Mechanosensitive channels TMEM63A and TMEM63B mediate lung inflation-induced surfactant secretion.

Pulmonary surfactant is a lipoprotein complex lining the alveolar surface to decrease the surface tension and facilitate inspiration. Surfactant deficiency is often seen in premature infants and in children and adults with respiratory distress syndrome. Mechanical stretch of alveolar type 2 epithelial (AT2) cells during lung expansion is the primary physiological factor that stimulates surfactant secretion; however, it is unclear whether there is a mechanosensor dedicated to this process. Here, we show that loss of the mechanosensitive channels TMEM63A and TMEM63B (TMEM63A/B) resulted in atelectasis and respiratory failure in mice due to a deficit of surfactant secretion. TMEM63A/B were predominantly localized at the limiting membrane of the lamellar body (LB), a lysosome-related organelle that stores pulmonary surfactant and ATP in AT2 cells. Activation of TMEM63A/B channels during cell stretch facilitated the release of surfactant and ATP from LBs fused with the plasma membrane. The released ATP evoked Ca2+ signaling in AT2 cells and potentiated exocytic fusion of more LBs. Our study uncovered a vital physiological function of TMEM63 mechanosensitive channels in preparing the lungs for the first breath at birth and maintaining respiration throughout life.

Death-seq identifies regulators of cell death and senolytic therapies.

Selectively ablating damaged cells is an evolving therapeutic approach for age-related disease. Current methods for genome-wide screens to identify genes whose deletion might promote the death of damaged or senescent cells are generally underpowered because of the short timescales of cell death as well as the difficulty of scaling non-dividing cells. Here, we establish "Death-seq," a positive-selection CRISPR screen optimized to identify enhancers and mechanisms of cell death. Our screens identified synergistic enhancers of cell death induced by the known senolytic ABT-263. The screen also identified inducers of cell death and senescent cell clearance in models of age-related diseases by a related compound, ABT-199, which alone is not senolytic but exhibits less toxicity than ABT-263. Death-seq enables the systematic screening of cell death pathways to uncover molecular mechanisms of regulated cell death subroutines and identifies drug targets for the treatment of diverse pathological states such as senescence, cancer, and fibrosis.

Malnutrition and visceral obesity predicted adverse short-term and long-term outcomes in patients undergoing proctectomy for rectal cancer.

BACKGROUND: To the best of our knowledge, no previous studies have explored the relationship between visceral obesity and malnutrition. Therefore, this study has aimed to investigate the association between them in patients with rectal cancer. METHODS: Patients with rectal cancer who underwent proctectomy were included. Malnutrition was defined according to the Global Leadership Initiative on Malnutrition (GLIM). Visceral obesity was measured using computed tomography (CT). The patients were classified into four groups according to the presence of malnutrition or visceral obesity. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors for postoperative complications. Univariate and multivariate cox regression analyses were performed to evaluate the risk factors for overall survival (OS) and cancer-specific survival (CSS). Kaplan-Meier survival curves and log-rank tests were performed for the four groups. RESULTS: This study enrolled 624 patients. 204 (32.7%) patients were included in the well-nourished non-visceral obesity (WN) group, 264 (42.3%) patients were included in the well-nourished visceral obesity (WO) group, 114 (18.3%) patients were included in the malnourished non-visceral obesity (MN) group, and 42 (6.7%) patients were included in the malnourished visceral obesity (MO) group. In the multivariate logistic regression analysis, the Charlson comorbidity index (CCI), MN, and MO were associated with postoperative complications. In the multivariate cox regression analysis, age, American Society of Anesthesiologists (ASA) score, tumor differentiation, tumor node metastasis (TNM), and MO were associated with worsened OS and CSS. CONCLUSIONS: This study demonstrated that the combination of visceral obesity and malnutrition resulted in higher postoperative complication and mortality rates and was a good indicator of poor prognosis in patients with rectal cancer.

Case report: Muscle involvement in a Chinese patient with TRNT1-related disorder.

