Cytosolic pH is a direct nexus in linking environmental cues with insulin processing and secretion in pancreatic ß cells.

Pancreatic ß cells actively respond to glucose fluctuations through regulating insulin processing and secretion. However, how this process is elaborately tuned in circumstance of variable microenvironments as well as ß cell-intrinsic states and whether its dysfunction links to metabolic diseases remain largely elusive. Here, we show that the cytosolic pH (pHc) in ß cells is increased upon glucose challenge, which can be sensed by Smad5 via its nucleocytoplasmic shuttling. Lesion of Smad5 in ß cells results in hyperglycemia and glucose intolerance due to insulin processing and secretion deficiency. The role of Smad5 in regulating insulin processing and secretion attributes to its non-canonical function by regulating V-ATPase activity for granule acidification. Genetic mutation of Smad5 or administration of alkaline water to mirror cytosolic alkalization ameliorated glucose intolerance in high-fat diet (HFD)-treated mice. Collectively, our findings suggest that pHc is a direct nexus in linking environmental cues with insulin processing and secretion in ß cells.

Down-regulation of miR-133a-3p protects lung tissue against sepsis-induced acute respiratory distress syndrome by up-regulating SIRT1.

Introduction: MicroRNA-133a-3p (miR-133a-3p) is a potential gene regulator having an important role in the process of inflammation and lung injury. The present work studied the role of miR-133a-3p in sepsis-mediated acute respiratory distress syndrome (ARDS) and the mechanism involved. Material and methods: C57BL/6 mice were selected for the study. Protein expression of Bcl-2, cleaved caspase-3 and Bax was assessed by western blot analysis. Expression of mRNA was assessed by RT-PCR. Effects of inflammation were studied by myeloperoxidase (MPO) activity. Quantification of albumin was done by measuring the albumin conjugated with Evan's blue. The alveolar macrophages were separated from the lungs of mice by the bronchoalveolar lavage procedure and were submitted to sepsis challenge in vitro; the macrophages were treated with lipopolysaccharide (LPS). Results: Treatment of LPS resulted in upregulation of miR-133a-3p in alveolar macrophages. Suppression of miR-133a-3p halted the over-expression of inflammatory cytokines in macrophages and caused remission of histopathologic changes. The ARDS lungs showed a decrease in levels of proinflammatory cytokines and an increase in levels of apoptotic protein, establishing the protective role for miR-133a-3p. The results suggested sirtuin 1 (SIRT1) as a potential target of miR-133a-3p in the macrophages, also showing that expression of SIRT1 was inversely associated with expression of miR-133a-3p. The protective effect of miR-133a-3p down-regulation in LPS-mediated alveolar macrophages and sepsis-induced ARDS could be corrected by a SIRT1 inhibitor. Conclusions: Down-regulation of miR-133a-3p may exert a protective effect on lung tissue against sepsis-mediated ARDS by up-regulating the levels of SIRT1 via suppressing the inflammatory response and inhibiting the cellular apoptosis in lung tissues.

Hypoimmunogenic human pluripotent stem cells are valid cell sources for cell therapeutics with normal self-renewal and multilineage differentiation capacity.

Hypoimmunogenic human pluripotent stem cells (hPSCs) are expected to serve as an unlimited cell source for generating universally compatible "off-the-shelf" cell grafts. However, whether the engineered hypoimmunogenic hPSCs still preserve their advantages of unlimited self-renewal and multilineage differentiation to yield functional tissue cells remains unclear. Here, we systematically studied the self-renewal and differentiation potency of three types of hypoimmunogenic hPSCs, established through the biallelic lesion of B2M gene to remove all surface expression of classical and nonclassical HLA class I molecules (B2Mnull), biallelic homologous recombination of nonclassical HLA-G1 to the B2M loci to knockout B2M while expressing membrane-bound ß2m-HLA-G1 fusion proteins (B2MmHLAG), and ectopic expression of soluble and secreted ß2m-HLA-G5 fusion proteins in B2MmHLAG hPSCs (B2Mm/sHLAG) in the most widely used WA09 human embryonic stem cells. Our results showed that hypoimmunogenic hPSCs with variable expression patterns of HLA molecules and immune compromising spectrums retained their normal self-renewal capacity and three-germ-layer differentiation potency. More importantly, as exemplified by neurons, cardiomyocytes and hepatocytes, hypoimmunogenic hPSC-derived tissue cells were fully functional as of their morphology, electrophysiological properties, macromolecule transportation and metabolic regulation. Our findings thus indicate that engineered hypoimmunogenic hPSCs hold great promise of serving as an unlimited universal cell source for cell therapeutics.

