Dynamically changed HSP70 after reperfusion following cerebral infarction in human and rats: correlation with p38 MAPK.

We aimed to clarify the correlation between dynamic change of blood HSP70 and the prognosis of thrombolysis in human and rats, so as to explain the neuroprotection and early warning role of HSP70 in cerebral ischemia-reperfusion. Forty-two patients with acute ischemic stroke were divided into two groups according to the time from onset to thrombolytic therapy: 0 h-3 h (27 patients) and 3-4.5 h group (15 patients). The level of HSP70 in serum before and after thrombolysis was detected by ELISA. Furthermore, a rat model was also used to mimic the ischemic stroke and reperfusion. Peripheral blood of rat samples was collected to detect the level of HSP70 using Elisa. Several signal proteins from MAPK signaling pathway including JNK, p38, ERK (p42/44) were detected at different time points by Western blot of brain tissue. Patients who underwent thrombolytic therapy within 0-3 h had the highest HSP70 level at 1 h after thrombolysis. The higher HSP70 after thrombolysis, the better the patient prognosis. NIHSS scores showed HSP70 was positively correlated with cerebral ischemia. The levels of ERK family (p42/44 MAPK) and p-JNK were decreased gradually along with the time suffering cerebral ischemia. P-ERK, JNK, p-p38 had dynamic changes with increased ischemic time in the middle cerebral artery occlusion model. Dynamic change of HSP70 level in blood may be a biological index that reflects the functional condition of cell survival for cerebral ischemia and estimating the prognostic conditions. Importantly, HSP70 levels in blood were positively correlated with the p38 MAPK pathway in brain tissue.

Effects of PEG antibodies on in vivo performance of LNP-mRNA vaccines.

Polyethylene glycol (PEG) plays important roles in stabilizing and lengthening circulation time of lipid nanoparticle (LNP) vaccines. Nowadays various levels of PEG antibodies have been detected in human blood, but the impact and mechanism of PEG antibodies on the in vivo performance of LNP vaccines has not been clarified thoroughly. By illustrating the distribution characteristics of PEG antibodies in human, the present study focused on the influence of PEG antibodies on the safety and efficacy of LNP-mRNA vaccine against COVID-19 in animal models. It was found that PEG antibodies led to shortened blood circulation duration, elevated accumulation and mRNA expression in liver and spleen, enhanced expression in macrophage and dendritic cells, while without affecting the production of anti-Spike protein antibodies of COVID-19 LNP vaccine. Noteworthily, PEG antibodies binding on the LNP vaccine increased probability of complement activation in animal as well as in human serum and led to lethal side effect in large dosage via intravenous injection of mice. Our data suggested that PEG antibodies in human was a risky factor of LNP-based vaccines for biosafety concerns but not efficacy.

Integrated Analysis of Chromatin and Transcriptomic Profiling Identifies PU.1 as a Core Regulatory Factor in Microglial Activation Induced by Chronic Cerebral Hypoperfusion.

In addition to causing white matter lesions, chronic cerebral hypoperfusion (CCH) can also cause damage to gray matter, but the underlying molecular mechanisms remain largely unknown. In order to obtain a better understanding of the relationship between gene expression and transcriptional regulation alterations, novel upstream regulators could be identified using integration analysis of the transcriptome and epigenetic approaches. Here, a bilateral common carotid artery stenosis (BCAS) model was established for inducing CCH in mice. The spatial cognitive function of mice was evaluated, and changes in cortical microglia morphology were observed. RNA-sequencing (RNA-seq) and the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) were performed on isolated mouse cortical brain tissue. Then, a systematic joint analysis of BCAS hypoperfusion-induced cortex-specific RNA-seq and ATAC-seq was conducted in order to assess the extent of the correlation between the two, and PU.1 was found to be greatly enriched through motif analysis and transcription factor annotation. Also, the core regulatory factor PU.1 induced by BCAS hypoperfusion was shown to be colocalized with microglia. Based on the above analysis, PU.1 plays a key regulatory role in microglial activation induced by CCH. And the transcriptome and epigenomic data presented in this study can help identify potential targets for future research exploring chronic hypoperfusion-induced brain injury.

Transcriptome Profiling of Hippocampus After Cerebral Hypoperfusion in Mice.

