Two simple assays for assessing the seeding activity of proteopathic tau

The regional distribution of neurofibrillary tangles of hyperphosphorylated tau aggregates is associated with the progression of Alzheimer’s disease (AD). Misfolded proteopathic tau recruits naïve tau and templates its misfolding and aggregation in a prion-like fashion, which is believed to be the molecular basis of propagation of tau pathology. A practical way to assess tau seeding activity is to measure its ability to recruit/bind other tau molecules and to induce tau aggregation. Based on the properties of proteopathic tau, here we report the development of two simple assays to assess tau seeding activity ----- capture assay in vitro and seeded-tau aggregation assay in cultured cells. In the capture assay, proteopathic tau was applied onto a nitrocellulose membrane and the membrane was incubated with cell lysate containing HA-tagged tau151-391 (HA-tau151-391). The captured tau on the membrane was determined by immuno-blots developed with anti-HA. For the seeded-tau aggregation assay, HEK-293FT cells transiently expressing HA-tau151-391 were treated with proteopathic tau in the presence of Lipofectamine 2000 and then lysed with RIPA buffer. RIPA-insoluble fraction containing aggregated tau was obtained by ultracentrifugation and analyzed by immuno-blot developed with anti-HA. To validate these two assays, we assessed the seeding activity of tau in the middle frontal gyrus, middle temporal gyrus and basal forebrain of AD and control brains and found that AD, but not control, brain extracts effectively captured and seeded tau151-391 aggregation. Basal forebrain contained less phospho-tau and tau seeding activity. The levels of captured tau or seeded-tau aggregates were positively correlated to the levels of phospho-tau, Braak stages and tangle sores. These two assays are specific and sensitive and can be carried out in a regular biomedical laboratory setting by using routine biochemical techniques.

Gut Microbiota and Immunotherapy for Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that eventually leads to dementia and death of the patient. Currently, no effective treatment is available that can slow or halt the progression of the disease. The gut microbiota can modulate the host immune system in the peripheral and central nervous system through the microbiota-gut-brain axis. Growing evidence indicates that gut microbiota dysbiosis plays an important role in the pathogenesis of AD, and modulation of the gut microbiota may represent a new avenue for treating AD. Immunotherapy targeting Aβ and tau has emerged as the most promising disease-modifying therapy for the treatment of AD. However, the underlying mechanism of AD immunotherapy is not known. Importantly, preclinical and clinical studies have highlighted that the gut microbiota exerts a major influence on the efficacy of cancer immunotherapy. However, the role of the gut microbiota in AD immunotherapy has not been explored. We found that immunotherapy targeting tau can modulate the gut microbiota in an AD mouse model. In this article, we focused on the crosstalk between the gut microbiota, immunity, and AD immunotherapy. We speculate that modulation of the gut microbiota induced by AD immunotherapy may partially underlie the efficacy of the treatment.

[Efficacy of recombinant human growth hormone treatment in children born small for gestational age with syndromic and non-syndromic short stature]

Objective: To analyse the efficacy of recombinant human growth hormone (rhGH) treatment in children born small for gestational age (SGA) with syndormic and non-syndormic short stature. Methods: The clinical data of 59 children born SGA who were diagnosed as short stature and admitted to the Center of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital from July 2012 to June 2021 were collected and analyzed. According to the 2019 consensus on short stature, they were divided into syndromic group and non-syndromic group. Before treatment and 6, 12, 18 and 24 months after treatment, height standard deviation score (Ht-SDS), difference of height standard deviation (∆Ht-SDS) and homeostasis model assessment-insulin resistance index (HOMA-IR) were compared between groups, while Ht-SDS and HOMA-IR were compared before and after treatment. Independent t test or Kruskal-Wallis test were used for comparison between the 2 groups, and paired t test or Mann-Whitney U test were used for the intra-group comparison. Results: Among the 59 cases, 37 were males and 22 females, aged (5.5±2.3) years. There was no significant difference in Ht-SDS after 12 months of treatment between 2 groups (0.9±0.4 vs. 1.2±0.4, t=1.68, P=0.104) or in height SDS after 24 months of treatment (1.4±0.7 vs. 1.9±0.5, t=1.52, P=0.151). After 12 months of treatment, the insulin resistance index of the non-syndromic group was significantly higher than that of the syndromic group (2.29 (1.43, 2.99) vs. 0.90 (0.55, 1.40), Z=-2.95, P=0.003). There were significant differences in Ht-SDS between 6 months and before treatment, 12 months and 6 months in syndromic type (Z=7.65, 2.83 P<0.001, P=0.020), but all were significant differences in non-syndromic type between 6 months and before treatment, 12 months and 6 months, 18 months and 12 months, 24 months and 18 months (Z=11.95, 7.54, 4.26, 3.83, all P<0.001). Conclusion: The efficacy of rhGH treatment in children born SGA is comparable between syndromic and non-syndromic short stature cases, but non-syndromic children treated with rhGH need more frequent follow-up due to the risk of insulin resistance.