Membrane-delimited signaling and cytosolic action of MG53 preserve hepatocyte integrity during drug-induced liver injury.

BACKGROUND & AIMS: Drug-induced liver injury (DILI) remains challenging to treat and is still a leading cause of acute liver failure. MG53 is a muscle-derived tissue-repair protein that circulates in the bloodstream and whose physiological role in protection against DILI has not been examined. METHODS: Recombinant MG53 protein (rhMG53) was administered exogenously, using mice with deletion of Mg53 or Ripk3. Live-cell imaging, histological, biochemical, and molecular studies were used to investigate the mechanisms that underlie the extracellular and intracellular action of rhMG53 in hepatoprotection. RESULTS: Systemic administration of rhMG53 protein, in mice, can prophylactically and therapeutically treat DILI induced through exposure to acetaminophen, tetracycline, concanavalin A, carbon tetrachloride, or thioacetamide. Circulating MG53 protects hepatocytes from injury through direct interaction with MLKL at the plasma membrane. Extracellular MG53 can enter hepatocytes and act as an E3-ligase to mitigate RIPK3-mediated MLKL phosphorylation and membrane translocation. CONCLUSIONS: Our data show that the membrane-delimited signaling and cytosolic dual action of MG53 effectively preserves hepatocyte integrity during DILI. rhMG53 may be a potential treatment option for patients with DILI. LAY SUMMARY: Interventions to treat drug-induced liver injury and halt its progression into liver failure are of great value to society. The present study reveals that muscle-liver cross talk, with MG53 as a messenger, serves an important role in liver cell protection. Thus, MG53 is a potential treatment option for patients with drug-induced liver injury.

Developmental programming and lineage branching of early human telencephalon.

The dorsal and ventral human telencephalons contain different neuronal subtypes, including glutamatergic, GABAergic, and cholinergic neurons, and how these neurons are generated during early development is not well understood. Using scRNA-seq and stringent validations, we reveal here a developmental roadmap for human telencephalic neurons. Both dorsal and ventral telencephalic radial glial cells (RGs) differentiate into neurons via dividing intermediate progenitor cells (IPCs_div) and early postmitotic neuroblasts (eNBs). The transcription factor ASCL1 plays a key role in promoting fate transition from RGs to IPCs_div in both regions. RGs from the regionalized neuroectoderm show heterogeneity, with restricted glutamatergic, GABAergic, and cholinergic differentiation potencies. During neurogenesis, IPCs_div gradually exit the cell cycle and branch into sister eNBs to generate distinct neuronal subtypes. Our findings highlight a general RGs-IPCs_div-eNBs developmental scheme for human telencephalic progenitors and support that the major neuronal fates of human telencephalon are predetermined during dorsoventral regionalization with neuronal diversity being further shaped during neurogenesis and neural circuit integration.

Protocol for genome-scale CRISPR screening in engineered lineage reporter hPSCs to study cell fate determination.

PAX6 is a key determinant of human neuroectoderm cell fate. Here, we describe a protocol for genome-scale CRISPR screening for use in genetically engineered human pluripotent stem cells (hPSCs). Using the germ layer reporter PAX6 and an inducible CRISPR/Cas9 knockout system, we describe how to identify lineage-specific preventing genes. This protocol can be applied for use with other reporter genes to study cell fate determination in hPSCs. For complete details on the use and execution of this protocol, please refer to Xu et al. (2021).

Mapping germ-layer specification preventing genes in hPSCs via genome-scale CRISPR screening.