Chronic cerebral hypoperfusion (CCH) is considered to be one of the major mechanism in the pathogenesis of vascular cognitive impairment (VCI). Increased inflammatory cells, particularly microglia, often parallel hypoperfusion-induced gray matter damage such as hippocampal lesions, but the exact mechanism remains largely unknown. To understand the pathological mechanisms, we analyzed hippocampus-specific transcriptome profiles after cerebral hypoperfusion. The mouse hypoperfusion model was induced by employing the 0.16/0.18 mm bilateral common carotid artery stenosis (BCAS) procedure. Cerebral blood flow (CBF) was assessed after 3-week hypoperfusion. Pathological changes were evaluated via hematoxylin staining and immunofluorescence staining. RNA-sequencing (RNA-seq) was performed using RNA samples of sham- or BCAS-operated mice, followed by quantitative real-time PCR (qRT-PCR) validation. We found that the 0.16/0.18 mm BCAS induced decreased CBF, hippocampal neuronal loss, and microglial activation. Furthermore, GSEA between sham and BCAS mice showed activation of interferon-beta signaling along with inflammatory immune responses. In addition, integrative analysis with published single-cell RNA-seq revealed that up-regulated differentially expressed genes (DEGs) were enriched in a distinct cell type of "microglia," and down-regulated DEGs were enriched in "CA1 pyramidal," not in "interneurons" or "S1 pyramidal." This database of transcriptomic profiles of BCAS-hypoperfusion will be useful for future studies to explore potential targets for vascular cognitive dysfunction.

Cortex-specific transcriptome profiling reveals upregulation of interferon-regulated genes after deeper cerebral hypoperfusion in mice.

Background: Chronic cerebral hypoperfusion (CCH) is commonly accompanied by brain injury and glial activation. In addition to white matter lesions, the intensity of CCH greatly affects the degree of gray matter damage. However, little is understood about the underlying molecular mechanisms related to cortical lesions and glial activation following hypoperfusion. Efforts to investigate the relationship between neuropathological alternations and gene expression changes support a role for identifying novel molecular pathways by transcriptomic mechanisms. Methods: Chronic cerebral ischemic injury model was induced by the bilateral carotid artery stenosis (BCAS) using 0.16/0.18 mm microcoils. Cerebral blood flow (CBF) was evaluated using laser speckle contrast imaging (LSCI) system. Spatial learning and memory were assessed by Morris water maze test. Histological changes were evaluated by Hematoxylin staining. Microglial activation and neuronal loss were further examined by immunofluorescence staining. Cortex-specific gene expression profiling analysis was performed in sham and BCAS mice, and then validated by quantitative RT-PCR and immunohistochemistry (IHC). Results: In our study, compared with the sham group, the right hemisphere CBF of BCAS mice decreased to 69% and the cognitive function became impaired at 4 weeks postoperation. Besides, the BCAS mice displayed profound gray matter damage, including atrophy and thinning of the cortex, accompanied by neuronal loss and increased activated microglia. Gene set enrichment analysis (GSEA) revealed that hypoperfusion-induced upregulated genes were significantly enriched in the pathways of interferon (IFN)-regulated signaling along with neuroinflammation signaling. Ingenuity pathway analysis (IPA) predicted the importance of type I IFN signaling in regulating the CCH gene network. The obtained RNA-seq data were validated by qRT-PCR in cerebral cortex, showing consistency with the RNA-seq results. Also, IHC staining revealed elevated expression of IFN-inducible protein in cerebral cortex following BCAS-hypoperfusion. Conclusion: Overall, the activation of IFN-mediated signaling enhanced our understanding of the neuroimmune responses induced by CCH. The upregulation of IFN-regulated genes (IRGs) might exert a critical impact on the progression of cerebral hypoperfusion. Our improved understanding of cortex-specific transcriptional profiles will be helpful to explore potential targets for CCH.

The m6A reader PRRC2A is essential for meiosis I completion during spermatogenesis.