The TRNT1 gene encodes tRNA nucleotidyltransferase 1, which catalyzes the addition of cytosine-cytosine-adenosine (CCA) to the ends of cytoplasmic and mitochondrial tRNAs. The most common clinical phenotype associated with TRNT1 is autosomal recessive sideroblastic anemia with B-cell immunodeficiency, periodic fever, and developmental delay (SIFD). Muscle involvement has rarely been reported in TRNT1-related disorders. Here we report a Chinese patient with incomplete SIFD and hyperCKemia, and explored the skeletal muscle pathological changes. The patient was a 3-year-old boy with sensorineural hearing loss, sideroblastic anemia, and developmental delay since infancy. At the age of 11 months, significantly increased levels of creatine kinase were noted, accompanied by mild muscle weakness. Whole-exome sequencing revealed compound heterozygous variants of the TRNT1 gene, c.443C > T (p.Ala148Val) and c.692C > G (p.Ala231Gly), in the patient. Western blot showed a decreased expression of TRNT1 and cytochrome c oxidase subunit IV (COX IV) in the skeletal muscle of the patient. Electron microscopy observation of skeletal muscle pathology revealed abnormal mitochondria of various sizes and shapes, supporting a diagnosis of mitochondrial myopathy. The present case indicates that in addition to the classic SIFD phenotype, TRNT1 mutations can cause mitochondrial myopathy, a rare clinical phenotype of TRNT1-related disorders.

The influence of three-dimensional structure on naïve T cell homeostasis and aging.

A breakdown in cellular homeostasis is thought to drive naïve T cell aging, however the link between naïve T cell homeostasis and aging in humans is poorly understood. To better address this, we developed a lymphoid organoid system that maintains resting naïve T cells for more than 2 weeks, in conjunction with high CD45RA expression. Deep phenotypic characterization of naïve T cells across age identified reduced CD45RA density as a hallmark of aging. A conversion from CD45RAhigh naive cells to a CD45RAlow phenotype was reproduced within our organoid system by structural breakdown, but not by stromal cell aging or reduced lymphocyte density, and mediated by alternative CD45 splicing. Together, these data suggest that external influences within the lymph node microenvironment may cause phenotypic conversion of naïve T cells in older adults.

Design, Synthesis and Structure-Activity Relationship Studies of Meridianin Derivatives as Novel JAK/STAT3 Signaling Inhibitors.

Hyperactivation of Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling is an attractive therapeutic target for tumor therapy. Herein, forty-eight novel meridianin derivatives were designed and synthesized, and their antitumor activity was evaluated in vitro both for activity optimization and structure-activity relationship (SAR) study. The results indicated that most derivatives exhibited significantly improved antitumor activity, especially for compound 6e. The compound 6e contains an isothiouronium linked by an alkyl chain consisting of six carbon atoms with IC50 ranging from 1.11 to 2.80 µM on various cancer cell lines. Consistently, the 6e dose dependently induced the apoptosis of A549 and DU145 cells, in which STAT3 is constitutively active. Western blotting assays indicated that the phosphorylation levels of JAK1, JAK2 and STAT3 were inhibited by 6e at 5 µM without significant change in the total STAT3 level. Moreover, 6e also suppressed the expression of STAT3 downstream genes, including c-Myc, Cyclin D1 and Bcl-XL at 10 µM. An additional in vivo study revealed that 6e at the dose of 10 mg/kg could potently inhibit the DU145 xenograft tumor without obvious body weight loss. These results clearly indicate that 6e could be a potential antitumor agent by targeting the JAK/STAT3 signaling pathway.

A new phenotype of syndromic retinitis pigmentosa with myopathy is caused by mutations in retinol dehydrogenase 11.

Retinol dehydrogenase 11 (RDH11) is an 11-cis-retinol dehydrogenase that has a well-characterized, albeit auxiliary role in the retinoid cycle. Diseases caused by mutations in the RDH11 gene are very rare, and only one affected family with eye and intelligence involvement has been reported. In the present study, we describe the clinical and genetic findings in a Chinese patient with retinitis pigmentosa (RP), juvenile cataracts, intellectual disability, and myopathy. Trio-based whole-exome sequencing and whole genomic copy number variation detection were performed in this family, and compound heterozygous mutations were identified in RDH11 of the patient: c.938T>C (p.Leu313Pro) derived from the father and c.75-3C>A derived from the mother. Variant c.75-3C>A was confirmed to be a splice-site mutation by cDNA sequencing. It caused exon 2 skipping, resulting in a frameshift mutation and premature translation termination (p.Lys26Serfs*38). Moreover, we found mislocalization of RDH11 protein in muscle cells of the patient by using immunofluorescence staining. This is the first case reported in the Chinese population harboring mutations in RDH11 and revealing a new phenotype of syndromic RP with myopathy.

