Case report: Whole exome sequencing identified a novel mutation (p.Y301H) of MAF in a Chinese family with congenital cataracts.

Background: Congenital cataracts stand as the primary cause of childhood blindness globally, characterized by clouding of the eye's lens at birth or shortly thereafter. Previous investigations have unveiled that a variant in the V-MAF avian musculoaponeurotic-fibrosarcoma oncogene homolog (MAF) gene can result in Ayme-Gripp syndrome and solitary cataract. Notably, MAF mutations have been infrequently reported in recent years. Methods: In this investigation, we recruited a Chinese family with non-syndromic cataracts. Whole exome sequencing and Sanger sequencing were applied to scrutinize the genetic anomaly within the family. Results: Through whole exome sequencing and subsequent data filtration, a new mutation (NM_005360, c.901T>C/p.Y301H) in the MAF gene was detected. Sanger sequencing validated the presence of this mutation in another affected individual. The p.Y301H mutation, situated in an evolutionarily preserved locus, was not detected in our 200 local control cohorts and various public databases. Additionally, multiple bioinformatic programs predicted that the mutation was deleterious and disrupted the bindings between MAF and its targets. Conclusion: Hence, we have documented a new MAF mutation within a Chinese family exhibiting isolated congenital cataracts. Our study has the potential to broaden the spectrum of MAF mutations, offering insights into the mechanisms underlying cataract formation and facilitating genetic counseling and early diagnosis for congenital cataract patients.

miR-29b-1-5p exacerbates myocardial injury induced by sepsis in a mouse model by targeting TERF2.

Myocardial damage is a critical complication and a significant contributor to mortality in sepsis. MicroRNAs (miRNAs) have emerged as key players in sepsis pathogenesis. In this study, we explore the effect and mechanisms of miR-29b-1-5p on sepsis-induced myocardial damage. Sepsis-associated Gene Expression Omnibus datasets (GSE72380 and GSE29914) are examined for differential miRNAs. The mouse sepsis-induced cardiac injury was established by Lipopolysaccharide (LPS) or cecal ligation and puncture (CLP). LPS-treated HL-1 mouse cardiomyocytes simulate myocardial injury in vitro. miR-29b-1-5p is co-upregulated in both datasets and in cardiac tissue from sepsis mouse and HL-1 cell models. miR-29b-1-5p expression downregulation was achieved by antagomir transduction and confirmed by real-time quantitative reverse transcription PCR. Survival analysis and echocardiography examination show that miR-29b-1-5p inhibition improves mice survival cardiac function in LPS- and CLP-induced sepsis mice. Hematoxylin and eosin and Masson's trichrome staining and Immunohistochemistry analysis of mouse myocardial α-smooth muscle actin show that miR-29b-1-5p inhibition reduces myocardial tissue injury and fibrosis. The inflammatory cytokines and cardiac troponin I (cTnI) levels in mouse serum and HL-1 cells are also decreased by miR-29b-1-5p inhibition, as revealed by enzyme-linked immunosorbent assay. The expressions of autophagy-lysosomal pathway-related and apoptosis-related proteins in the mouse cardiac tissues and HL-1 cells are evaluated by western blot analysis. The sepsis-induced activation of the autophagy-lysosomal pathway and apoptosis are also reversed by miR-29b-1-5p antagomir. MTT and flow cytometry measurement further confirm the protective role of miR-29b-1-5p antagomir in HL-1 cells by increasing cell viability and suppressing cell apoptosis. Metascape functionally enriches TargetScan-predicted miR-29b-1-5p target genes. TargetScan prediction and dual luciferase assay validate the targeting relationship between miR-29b-1-5p and telomeric repeat-binding factor 2 (TERF2). The expression and function of TERF2 in HL-1 cells and mice are also evaluated. MiR-29b-1-5p negatively regulates the target gene TERF2. TERF2 knockdown partly restores miR-29b-1-5p antagomir function in LPS-stimulated HL-1 cells. In summary, miR-29b-1-5p targetedly inhibits TERF2, thereby enhancing sepsis-induced myocardial injury.

Whole-exome sequencing detected a novel AIFM1 variant in a Han-Chinese family with Cowchock syndrome.

Charcot-Marie-Tooth disease(CMT) is a hereditary peripheral neuropathy, characterized by progressive distal hypoesthesia and amyotrophia. CMT is characterized by an X- linked recessive inheritance pattern. The apoptosis-inducing factor mitochondria associated-1 (AIFM1) is the main pathogenic gene of the X-linked recessive Charcot-Marie-Tooth disease-4 with or without cerebellar ataxia (CMTX4), also known as Cowchock syndrome. In this study, we enrolled a family with CMTX from the southeast region of China and identified a novel AIFM1 variant (NM_004208.3: c.931C>G; p.L311V) using whole exon sequencing technology. The results of our study may also be useful for genetic counseling, embryo screening of in vitro fertilization embryos, and prenatal genetic diagnosis.