Tau seeding activity in various regions of down syndrome brain assessed by two novel assays

Propagation of tau pathology via the seeding of naive tau aggregation underlies the progression of Alzheimer's disease (AD) and related tauopathies. Individuals with Down syndrome (DS) develop tau pathology at the fourth decade of life, but tau seeding activity in DS brain has not yet been determined. To measure tau seeding activity, we developed capture assay and seeded-tau aggregation assay with truncated tau151-391. By using brain extracts from AD and related tauopathies, we validated these two methods and found that the brain extracts from AD and related tauopathies, but not from controls and the diseases in which tau was not hyperphosphorylated, captured in vitro and seeded 3R-tau151-391 and 4R-tau151-391 to aggregate in cultured cells similarly. Captured tau151-391 levels were strongly correlated with the seeded-tau151-391 aggregation. Employing these two newly developed assays, we analyzed tau seeding activity in the temporal (TC), frontal (FC), and occipital cortex (OC); corpus callosum (CC); and cerebellar cortex (CBC) of DS and control brains. We found that the extracts of TC, FC, or OC, but not the CC or CBC of DS or the corresponding brain regions of control cases, captured tau151-391. Levels of the captured tau151-391 by brain extracts were positively correlated with their levels of phosphorylated tau. Extracts of cerebral cortex and CC, but not CBC of DS with a similar tau level, induced more tau151-391 aggregation than did the corresponding samples from the control cases. Thus, higher tau seeding activity associated with tau hyperphosphorylation was found in the TC, FC, and OC of DS compared with the corresponding control regions as well as with the CBC and CC of DS. Of note, these two assays are sensitive, specific, and repeatable at a low cost and provide a platform for measuring tau seeding activity and for drug screening that targets tau propagation.

[Consistency evaluation of 2 methods in detecting serum insulin-like growth factorⅠ in children]

Objective: To evaluate the consistency of mass spectrometry (MS) and chemiluminescence immunoassay (CLIA) in detecting serum insulin-like growth factor-1 (IGF-1) and IGF-1 standard deviation score (SDS). Methods: This cross-sectional parallel control study prospectively collected the serum samples of 115 children with short stature disorders who were admitted in the Department of Endocrinology, Beijing Children's Hospital, Capital Medical University from February 2020 to December 2021. The serum IGF-1 level was detected by CLIA and MS, and converted to SDS for consistency analysis. Pearson analysis was used to analyze the correlation between the 2 methods, and Deming regression equation was established. Bland-Altman diagram and weighted Kappa coefficient were used to evaluate the consistency of the 2 methods. Results: There were 46 boys (40.0%) and 69 girls (60.0%), aged (8±3) years. Among the 115 cases, 37 were Turner syndrome, 59 were small for gestational age (SGA) at term, 1 was growth hormone deficiency (GHD) and 18 were other diseases. Pearson correlation analysis showed a preferable correlation between IGF-1 measured by the 2 detection methods (r=0.94, P<0.01), and IGF-1 SDS was also significantly correlated (r=0.92, P<0.01). Bland-Altman analysis showed that the consistency of serum IGF-1 levels detected by the 2 methods was poor, and the mean difference between CLIA and MS was 33.38 μg/L. The result detected by CLIA was significantly higher than that by MS, with SDS of 43.51 μg/L (95%CI -51.89-118.7 μg/L). After converting the results to SDS and removing 3 outliers (including 1 GHD patient), the weighted Kappa showed acceptable consistency (κ=0.68). Conclusion: In clinical application, after converting to IGF-1 SDS, IGF-1 detected by MS and CLIA can be used for cross-reference, but too high or too low levels should be cautious about.

AKT/GSK-3β signaling is altered through downregulation of mTOR during cerebral Ischemia/Reperfusion injury

PURPOSE

Cellular responses following cerebral ischemia/reperfusion injury are critical to recovery and survival after ischemic stroke. Understanding of these cellular responses can help the design of therapies to protect brain tissue and promote recovery after stroke. One of these cellular responses may be mediated by the AKT (protein kinase B) signal transduction pathway. This study was aimed to investigate the cerebral ischemia-induced alterations of AKT signaling and the upstream molecular pathways.

