Glioblastoma stem cells generate vascular pericytes to support vessel function and tumor growth.

Glioblastomas (GBMs) are highly vascular and lethal brain tumors that display cellular hierarchies containing self-renewing tumorigenic glioma stem cells (GSCs). Because GSCs often reside in perivascular niches and may undergo mesenchymal differentiation, we interrogated GSC potential to generate vascular pericytes. Here, we show that GSCs give rise to pericytes to support vessel function and tumor growth. In vivo cell lineage tracing with constitutive and lineage-specific fluorescent reporters demonstrated that GSCs generate the majority of vascular pericytes. Selective elimination of GSC-derived pericytes disrupts the neovasculature and potently inhibits tumor growth. Analysis of human GBM specimens showed that most pericytes are derived from neoplastic cells. GSCs are recruited toward endothelial cells via the SDF-1/CXCR4 axis and are induced to become pericytes predominantly by transforming growth factor ß. Thus, GSCs contribute to vascular pericytes that may actively remodel perivascular niches. Therapeutic targeting of GSC-derived pericytes may effectively block tumor progression and improve antiangiogenic therapy.

mTORC1 Signaling in Brain Endothelial Progenitors Contributes to CCM Pathogenesis.

BACKGROUND: Cerebral vascular malformations (CCMs) are primarily found within the brain, where they result in increased risk for stroke, seizures, and focal neurological deficits. The unique feature of the brain vasculature is the blood-brain barrier formed by the brain neurovascular unit. Recent studies suggest that loss of CCM genes causes disruptions of blood-brain barrier integrity as the inciting events for CCM development. CCM lesions are proposed to be initially derived from a single clonal expansion of a subset of angiogenic venous capillary endothelial cells (ECs) and respective resident endothelial progenitor cells (EPCs). However, the critical signaling events in the subclass of brain ECs/EPCs for CCM lesion initiation and progression are unclear. METHODS: Brain EC-specific CCM3-deficient (Pdcd10BECKO) mice were generated by crossing Pdcd10fl/fl mice with Mfsd2a-CreERT2 mice. Single-cell RNA-sequencing analyses were performed by the chromium single-cell platform (10× genomics). Cell clusters were annotated into EC subtypes based on visual inspection and GO analyses. Cerebral vessels were visualized by 2-photon in vivo imaging and tissue immunofluorescence analyses. Regulation of mTOR (mechanistic target of rapamycin) signaling by CCM3 and Cav1 (caveolin-1) was performed by cell biology and biochemical approaches. RESULTS: Single-cell RNA-sequencing analyses from P10 Pdcd10BECKO mice harboring visible CCM lesions identified upregulated CCM lesion signature and mitotic EC clusters but decreased blood-brain barrier-associated EC clusters. However, a unique EPC cluster with high expression levels of stem cell markers enriched with mTOR signaling was identified from early stages of the P6 Pdcd10BECKO brain. Indeed, mTOR signaling was upregulated in both mouse and human CCM lesions. Genetic deficiency of Raptor (regulatory-associated protein of mTOR), but not of Rictor (rapamycin-insensitive companion of mTOR), prevented CCM lesion formation in the Pdcd10BECKO model. Importantly, the mTORC1 (mTOR complex 1) pharmacological inhibitor rapamycin suppressed EPC proliferation and ameliorated CCM pathogenesis in Pdcd10BECKO mice. Mechanistic studies suggested that Cav1/caveolae increased in CCM3-depleted EPC-mediated intracellular trafficking and complex formation of the mTORC1 signaling proteins. CONCLUSIONS: CCM3 is critical for maintaining blood-brain barrier integrity and CCM3 loss-induced mTORC1 signaling in brain EPCs initiates and facilitates CCM pathogenesis.

N6-methyladenine in DNA antagonizes SATB1 in early development.

The recent discovery of N6-methyladenine (N6-mA) in mammalian genomes suggests that it may serve as an epigenetic regulatory mechanism1. However, the biological role of N6-mA and the molecular pathways that exert its function remain unclear. Here we show that N6-mA has a key role in changing the epigenetic landscape during cell fate transitions in early development. We found that N6-mA is upregulated during the development of mouse trophoblast stem cells, specifically at regions of stress-induced DNA double helix destabilization (SIDD)2-4. Regions of SIDD are conducive to topological stress-induced unpairing of the double helix and have critical roles in organizing large-scale chromatin structures3,5,6. We show that the presence of N6-mA reduces the in vitro interactions by more than 500-fold between SIDD and SATB1, a crucial chromatin organizer that interacts with SIDD regions. Deposition of N6-mA also antagonizes SATB1 function in vivo by preventing its binding to chromatin. Concordantly, N6-mA functions at the boundaries between euchromatin and heterochromatin to restrict the spread of euchromatin. Repression of SIDD-SATB1 interactions mediated by N6-mA is essential for gene regulation during trophoblast development in cell culture models and in vivo. Overall, our findings demonstrate an unexpected molecular mechanism for N6-mA function via SATB1, and reveal connections between DNA modification, DNA secondary structures and large chromatin domains in early embryonic development.