Silencing MYOT Expression May Inhibit Autophagy in Human Skeletal Muscle Cells.

Muscle diseases are closely related to autophagy disorders. Studies of autophagy inhibition indicated the importance of autophagy in muscle regeneration, while activation of autophagy can restore muscle function in some myopathies. Previous studies have revealed that mutations in the MYOT gene may lead to several kinds of hereditary myopathies. However, whether the autophagy played a crucial role in hereditary myopathy caused by MYOT mutations was still not clear. In this study, we established the MYOT knockdown human skeletal muscle cell models (HSkMCs) by small interfering RNA. Real-time PCR and Western blot studies found that the expression of p62 and LC3B-II was decreased dramatically, which suggested that silencing MYOT expression may regulate the autophagy in HSkMCs. Further immunofluorescence study on Ad-mCherry-GFP-LC3B adenovirus transfection and monodansylcadaverine (MDC) staining revealed that knocking down the expression of MYOT may inhibit the autophagy. Next, we used the autophagy inducer Earle's balanced salt solution (EBSS) and late-autophagy inhibitor bafilomycin A1 (BAF A1) to treat the HSkMCs, respectively, and found that silencing MYOT expression can inhibit the activation of autophagy by EBSS and aggravate the inhibition of autophagy by BAF A1. Finally, we also found that silencing MYOT expression can downregulate the expression of ATG7 and ATG5, two important autophagy regulatory molecules. Hence, our study may first reveal that knocking down the expression of MYOT may inhibit the autophagy. Hereditary myopathies caused by MYOT mutations may partly result from the inhibition of autophagy in HSkMCs.

Glutamatergic neurons in the paraventricular hypothalamic nucleus regulate isoflurane anesthesia in mice.

The glutamatergic-mediated excitatory system in the brain is vital for the regulation of sleep-wake and general anesthesia. Specifically, the paraventricular hypothalamic nucleus (PVH), which contains mainly glutamatergic neurons, has been shown to play a critical role in sleep-wake. Here, we sought to explore whether the PVH glutamatergic neurons have an important effect on the process of general anesthesia. We used c-fos staining and in vivo calcium signal recording to observe the activity changes of the PVH glutamatergic neurons during isoflurane anesthesia and found that both c-fos expression in the PVH and the calcium activity of PVH glutamatergic neurons decreased in isoflurane anesthesia and significantly increased during the recovery process. Chemogenetic activation of PVH glutamatergic neurons prolonged induction time and shortened emergence time from anesthesia by decreasing the depth of anesthesia. Using chemogenetic inhibition of PVH glutamatergic neurons under isoflurane anesthesia, we found that inhibition of PVH glutamatergic neurons facilitated the induction process and delayed the emergence accompanied by deepening the depth of anesthesia. Together, these results identify a crucial role for PVH glutamatergic neurons in modulating isoflurane anesthesia.

A de novo mutation (p.S1419F) of Retinoic acid induced 1 is responsible for a patient with Smith-Magenis syndrome exhibiting schizophrenia.

Smith-Magenis syndrome (SMS, OMIM# 182290) is a rare congenital disorder which characterized by multiple abnormalities involving in craniofacial, skeletal, otorhinolaryngolocial, neurological, behavioral and others. 17p11.2 microdeletion and RAI1 mutations have been proven to be genetic lesions of this disease. However, the relationship between RAI1 variants and different phenotypes is still unclear. The discoveries of more RAI1 mutations in patients with different phenotypes will help to elucidate the pathogenesis of the RAI1 gene. Here, we describe a young patient with schizophrenia and headache as the main clinical presentation, with SMS-like features including depression, sleep disturbance and pain-free status. Whole exome sequencing and Sanger sequencing suggested that a de novo mutation (NM_030665.3: c.4256C > T/p.S1419F) of RAI1 may be the genetic lesion of the patient. The bioinformatic program predicted that the new mutation (p.S1419F), located in an evolutionarily conserved site of RAI1, was deleterious. Further, western blot analysis suggested that the novel mutation may decrease the protein levels of RAI1 in the patient. Hence, we reported a novel mutation of RAI1 in a patient with SMS, schizophrenia and headache. Our study may expand the spectrum of RAI1 mutations which may further contribute to the mechanisms underlying SMS, schizophrenia and headache.