N6-methyladenosine (m6A) and its reader proteins YTHDC1, YTHDC2, and YTHDF2 have been shown to exert essential functions during spermatogenesis. However, much remains unknown about m6A regulation mechanisms and the functions of specific readers during the meiotic cell cycle. Here, we show that the m6A reader Proline rich coiled-coil 2A (PRRC2A) is essential for male fertility. Germ cell-specific knockout of Prrc2a causes XY asynapsis and impaired meiotic sex chromosome inactivation in late-prophase spermatocytes. Moreover, PRRC2A-null spermatocytes exhibit delayed metaphase entry, chromosome misalignment, and spindle disorganization at metaphase I and are finally arrested at this stage. Sequencing data reveal that PRRC2A decreases the RNA abundance or improves the translation efficiency of targeting transcripts. Specifically, PRRC2A recognizes spermatogonia-specific transcripts and downregulates their RNA abundance to maintain the spermatocyte expression pattern during the meiosis prophase. For genes involved in meiotic cell division, PRRC2A improves the translation efficiency of their transcripts. Further, co-immunoprecipitation data show that PRRC2A interacts with several proteins regulating mRNA metabolism or translation (YBX1, YBX2, PABPC1, FXR1, and EIF4G3). Our study reveals post-transcriptional functions of PRRC2A and demonstrates its critical role in the completion of meiosis I in spermatogenesis.

Multicentre registration of wake-up stroke in China (MCRWUSC): a protocol for a prospective, multicentre, registry-based cohort study.

INTRODUCTION: Wake-up stroke (WUS) is a type of acute ischaemic stroke (AIS) that occurs during sleep with unknown time of symptom onset. The best treatment is usually not suitable for WUS, as thrombolysis is usually provided to patients who had a symptomatic AIS within a definite 4.5 hours, and WUS remains a therapeutic quandary. Efforts to explore the onset time characteristics of patients who had a WUS and the risk factors affecting poor prognosis support a role for providing new insights by performing multicentre cohort study. METHODS AND ANALYSIS: This multicentre, nationwide prospective registry will include 21 comprehensive stroke centres, with a goal of recruiting 550 patients who had a WUS in China. In this study, clinical data including patient's clinical characteristics, stroke onset time, imaging findings, therapeutic interventions and prognosis (the National Institutes of Health Stroke Scale Score and the modified Rankin Scale Score at different time points) will be used to develop prediction models for stroke onset time and prognostic evaluation using the fast-processing of ischemic stroke software. The purpose of this study is to identify risk factors influencing prognosis, to investigate the relationship between the time when the symptoms are found and the actual onset time and to establish an artificial intelligence-based model to predict the prognosis of patients who had a WUS. ETHICS AND DISSEMINATION: This study is approved by the ethics committee of Shanghai Pudong Hospital (Shanghai, China) and rest of all participating centres. The findings will be disseminated through peer-reviewed publications and conference presentations. PROSPERO REGISTRATION NUMBER: ChiCTR2100049133.

TBC1D21 is an essential factor for sperm mitochondrial sheath assembly and male fertility‡.

During spermiogenesis, the formation of the mitochondrial sheath is critical for male fertility. The molecular processes that govern the development of the mitochondrial sheath remain unknown. Whether TBC1D21 serves as a GTPase-activating protein (GAP) for GTP hydrolysis in the testis is unclear, despite recent findings indicating that it collaborates with numerous proteins to regulate the formation of the mitochondrial sheath. To thoroughly examine the property of TBC1D21 in spermiogenesis, we applied the CRISPR/Cas9 technology to generate the Tbc1d21-/- mice, Tbc1d21D125A R128K mice with mutation in the GAP catalytic residues (IxxDxxR), and Tbc1d21-3xFlag mice. Male Tbc1d21-/- mice were infertile due to the curved spermatozoa flagella. In vitro fertilization is ineffective for Tbc1d21-/- sperm, although healthy offspring were obtained by intracytoplasmic sperm injection. Electron microscopy revealed aberrant ultrastructural changes in the mitochondrial sheath. Thirty-four Rab vectors were constructed followed by co-immunoprecipitation, which identified RAB13 as a novel TBC1D21 binding protein. Interestingly, infertility was not observed in Tbc1d21D125A R128K mice harboring the catalytic residue, suggesting that TBC1D21 is not a typical GAP for Rab-GTP hydrolysis. Moreover, TBC1D21 was expressed in the sperm mitochondrial sheath in Tbc1d21-3xFlag mice. Immunoprecipitation-mass spectrometry demonstrated the interactions of TBC1D21 with ACTB, TPM3, SPATA19, and VDAC3 to regulate the architecture of the sperm midpiece. The collective findings suggest that TBC1D21 is a scaffold protein required for the organization and stabilization of the mitochondrial sheath morphology.