Downregulation of c-Myc expression confers sensitivity to CHK1 inhibitors in hematologic malignancies.

Checkpoint kinase 1 inhibitors (CHK1i) have shown impressive single-agent efficacy in treatment of certain tumors, as monotherapy or potentiators of chemotherapy in clinical trials, but the sensitive tumor types and downstream effectors to dictate the therapeutic responses to CHK1i remains unclear. In this study we first analyzed GDSC (Genomics of Drug Sensitivity in Cancer) and DepMap database and disclosed that hematologic malignancies (HMs) were relatively sensitive to CHK1i or CHK1 knockdown. This notion was confirmed by examining PY34, a new and potent in-house selective CHK1i, which exhibited potent anti-HM effect in vitro and in vivo, as single agent. We demonstrated that the downregulation of c-Myc and its signaling pathway was the common transcriptomic profiling response of sensitive HM cell lines to PY34, whereas overexpressing c-Myc could partially rescue the anticancer effect of PY34. Strikingly, we revealed the significant correlations between downregulation of c-Myc and cell sensitivity to PY34 in 17 HM cell lines and 39 patient-derived cell (PDC) samples. Thus, our results demonstrate that HMs are more sensitive to CHK1i than solid tumors, and c-Myc downregulation could represent the CHK1i efficacy in HMs.

Habitual tea consumption and 5-year incident metabolic syndrome among older adults: a community-based cohort study.

BACKGROUND: The effect of tea consumption on metabolic syndrome (MetS) remains controversial. The objective of this study is to examine the prospective association of tea consumption with 5-year incident MetS among aged population in China. METHODS: This analysis included 3005 Chinese adults aged 60 years or older who were free of MetS at baseline examination. MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III. Information regarding tea consumption was collected via an interviewer-administrated questionnaire. The prospective associations between tea consumption at baseline and 5-year incident MetS, as well as its individual components, were assessed by multiple logistic regression models. RESULTS: Of the 3005 participants free of MetS at baseline, 406 participants (cumulative incidence: 13.5%) developed MetS at the 5-year follow-up examination. In multiple logistic regressions, 5-year cumulative incidence of MetS was found to be higher in those who drank tea more than 5 times per week as compared with non-habitual drinkers (OR = 1.38, 95% CI: 1.05-1.82; P = 0.02). This relationship still existed in men (OR = 1.43, 95%CI: 1.00-2.01; P = 0.05) when stratified by gender. Among the five major components of MetS, low high-density lipoprotein cholesterol was observed in men, while high body mass index, elevated blood pressure and the presence of diabetes mellitus were significant in women. CONCLUSIONS: High-frequent tea consumption increased the risk of MetS among older Chinese adults. These findings may add novel knowledge to the current studies regarding the controversial effect of tea consumption on cardiovascular and metabolic health among the aged population.

Phenotype and Genotype Study of Chinese POMT2-Related α-Dystroglycanopathy.