METHODS

We modeled cerebral ischemia by middle cerebral artery occlusion in 2-3-month-old male C57BL/6J mice and then analyze the brain samples by using quantitative Western blots and phosphorylation/activation-dependent kinase antibodies. Cerebral ischemia was confirmed by staining of brain slices with 1% 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl, as well as neurological assessments of the mice 24 h after ischemia-reperfusion surgery.

RESULTS

We found marked downregulation of AKT within 12 h of cerebral ischemia/reperfusion, which leads to overactivation of glycogen synthase kinase-3β (GSK-3β). Furthermore, we found that the downregulation of AKT was mediated by downregulation of mTORC2 (the complex 2 of the mechanistic target of rapamycin) instead of its common upstream kinases, phosphatidylinositol 3-kinase and phosphoinositide-dependent kinase-1.

CONCLUSION

Our findings provide new insight into the cellular responses to ischemia/reperfusion brain injury and will help develop new treatments targeting the AKT signaling pathway for the treatment of ischemic stroke.

Multi-Targets: An Unconventional Drug Development Strategy for Alzheimer’s Disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that eventually leads to dementia and death of the patient. Despite the enormous amounts of resources and efforts for AD drug development during the last three decades, no effective treatments have been developed that can slow or halt the progression of the disease. Currently available drugs for treating AD can only improve clinical symptoms temporarily with moderate efficacies. In recent years, the scientific community has realized these challenges and reconsidered the future directions of AD drug development. The most significant recent changes in AD drug development strategy include shifting from amyloid-based targets to other targets, such as tau, and efforts toward better designs for clinical trials. However, most AD drug development is still focused on a single mechanism or target, which is the conventional strategy for drug development. Although multifactorial mechanisms and, on this basis, multi-target strategies have been proposed in recent years, this approach has not been widely recognized and accepted by the mainstream of AD drug development. Here, we emphasize the multifactorial mechanisms of AD and discuss the urgent need for a paradigm shift in AD drug development from a single target to multiple targets, either with the multi-target–directed ligands approach or the combination therapy approach. We hope this article will increase the recognition of the multifactorial nature of AD and promote this paradigm shift. We believe that such a shift will facilitate successful development of effective AD therapies.

[Changing prevalence of overweight and obesity among Chinese children aged 6-15 from 2009-2019]

Objective: To analyze the trends of overweight and obesity prevalence in Chinese children, aged from 6 to 15 years old among 4 provinces and cities from 2009 to 2019. Methods: Reviewed the national multi-center epidemiological survey data of children from the National Key Technology R&D Program of China during the Eleventh Five-Year Plan (2009 to 2010) and the National Key Research and Development Program of China during the Thirteenth Five-Year Plan (2017 to 2019). The participants' data were selected from four provinces,municipalities and autonomous region,including Beijing, Tianjin (Northern region), Zhejiang (Eastern region), and Guangxi (Southern region). Totally 14 597 pairs of 6-15 year-old children were surveyed. According to the body mass index (BMI) and standard deviation score (SDS) of children among different genders, ages, and regions, t test or chi-square test was used to evaluate the changes in overweight and obesity over a 10-year span. Results: Totally 7 721 pairs of boys and 6 876 pairs of girls were collectted in this study, whose mean age was (10.7±2.5) years. In the past 10 years, the overall BMISDS were 0.39±1.24 and 0.36±1.31 and the overall obesity rate were 11.8% (n=1 773) anel 12.5% (n=1 813) of children in the 4 administrative regions did not have statistically significant differences (all P>0.05). However, the overall overweight rate rose from 17.1% (n=2 496) to 19.1% (n=2 781) (χ²=18.657, P<0.01), and the average annual growth rate was 0.20%. The BMISDS in the Eastern region increased from 0.10±1.07 to 0.19±1.22 (t=-4.095, P<0.01), and the overweight rate and obesity rate increased by 3.8% (n=202) and 3.1% (n=169) respectively (both P<0.01); the BMISDS in the Northern region and the obesity rate did not have statistically significant differences(all P>0.05), but the overweight rate rose from 20.5% (n=1 233) to 22.8% (n=1 365) significantly (χ²=7.431, P<0.01); BMISDS in the Southern region was significantly decreased from 0.30±1.19 to 0.09±1.25 (t=1.426, P<0.01), and the rate of obesity decreased from 9.8% (n=315) to7.9% (n=256) (χ²=6.46, P<0.05), the overweight rate was not stafistically significant (P=0.10), respectively. The obesity rate of boys had risen from 16.4% (n=1 265) to 18.2% (1 407) (χ²=8.997, P<0.01) in the past 10 years, and the overweight rate had risen from 18.0% (n=1 393) to 20.5% (n=1 579) (χ²=14.26, P<0.01). The overweight+obesity rate rose from 34.4% (n=2 658) to 38.7% (n=2 986) (χ²=29.859, P<0.01), and the weight problem in the age group of 8 to 11 years was particularly severe (all P<0.01). The obesity rate of girls dropped from 6.8% (n=468) to 5.9% (n=406) (χ²=4.546, P<0.05), the overweight rate rose from 16.0% (n=1 103) to 17.5% (n=1 202) (χ²=5.006, P<0.05), and the overall overweight+obesity rate rose from 22.8% (n=1 571) to 23.4% (n=1 608) (χ²=0.53, P>0.05). Conclusions: The growth rate of obesity among children in China had slowed down from 2009 to 2019, but the overweight rate was still on the rise. The overall base of overweight and obesity population continued to expand. The weight problem of peri-adolescent boys was particularly prominent. The current status of obesity epidemics in different regions, ages, and genders are significantly different and had their own characteristics. It is necessary to establish a personalized prevention and control strategy.