Arabidopsis retromer subunit AtVPS29 is involved in SLY1-mediated gibberellin signaling.

KEY MESSAGE: Retromer protein AtVPS29 upregulates the SLY1 protein and downregulates the RGA protein, positively stimulating the development of the root meristematic zone, which indicates an important role of AtVPS29 in gibberellin signaling. In plants, the large retromer complex is known to play roles in multiple development processes, including cell polarity, programmed cell death, and root hair growth in Arabidopsis. However, many of its roles in plant development remain unknown. Here, we show that Arabidopsis trimeric retromer protein AtVPS29 (vacuolar protein sorting 29) modulates gibberellin signaling. The SLEEPY1 (SLY1) protein, known as a positive regulator of gibberellic acid (GA) signaling, exhibited lower abundance in vps29-3 mutants compared to wild-type (WT) plants. Conversely, the DELLA repressor protein, targeted by the E3 ubiquitin ligase SCF (Skp, Cullin, F-box) complex and acting as a negative regulator of GA signaling, showed increased abundance in vps29-3 mutants compared to WT. The vps29-3 mutants exhibited decreased sensitivity to exogenous GA supply in contrast to WT, despite an upregulation in the expression of GA receptor genes within the vps29-3 mutants. In addition, the expression of the GA synthesis genes was downregulated in vps29-3 mutants, implying that the loss of AtVPS29 causes the downregulation of GA synthesis and signaling. Furthermore, vps29-3 mutants exhibited a reduced meristematic zone accompanied by a decreased cell number. Together, these data indicate that AtVPS29 positively regulates SLY1-mediated GA signaling and plant growth.

Treatment persistence of bictegravir/emtricitabine/tenofovir alafenamide and efavirenz + lamivudine + tenofovir disoproxil among HIV-1 patients newly starting treatment in Hunan Province in China.

BACKGROUND: Though bictegravir/emtricitabine/tenofovir (BIC/FTC/TAF) have been regulatory approved and included in the National Reimbursement Drug List in China, due to the affordability concern, generic version of efavirenz + lamivudine + tenofovir (EFV + 3TC + TDF) is still recommended as the first-line therapy in the clinical guideline and widely used in clinical practice. The aim of the study is to assess the persistence with first-line BIC/TAF/TAF and EFV + 3TC + TDF in newly treated HIV-1 patients in the real-world setting in Hunan Province in China. METHODS: A retrospective analysis of the medical records of HIV patients initiating first-line antiretroviral therapy in the First Hospital of Changsha in January 1st, 2021-July 31st, 2022 was conducted. Persistence was assessed as the number of days on the therapy from the index until treatment discontinuation or end of data availability. Kaplan-Meier Curves and Cox Proportional Hazard models were used to evaluate the discontinuation rates. Subgroup analysis was performed excluding BIC/FTC/TAF patients with treatment discontinuation due to economic reason, and EFV + 3TC + TDF patients with a viral load > 500,000 copies/mL. RESULTS: A total of 310 eligible patients were included in the study, with 244 and 66 patients in the BIC/FTC/TAF group and EFV + 3TC + TDF group, respectively. Compared with EFV + 3TC + TDF patients, BIC/FTC/TAF patients were older, more living in the capital city currently, and had significantly higher total cholesterol and low-density level (all p < 0.05). No significant difference was shown in the time to discontinuation between BIC/FTC/TAF patients and EFV + 3TC + TDF patients. After excluding BIC/FTC/TAF patients with treatment discontinuation due to economic reason, EFV + 3TC + TDF group were shown to have a significantly higher risk of discontinuation than BIC/FTC/TAF group (hazard ratio [HR] = 11.1, 95% confidence interval [CI] = 1.3-93.2). After further removing the EFV + 3TC + TDF patients with a viral load > 500,000 copies/mL, the analysis showed similar results (HR = 10.1, 95% CI = 1.2-84.1). 79.4% of the EFV + 3TC + TDF patients discontinued treatment due to clinical reasons, while 83.3% of the BIC/FTC/TAF patients discontinued treatment due to economic reasons. CONCLUSIONS: Compared with BIC/FTC/TAF, EFV + TDF + 3TC patients were significantly more likely to discontinue the first-line treatment in Hunan Province in China.