OBJECTIVE: Alpha-dystroglycanopathy (α-DGP) is a subtype of muscular dystrophy caused by defects in the posttranslational glycosylation of α-dystroglycan (α-DG). Our study aimed to summarize the clinical and genetic features of POMT2-related α-DGP in a cohort of patients in China. METHODS: Pedigrees, clinical data, and laboratory tests of patients diagnosed with POMT2-related α-DGP were analyzed retrospectively. The pathogenicity of variants in POMT2 were predicted by bioinformatics software. The variants with uncertain significance were verified by further analysis. RESULTS: The 11 patients, comprising eight males and three females, were from nine non-consanguineous families. They exhibited different degrees of muscle weakness, ambulation, and intellectual impairment. Among them, three had a muscle-eye-brain disease (MEB)-like phenotype, five presented congenital muscular dystrophy with intellectual disability (CMD-ID), and three presented limb-girdle muscular dystrophy (LGMD). Overall, nine novel variants of POMT2, including two non-sense, one frameshift and six missense variants, were identified. The pathogenicity of two missense variants, c.1891G > C and c.874G > C, was uncertain based on bioinformatics software prediction. In vitro minigene analysis showed that c.1891G > C affects the splicing of POMT2. Immunofluorescence staining with the IIH6C4 antibody of muscle biopsy from the patient carrying the c.874G > C variant showed an apparent lack of expression. CONCLUSION: This study summarizes the clinical and genetic characteristics of a cohort of POMT2-related α-DGP patients in China for the first time, expanding the mutational spectrum of the disease. Further study of the pathogenicity of some missense variants based on enzyme activity detection is needed.

Potential Biomolecules Capable of Assessing Risk of Osteoporotic Fracture: A Scoping Review.

Osteoporosis as a systemic chronic skeletal disease is characterized by low bone mineral density and increased risk to osteoporotic fractures. Osteoporosis is prevalent in the middle-aged and elderly population, especially in the postmenopausal women. With population aging, osteoporosis has become a world-wide serious public health problem. Early recognition of the high-risk population followed by timely and efficient intervention and/or treatment is important for preventing osteoporotic fractures. In light of the high heritability and complex pathogenesis of osteoporosis, comprehensive consideration of vital biological/biochemical factors is necessary for accurate risk evaluation of fractures. For this purpose, we review recent research progress on molecules which can be applied to assess risk for osteoporotic fractures. Future integrative analyses and systematic evaluation of these molecules may facilitate developing novel methodologies and/or test strategies, i.e., biochips, for early recognition of osteoporosis, hence contributing to preventing osteoporotic fractures.

The effect of candesartan on chronic stress induced imbalance of glucose homeostasis.

OBJECTIVE: To explore whether chronic stress induces imbalance of glucose homeostasis, and to investigate the possible involvement of the renin-angiotensin system (RAS). METHODS: Male Sprague-Dawley rats were divided into four groups: control, chronic stress, chronic stress plus low dose candesartan (an angiotensin II receptor-1 blocker, ARB, 5 mg/kg/d, i.p.), chronic stress plus high dose candesartan (15 mg/kg/d, i.p.). Rats were received restraint stress for 14 days. Glucose transporter 2 (GLUT2) mRNA was quantified in liver by real-time polymerase chain reaction. The concentration of glucokinase (GK), glucose-6-phosphatase (G-6-P), glycogen synthase (GS), insulin receptor (ISR), glucocorticoid receptor (GR)-alpha and -beta in liver, hexokinase (HK), lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) in muscle, and serum insulin were measured by ELISA. Body weights, systolic blood pressure, heart rate and fasting blood glucose were monitored. Glucose tolerance test were performed after 14 days restraint stress. RESULTS: After 14 days restraint stress, systolic blood pressure, increase of plasma glucose concentration at 15 minutes were higher and the fasting plasma concentration of glucose was lower compared with control group (P < 0.05), which were reversed by high dose ARB treatment (P < 0.05). In addition, chronic stress decreased expression of GLUT2 and increased expression of GR beta in liver. High dose ARB treatment normalized GLUT2 and GR beta expressions in liver. CONCLUSIONS: Our present data indicate chronic stress induces the imbalance of glucose homeostasis and RAS contributes to the imbalance of glucose homeostasis induced by chronic stress.

Controlled induction and targeted elimination of p16INK4a-expressing chondrocytes in cartilage explant culture.