[Genetic and clinical analysis of X-linked hypophosphatemic rickets]

Objective: To investigate the clinical and genetic features, and treatment of X-linked hypophosphatemic rickets (XLH). Methods: In this retrospective study, we reviewed the medical records of 25 pediatric patients with XLH who were admitted to Department of Endocrinology Genetics and Metabolism,Beijing Children's Hospital from January 2010 to January 2020. The clinical characteristics, PHEX gene variants, as well as clinical outcome of the patients were summarized. To analyze the correlation between genotype and phenotype, the patients were divided into different subgroups according to the location of the variants, including N-terminal-located vs. C-terminal-located variant, and Zn-binding domain exon 17 or 19 variant vs. non-exon 17 or 19 variant. The age at onset, height standard deviation score (HtSDS), intercondylar or intermalleolar distance, fasting serum phosphorus, and HtSDS and intercondylar or intermalleolar distance at the final follow-up were compared by rank sum test or t text. Results: Among the 25 children with XLH, 8 were boys and 17 were girls. The median age of onset was 1.2 (1.0, 1.8) years, and the median age of diagnosis was 2.5 (1.5, 4.3) years. The main clinical manifestations were abnormal gait and lower limb deformity. The HtSDS was -2.0(-3.2, -0.8), and the intercondylar or intermalleolar distance was 4.5 (3.0, 6.0) cm. The fasting serum phosphorus level was 0.8 (0.7, 0.9) mmol/L, while the serum alkaline phosphatase level was (721±41) U/L and the serum calcium level was (2.5±0.1) mmol/L. Three patients (12%) had parathyroid hormone levels above the upper limit of the normal range. Twenty-five patients (100%) showed radiographic changes of active rickets. Nephrocalcinosis was found in 2 cases (9%). Twenty-four different PHEX variations were detected in 25 patients, among whom 11 (44%) had not been reported previously. No hot spot variation was found. No statistical differences (all P>0.05) were identified in clinical features and outcomes either in comparing patients with N-terminal (21 cases) and C-terminal (4 cases) variants, or in comparing patients with variant located in exon 17 or 19 (4 cases) or not (21 cases). Twenty-four cases (96%) were treated regularly with phosphate supplements and active vitamin D. After 2.7 (1.6, 5.0) years of follow-up, clinical symptoms were relieved in 96% (24/25) of the patients. The HtSDS after treatment had no significant difference compared to that before treatment (-2.0(-3.2, -0.8) vs.-2.0(-2.8, -1.1),Z =-0.156, P>0.05), while the intercondylar or intermalleolar distance after treatment was significantly reduced compared to that before treatment (4.5(3.0, 6.0) vs. 1.5(0, 3.3) cm, Z =-3.043, P<0.05). Bone X-rays were reexamined in 17 cases after treatment, and radiographic signs of rickets were improved. Eighteen cases had secondary hyperparathyroidism and 7 cases had nephrocalcinosis. Conclusions: The main clinical manifestations of XLH are abnormal gait, lower limb deformity and short stature. A high proportion of novel variations of PHEX gene but no hot spot variation neither genotype-phenotype correlation are found. Regular treatment with phosphate supplements and active vitamin D can significantly improve the symptoms except for the height. However, the rate of adverse events including secondary hyperparathyroidism and nephrocalcinosis seems to be high.