Cardiac CIP protein regulates dystrophic cardiomyopathy.

Heart failure is a leading cause of fatality in Duchenne muscular dystrophy (DMD) patients. Previously, we discovered that cardiac and skeletal-muscle-enriched CIP proteins play important roles in cardiac function. Here, we report that CIP, a striated muscle-specific protein, participates in the regulation of dystrophic cardiomyopathy. Using a mouse model of human DMD, we found that deletion of CIP leads to dilated cardiomyopathy and heart failure in young, non-syndromic mdx mice. Conversely, transgenic overexpression of CIP reduces pathological dystrophic cardiomyopathy in old, syndromic mdx mice. Genome-wide transcriptome analyses reveal that molecular pathways involving fibrogenesis and oxidative stress are affected in CIP-mediated dystrophic cardiomyopathy. Mechanistically, we found that CIP interacts with dystrophin and calcineurin (CnA) to suppress the CnA-Nuclear Factor of Activated T cells (NFAT) pathway, which results in decreased expression of Nox4, a key component of the oxidative stress pathway. Overexpression of Nox4 accelerates the development of dystrophic cardiomyopathy in mdx mice. Our study indicates CIP is a modifier of dystrophic cardiomyopathy and a potential therapeutic target for this devastating disease.

A decision tree model of hypertension among college students in Yunnan Province, China.

PURPOSE: Previous studies have indicated that the prevalence rate of hypertension in adolescents is high, but it has not received much attention and the influencing factors are unclear, especially in Yunnan Province, China. MATERIALS AND METHODS: A cluster sampling method was used to investigate 4781 freshmen in a college in Kunming, Yunnan Province from November to December. Demographic and lifestyle data were collected using questionnaires, and height, weight and blood pressure were measured. Decision tree model of hypertension in college students was established by Chi-square automatic interactive detection method. RESULTS: Prevalence of prehypertension of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were detected in 33.9% and 32.1%, respectively. Prevalence of hypertension of SBP and DBP was detected in 1.2% and 7.2%, respectively. The hypertension and prehypertension decision tree of SBP has gender (χ2 = 728.64, p < .001) at the first level and body mass index (BMI) (boys: χ2 = 55.98, p < .001; girls: χ2 = 79.58, p < .001) at the second level. The hypertension and prehypertension decision tree of DBP has gender (χ2 = 381.83, p < .001) at the first level, BMI (boys: χ2 = 40.54, p < .001; girls: χ2 = 48.79, p < .001) at the second level, only children (χ2 = 6.43, p = .04) and red wine consumption (χ2 = 8.17, p = .017) at the third level. CONCLUSIONS: The present study suggests that gender, BMI, only children and red wine consumption were the main factors affecting hypertension in college students in southwest border areas of China.

Hypertension in Chinese adolescent is generally ignored. This study first reports the prevalence of hypertension in adolescents in Yunnan Province, China.Four thousand seven hundred and eighty-one freshmen were surveyed and height, weight and blood pressure were measured. A decision tree model was used to analyze the predictors of hypertension.The study demonstrated that gender, BMI, only children and red wine predict hypertension in adolescents.

A Phase I Study to Evaluate the Safety and Pharmacokinetics of SHR0302 Base Ointment in Healthy Adult Volunteers.

