Abstract:The mangrove ecosystem is a largely unexplored source for actinomycetes with the potential to produce biologically active secondary metabolites. Consequently, we set out to isolate, characterize and screen actinomycetes from soil and plant material collected from eight mangrove sites in China. Over 2,000 actinomycetes were isolated and of these approximately 20%, 5%, and 10% inhibited the growth of Human Colon Tumor 116 cells, Candida albicans and Staphylococcus aureus, respectively, while 3% inhibited protein tyrosine phosphatase 1B (PTP1B), a protein related to diabetes. In addition, nine isolates inhibited aurora kinase A, an anti-cancer related protein, and three inhibited caspase 3, a protein related to neurodegenerative diseases. Representative bioactive isolates were characterized using genotypic and phenotypic procedures and classified to thirteen genera, notably to the genera Micromonospora and Streptomyces. Actinomycetes showing cytotoxic activity were assigned to seven genera whereas only Micromonospora and Streptomyces strains showed anti-PTP1B activity. We conclude that actinomycetes isolated from mangrove habitats are a potentially rich source for the discovery of anti-infection and anti-tumor compounds, and of agents for treating neurodegenerative diseases and diabetes.

Ultrasound is a safe bedside imaging tool that obviates the use of ionizing radiation diagnostic procedures. Due to its convenience, the lung ultrasound has received increasing attention from neonatal physicians. Nevertheless, clear reference standards and guideline limits are needed for accurate application of this diagnostic modality. This document aims to summarize expert opinions and to provide precise guidance to help facilitate the use of the lung ultrasound in the diagnosis of neonatal lung diseases.

Five nicotinic acetylcholine receptor (nAChR) mutations are currently linked to autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). The similarity of their clinical symptoms suggests that a common functional anomaly of the mutations underlies ADNFLE seizures. To identify this anomaly, we constructed rat orthologues (S252F, +L264, S256L, V262L, V262M) of the human ADNFLE mutations, expressed them in Xenopus oocytes with the appropriate wild‐type (WT) subunit (α4 or β2), and studied the Ca2+ dependence of their ACh responses. All the mutations significantly reduced 2 mM Ca2+‐induced increases in the 30 μM ACh response (P < 0.05). Consistent with a dominant mode of inheritance, this reduction persisted in oocytes injected with a 1:1 mixture of mutant and WT cRNA. BAPTA injections showed that the reduction was not due to a decrease in the secondary activation of Ca2+‐activated Cl− currents. The S256L mutation also abolished 2 mM Ba2+ potentiation of the ACh response. The S256L, V262L and V262M mutations had complex effects on the ACh concentration‐response relationship but all three mutations shifted the concentration‐response relationship to the left at [ACh]⩾ 30 μM. Co‐expression of the V262M mutation with a mutation (E180Q) that abolished Ca2+ potentiation resulted in 2 mM Ca2+ block, rather than potentiation, of the 30 μM ACh response, suggesting that the ADNFLE mutations reduce Ca2+ potentiation by enhancing Ca2+ block of the α4β2 nAChR. Ca2+ modulation may prevent presynaptic α4β2 nAChRs from overstimulating glutamate release at central excitatory synapses during bouts of synchronous, repetitive activity. Reducing the Ca2+ dependence of the ACh response could trigger seizures by increasing α4β2‐mediated glutamate release during such bouts.

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A total of 25 Chinese patients aged 6 to 36 months hospitalised at Beijing Children’s Hospital due to melamine-induced kidney stones complicated by acute obstructive renal failure in 2008 were included in a study in order to diagnose and treat these special cases more effectively. Feeding history, clinical presentation, ultrasound findings, treatments and effects were summarised. Twelve to seventeen months follow-up was reported also. Ultrasound examination showed that calculi were located at the kidney and ureters. Stones were composed of both uric acid and melamine in a molar ratio of 1.2:1 to 2.1:1. Treatments providing liquid plus alkalisation of urine proved to be effective in helping the patients pass the stones. Surgical intervention was needed in severe cases. Renal function returned to normal in all 25 patients after various durations of therapy. Sixty-eight percent of the patients expelled all of the calculi within 3 months, 90% in 6 months and 95% in 9 months, without sequelae till now. Melamine-contaminated milk formula can cause kidney stones in infants, which should be diagnosed by feeding history, clinical symptoms and ultrasound examination. Composition of the stones was not only of melamine but also uric acid. Providing liquid orally or intravenously plus alkalisation of urine proved to promote the removal of the stones. Follow-up of 12 to 17 months after discharge showed no sequelae.

ObjectiveClinical trials showed that sodium-glucose cotransporter 2 (SGLT2) inhibitors can improve non-alcoholic fatty liver disease (NAFLD). In this work, a meta-analysis of randomized controlled trials was conducted to evaluate the effect of SGLT2 inhibitors on type 2 diabetes mellitus (T2DM) with NAFLD.MethodsPubMed, Embase, Web of Science, and Cochrane Libraries were used for the systematic literature review to determine eligible studies. A randomized effect model was adapted to perform a meta-analysis on these eligible studies to estimate the combined effect sizes. Differences were expressed as the weighted average difference (WMD) of the continuous results and the 95% confidence interval (CI).ResultsTen randomized controlled trials with 573 participants were included. SGLT2 inhibitors significantly reduced the levels of alanine transaminase (WMD -5.36 [95% CI: -8.86, -1.85], p = 0.003) and Aspartate Transaminase (WMD -2.56 [95% CI: -3.83, -1.29], p &lt;0.0001). In terms of body composition, liver proton density fat fraction (WMD -2.20 [95% CI: -3.67, -0.74], p = 0.003), visceral fat mass area (WMD -20.71 [95% CI: -28.19, -13.23], p &lt;0.00001), subcutaneous fat areas (WMD -14.68 [95% CI: -26.96, -2.40], p = 0.02) were also significantly reduced.ConclusionSGLT2 inhibitors can remarkably reduce hepatic enzymes, hepatic fat and improve body composition. Thus, they may become a new treatment option for NAFLD.Systematic Review RegistrationPROSPERO, identifier CRD42020215570.