Interrogating preclinical study of liposomes: The effect of mouse strain reexamined.

Mice are arguably the most important tool in the preclinical evaluation of liposomes; however, the effects of inter-strain physiological variabilities on in vivo performance of liposomes have been seriously overlooked. The present study validated that plasma proteins (PPs) and the capability of mononuclear phagocyte system (MPS) (typically expressed by phagocytosis rate, K) were mice strain-dependent. Physiological variabilities in PPs and the phagocytosis rate jointly contributed to the inter-strain inconsistency of pharmacokinetic (PK) profiles of liposomes. For the PPs sensitive liposomes (such as plain PEGylated liposomes and folic acid functionalized PEGylated liposomes), inter-strain variabilities in PK profiles could be calibrated using the corrected phagocytic rate (KC = K×(c × Ig)/(alb×apo)), where c, Ig, alb and apo were respective the total content of complement proteins, immunoglobulins, albumin and apolipoproteins. While for the PPs insensitive liposomes (e.g., cRGD functionalized liposomes), phagocytic rate could be directly used to calibrate inter-strain difference of liposome PK profiles. Our data also warn that the reciprocal interaction between payloads and organisms would be much more complicated than that between liposomes and organisms, thus independent investigation should be conducted for each individual therapeutic agent.

Interrogation of Folic Acid-Functionalized Nanomedicines: The Regulatory Roles of Plasma Proteins Reexamined.

Folic acid (FA) has been extensively exploited to facilitate targeted delivery of nanomedicines by recognizing the folate receptor-α (FR-α) overexpressed in many human cancers. Unfortunately, none have been approved for clinical use yet. Here we reveal that FA functionalization induces heavy natural IgM absorption on the liposomal surface, depriving FA of receptor recognition and accelerating complement activation in vivo. FA functionalization does not enhance distribution of liposomes in FR-α-overexpressed tumors in comparison to plain liposomes (without FA), but leads to aggravated capture of liposomes by macrophages in the tumor, liver, and spleen. In addition, FA-functionalized polymeric nanoparticles are also vulnerable to natural IgM absorption. This work highlights the pivotal roles of natural IgM in regulating in vivo delivery of FA-functionalized nanomedicines. Due to the prevalent association of immune disorders and varying levels of immunoglobulins with cancer patients, extraordinary cautiousness is urged for clinical translation of FA-enabled targeted delivery systems.

Spatiotemporal expression of NDRG2 in the human fetal brain.

N-myc downstream-regulated gene 2 (NDRG2) has been implicated in the development of central nervous system and brain diseases such as brain tumors, ischemic stroke and neurodegenerative disorders. However, it remains unclear that the spatiotemporal distribution of NDRG2 in the human fetal brain. In this study, we examined the expression pattern of NDRG2 in different regions of human fetal brain at 16-28 gestational weeks (GWs) by using RT-PCR, western blot and immunohistochemistry. Firstly, RT-PCR revealed that mRNA of NDRG2 was detected in the human brain regions of fetuses at 16-28 GWs such as medulla oblongata (MdO), mesencephalon (MeE), cerebellum (Cbl), frontal lobe (Fr), ventricular (VZ)/subventricular zone (SVZ) and hippocampus (hip), and the expressions of NDRG2 mRNA in these human fetal brain regions were increased with gestational maturation. Furthermore, western blot and immunohistochemistry results revealed that at 28 GWs, the expression of NDRG2 protein was restricted to the MdO's olivary nucleus, MeE's aqueduct, cerebellar internal granular layers, cerebral cortex of the Fr, VZ/SVZ of lateral ventricle, and hippocampal dentate gyrus, and highest expression in the VZ/SVZ, and lowest in the MeE. Finally, double immunohistochemistry results showed that NDRG2 in the MdO, Cbl and VZ/SV at 28 GWS was mainly expressed in neurons (NeuN positive cells), and in some astrocytes (GFAP positive cells). Taken together, these results suggest that NDRG2 is mainly expressed in human fetal neurons of various brain regions during development, which may be involved in neuronal growth and maturation.

Silibinin inhibits endometrial carcinoma via blocking pathways of STAT3 activation and SREBP1-mediated lipid accumulation.