Understanding the biological processes that determine the entry of three germ layers of human pluripotent stem cells (hPSCs) is a central question in developmental and stem cell biology. Here, we genetically engineered hPSCs with the germ layer reporter and inducible CRISPR/Cas9 knockout system, and a genome-scale screening was performed to define pathways restricting germ layer specification. Genes clustered in the key biological processes, including embryonic development, mRNA processing, metabolism, and epigenetic regulation, were centered in the governance of pluripotency and lineage development. Other than typical pluripotent transcription factors and signaling molecules, loss of function of mesendodermal specifiers resulted in advanced neuroectodermal differentiation, given their inter-germ layer antagonizing effect. Regarding the epigenetic superfamily, microRNAs enriched in hPSCs showed clear germ layer-targeting specificity. The cholesterol synthesis pathway maintained hPSCs via retardation of neuroectoderm specification. Thus, in this study, we identified a full landscape of genetic wiring and biological processes that control hPSC self-renewal and trilineage specification.

Charge transfer in SnS2/Na0.9Mg0.45Ti3.55O8 heterojunction in photocatalytic process.

SnS2/Na0.9Mg0.45Ti3.55O8 (SNMTO) composite photocatalyst was synthesized by a hydrothermal method. The chemical combination in lattice scale between SnS2 and Na0.9Mg0.45Ti3.55O8 (NMTO) was observed by high-resolution transmission electron microscopy, indicating that heterojunctions were obtained between SnS2 and NMTO. The photocatalytic activity of SNMTO heterojunctions was improved in comparison with that of pure NMTO and SnS2 for the photocatalytic degradation of methylene blue and Rhodamine B. Electrons were excited in n-type semiconductors NMTO and SnS2 under light illumination, and a part of them moved to the interface, determined with the surface potential reduction observed directly by Kelvin probe force microscopy. The charge redistribution in the composite illustrates a high density of interface states between SnS2 and NMTO, which attract lots of photoelectrons, as a result enhancing the photocatalytic performance. This finding is very different from the speculation that the photogenerated electrons and holes migrate from one part to another because it is difficult for charge carriers to travel through the interface with high energy.

TSPO ligands prevent the proliferation of vascular smooth muscle cells and attenuate neointima formation through AMPK activation.

Abnormal growth of the intimal layer of blood vessels (neointima formation) contributes to the progression of atherosclerosis and in-stent restenosis. Recent evidence shows that the 18-kDa translocator protein (TSPO), a mitochondrial membrane protein, is involved in diverse cardiovascular diseases. In this study we investigated the role of endogenous TSPO in neointima formation after angioplasty in vitro and in vivo. We established a vascular injury model in vitro by using platelet-derived growth factor-BB (PDGF-BB) to stimulate rat thoracic aortic smooth muscle cells (A10 cells). We found that treatment with PDGF-BB (1-20 ng/mL) dose-dependently increased TSPO expression in A10 cells, which was blocked in the presence of PKC inhibitor or MAPK inhibitor. Overexpression of TSPO significantly promoted the proliferation and migration in A10 cells, whereas downregulation of TSPO expression by siRNA or treatment with TSPO ligands PK11195 or Ro5-4864 (104 nM) produced the opposite effects. Furthermore, we found that PK11195 (10-104 nM) dose-dependently activated AMPK in A10 cells. PK11195-induced inhibition on the proliferation and migration of PDGF-BB-treated A10 cells were abolished by compound C (an AMPK-specific inhibitor, 103 nM). In rats with balloon-injured carotid arteries, TSPO expression was markedly upregulated in the carotid arteries. Administration of PK11195 (3 mg/kg every 3 days, ip), starting from the initial balloon injury and lasting for 2 weeks, greatly attenuated carotid neointima formation by suppressing balloon injury-induced phenotype switching of VSMCs (increased α-SMA expression). These results suggest that TSPO is a vascular injury-response molecule that promotes VSMC proliferation and migration and is responsible for the neointima formation after vascular injury, which provides a novel therapeutic target for various cardiovascular diseases including atherosclerosis and restenosis.

Clinical features of benign convulsions with mild gastroenteritis in Chinese infants.