INTRODUCTION: SHR0302 is a highly selective JAK1 inhibitor. This study aimed to investigate the safety, tolerability, and pharmacokinetics of single and multiple-dose topical skin application of SHR0302 base ointment in healthy adult subjects. METHODS: This phase I clinical trial (registration number: CTR20192188) consisted of two parts. Part 1 was a single-dose ascending study with four dose levels in 32 healthy Australian adults (8 subjects in each dose group). All Australian subjects were randomized 3:1 to a single-dose topical skin application of SHR0302 base ointment or placebo. The dose escalated from 1% SHR0302 base ointment on 3% of body surface area (BSA) to 2% SHR0302 base ointment on 20% of BSA. Part 2 combined single and multiple-dose ascension studies with two dose levels in 20 healthy Chinese adults (10 subjects in each dose group). All Chinese subjects were randomized 4:1 to a combination of single and multiple doses for consecutive 10 days of topical application of 1% SHR0302 base ointment on 20% BSA or 2% SHR0302 base ointment on 20% BSA. The safety and pharmacokinetics of the SHR0302 base ointment were evaluated. RESULTS: The incidence of treatment-emergent adverse events (TEAEs) in both parts was comparable between the SHR0302 base ointment group and the vehicle group (part 1: 33.3% vs. 37.5%; part 2: 56.3% vs. 75.0%). All TEAEs were transient, recovered, and equally well-tolerated in the two racial groups. The overall absorption of the SHR0302 base ointment was slow after topical application, with Tmax>10 h. After a single dose of the SHR0302 base ointment, drug exposure in healthy Australian and Chinese subjects increased nonlinearly with the increase in the administration area and drug content. Drug exposure increased in a less-than-dose-proportional manner within the dose range tested. Due to differences in the clinical practice of topical application, the Tmax of the drug in Australian subjects was earlier than in Chinese subjects, but the overall extent of absorption seemed comparable in Australian and Chinese subjects (with comparable AUC0-t). CONCLUSION: The SHR0302 base ointment (either single or multiple doses) was well tolerated and safe, with no racial disparity. KEY MESSAGE: The SHR0302 base ointment (either single or multiples doses) was well tolerated and safe.

BMX Represses Thrombin-PAR1-Mediated Endothelial Permeability and Vascular Leakage During Early Sepsis.

RATIONALE: BMX (bone marrow kinase on the X chromosome) is highly expressed in the arterial endothelium from the embryonic stage to the adult stage in mice. It is also expressed in microvessels and the lymphatics in response to pathological stimuli. However, its role in endothelial permeability and sepsis remains unknown. OBJECTIVE: We aimed to delineate the function of BMX in thrombin-mediated endothelial permeability and the vascular leakage that occurs with sepsis in cecal ligation and puncture models. METHODS AND RESULTS: The cecal ligation and puncture model was applied to WT (wild type) and BMX-KO (BMX global knockout) mice to induce sepsis. Meanwhile, the electric cell-substrate impedance sensing assay was used to detect transendothelial electrical resistance in vitro and, the modified Miles assay was used to evaluate vascular leakage in vivo. We showed that BMX loss caused lung injury and inflammation in early cecal ligation and puncture-induced sepsis. Disruption of BMX increased thrombin-mediated permeability in mice and cultured endothelial cells by 2- to 3-fold. The expression of BMX in macrophages, neutrophils, platelets, and lung epithelial cells was undetectable compared with that in endothelial cells, indicating that endothelium dysfunction, rather than leukocyte and platelet dysfunction, was involved in vascular permeability and sepsis. Mechanistically, biochemical and cellular analyses demonstrated that BMX specifically repressed thrombin-PAR1 (protease-activated receptor-1) signaling in endothelial cells by directly phosphorylating PAR1 and promoting its internalization and deactivation. Importantly, pretreatment with the selective PAR1 antagonist SCH79797 rescued BMX loss-mediated endothelial permeability and pulmonary leakage in early cecal ligation and puncture-induced sepsis. CONCLUSIONS: Acting as a negative regulator of PAR1, BMX promotes PAR1 internalization and signal inactivation through PAR1 phosphorylation. Moreover, BMX-mediated PAR1 internalization attenuates endothelial permeability to protect vascular leakage during early sepsis.

CCM3 Loss-Induced Lymphatic Defect Is Mediated by the Augmented VEGFR3-ERK1/2 Signaling.

