Glioma stem cells and neural stem cells respond differently to BMP4 signaling.

Malignant glioma is a highly heterogeneous and invasive primary brain tumor characterized by high recurrence rates, resistance to combined therapy, and dismal prognosis. Glioma stem cells (GSCs) are likely responsible for tumor progression, resistance to therapy, recurrence, and poor prognosis owing to their high self-renewal and tumorigenic potential. As a family member of BMP signaling, bone morphogenetic protein4 (BMP4) has been reported to induce the differentiation of GSCs and neural stem cells (NSCs). However, the molecular mechanisms underlying the BMP4-mediated effects in these two cell types are unclear. In this study, we treated hGSCs and hNSCs with BMP4 and compared the phenotypic and transcriptional changes between these two cell types. Phenotypically, we found that the growth of hGSCs was greatly inhibited by BMP4, but the same treatment only increased the cell size of hNSCs. While the RNA sequencing results showed that BMP4 treatment evoked significantly transcriptional changes in both hGSCs and hNSCs, the profiles of differentially expressed genes were distinct between the two groups. A gene set that specifically targeted the proliferation and differentiation of hGSCs but not hNSCs was enriched and then validated in hGSC culture. Our results suggested that hGSCs and hNSCs responded differently to BMP4 stimulation. Understanding and investigating different responses between hGSCs and hNSCs will benefit finding partner factors working together with BMP4 to further suppress GSCs proliferation and stemness without disturbing NSCs.

A Fast and Efficient Approach to Obtaining High-Purity Glioma Stem Cell Culture.

Glioma is the most common and malignant primary brain tumor. Patients with malignant glioma usually have a poor prognosis due to drug resistance and disease relapse. Cancer stem cells contribute to glioma initiation, progression, resistance, and relapse. Hence, quick identification and efficient understanding of glioma stem cells (GSCs) are of profound importance for therapeutic strategies and outcomes. Ideally, therapeutic approaches will only kill cancer stem cells without harming normal neural stem cells (NSCs) that can inhibit GSCs and are often beneficial. It is key to identify the differences between cancer stem cells and normal NSCs. However, reports detailing an efficient and uniform protocol are scarce, as are comparisons between normal neural and cancer stem cells. Here, we compared different protocols and developed a fast and efficient approach to obtaining high-purity glioma stem cell by tracking observation and optimizing culture conditions. We examined the proliferative and differentiative properties confirming the identities of the GSCs with relevant markers such as Ki67, SRY-box containing gene 2, an intermediate filament protein member nestin, glial fibrillary acidic protein, and s100 calcium-binding protein (s100-beta). Finally, we identified distinct expression differences between GSCs and normal NSCs including cyclin-dependent kinase 4 and tumor protein p53. This study comprehensively describes the features of GSCs, their properties, and regulatory genes with expression differences between them and normal stem cells. Effective approaches to quickly obtaining high-quality GSCs from patients should have the potential to not only help understand the diseases and the resistances but also enable target drug screening and personalized medicine for brain tumor treatment.

[Biological characteristics of periodontal ligament stem cells modified by platelet derived growth factor BB].

PURPOSE: To investigate the biological characteristics of human periodontal stem cells (hPDLSCs) modified with platelet derived growth factor BB(PDGFBB) gene, and to explore its influence on proliferation, migration and osteogenic induction of hPDLSCs. METHODS: hPDLSCs were isolated and amplified, and immunofluorescence staining was performed to identify cell surface markers and osteogenic differentiation ability. hPDLSCs were transfected with PDGFBB gene by lentivirus vector, and the effects on cell proliferation and migration were detected by CCK-8 and scratch test after transfection. Real-time PCR was performed to analyze the mRNA expression levels of osteogenic and angiogenic genes in hPDLSCs cells transfected with PDGFBB gene. Statistical analysis was performed using SPSS 22.0 software package. RESULTS: hPDLSCs were successfully obtained by tissue mass culture and finite dilution method. Compared with the blank virus group and non-transfected group, the proliferation and migration ability of the cells in the transfection group were significantly increased, and the mRNA expression levels of OPN, COL-1 and VEGF were significantly up-regulated(P<0.05). CONCLUSIONS: Lentiviral vector can transfer PDGFBB gene into hPDLSCs in vitro and obtain continuous and stable expression. PDGFBB can promote proliferation and migration of hPDLSCs cells and up-regulate expression of osteogenic and angiogenic genes.

Cytokines Induce Monkey Neural Stem Cell Differentiation through Notch Signaling.