AIMS: To seek new conservative treatments for young women with early-stage endometrial carcinoma (EC) who desire to retain fertility, we investigated the effects and the underlying mechanism of silibinin in EC, which exhibits promising anti-cancer and tumour-suppressing properties in many malignant tumours. MAIN METHODS: Through relevant experiments such as MTT assay, cell colony formation assay and subcutaneous xenograft experiment, we showed that silibinin inhibited the proliferation of EC cells and tumours. Silibinin significantly induced cell cycle arrest and promoted apoptosis in vitro. In vivo TUNEL assay confirmed the apoptotic effect caused by silibinin. STAT3 is activated in the development of tumours. Silibinin notably inhibited the expression of STAT3 phosphorylation and regulated the expression of downstream genes involved in cell cycle and apoptosis at protein and mRNA levels in EC cells. Furthermore, silibinin decreased the expression of intranuclear SREBP1, which is a key regulator of lipid metabolism in the nucleus, and reduced the lipid accumulation in EC cells. Downregulation of the expression levels of SREBP1 and its downstream genes associated with lipid metabolism was also observed in silibinin-treated EC cells. KEY FINDINGS: The results revealed that a novel anticancer drug, silibinin, markedly suppressed cell proliferation, cell cycle progression, apoptosis inhibition and lipid accumulation by blocking STAT3 and SERBP1 signalling pathways in EC cells. SIGNIFICANCE: Silibinin has anti-tumour characteristics and inhibits abnormal lipid metabolism in EC. This compound is expected to contribute to the conservative and adjuvant treatment of EC and should therefore be investigated further.

Role of leptin and the leptin receptor in the pathogenesis of varicocele-induced testicular dysfunction.

The present study investigated the expression of leptin and its receptor in the left testis and hypothalamus of rats with varicocele and clarified their roles in the pathogenesis of varicocele­induced testicular dysfunction. A total of 40 male rats were divided randomly into four groups. Groups 1 (G1) and 3 (G3) underwent a sham operation. Groups 2 (G2) and 4 (G4) underwent operations to form a varicocele created by partial ligation of the left renal vein. G1 and G2 rats were euthanized 4 weeks after the operation while G3 and G4 rats were euthanized at 8 weeks. The expression of leptin and its receptor was analyzed by immunohistochemistry. The mRNA levels of leptin, its receptor, kisspeptin (KiSS­1), G­protein coupled receptor 54 (GPR54), gonadotropin releasing hormone (GnRH), luteinizing hormone (LH), and follicle­stimulating hormone (FSH) were measured by reverse transcription­quantitative polymerase chain reaction. Testicular spermatogenesis function and gonadal hormone levels were measured. Compared with G1 and G3, the expression of leptin and its receptor in rat testis was significantly higher in G2 and G4, respectively. Leptin expression was inversely associated with the number of sperm in the left epididymis, thickness of the seminiferous epithelium and the diameter of seminiferous tubules. The expression of leptin receptors in the hypothalamus of G2 and G4 was significantly increased compared with that in G1 and G3, respectively. The mRNA levels of KiSS­1, GPR54, GnRH, LH and FSH in G2 and G4 were significantly increased compared with that in G1 and G3, respectively. Serum testosterone levels in G2 and G4 rats were significantly lower than those in G1 and G3 rats, respectively. There was no significant difference between the serum levels of FSH, LH and leptin. These results suggest that leptin and its receptor may serve significant roles in the pathogenesis of varicocele-induced testicular dysfunction.

MiR-9 Promotes Apoptosis Via Suppressing SMC1A Expression in GBM Cell Lines.

OBJECTIVE: Glioblastomas multiforme (GBM) is the most malignant brain cancer, which presented vast genomic variation with complicated pathologic mechanism. METHOD: MicroRNA is a delicate post-transcriptional tuner of gene expression in the organisms by targeting and regulating protein coding genes. MiR-9 was reported as a significant biomarker for GBM patient prognosis and a key factor in regulation of GBM cancer stem cells. To explore the effect of miR-9 on GBM cell growth, we over expressed miR-9 in U87 and U251 cells. The cell viability decreased and apoptosis increased after miR-9 overexpression in these cells. To identify the target of miR-9, we scanned miR-9 binding site in the 3'UTRs region of expression SMC1A (structural maintenance of chromosomes 1A) genes and designed a fluorescent reporter assay to measure miR-9 binding to this region. Our results revealed that miR-9 binds to the 3'sUTR region of SMC1A and down-regulated SMC1A expression. RESULT: Our results indicated that miR-9 was a potential therapeutic target for GBM through triggering apoptosis of cancer cells.