OBJECTIVE: Cerebral cavernous malformations (CCMs) can happen anywhere in the body, although they most commonly produce symptoms in the brain. The role of CCM genes in other vascular beds outside the brain and retina is not well-examined, although the 3 CCM-associated genes (CCM1, CCM2, and CCM3) are ubiquitously expressed in all tissues. We aimed to determine the role of CCM gene in lymphatics. Approach and Results: Mice with an inducible pan-endothelial cell (EC) or lymphatic EC deletion of Ccm3 (Pdcd10ECKO or Pdcd10LECKO) exhibit dilated lymphatic capillaries and collecting vessels with abnormal valve structure. Morphological alterations were correlated with lymphatic dysfunction in Pdcd10LECKO mice as determined by Evans blue dye and fluorescein isothiocyanate(FITC)-dextran transport assays. Pdcd10LECKO lymphatics had increased VEGFR3 (vascular endothelial growth factor receptor-3)-ERK1/2 (extracellular signal-regulated kinase 1/2) signaling with lymphatic hyperplasia. Mechanistic studies suggested that VEGFR3 is primarily regulated at a transcriptional level in Ccm3-deficient lymphatic ECs, in an NF-κB (nuclear factor κB)-dependent manner. CCM3 binds to importin alpha 2/KPNA2 (karyopherin subunit alpha 2), and a CCM3 deletion releases KPNA2 to activate NF-κB P65 by facilitating its nuclear translocation and P65-dependent VEGFR3 transcription. Moreover, increased VEGFR3 in lymphatic EC preferentially activates ERK1/2 signaling, which is critical for lymphatic EC proliferation. Importantly, inhibition of VEGFR3 or ERK1/2 rescued the lymphatic defects in structure and function. CONCLUSIONS: Our data demonstrate that CCM3 deletion augments the VEGFR3-ERK1/2 signaling in lymphatic EC that drives lymphatic hyperplasia and malformation and warrant further investigation on the potential clinical relevance of lymphatic dysfunction in patients with CCM.

Dexmedetomidine combined with ropivacaine for erector spinae plane block after posterior lumbar spine surgery: a randomized controlled trial.

PURPOSE: Due to lumbar spinal surgery is frequently accompanied with moderate-to-severe postoperative pain, it is necessary to find an effective postoperative analgesia for patients with this surgery. This study aimed to observe the analgesic effect of dexmedetomidine combined with ropivacaine erector spinae plane block (ESPB) used in posterior lumbar spine surgery. METHODS: In this clinical trial, patients undergoing posterior lumbar spine surgery were recruited and randomly divided into two groups: intervention and control. The intervention group (Group E) received 0.375% ropivacaine with 1 µg/kg dexmedetomidine in a total of 20 ml for ESPB; the control group (Group C) received 20 ml ropivacaine 0.375% for ESPB. US-guided ESPB was performed preoperatively in all patients. Demographics, anesthesia time, surgery time, and ASA grade from the participants were recorded at baseline. The primary clinical outcome measures were 2-, 4-, 8-, 12-, 24-and 48-h visual analog scale (VAS) pain scores after surgery at rest and movement state. Other end points included opioid consumption, number of PCIA presses, flurbiprofen-axetil consumption, quality of recovery and pain management after surgery. RESULTS: One hundred twenty patients were enrolled in the study (mean [SD] ages: Group E, 54.77 [8.61] years old; Group C,56.40 [7.87] years old; P = 0.280). The mean anesthesia time was 152.55 (15.37) min in Group E and 152.60 (16.47) min in Group C (P = 0.986). Additionally, the surgery time was 141.70 (15.71) min in Group E compared to 141.48 (17.13) min in Group C (P = 0.943). In addition, we found that the VAS pain scores in the resting state during the postoperative period at 8-48 h were lower in Group E than in Group C. However, the VAS pain scores in the active state were lower in Group E at 12-48 h (P < 0.05). More importantly, the consumption of opioids and flurbiprofen-axetil after surgery was also lower in Group E (P < 0.05). Subsequently, we administered questionnaires on the quality of recovery and pain management after surgery that were positively correlated with the postoperative analgesic effect. It was worth affirming that the QoR-15 scores and APS-POQ-R questionnaire results were different between the two groups, further confirming that the combination of drugs not only could obtain an ideal analgesic effect but also had no obvious adverse reactions (P < 0.05). CONCLUSIONS: All the findings suggested that dexmedetomidine could significantly relieve postoperative pain and reduce the consumption of opioids in patients undergoing posterior lumbar spine surgery without obvious adverse reactions as a local anesthetic adjuvant. Further studies with larger sample sizes and different drug dosages may be useful in understanding the potential clinical benefits of dexmedetomidine.

Pontine warning syndrome and restless legs syndrome secondary to paramedian pontine infarction: a case report.

Pontine warning syndrome (PWS) occurs rarely and is characterized by recurrent, stereotyped episodes of motor or sensory dysfunction, dysarthria, or ophthalmoplegia leading to pontine infarction. Restless legs syndrome (RLS) is a distinct neurological sensorimotor disorder. Pontine infarction is a rare but possible cause of RLS. Here, we report the case of a 58-year-old woman who experienced unilateral RLS in concomitance with stereotyped episodes of left-sided weakness and dysarthria, and developed an acute paramedian pontine infarction eventually. To the best of our knowledge, no other cases of PWS coinciding with RLS in the progression of pontine infarction have been reported in the literature. Furthermore, we discussed the potential mechanisms of PWS and RLS secondary to pontine infarction, which may be helpful for managing such patients.