[Clinical and genetic analysis of Noonan syndrome in 20 children]

Objective: To explore the clinical and genetic characteristics of Noonan syndrome in children. Methods: The clinical characteristics,genetic analysis and follow-up data of 20 children diagnosed with Noonan syndrome who were admitted to Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, Capital Medical University from March 2016 to December 2020 were retrospectively analyzed. Results: Among 20 children with Noonan syndrome, 13 were males and 7 were females. The age at diagnosis was 5.9 years (1.1 years to 12.2 years). The most common clinical complaints were delayed height growth, followed by hypospadias or cryptorchidism in 2 cases, and special facial appearance in 1 case. Physical examination revealed 12 cases of Noonan syndrome with facial features, 9 cases with cryptorchidism and hypospadias, 10 cases with abnormal cardiac structure, and 10 cases with mental retardation; Twelve patients were detected with PTPN11 variations, 4 patients carried SOS2 variations, 2 cases were confirmed with variations in SHOC2 and SOS1. Six children received recombinant human growth hormone treatment, and their height increased by 4.0 (2.5-6.0) cm to varying degrees at 9 months. No adverse events occurred. Conclusions: Male Noonan syndrome is more frequently found with external genitalia. In addition to the high frequency of PTPN11 variation, the frequency of gene variation in SOS2 gene is higher than previously reported. All of the SOS2 variations are de novo. The syndrome phenotype profiles could vary with the admitted clinical departments. To understand the full picture of the syndrome, it is necessary to collect medical information from different departments.

Expression of Microtubule Associated Protein Tau in Mouse Pancreatic Islets Is Restricted to Autonomic Nerve Fibers

BACKGROUND

Evidence from clinical studies and basic research has shown a strong correlation between Alzheimer's disease (AD) and type 2 diabetes. Tau, a neuronal microtubule-associated protein, is hyperphosphorylated and aggregated into neurofibrillary tangles in the AD brain. However, the expression of tau in pancreas is under debate.

OBJECTIVE

We determined the expression of tau in mouse pancreas.

METHODS

We used western blots, immunoprecipitation, and immunohistochemical staining to analyze pancreatic expression of tau in mice.

RESULTS

We found that neither total tau nor phosphorylated tau was detectable in the mouse pancreas by western blots. Immunostaining with pan tau antibodies R134d and Tau-5 revealed bright and dense varicosities in the pancreatic islets and the exocrine pancreas. These varicosities were immunoreactive to synapsin 1, a presynaptic marker which can outline autonomic nerve profiles in pancreas, exhibiting complete colocalization with tau. Importantly, endocrine cells in islets did not exhibit specific immunoreactivity to any of pan tau antibodies tested, nor did the exocrine cells.

CONCLUSION

In the mouse pancreas, we found that tau is exclusively expressed in autonomic nerve fibers, but there is no detectable expression in endocrine cells in the islet.

High Mobility Group Box 1 Ameliorates Cognitive Impairment in the 3×Tg-AD Mouse Model

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia. Studies indicate that neuroinflammation plays an important role in the pathophysiology of AD. High-mobility group box 1 (HMGB1) is an important chromatin protein. It can be secreted by immune cells and passively released from damaged cells to promote inflammation. HMGB1 also can recruit stem cells and promote their proliferation and tissue repairing. However, the role of HMGB1 in the progression of AD is currently unknown.

OBJECTIVE

The aims were to investigate the effect of HMGB1 on the AD-related pathologies and cognitive function using 3×Tg-AD mouse model.

METHODS

Female 5-month-old 3×Tg-AD mice were intracerebroventricularly injected with 4.5 μg of HMGB1 or with saline as a control. The levels of interesting protein were assessed by western blots or immunofluorescence. The effect of HMGB1 on the cognitive function was evaluated by one-trial novel object recognition test and Morris water maze.

RESULTS

Intracerebroventricular injection of recombinant HMGB1 ameliorated cognitive impairment in 5-6-month-old 3×Tg-AD mice. The levels of synapsin 1, synaptophysin, MAP2, NeuN, and phosphorylated CREB were increased in HMGB1-treated 3×Tg-AD mouse brains. HMGB1 decreased intracellular amyloid-β level but did not affect tau phosphorylation. HMGB1 treatment also promoted neurogenesis in the dentate gyrus and increased the level of GFAP in the 3×Tg-AD mouse brains.