Human Leukocyte Antigen DQB1 (HLA-DQB1) Polymorphisms and the Risk for Guillain-Barré Syndrome: A Systematic Review and Meta-Analysis.

Guillain-Barré syndrome (GBS) is an autoimmune disorder of the peripheral nervous system. There is no consensus regarding reported associations between human leukocyte antigen DQB1 (HLA-DQB1) polymorphisms and the risk for developing GBS. Here, we evaluated possible associations between HLA-DQB1 polymorphisms and the risk for GBS using a meta-analysis. We searched PubMed for case-control genetic association studies for HLA-DQB1 polymorphisms (*020x, *030x, *040x, *050x, and *060x) and the risk for GBS. Fixed-effect meta-analytical methods were used for the outcome measure and subgroup analyses. Estimated odds ratios (ORs) and 95% confidence intervals (CIs) were used to investigate the associations between HLA-DQB1 polymorphisms and the risk for GBS. Nine case-control studies involving 780 cases of GBS and 1353 controls were identified in the current study. The meta-analysis demonstrated no significant associations between HLA-DQB1 polymorphisms and the risk for GBS in Asian and Caucasian populations. There were two associations that approached significance: HLA-DQB1*030x in Asian patients (P = 0.07; OR: 0.76, 95% CI: 0.57-1.03) and HLA-DQB1*060x in all patients (P = 0.08; OR: 1.48, 95% CI: 0.96-2.29). Additional studies with larger sample sizes are required to establish a definitive assessment of the contribution of HLA-DQB1 polymorphisms to GBS risk.

Impaired mitochondrial dynamics and bioenergetics in diabetic skeletal muscle.

In most cells, mitochondria are highly dynamic organelles that constantly fuse, divide and move. These processes allow mitochondria to redistribute in a cell and exchange contents among the mitochondrial population, and subsequently repair damaged mitochondria. However, most studies on mitochondrial dynamics have been performed on cultured cell lines and neurons, and little is known about whether mitochondria are dynamic organelles in vivo, especially in the highly specialized and differentiated adult skeletal muscle cells. Using mitochondrial matrix-targeted photoactivatable green fluorescent protein (mtPAGFP) and electroporation methods combined with confocal microscopy, we found that mitochondria are dynamic in skeletal muscle in vivo, which enables mitochondria exchange contents within the whole mitochondrial population through nanotunneling-mediated mitochondrial fusion. Mitochondrial network promotes rapid transfer of mtPAGFP within the cell. More importantly, the dynamic behavior was impaired in high-fat diet (HFD)-induced obese mice, accompanying with disturbed mitochondrial respiratory function and decreased ATP content in skeletal muscle. We further found that proteins controlling mitochondrial fusion MFN1 and MFN2 but not Opa1 were decreased and proteins governing mitochondrial fission Fis1 and Drp1 were increased in skeletal muscle of HFD-induced mice when compared to normal diet-fed mice. Altogether, we conclude that mitochondria are dynamic organelles in vivo in skeletal muscle, and it is essential in maintaining mitochondrial respiration and bioenergetics.

Association between MTHFR gene polymorphisms, smoking, and the incidence of vascular dementia.

This study investigated the relationship between N5,N10-methylene tetrahydrofolic acid reductase (MTHFR) polymorphisms, smoking, and vascular dementia (VD). Polymerase chain reaction-restriction fragment length polymorphism analysis was used to analyze the frequency of the C/T polymorphism at position 677 of the MTHFR gene in 304 VD patients and 300 control patients with nondementia cerebral infarction. The CC, CT, and TT genotype frequencies of the MTHFR gene were 43.42%, 32.57%, and 24.01%, respectively, in the VD group, and 50.67%, 32.00%, and 17.33%, respectively, in the control group. The T allele frequency was significantly higher in the VD group than in the control group (P < .05). Among patients who smoked, the relative risk of VD in patients with the TT genotype and T allele was higher than in the control group (P < .05). Therefore, the smoking group with the T allele has the highest risk of VD, and synergy appears to exist between the MTHFR gene polymorphisms and smoking in susceptibility to VD.