Short AIP1 (ASK1-Interacting Protein-1) Isoform Localizes to the Mitochondria and Promotes Vascular Dysfunction.

OBJECTIVE: Vascular endothelial cells (ECs) normally maintain vascular homeostasis and are regulated by proinflammatory cytokines and reactive oxygen species. A human genome-wide association study identified that AIP1 (ASK1 [apoptosis signal-regulating kinase 1]-interacting protein-1; also identified as DAB2IP) gene variants confer susceptibility to cardiovascular disease, but the underlying mechanism is unknown. Approach and Results: We detected a normal AIP1 form (named AIP1A) in the healthy aorta, but a shorter form of AIP1 (named AIP1B) was found in diseased aortae that contained atherosclerotic plaques and graft arteriosclerosis. AIP1B transcription in resting ECs was suppressed through epigenetic inhibition by RIF1 (Rap1 [ras-related protein 1]-interacting factor 1)/H3K9 (histone H3 lysine 9) methyltransferase-mediated H3K9 trimethylation, and this inhibition was released by proinflammatory cytokines. AIP1A, but not AIP1B, was downregulated by proteolytic degradation through a Smurf1 (SMAD [suppressor of mothers against decapentaplegic miscellaneous] ubiquitylation regulatory factor 1)-dependent pathway in ECs under inflammation. Therefore, AIP1B was the major form present during inflammatory conditions. AIP1B, which lacks the N-terminal pleckstrin homology domain of AIP1A, localized to the mitochondria and augmented TNFα (tumor necrosis factor alpha)-induced mitochondrial reactive oxygen species generation and EC activation. AIP1B-ECTG (EC-specific AIP1B transgenic) mice exhibited augmented reactive oxygen species production, EC activation, and neointima formation in vascular remodeling models. CONCLUSIONS: Our current study suggests that a shift from anti-inflammatory AIP1A to proinflammatory AIP1B during chronic inflammation plays a key role in inflammatory vascular diseases.

Mural Cell-Specific Deletion of Cerebral Cavernous Malformation 3 in the Brain Induces Cerebral Cavernous Malformations.

OBJECTIVE: Cerebral cavernous malformations (CCM), consisting of dilated capillary channels formed by a single layer of endothelial cells lacking surrounding mural cells. It is unclear why CCM lesions are primarily confined to brain vasculature, although the 3 CCM-associated genes (CCM1, CCM2, and CCM3) are ubiquitously expressed in all tissues. We aimed to determine the role of CCM gene in brain mural cell in CCM pathogenesis. Approach and Results: SM22α-Cre was used to drive a specific deletion of Ccm3 in mural cells, including pericytes and smooth muscle cells (Ccm3smKO). Ccm3smKO mice developed CCM lesions in the brain with onset at neonatal stages. One-third of Ccm3smKO mice survived upto 6 weeks of age, exhibiting seizures, and severe brain hemorrhage. The early CCM lesions in Ccm3smKO neonates were loosely wrapped by mural cells, and adult Ccm3smKO mice had clustered and enlarged capillary channels (caverns) formed by a single layer of endothelium lacking mural cell coverage. Importantly, CCM lesions throughout the entire brain in Ccm3smKO mice, which more accurately mimicked human disease than the current endothelial cell-specific CCM3 deletion models. Mechanistically, CCM3 loss in brain pericytes dramatically increased paxillin stability and focal adhesion formation, enhancing ITG-ß1 (integrin ß1) activity and extracellular matrix adhesion but reducing cell migration and endothelial cell-pericyte associations. Moreover, CCM3-wild type, but not a paxillin-binding defective mutant, rescued the phenotypes in CCM3-deficient pericytes. CONCLUSIONS: Our data demonstrate for the first time that deletion of a CCM gene in the brain mural cell induces CCM pathogenesis.

The imprinted H19 lncRNA antagonizes let-7 microRNAs.