BACKGROUND: Benign convulsions occur in infants during the course of mild gastroenteritis. It is now recognized as a distinct clinical entity in many countries. However, its occurrence in China has not yet been widely recognized by Chinese pediatricians. METHODS: A retrospective study was conducted in 48 patients with convulsions between January 1, 2004 and December 31, 2009. RESULTS: The age of onset of gastroenteritis was between 13 months and 24 months in 34 patients (70.83%). The episodes occurred at a distinct autumn/winter peak (75%). The seizures mostly occurred within the first 5 days of gastroenteritis, especially within the first 3 days, peaking on day 2 (39.58%). Thirty-five patients (72.92%) had clustered seizures in their episodes. Most episodes were symmetric, generalized tonic-clonic (83.33%) and brief (93.75%). The seizures were induced by pain and/or crying in 19 (39.58%) patients. Stool culture was positive for rotavirus in 21 (53.85%) of the 39 patients. Twenty patients (20/41, 48.78%) still had clustered seizures after the administration of a single anticonvulsant. The seizures persisted even after the administration of two combined anticonvulsants in 5 (26.32%) of 19 episodes. All patients exhibited normal psychomotor development. CONCLUSIONS: Benign convulsions with mild gastroenteritis are not rare in China, and rotavirus infection is a major cause.

[Efficacy and safety of glucocorticoids in addition to intravenous immunoglobulin in the initial treatment of Kawasaki disease: a meta-analysis of randomized trials].

OBJECTIVE: To evaluate the efficacy and safety of glucocorticoids (GC) plus intravenous immunoglobulin (IVIG) in the initial treatment of Kawasaki disease. METHODS: Fourteen electronic databases and 3 Japanese magazines were searched. Randomized controlled trials (RCT) describing the use of GC plus IVIG in the initial treatment of Kawasaki disease in children were collected. The data of methodological quality and trial information were extracted by two independent researchers. Cochrane review methodology was used for assessing the trial quality and efficacy. Each dichotomous outcome was measured in terms of odds risk (OR) while continuous outcomes shown as weighted mean differences (WMD). And a meta-analysis was made with RevMan5.0.23.0 software. RESULTS: A total of 416 cases in 3 trials were included. There were 209 cases in GC + IVIG group and 207 cases in IVIG group. The incidence of coronary artery lesion (CAL) was not different between GC + IVIG and IVIG groups within 1 month or 1 month post-treatment (OR: 0.74, 0.69; 95%CI: 0.23 - 2.40, 0.35 - 1.38; P = 0.62, 0.30]. The fever duration was shorter in GC + IVIG group than that in IVIG group (WMD: -0.93 d, 95%CI: -1.15 - -0.70, P = 0.00). The treatment failure rate was less in GC + IVIG group than IVIG group (9.09% vs 17.48%, OR: 0.49, 95%CI: 0.28 - 0.86, P = 0.01). No difference in adverse events was found between two groups (OR: 0.81, 95%CI: 0.22 - 3.03, P = 0.76). CONCLUSION: There is no evidence to support that GC plus IVIG can further reduce the CAL risk of KD patients. But it may lower the treatment failure rate in KD patients.

[Clinical application of proton magnetic resonance spectroscopy in children with idiopathic epilepsy].

OBJECTIVE: This study examined the biochemical metabolism by proton magnetic resonance spectroscopy ('H-MRS) in order to explore the value of 'H-MRS in idiopathic epilepsy in children. METHODS: Thirty-three children with idiopathic epilepsy (14 cases with history of febrile seizures and 19 cases without) and six normal controls experienced MRI of the skull and brain and single-voxel 'H-MRS examinations of the hippocampi-temporal lobe. The signal intensities of N-acetylaspartate (NAA), eatine+phosphocreatine (Cr), choline-containing compounds (Cho) and lactate (Lac) and the ratios of NAA/ (Cho+Cr) and Lac/Cr were compared between the patients and normal controls. RESULTS: MRI examination showed that only one child with epilepsy had myelin dysplasia. 'H-MRS examination showed that the ratio of NAA/ (Cho+Cr) in the epilepsy group was lower than that in the control group (0.64+/-0.07 vs 0.73+/-0.05; P<0.01). The epileptic children with history of febrile seizures had a more decreased ratio of NAA/ (Cho+Cr) compared with those without the history (0.61+/-0.07 vs 0.66+/-0.06; P<0.05). There were no significant differences in the ratio of Lac/Cr between the epilepsy and the control groups. CONCLUSIONS: 'H-MRS may provide early information on brain injury sensitively and non-invasively in children with epilepsy. It may be used for diagnosis and prognosis evaluation of epilepsy.

Submicroscopic subtelomeric aberrations in Chinese patients with unexplained developmental delay/mental retardation.