Low dose bisphenol A impairs spermatogenesis by suppressing reproductive hormone production and promoting germ cell apoptosis in adult rats.

Bisphenol A (BPA), an estrogenic chemical, has been shown to reduce sperm count; however, the underlying mechanisms remain unknown. Herein, we show that oral administration of BPA (2 µg/kg) for consecutive 14 days in adult rats (BPA rats) significantly reduced the sperm count and the number of germ cells compared to controls. The serum levels of testosterone and follicle-stimulating hormone (FSH), as well as the level of GnRH mRNA in BPA rats were lower than those of control rats. Testosterone treatment could partially rescue the reduction of germ cells in BPA rats. Notably, the number of apoptotic germ cells was significantly increased in BPA rats, which was insensitive to testosterone. Furthermore, the levels of Fas, FasL and caspase-3 mRNA in the testicle of BPA rats were increased in comparison with controls. These results indicate that exposure to a low dose of BPA impairs spermatogenesis through decreasing reproductive hormones and activating the Fas/FasL signaling pathway.

A clinical study of the effects of lead poisoning on the intelligence and neurobehavioral abilities of children.

BACKGROUND: Lead is a heavy metal and important environmental toxicant and nerve poison that can destruction many functions of the nervous system. Lead poisoning is a medical condition caused by increased levels of lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and issues, including the central nervous system. It interferes with the development of the nervous system, and is therefore particularly toxic to children, causing potentially permanent neural and cognitive impairments. In this study, we investigated the relationship between lead poisoning and the intellectual and neurobehavioral capabilities of children. METHODS: The background characteristics of the research subjects were collected by questionnaire survey. Blood lead levels were detected by differential potentiometric stripping analysis (DPSA). Intelligence was assessed using the Gesell Developmental Scale. The Achenbach Child Behavior Checklist (CBCL) was used to evaluate each child's behavior. RESULTS: Blood lead levels were significantly negatively correlated with the developmental quotients of adaptive behavior, gross motor performance, fine motor performance, language development, and individual social behavior (P < 0.01). Compared with healthy children, more children with lead poisoning had abnormal behaviors, especially social withdrawal, depression, and atypical body movements, aggressions and destruction. CONCLUSION: Lead poisoning has adverse effects on the behavior and mental development of 2-4-year-old children, prescribing positive and effective precautionary measures.

Increase of anteroventral periventricular kisspeptin neurons and generation of E2-induced LH-surge system in male rats exposed perinatally to environmental dose of bisphenol-A.

Perinatal exposure to environmental levels of bisphenol-A (BPA) impairs sexually dimorphic behaviors in rodents. Kisspeptin neurons in anteroventral periventricular nucleus (AVPV), which plays an important role in the activation of GnRH neurons and the initiation of LH-surge, have been suggested to be sexual dimorphism in rats. This study focused on exploring the influence of a perinatal exposure to an environmental dose of BPA on the development and maturation of male AVPV kisspeptin neurons and hypothalamus-pituitary-gonadal axis. Female rats were injected sc with 2 µg BPA/kg·d from gestation d 10 through lactation d 7. Anatomical and functional changes in AVPV kisspeptin neurons and hypothalamus-pituitary-gonadal axis were examined in prepubertal, pubertal, and adult male rats exposed perinatally to BPA (BPA-rats). Here, we show that in postnatal d (PND)30/50/90 BPA-rats, the number of AVPV kisspeptin-immunoreactive cells was persistently increased in comparison with age-matched control male rats. The number of GnRH-immunoreactive cells in PND30 BPA-rats declined approximately 40% compared with control male rats, whereas that in PND50/90 BPA-rats was increased in a G protein-coupled receptor 54-dependent manner. Estradiol could induce a stable LH-surge in PND90 BPA-rats and control female rats, which was sensitive to the G protein-coupled receptor 54 inhibitor. In PND30/50 BPA-rats, plasma level of LH was higher, but the level of testosterone was lower than control male rats. These findings provide evidence that perinatal exposure to an environmental dose of BPA causes a sustained increase in AVPV kisspeptin neurons in male rats, leading to the generation of estradiol-induced LH-surge system.