The mammalian central nervous system (CNS) has a limited ability to renew the damaged cells after a brain or spinal cord injury whether it is nonhuman primates like monkeys or humans. Transplantation of neural stem cells (NSCs) is a potential therapy for CNS injuries due to their pluripotency and differentiation abilities. Cytokines play an important role in CNS development and repair of CNS injuries. However, the detailed cytokine signaling response in monkey neural stem cells is rarely studied. In our previous research, we isolated NSCs from the adult monkey brain and found the effects of cytokines on monkey NSCs. Now, we further analyzed the regulation mechanisms of cytokines to the proliferation of monkey NSCs such as bone morphogenic protein 4 (BMP4), BMP4/leukaemia inhibitory factor (LIF), or retinoic acid (RA)/Forskolin. The data showed that BMP4 inhibited cell proliferation to arrest, but it did not affect the stemness of NSCs. BMP4/LIF promoted the astrocyte-like differentiation of monkey NSCs, and RA/forskolin induced the neuronal differentiation of monkey NSCs. BMP4/LIF and RA/forskolin induced monkey NSC differentiation by regulating Notch signaling. These results provide some theoretical evidence for NSC therapy to brain or spinal cord injury in regenerative medicine.

Aging Induced p53/p21 in Genioglossus Muscle Stem Cells and Enhanced Upper Airway Injury.

Aging of population brings related social problems, such as muscle attenuation and regeneration barriers with increased aging. Muscle repair and regeneration depend on muscle stem cells (MuSCs). Obstructive sleep apnea (OSA) rises in the aging population. OSA leads to hypoxia and upper airway muscle injury. However, little is known about the effect of increasing age and hypoxia to the upper airway muscle. The genioglossus (GG) is the major dilator muscle to keep the upper airway open. Here, we reported that muscle fiber and MuSC function declined with aging in GG. Increasing age also decreased the migration and proliferation of GG MuSCs. p53 and p21 were high expressions both in muscle tissue and in GG MuSCs. We further found that hypoxia inhibited GG MuSC proliferation and decreased myogenic differentiation. Then, hypoxia enhanced the inhibition effect of aging to proliferation and differentiation. Finally, we investigated that hypoxia and aging interact to form a vicious circle with upregulation of p53 and p21. This vicious hypoxia plus aging damage accelerated upper airway muscle injury. Aging and hypoxia are the major damage elements in OSA patients, and we propose that the damage mechanism of hypoxia and aging in GG MuSCs will help to improve upper airway muscle regeneration.

[Human dental pulp stem cells conditioned medium protects genioglossus myoblast from cobalt chloride-induced hypoxia injury through AMPK/PGC-1α pathway].

PURPOSE: To study the effect of hypoxia induced by cobalt chloride (CoCl2) on viability and oxidative stress of genioglossus myoblast, and to explore the mechanism of the protective effect of conditioned medium (CM) on human dental pulp stem cells (hDPSCs). METHODS: The hDPSCs were isolated and cultured, and the conditioned medium was prepared by ultrafiltration concentration. Mouse genioglossus myoblasts were isolated and divided into control group, CM group, CoCl2 group and CoCl2+CM group. The cell viability of genioglossus myoblasts was detected by CCK-8. The intracellular and mitochondrial ROS levels were evaluated by DCFH-DA and MitoSOX, respectively. The expression level of mitochondria-related genes in NRF-1 and NRF-2 were analyzed by real-time PCR. The expression of PGC-1α, p-AMPK and total AMPK protein was detected by Western blot. Statistical analysis was performed using SPSS 22.0 software package. RESULTS: The proliferation of genioglossus myoblasts was significantly decreased after 200 µmol/L CoCl2 treatment for 24 h (P<0.05), and the levels of reactive oxygen species (ROS) were significantly increased in intracellular and mitochondria (P<0.05). Compared with CoCl2 group, the proliferation ability of hDPSCs-CM was dramatically raised (P<0.05), and the intracellular and mitochondrial ROS content was remarkably decreased(P<0.05). hDPSCs-CM up-regulated the protein expression levels of pAMPK and PGC-1α in genioglossus myoblasts and mitochondrial downstream effectors of PGC-1α, including mRNA expression levels of NRF-1, NRF-2 (P<0.05). CONCLUSIONS: Human dental pulp stem cells conditioned medium can alleviate hypoxia injury induced by CoCl2 in genioglossus myoblasts, and its mechanism may be related to AMPK/PGC-1α signaling pathway.

Hypoxia-Induced ROS Contribute to Myoblast Pyroptosis during Obstructive Sleep Apnea via the NF-κB/HIF-1α Signaling Pathway.

Tissue hypoxia caused by upper airway collapse is a main cause of excessive oxidative stress and systemic inflammation in obstructive sleep apnea (OSA) patients. Increased reactive oxygen species (ROS) and inflammatory responses affect cell survival and ultimately contribute to tissue injury. In the present study, we proposed that the induction of ROS by hypoxia, as an intrinsic stress, activates myoblast pyroptosis in OSA. We found increased cell death and abnormal expression of pyroptosis markers in the skeletal muscle of OSA mice. In vitro studies showed hypoxia-induced pyroptotic death of C2C12 myoblasts, as evidenced by the activation of caspase-1 and gasdermin D (GSDMD). Hypoxia induced ROS overproduction and accumulation in myoblasts. More importantly, applying N-acetylcysteine (NAC), an ROS scavenger, rescued cell swelling, downregulated the inflammatory response, and prevented pyroptotic death in hypoxia-cultured myoblasts. Hypoxia stimulation promoted NF-κB P65 phosphorylation and HIF-1α nuclear translocation. Moreover, hypoxia increased the nuclear level of cleaved caspase-1 and GSDMD. NAC inhibited hypoxia-induced variations in the HIF-1α and NF-κB signaling pathway. Taken together, our results determined that hypoxia-induced ROS contribute to myoblast pyroptosis. Therefore, our findings suggest that ROS may be a potential therapeutic target for ameliorating hypoxia-induced cell death and tissue injury, especially in OSA and hypoxia-related diseases.