BACKGROUND: Subtelomeric imbalance is widely accepted as related to developmental delay/mental retardation (DD/MR). Fine mapping of aberrations in gene-enriched subtelomeric regions provides essential clues for localizing critical regions, and provides a strategy for identifying new candidate genes. To date, no large-scale study has been conducted on subtelomeric aberrations in DD/MR patients in mainland China. METHODS: This study included 451 Chinese children with moderate to severe clinically unexplained DD/MR. The subtelomere-MLPA (multiplex ligation dependent probe amplification) and Affymetrix human SNP array 6.0 were used to determine the subtelomeric copy number variations. The exact size and the breakpoint of each identified aberration were well defined. RESULTS: The submicroscopic subtelomeric aberrations were identified in 23 patients, with a detection rate of 5.1%. 16 patients had simple deletions, 2 had simple duplications and 5 with both deletions and duplications. The deletions involved 14 different subtelomeric regions (1p, 2p, 4p, 6p, 7p, 7q, 8p, 9p, 10p, 11q, 14q, 15q, 16p and 22q), and duplications involved 7 subtelomeric regions (3q, 4p, 6q, 7p, 8p, 12p and 22q). Of all the subtelomeric aberrations found in Chinese subjects, the most common was 4p16.3 deletion. The sizes of the deletions varied from 0.6 Mb to 12 Mb, with 5-143 genes inside. Duplicated regions were 0.26 Mb to 11 Mb, with 6-202 genes inside. In this study, four deleted subtelomeric regions and one duplicated region were smaller than any other previously reported, specifically the deletions in 11q25, 8p23.3, 7q36.3, 14q32.33, and the duplication in 22q13. Candidate genes inside each region were proposed. CONCLUSIONS: Submicroscopic subtelomeric aberrations were detected in 5.1% of Chinese children with clinically unexplained DD/MR. Four deleted subtelomeric regions and one duplicated region found in this study were smaller than any previously reported, which will be helpful for further defining the candidate dosage sensitive gene associated with DD/MR.

[Comparison of efficacy among early, conventional and late intravenous gamma globulin treatment of Kawasaki disease].

OBJECTIVE: To compare the rates of intravenous gamma globulin (IVIG) non-responder and coronary complication among early, conventional and late IVIG treatment in children with Kawasaki disease (KD). METHODS: All children with KD and IVIG treatment were retrospectively analyzed at 45 hospitals in Beijing during the 5-year period from 2000 through 2004. The time of IVIG treatment was classified as early (Day 1 - 4), conventional (Day 5 - 9) and late treatment group (Day 10 or later). The efficacy of IVIG was judged by the rate of IVIG non-responder. Echocardiography was used to assess the coronary complication at acute (1 - 2 weeks after onset) and sub-acute (3 - 6 weeks after onset) stage. RESULTS: A total of 1052 patients (680 boys, 372 girls) aged 2 months to 13.8 years were included. They were grouped as early, conventional and late treatment in 108, 763 and 181 children respectively. The rate of IVIG non-responders was higher in early (28.7%, 31/108) as compared with conventional (11.9%, 91/763) and late treatment group (7.2%, 13/181, both P < 0.01). The incidences of coronary complications were similar in early (17.6%, 19/108 and 5.9%, 4/68) and conventional treatment group (18.3%, 140/ 763 and 5.5%, 25/452), while significantly higher in late treatment group (33.7%, 61/181 and 12.8%, 15/117) in acute and sub-acute stages (both P < 0.01). CONCLUSIONS: IVIG treatment in children with KD for a disease duration of 1 - 4 days appeared to increase the rate of IVIG non-responders. Children with IVIG given at Day 10 or later had a higher incidence of acute and sub-acute coronary complications. IVIG given at Day 5 - 9 seems to be the best time for IVIG therapy in KD.

[Quantification of phenylalanine in the brain of patients with hyperphenylalaninemia by (1)H magnetic resonance spectroscopy].