To determine whether prolonged nicotine exposure persistently inactivates rat a4b2 nicotinic receptors expressed in Xenopus oocytes, we measured the voltage-clamped a4b2 response to acetylcholine (ACh) before and 24 h after, 1-h or 12-h incubations in 10 lM nicotine. A 12-h incubation in 10 lM nicotine depressed the a4b2 ACh response for 24 h without affecting total or surface a4b2 expression. To determine whether oocyte-mediated nicotine release caused this depression, we co-incubated an a4b2-expressing oocyte with an un-injected one (pre-incubated in 10 lM nicotine for 12 h) for 24 h and measured the change in the a4b2 ACh response. The response decreased by the same factor after the co-incubation as it did after a 12-h incubation in 10 lM nicotine and a 24-h incubation in nicotine-free media. Thus, oocytemediated nicotine release caused the persistent desensitization we observed after a 12-h incubation in 10 lM nicotine. Prolonged nicotine exposure persistently depresses the agonist response of a4b2 nicotinic acetylcholine receptors (nAChRs) expressed in Xenopus oocytes (Peng et al. 1994;Hsu et al. 1996;Olale et al. 1997;Kuryatov et al. 2000). For example, incubations in 0.05-10 lM nicotine for 1-6 days reduce the response of a4b2 nAChRs expressed in Xenopus oocytes by 40-80% for a period of 24-48 h after the incubation ends (Peng et al. 1994;Hsu et al. 1996;Olale et al. 1997;Kuryatov et al. 2000). The molecular mechanism that underlies this persistent depression has not been established. However, it is thought to involve some kind of post-translational modification of the receptor (reviewed in Ochoa et al. 1989). It does not require persistent nicotine binding because [ 3 H]nicotine dissociates from rat brain nAChRs with a time constant of 2.5 min at 22°C (Lippiello et al. 1987).In contrast to oocytes, incubation in 0.1-10 lM nicotine for 1-7 days does not persistently inhibit the agonist response of a4b2 nAChRs expressed in mammalian cell lines (Gopalakrishnan et al. 1996;Buisson and Bertrand 2001). For example, a 7-day incubation in 100 nM nicotine increases the maximum ACh-induced 86 Rb influx from HEK cells expressing a4b2 nAChRs by 45% (Gopalakrishnan et al. 1996), and a 24-h incubation in 10 lM nicotine increases the maximum voltage-clamped ACh response of HEK cells expressing a4b2 nAChRs by 63% (Buisson and Bertrand 2001). Consistent with these increases, twice daily injections of nicotine tartrate (2 mg/kg) for 10 days 3 H]nicotine concentration at time t; NR, peak post-incubation a4b2 ACh response normalized to the pre-incubation value; NR 1 , final steady-state normalized response for recovery from ACh-induced desensitization; P solute , solute permeability coefficient; P nicotine , P solute for nicotine; t, time; s D , time constant for diffusion between two compartments; V cell , intracellular volume.

Atrial fibrillation (AF) affects >30 million individuals worldwide. However, no genetic mutation from human patients with AF has been linked to inflammation. Here, we show that AF‐associated human variant p.Ile138Thr in natriuretic peptide A (NPPA) encoding the atrial natriuretic peptide (ANP) causes inflammation, fibroblast activation, atrial fibrosis, and AF in knock‐in (KI) rats. Variant p.Ile138Thr inhibits the interaction between ANP and its receptor natriuretic peptide receptor A and reduces intracellular cGMP levels. RNA sequencing and follow‐up analyses showed that mutant ANP (mANP) activates multiple innate immunity pathways, including TNF‐α, NF‐κB, and IL‐1β signaling. mANP induces differentiation of cardiac fibroblasts (CFs) to myofibroblasts and promotes CF proliferation and fibrosis. These results suggest that NPPA variant p.Ile138Thr causes AF by activating TNF‐α, NF‐κB, and IL‐1β signaling, inflammation, and fibrosis. Multiple computational programs suggest that p.Ile138Thr is damaging or deleterious. Based on the 2015 American College of Medical Genetics and Genomics Standards and Guidelines, p.Ile138Thr can be classified as a likely pathogenic variant. Variant p.Ile138Thr was found only in Asian people in the Genome Aggregation Database and Exome Aggregation Consortium database at an averaged frequency of 0.026%. An estimated 1.15 million Asian people carry the variant and might be at risk of AF. The KI rats may provide an inflammation‐based, genetic animal model for AF valuable for testing anti‐inflammation or other therapies for AF.—Cheng, C., Liu, H., Tan, C., Tong, D., Zhao, Y., Liu, X., Si, W., Wang, L., Liang, L., Li, J., Wang, C., Chen, Q., Du, Y., Wang, Q. K., Ren, X. Mutation in NPPA causes atrial fibrillation by activating inflammation and cardiac fibrosis in a knock‐in rat model. FASEB J. 33, 8878–8891 (2019). http://www.fasebj.org