A Case of a Persistent Postoperative Infection Caused by Multidrug-Resistant Kluyvera ascorbata in the Oral and Maxillofacial Region.

INTRODUCTION: Kluyvera ascorbata infection is rare, but it has been extensively studied because of its potential to cause a wide range of infections and its ability to transfer the gene encoding for CTX-M-type extended spectrum ß-lactamases (ESBLs) to other Enterobacteriaceae. CASE PRESENTATION: The authors report a case of a 61-year-old Chinese male with a persistent postoperative infection caused by a multidrug-resistant ESBL-producing K. ascorbata. Following antimicrobial susceptibility testing, he was aggressively treated with gentamicin and levofloxacin with a favorable outcome. CONCLUSION: To our knowledge, this is the first case report of a persistent postoperative infection caused by a multidrug-resistant K. ascorbata in the oral and maxillofacial region. The authors suggest that K. ascorbata infection warrants prompt identification and aggressive antibiotic management, given that ESBL-producing K. ascorbata is resistant to penicillins and first-generation to third-generation cephalosporins.

Overexpression of the NDR1/HIN1-Like Gene NHL6 Modifies Seed Germination in Response to Abscisic Acid and Abiotic Stresses in Arabidopsis.

NHL (NDR1/HIN1-like) genes play crucial roles in pathogen induced plant responses to biotic stress. Here, we report the possible function of NHL6 in plant response to abscisic acid (ABA) and abiotic stress. NHL6 was highly expressed in non-germinated seeds, and its expression was strongly induced by ABA and multiple abiotic stress signals. Loss-of-function of NHL6 decreased sensitivity to ABA in the early developmental stages including seed germination and post-germination seedling growth of the nhl6 mutants. However, overexpression of NHL6 increased sensitivity to ABA, salt and osmotic stress of the transgenic plants. Further studies indicated that the increased sensitivity in the 35S::NHL6 overexpressing plants could be a result of both ABA hypersensitivity and increased endogenous ABA accumulation under the stress conditions. It was also seen that the ABA-responsive element binding factors AREB1, AREB2 and ABF3 could regulate NHL6 expression at transcriptional level. Our results indicate that NHL6 plays an important role in the abiotic stresses-induced ABA signaling and biosynthesis, particularly during seed germination and early seedling development in Arabidopsis.

Association among IRF6 polymorphism, environmental factors, and nonsyndromic orofacial clefts in western china.

The interferon regulatory factor 6 (IRF6) gene and environmental factors have been shown to be associated with nonsyndromic cleft lip with or without cleft palate (NSCL/P) in several populations. This study aimed to confirm the contribution of IRF6 and environmental factors to NSCL/P risk in western Han Chinese. Five single nucleotide polymorphisms (SNPs) were investigated in 107 case trios (child and parents) and 100 normal peers in western China using transmission disequilibrium test, case-control analysis, and logistic regression models. Strong evidence of linkage disequilibrium was found between these markers and the disease in both SNP analysis (A allele at rs4844880, G allele at rs2073485, and C allele at rs599021) and haplotype analysis (A-A for rs861019 and rs4844880, A-C for rs4844880 and rs599021, among others). Both mothers' medication and passive smoking during the first trimester of pregnancy may increase the risk of NSCL/P, but mothers' vitamins (including folic acid) supplementation during the first trimester was a protective factor. Interactions between mothers' abortion history and TT genotype of rs2235373 were statistically significant (odds ratio = 6.70, 95% confidence interval =1.69-26.52). Risk factors identified in this study may provide a better understanding of the etiological role IRF6 and environmental factors play in NSCL/P incidence.

Anthropometric study of the upper lip of 1500 healthy children in Chengdu, Western China.

The aim of this study was to measure and analyse morphological data about the upper lips of healthy children in Chengdu, Western China. The characteristics and patterns of growth and development of the upper lip may be helpful in guiding the treatment of cleft lip. A total of 1500 healthy children aged between 2 and 12 were divided into 11 groups according to their age. Seven points on the upper lip were measured directly: the length from the alar base to the commissure, the length of the philtrum, the length from the tip of the Cupid's bow to the commissure, the width of one limb of the Cupid's bow, the length from the alar base to the central columella, the area of the unilateral upper lip, and the angle of the line of the alar base to the commissure and the line of the tip of the Cupid's bow to the commissure. Five aspects were significantly different among the groups: the length from the alar base to the commissure (p=0.04), the length from the tip of the Cupid's bow to the commissure (p=0.02), the width of the upper lip (p=0.02), the area adjacent to the lip (p=0.03), and the area of the unilateral upper lip (p=0.04). These data may be useful for reference to cleft lip repair.