) mice. However, it is unclear whether this defect plays a critical role in axonal degeneration or simply reflects sequelae of general transport alteration. Using genetic mouse models combined with time-lapse imaging of live neurons, we previously discovered that axon-targeted syntaphilin (SNPH) acts as a docking receptor specific for axonal mitochondria. Deletion of the snph gene in mice results in a substantially higher proportion of axonal mitochondria in the mobile state without any effect on the transport of other axonal organelles. Here we address whether increased (rescued) axonal mitochondrial mobility changes the disease course by crossing fALS-linked transgenic SOD1(G93A) and snph(-/-) knock-out mice. We found that a 2-fold increase in axonal mitochondrial mobility in SOD1(G93A)/snph(-/-) mice did not affect the onset of ALS-like symptoms. Both SOD1(G93A) and SOD1(G93A)/snph(-/-) mice exhibit similar weight loss, deterioration in motor function and motor neuron loss, significant gliosis, and a lifespan of 152-154 days. Thus, for the first time, our study provides genetic and pathological evidence that the impairment of mitochondrial transport seen in SOD1(G93A) mice plays a minimal role in the rapid-onset of fALS-linked pathology.

Reciprocal regulation of phosphatidylcholine synthesis and H3K36 methylation programs metabolic adaptation.

Phospholipid biosynthesis plays a role in mediating membrane-to-histone communication that influences metabolic decisions. Upon nutrient deprivation, phospholipid methylation generates a starvation signal in the form of S-adenosylmethionine (SAM) depletion, leading to dynamic changes in histone methylation. Here we show that the SAM-responsive methylation of H3K36 is critical for metabolic adaptation to nutrient starvation in the budding yeast Saccharomyces cerevisiae. We find that mutants deficient in H3K36 methylation exhibit defects in membrane integrity and pyrimidine metabolism and lose viability quickly under starvation. Adjusting the synthesis of phospholipids potently rewires metabolic pathways for nucleotide synthesis and boosts the production of antioxidants, ameliorating the defects resulting from the loss of H3K36 methylation. We further demonstrate that H3K36 methylation reciprocally regulates phospholipid synthesis by influencing redox balance. Our study illustrates an adaptive mechanism whereby phospholipid synthesis entails a histone modification to reprogram metabolism for adaptation in a eukaryotic model organism.

Nitrogen balance and outcomes in critically ill patients: A systematic review and meta-analysis.

Objective: Nitrogen balance (NB) is a commonly used nutrition indicator in clinical practice, while its relation to the interpretation of protein malnutrition and outcomes in critically ill patients remains unclear. This study aimed to evaluate the impact of NB on prognosis in such a patient population. Methods: We searched for relevant studies in PubMed, EMBASE, and the Cochrane Database up to May 10, 2022. Meta-analyses were performed to evaluate the relationship between NB (initial, final, or absolute change of NB levels) and prognosis and important clinical outcomes in critically ill patients. Pooled odds ratios (ORs) and mean differences (MDs) together with their 95% confidence intervals (CIs) were calculated. We also conducted subgroup analyses to explore the sources of heterogeneity. Results: Eight studies with 1,409 patients were eligible. These studies were moderate to high quality. When pooled, the initial NB was comparable between the survival and non-survival groups (five studies, MD 1.20, 95% CI, -0.70 to 3.11, I 2 = 77%; P = 0.22), while a significantly higher final NB in the survival group than that in the death group (two studies, MD 3.69, 95% CI, 1.92-5.46, I 2 = 55%; P < 0.0001). Two studies provided the absolute change of NB over time and suggested survival patients had more increased NB (MD 4.16 g/day, 95% CI, 3.70-4.61, I 2 = 0%; P < 0.00001). Similarly, for studies utilizing multivariate logistic regression, we found an improved NB (four studies, OR 0.85, 95% CI, 0.73-0.99, I 2 = 61%; P = 0.04) but not an initial NB (two studies, OR 0.92, 95% CI 0.78-1.08, I 2 = 55%; P = 0.31) was significantly associated the risk of all-cause mortality. These results were further confirmed in subgroup analyses. In addition, patients with improved NB had more protein and calorie intake and a similar length of stay in hospital than those without. Conclusions: Our results suggested that an improved NB but not the initial NB level was associated with all-cause mortality in critically ill patients. This highlights the requirement for dynamic monitoring of NB during nutrition treatment. Further randomized clinical trials examining the impact of NB-guided protein intake on clinical outcomes in critically ill patients are warranted. Systematic review registration: INPLASY202250134, https://doi.org/10.37766/inplasy2022.5.0134.