Cellular senescence is a phenotypic state that contributes to age-related diseases through the secretion of matrix-degrading and inflammatory molecules. An emerging therapeutic strategy for osteoarthritis (OA) is to selectively eliminate senescent cells by initiating apoptosis. This study establishes a cartilage explant model of senescence induction and senolytic clearance using p16Ink4a expression as a biomarker of senescence. Growth-factor stimulation of explants increased the expression of p16Ink4a at both the mRNA and protein levels. Applying this culture system to cartilage from p16tdTom reporter mice (a knockin allele with tdTomato fluorescent protein regulated by the endogenous p16Ink4a promoter) demonstrated the emergence of a p16-high population that was quantified using flow cytometry for tdTomato. Cell sorting was used to separate chondrocytes based on tdTomato fluorescence and p16-high cells showed higher senescence-associated ß-galactosidase activity and increased gene expression of the senescence-associated secretory phenotype as compared with p16-low cells. The potential for effective senolysis within the cartilage extracellular matrix was assessed using navitoclax (ABT-263). Navitoclax treatment reduced the percentage of p16-high cells from 17.9 to 6.1% (mean of 13 matched pairs; P < 0.001) and increased cleaved caspase-3 confirmed apoptotic activity. Together, these findings establish a physiologically relevant cartilage explant model for testing the induction and elimination of senescent chondrocytes, which will support investigations of senolytic therapy for OA.-Sessions, G. A., Copp, M. E., Liu, J.-Y., Sinkler, M. A., D'Costa, S., Diekman, B. O. Controlled induction and targeted elimination of p16INK4a-expressing chondrocytes in cartilage explant culture.

Engineering NiO/NiFe LDH Intersection to Bypass Scaling Relationship for Oxygen Evolution Reaction via Dynamic Tridimensional Adsorption of Intermediates.

Oxygen evolution reaction (OER) is a pivotal reaction in many technologies for renewable energy, such as water splitting, metal-air batteries, and regenerative fuel cells. However, this reaction is known to be kinetically sluggish and proceeds at rather high overpotential due to the universal scaling relationship, namely, the adsorption energies of intermediates are linearly correlated and cannot be optimized simultaneously. Several approaches have been proposed to break the scaling relationship by introducing additional active sites; however, positive experimental results are still absent. Herein, a different solution is suggested on the basis of dynamic tridimensional adsorption of the OER intermediates at NiO/NiFe layered double hydroxide intersection, by which the adsorption energy of each intermediate can be adjusted independently, so as to bypass the scaling relationship and achieve high catalytic performance. Experimentally, the OER overpotential is reduced to ≈205 mV at current density of 30 mA cm-2 , which represents the best performance achieved by state-of-the-art OER catalysts.

Cells exhibiting strong p16INK4a promoter activation in vivo display features of senescence.

The activation of cellular senescence throughout the lifespan promotes tumor suppression, whereas the persistence of senescent cells contributes to aspects of aging. This theory has been limited, however, by an inability to identify and isolate individual senescent cells within an intact organism. Toward that end, we generated a murine reporter strain by "knocking-in" a fluorochrome, tandem-dimer Tomato (tdTom), into exon 1α of the p16INK4a locus. We used this allele (p16tdTom ) for the enumeration, isolation, and characterization of individual p16INK4a -expressing cells (tdTom+). The half-life of the knocked-in transcript was shorter than that of the endogenous p16INK4a mRNA, and therefore reporter expression better correlated with p16INK4a promoter activation than p16INK4a transcript abundance. The frequency of tdTom+ cells increased with serial passage in cultured murine embryo fibroblasts from p16tdTom/+ mice. In adult mice, tdTom+ cells could be readily detected at low frequency in many tissues, and the frequency of these cells increased with aging. Using an in vivo model of peritoneal inflammation, we compared the phenotype of cells with or without activation of p16INK4a and found that tdTom+ macrophages exhibited some features of senescence, including reduced proliferation, senescence-associated ß-galactosidase (SA-ß-gal) activation, and increased mRNA expression of a subset of transcripts encoding factors involved in SA-secretory phenotype (SASP). These results indicate that cells harboring activation of the p16INK4a promoter accumulate with aging and inflammation in vivo, and display characteristics of senescence.

Utility of GDF-15 as a diagnostic biomarker in gastric cancer: an investigation combining GEO, TCGA and meta-analysis.