Abundantly expressed in fetal tissues and adult muscle, the developmentally regulated H19 long noncoding RNA (lncRNA) has been implicated in human genetic disorders and cancer. However, how H19 acts to regulate gene function has remained enigmatic, despite the recent implication of its encoded miR-675 in limiting placental growth. We noted that vertebrate H19 harbors both canonical and noncanonical binding sites for the let-7 family of microRNAs, which plays important roles in development, cancer, and metabolism. Using H19 knockdown and overexpression, combined with in vivo crosslinking and genome-wide transcriptome analysis, we demonstrate that H19 modulates let-7 availability by acting as a molecular sponge. The physiological significance of this interaction is highlighted in cultures in which H19 depletion causes precocious muscle differentiation, a phenotype recapitulated by let-7 overexpression. Our results reveal an unexpected mode of action of H19 and identify this lncRNA as an important regulator of the major let-7 family of microRNAs.

Metabolic network of ammonium in cereal vinegar solid-state fermentation and its response to acid stress.

Shanxi aged vinegar (SAV), a Chinese traditional vinegar, is produced by various microorganisms. Ammonium is an important nitrogen source for microorganisms and a key intermediate for the utilization of non-ammonium nitrogen sources. In this work, an ammonium metabolic network during SAV fermentation was constructed through the meta-transcriptomic analysis of in situ samples, and the potential mechanism of acid affecting ammonium metabolism was revealed. The results showed that ammonium was enriched as the acidity increased. Meta-transcriptomic analysis showed that the conversion of glutamine to ammonia is the key pathway of ammonium metabolism in vinegar and that Lactobacillus and Acetobacter are the dominant genera. The construction and analysis of the metabolic network showed that amino acid metabolism, nucleic acid metabolism, pentose phosphate pathway and energy metabolism were enhanced to resist acid damage to the intracellular environment and cell structures. The enhancement of nitrogen assimilation provides nitrogen for metabolic pathways that resist acid cytotoxicity. In addition, the concentration gradient allows ammonium to diffuse outside the cell, which causes ammonium to accumulate during fermentation.

Mitochondrial thioredoxin-2 maintains HCN4 expression and prevents oxidative stress-mediated sick sinus syndrome.

OBJECTIVE: Sick sinus syndrome (SSS) is associated with loss of HCN4 (hyperpolarization-activated cyclic nucleotide-gated potassium channel 4) function in the cardiac conduction system. The underlying mechanism for SSS remains elusive. This study is to investigate how mitochondrial oxidative stress induces HCN4 downregulation associated with in sick sinus syndrome. METHODS AND RESULTS: Trx2lox/lox mice were crossed with α-myosin heavy chain (α-Mhc)-Cre and Hcn4-CreERT2 deleter mice to generate Trx2 deletion mice in the whole heart (Trx2cKO) and in the conduction system (Trx2ccsKO), respectively. Echocardiography was applied to measure hemodynamics and heart rhythm. Histological analyses, gene profiling and chromatin immunoprecipitation were performed to define the mechanism by which thioredoxin-2 (Trx2) regulates HCN4 expression and cardiac function. Trx2cKO mice displayed dilated cardiomyopathy, low heart rate, and atrial ventricular block (AVB) phenotypes. Immunofluorescence revealed that HCN4 expression was specifically reduced within the sinoatrial node in Trx2cKO mice. Interestingly, Trx2ccsKO mice displayed low heart rate and AVB without dilated cardiomyopathy. Both mRNA and protein levels of HCN4 were reduced in the sinoatrial node, suggesting transcriptional HCN4 regulation upon Trx2 deletion. ChIP indicated that the binding of MEF2 to the HCN4 enhancer was not altered by Trx2 deletion; however, histone 3 acetylation at the MEF2 binding site was decreased, and expression of histone deacetylase 4 (HDAC4) was elevated following Trx2 deletion. Moreover, HDAC4 binding to the HCN4 enhancer was mediated by MEF2. Mitochondrial ROS were increased by Trx2 deletion and importantly, mitochondria-specific ROS scavenger MitoTEMPO suppressed HDAC4 elevation, HCN4 reduction, and sinus bradycardia in Trx2ccsKO mice. CONCLUSION: In the conduction system, Trx2 is critical for maintaining HCN4-mediated normal heart rate. Loss of Trx2 reduces HCN4 expression via a mitochondrial ROS-HDAC4-MEF2C pathway and subsequently induces sick sinus syndrome in mice.

Stage-specific regulation of Gremlin1 on the differentiation and expansion of human urinary induced pluripotent stem cells into endothelial progenitors.