OBJECTIVE: Hyperphenylalaninemia (HPA) is an inborn error of metabolism in which the hydroxylation of phenylalanine (Phe) to tyrosine is disturbed. Accumulation of Phe leads to severe mental and psychomotor retardation. (1)H magnetic resonance spectroscopy ((1)HMRS) is a novel non-invasive method to quantitate the brain metabolites besides Phe concentration in HPA patients. And it could be acquired conveniently on clinical MRI routine scanners. This study aimed to investigate the correlation between blood Phe ([Phe](blood)) and [Phe](brain), the characteristics of blood-brain Phe metabolism and its impacts on mental retardation. METHOD: Totally 32 untreated patients diagnosed with HPA were studied, including 18 boys and 14 girls (age ranging from 33 days to 13 years). The patients were divided into two groups: elder than 4 months old (n = 22) and younger than 4 months old (n = 10). (1)HMRS were performed in all patients. [Phe](brain) were measured by absolute [Phe](brain) using Creatinine as an internal reference. [Phe](blood) were measured and developmental quotient (DQ) or intelligence quotients (IQ) were evaluated. RESULT: (1) [Phe](brain) measured by (1)HMRS ranged from 0.0640 to 0.6296 (M = 0.1542) while the [Phe](blood) was from 0.3804 to 2.5140 mmol/L (M = 1.5210 mmol/L) in all the 32 cases of HPA patients. (2) There was a positive linear correlation (r = 0.6103 (P < 0.01)) between [Phe](blood) and [Phe](brain). And there were interindividual differences in [Phe](brain) in several patients. (3) Variable mental retardation were observed in 23/32 cases in this study. (4) There was a negative correlation between [Phe](blood) and [Phe](brain) to the mental retardation (r(blood) = -0.5045, r(brain) = -0.6471 (P < 0.01)) in 22 cases of the HPA patients older than 4 months. And [Phe](brain) had more significant correlation with mental development than [Phe](blood). CONCLUSION: The [Phe](blood) could correspondingly represent the [Phe](brain) in most HPA patients. The Phe concentration could reflect the degree of mental retardation substantially in 22 cases with HPA older than 4 months. And the [Phe](brain) could more accurately illustrate it. (1)HMRS can be used to quantitate intracerebral Phe concentrations non-invasively in HPA patients. Preliminary findings suggest that interindividual variations in the kinetics of Phe uptake and metabolism do exist. (1)HMRS has great clinical significance in understanding the mechanism of HPA patient's mental retardation, providing proper objective standards for better diagnosis and treatment of HPA patients.

[Clinical study of tetrahydrobiopterin responsive phenylalanine hydroxylase deficiency in southern and northern Chinese patients].

OBJECTIVE: To analyze characteristics of different hyperphenylalaninemia (HPA) and to discuss the clinical difference between southern and northern Chinese patients with tetrahydrobiopterin (BH4) responsive phenylalanine hydroxylase (PAH) deficiency. METHODS: (1)BH4 (20 mg/kg) loading test was performed in all 108 HPA patients. These patients, 63 males and 45 females, were at a mean age of 7.05 months. A combined phenylalanine (Phe) and BH4 loading test was carried out in the patients who had a basic blood Phe concentration less than 600 micromol/L. The urine pterine profile analysis and the dihydropteridine reductase (DHPR) activity in dry blood filter spot were analyzed simultaneously. (2)BH4 responsive patients were divided to southern and northern groups by their parent's native place and geographic boundary determined by Changjiang River. The change of Phe concentration after BH4 loading test was compared between the two groups. RESULTS: (1)Among the 108 HPA cases, 36 patients (33.3%) were BH4 responsive PAH deficiency, 49 (45.4%) were non-BH4 no responsive phenylketonuria (PKU)and 23(21.3%)were BH4 deficiency (BH4D). The Phe concentration of patients with BH4 responsive PAH deficiency decreased by 49.24% and 65.35% at 8 h and 24 h after oral BH4, 23 in southern group and 13 in northern group among 36 patients. (2)The mean Phe concentration at 24 h after loading test in southern and northern groups were (217.02+/-189.03) micromol/L and 458.75+/-342.54 micromol/L respectively (P<0.05), although the decrease percent of plasma Phe concentration at 2 h, 4 h, 8 h, 24 h was no distinct difference between southern and northern groups (P>0.05). CONCLUSION: Most of mild and moderate HPA patients affected by PAH deficiency show plasma Phe concentration decrease >30% in 24 h after oral BH4 20 mg/kg, few are classic PKU. The responsiveness to BH4 is no difference between southern and northern Chinese patients with BH4 responsive PAH deficiency according to the decrease percent of plasma Phe concentration, although the Phe concentration is lower in southern patients than that in northern patients.