It was recently suggested that growth differentiation factor-15 (GDF-15) is associated with gastric cancer (GC) carcinogenesis. However, the diagnostic potential of GDF-15 for GC remains unclear. To address this issue, we obtained RNA sequencing and microarray data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases, and searched PubMed, Google Scholar and Web of Science for relevant literature. We then used STATA to perform a meta-analysis. In total, reports of 253 GC patients and 112 healthy controls who contributed peripheral blood samples were taken from the four literature sources, while information on 754 GC tumor and 263 gastric normal tissues was drawn from TCGA and seven GEO datasets. The expression level of GDF-15 mRNA was significantly higher in tumor tissues than in normal tissues, with a standard mean difference (SMD) of 0.79% and a 95% confidence interval (95% CI) of 0.63-0.95. Consistently, the GDF-15 protein in blood was significantly increased in GC patients as compared to controls (SMD  = 3.74, 95% CI = 1.81-5.68). In addition, based on information from TCGA and GEO datasets, the expression level of GDF-15 mRNA may be of use for the diagnosis of GC, with a combined sensitivity, specificity and odds ratio of 0.69 (95% CI = 0.58-0.79), 0.90 (95% CI = 0.84-0.93) and 6.32 (95% CI = 4.22-9.49), respectively. The summary receiver operating characteristic curve demonstrated that the area under the curve was 0.90 (95% CI = 0.87-0.93). The results suggest higher levels of GDF-15 may be associated with GC tumorigenesis and may have the potential to be a diagnostic biomarker of GC.

Identifying the Key Role of Pyridinic-N-Co Bonding in Synergistic Electrocatalysis for Reversible ORR/OER.

For many regenerative electrochemical energy-conversion systems, hybrid electrocatalysts comprising transition metal (TM) oxides and heteroatom-doped (e.g., nitrogen-doped) carbonaceous materials are promising bifunctional oxygen reduction reaction/oxygen evolution reaction electrocatalysts, whose enhanced electrocatalytic activities are attributed to the synergistic effect originated from the TM-N-C active sites. However, it is still ambiguous which configuration of nitrogen dopants, either pyridinic or pyrrolic N, when bonded to the TM in oxides, predominately contributes to the synergistic effect. Herein, an innovative strategy based on laser irradiation is described to controllably tune the relative concentrations of pyridinic and pyrrolic nitrogen dopants in the hybrid catalyst, i.e., NiCo2 O4 NPs/N-doped mesoporous graphene. Comparative studies reveal the dominant role of pyridinic-NCo bonding, instead of pyrrolic-N bonding, in synergistically promoting reversible oxygen electrocatalysis. Moreover, density functional theory calculations provide deep insights into the corresponding synergistic mechanism. The optimized hybrid, NiCo/NLG-270, manifests outstanding reversible oxygen electrocatalytic activities, leading to an overpotential different ΔE among the lowest value for highly efficient bifunctional catalysts. In a practical reversible Zn-air battery, NiCo/NLG-270 exhibits superior charge/discharge performance and long-term durability compared to the noble metal electrocatalysts.

Modest Oxygen-Defective Amorphous Manganese-Based Nanoparticle Mullite with Superior Overall Electrocatalytic Performance for Oxygen Reduction Reaction.

Manganese-based oxides have exhibited high promise as noncoinage alternatives to Pt/C for catalyzing oxygen reduction reaction (ORR) in basic solution and a mix of Mn3+/4+ valence is believed to be vital in achieving optimum ORR performance. Here, it is proposed that, distinct from the most studied perovskites and spinels, Mn-based mullites with equivalent molar ratio of Mn3+ and Mn4+ provide a unique platform to maximize the role of Mn valence in facile ORR kinetics by introducing modest content of oxygen deficiency, which is also beneficial to enhanced catalytic activity. Accordingly, amorphous mullite SmMn2 O5-δ nanoparticles with finely tuned concentration of oxygen vacancies are synthesized via a versatile top-down approach and the modest oxygen-defective sample with an Mn3+ /Mn4+ ratio of 1.78, i.e., Mn valence of 3.36 gives rise to a superior overall ORR activity among the highest reported for the family of Mn-based oxides, comparable to that of Pt/C. Altogether, this study opens up great opportunities for mullite-based catalysts to be a cost-effective alternative to Pt/C in diverse electrochemical energy storage and conversion systems.