Human urinary induced pluripotent stem cells (hUiPSCs) produced from exfoliated renal epithelial cells present in urine may provide a non-invasive source of endothelial progenitors for the treatment of ischaemic diseases. However, their differentiation efficiency is unsatisfactory and the underlying mechanism of differentiation is still unknown. Gremlin1 (GREM1) is an important gene involved in cell differentiation. Therefore, we tried to elucidate the roles of GREM1 during the differentiation and expansion of endothelial progenitors. HUiPSCs were induced into endothelial progenitors by three stages. After differentiation, GREM1 was obviously increased in hUiPSC-induced endothelial progenitors (hUiPSC-EPs). RNA interference (RNAi) was used to silence GREM1 expression in three stages, respectively. We demonstrated a stage-specific effect of GREM1 in decreasing hUiPSC-EP differentiation in the mesoderm induction stage (Stage 1), while increasing differentiation in the endothelial progenitors' induction stage (Stage 2) and expansion stage (Stage 3). Exogenous addition of GREM1 recombinant protein in the endothelial progenitors' expansion stage (Stage 3) promoted the expansion of hUiPSC-EPs although the activation of VEGFR2/Akt or VEGFR2/p42/44MAPK pathway. Our study provided a new non-invasive source for endothelial progenitors, demonstrated critical roles of GREM1 in hUiPSC-EP and afforded a novel strategy to improve stem cell-based therapy for the ischaemic diseases.

Nuclear localization of the tyrosine kinase BMX mediates VEGFR2 expression.

Vascular endothelial growth factor receptors (VEGFRs) are major contributors to angiogenesis and lymphangiogenesis through the binding of VEGF ligands. We have previously shown that the bone marrow tyrosine kinase BMX is critical for inflammatory angiogenesis via its direct transactivation of VEGFR2. In the present study, we show that siRNA-mediated silencing of BMX led to a significant decrease in the total levels of VEGFR2 mRNA and protein, without affecting their stability, in human endothelial cells (ECs). Interestingly, BMX was detected in the nuclei of ECs, and the SH3 domain of BMX was necessary for its nuclear localization. Luciferase assays showed a significant decrease in the Vegfr2 (kdr) gene promoter activity in ECs after BMX silencing, indicating that BMX is necessary for Vegfr2 transcription. In addition, we found that wild-type BMX, but not a catalytic inactive mutant BMX-K445R, promoted Vegfr2 promoter activity and VEGF-induced EC migration and tube sprouting. Mechanistically, we show that the enhancement of Vegfr2 promoter activity by BMX was mediated by Sp1, a transcription factor critical for the Vegfr2 promoter. Loss of BMX significantly reduced Sp1 binding to the Vegfr2 promoter as assayed by chromatin immunoprecipitation assays. Wild-type BMX, but not a kinase-inactive form of BMX, associated with and potentially phosphorylated Sp1. Moreover, a nuclear-targeted BMX (NLS-BMX), but not cytoplasm-localized form (NES-BMX), bound to Sp1 and augmented VEGFR2 expression. In conclusion, we uncovered a novel function of nuclear-localized BMX in regulating VEGFR2 expression and angiogenesis, suggesting that BMX is a therapeutic target for angiogenesis-related diseases.

[Content determination and principal component analysis of nine active components in Paeonia lactiflora flowers from different cultivars and drying methods].

This study aims to establish an UPLC-DAD method for the simultaneous determination of nine active components in phenolic acids, anthocyanins, monoterpene glucosides and flavonoids in the petals of Paeonia lactiflora flowers from different cultivars and processing methods. UPLC analysis was performed on a Waters ACQUITY UPLC HSS T3 C_(18) column(2.1 mm × 100 mm, 1.8 µm)for gradient elution with a mobile phase consisting of 0.5% formic acid solution(A)-acetonitrile(B)at a flow rate of 0.3 mL·min~(-1).The detection wavelength was determined with a switched wavelength method and the column temperature maintained at 20 ℃, with an injection volume of 2 µL.The contents of the above components in the samples with different sources and treatment methods were obtained. The principal component analysis(PCA)of P. lactiflora flowers was conducted by using SIMCA 14.0 software, and the results showed that the P. lactiflora flowers could be classified into two categories according to cultivars, including P. lactiflora 'Bozhou-shaoyao' as one category with high contents of the above components, P. lactiflora 'Baihuachuanshaoyao' and P. lactiflora 'Honghuachuanshaoyao' as the other category. Dried P. lactiflora flowers could be classified into three categories, including baking-drying, sun-drying and shade-drying, with baking-drying method as the optimal one.The P. lactiflora flowers were not greatly affected by origins, growing altitudes, growing years, or blooming stages.The results of contents determination can be used to guide the cultivar selection, harvest and processing of P. lactiflora flowers.