Arsenic disturbs neural tube closure involving AMPK/PKB-mTORC1-mediated autophagy in mice.

Arsenic exposure is a significant risk factor for folate-resistant neural tube defects (NTDs), but the potential mechanism is unclear. In this study, a mouse model of arsenic-induced NTDs was established to investigate how arsenic affects early neurogenesis leading to malformations. The results showed that in utero exposure to arsenic caused a decline in the normal embryos, an elevated embryo resorption, and a higher incidence of malformed embryos. Cranial and spinal deformities were the main malformation phenotypes observed. Meanwhile, arsenic-induced NTDs were accompanied by an oxidant/antioxidant imbalance manifested by elevated levels of reactive oxygen species (ROS) and decreased antioxidant activities. In addition, changes in the expression of autophagy-related genes and proteins (ULK1, Atg5, LC3B, p62) as well as an increase in autophagosomes were observed in arsenic-induced aberrant brain vesicles. Also, the components of the upstream pathway regulating autophagy (AMPK, PKB, mTOR, Raptor) were altered accordingly after arsenic exposure. Collectively, our findings propose a mechanism for arsenic-induced NTDs involving AMPK/PKB-mTORC1-mediated autophagy. Blocking autophagic cell death due to excessive autophagy provides a novel strategy for the prevention of folate-resistant NTDs, especially for arsenic-exposed populations.

Pharmacokinetics, Pharmacodynamics, and Safety of Single Dose HSK7653 Tablets in Chinese Subjects with Normal or Impaired Renal Function.

OBJECTIVE: HSK7653 is a novel, ultralong-acting dipeptidyl peptidase-4 (DPP-4) inhibitor, promising for type 2 diabetes mellitus with a dosing regimen of once every 2 weeks. This trial investigates the pharmacokinetics (PKs), pharmacodynamics (PDs),and safety of HSK7653 in outpatients with normal or impaired renal function. METHODS: This is a multicenter, open-label, nonrandomized, parallel-controlled phase I clinical study that investigates the pharmacokinetic profiles of HSK7653 after a single oral administration in 42 subjects with mild (n = 8), moderate (n = 10), severe renal impairment (n = 10), and end-stage renal disease (without dialysis, n = 5) compared with matched control subjects with normal renal function (n = 9). Safety was evaluated throughout the study, and the pharmacodynamic effects were assessed on the basis of a DPP-4 inhibition rate. RESULTS: HSK7653 exposure levels including the maximum plasma concentration (Cmax), area under the plasma concentration-time curve from zero to last time of quantifiable concentration (AUC0-t), and area under the plasma concentration-time curve from zero to infinity (AUC0-inf) showed no significant differences related to the severity of renal impairment. Renal clearance (CLR) showed a certain downtrend along with the severity of renal impairment. The CLR of the group with severe renal impairment and the group with end-stage renal disease were basically similar. The DPP-4 inhibition rate-time curve graph was similar among the renal function groups. All groups had favorable safety, and no serious adverse events occurred. CONCLUSIONS: HSK7653 is a potent oral DPP-4 inhibitor with a long plasma half-life, supporting a dosing regimen of once every 2 weeks. Impaired renal function does not appear to impact the pharmacokinetic and pharmacodynamic properties of HSK7653 after a single administration in Chinese subjects. HSK7653 is also well tolerated without an increase in adverse events with increasing renal impairment. These results indicate that dose adjustment of HSK7653 may not be required in patients with renal impairment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05497297.

Arsenic interferes with spermatogenesis involving Rictor/mTORC2-mediated blood-testis barrier disruption in mice.

Ingestion of arsenic interferes with spermatogenesis and increases the risk of male infertility, but the underlying mechanism remines unclear. In this study, we investigated spermatogenic injury with a focus on blood-testis barrier (BTB) disruption by administrating 5 mg/L and 15 mg/L arsenic orally to adult male mice for 60 d. Our results showed that arsenic exposure reduced sperm quality, altered testicular architecture, and impaired Sertoli cell junctions at the BTB. Analysis of BTB junctional proteins revealed that arsenic intake downregulated Claudin-11 expression and increased protein levels of ß-catenin, N-cadherin, and Connexin-43. Aberrant localization of these membrane proteins was also observed in arsenic-treated mice. Meanwhile, arsenic exposure altered the components of Rictor/mTORC2 pathway in mouse testis, including inhibition of Rictor expression, reduced phosphorylation of protein kinase Cα (PKCα) and protein kinase B (PKB), and elevated matrix metalloproteinase-9 (MMP-9) levels. Furthermore, arsenic also induced testicular lipid peroxidative damage, inhibited antioxidant enzyme (T-SOD) activity, and caused glutathione (GSH) depletion. Our findings suggest that disruption of BTB integrity is one of the main factors responsible for the decline in sperm quality caused by arsenic. PKCα-mediated rearrangement of actin filaments and PKB/MMP-9-increased barrier permeability jointly contribute to arsenic-induced BTB disruption.

Comparison of long-term outcomes of young patients after a coronary event associated with familial hypercholesterolemia.

OBJECTIVE: Familial hypercholesterolemia (FH) is an important cause of premature coronary artery disease (CAD). Prognosis data are lacking in patients with FH and coronary artery disease particularly in the era of widespread statin use. We compared long-term prognosis between patients with and without FH after a coronary event. METHODS: In this retrospective study, 865 patients younger than 40 years of age with CAD were enrolled. FH was diagnosed based on the Dutch Lipid Clinic Network algorithm. Baseline characteristics, coronary angiographic findings and prognosis during median follow-up of 5 (3-8) years were compared between patients with or without FH. RESULTS: Definite or probable FH was detected in 37 patients (4.3%) and possible FH in 259 patients (29.9%). FH was associated with significantly higher prevalence of multi-vessel lesions (p < 0.001) and higher Gensini score (p = 0.008). In the subset of 706 patients for whom follow-up data were available, 127 (18.0%) suffered major adverse cardiovascular and cerebrovascular events (MACCE). FH was associated with increased risk of MACCE, independently of age, sex, smoking, body mass index, hypertension or diabetes mellitus (HR = 2.30, 95%CI = 1.09 to 4.84, p = 0.028). CONCLUSIONS: FH is an independent risk factor for MACCE in young patients after a coronary event during long-term follow-up. It is necessary to optimize lipid treatment of patients with FH after a coronary event.