CONCLUSION

These results reveal a novel function of HMGB1 in enhancing neuroplasticity and improving cognitive function in 3×Tg-AD mice.

Thiamme2-G, a Novel O-GlcNAcase Inhibitor, Reduces Tau Hyperphosphorylation and Rescues Cognitive Impairment in Mice

BACKGROUND

Abnormal hyperphosphorylation of microtubule-associated protein tau plays a pivotal role in Alzheimer's disease (AD). We previously found that O-GlcNAcylation inversely correlates to hyperphosphorylation of tau in AD brain, and downregulation of brain O-GlcNAcylation promotes tau hyperphosphorylation and AD-like neurodegeneration in mice.

OBJECTIVE

Herein we investigated the effect of increasing O-GlcNAcylation by using intermittent dosing with low doses of a potent novel O-GlcNAcase (OGA) inhibitor on AD-like brain changes and cognitive function in a mouse model of sporadic AD (sAD) induced by intracerebroventricular (ICV) injection of streptozotocin (STZ).

METHODS

STZ was injected into the lateral ventricle of C57BL/6J mice. From the second day, Thiamme2-G (TM2G) or saline, as a vehicle control, was orally administered to the ICV-STZ mice three times per week for five weeks. A separate group of ICV-saline mice treated with saline was used as a baseline control. Behavioral tests, including open field and novel object recognition, were conducted three weeks after the first dose of the TM2G or saline. Protein O-GlcNAcylation, tau hyperphosphorylation, synaptic proteins, and neuroinflammation in the mouse brain were assessed by western blotting.

RESULTS

ICV-STZ caused decreased protein O-GlcNAcylation. Enhancement of O-GlcNAcylation to moderate levels by using low-dose OGA inhibitor in ICV-STZ mice prevented STZ-induced body weight loss, rescued cognitive impairments, and restored AD-like pathologies, including hyperphosphorylation of tau and abnormalities in synaptic proteins and neuroinflammation.

CONCLUSION

These findings suggest that moderately increasing protein O-GlcNAcylation by using low doses of OGA inhibitor may be a suitable therapeutic strategy for sAD.

[Clinical follow-up and genetic analysis of six cases with hypophosphatasia]

Objective: To analyze the clinical, genetic characteristics and follow-up data of Chinese patients with hypophosphatasia (HPP). Methods: A retrospective analysis was conducted on six children with HPP admitted to the Department of Endocrinology, Genetics and Metabolism in Beijing Children's Hospital from October 2010 to January 2019. Summarized the clinical and follow-up data of all six patients, as well as the pathogenic variants of five children. Results: The serum alkaline phosphatase levels of all six children (five males and one female) were significantly reduced (2-49 U/L). The 6 patients aged from 2 months to 6 years and 4 months, 4 infantile HPP, 1 childhood HIP and 1 odonto HPP. The four patients with infantile HPP presented with anorexia, slow weight gain and hypercalcemia, whereas the one patient with childhood HPP and the other patient with odonto HPP had tooth loss. The patient with childhood HPP also manifested with motor dysfunction. Genetic testing was conducted for five patients and 4 unrelated Chinese families and revealed 10 variations in ALPL gene, including 7 missense variation, 1 insertion variation, 1 frameshift variation, 1 deletion variation.Of which 3 were novel (p.Y28C, p.268, F>L, p.A176V).One of the infantile patients lost follow-up and the other three deceased. The clinical conditions were much improved with medical intervention for patients with childhood, orodonto HPP. Conclusions: While HPP patients with different ages of onset present with common features, the prognosis differ significantly. The prognosis is good for patients with childhood, orodonto HPP and poor for patients with infantile HPP. Genetic testing is the main method for definitive diagnosis.

Alzheimer's disease brain contains tau fractions with differential prion-like activities

Neurofibrillary tangles (NFTs) made of abnormally hyperphosphorylated tau are a hallmark of Alzheimer’s disease (AD) and related tauopathies. Regional distribution of NFTs is associated with the progression of the disease and has been proposed to be a result of prion-like propagation of misfolded tau. Tau in AD brain is heterogenous and presents in various forms. In the present study, we prepared different tau fractions by sedimentation combined with sarkosyl solubility from AD brains and analyzed their biochemical and pathological properties. We found that tau in oligomeric fraction (O-tau), sarkosyl-insoluble fractions 1 and 2 (SI₁-tau and SI₂-tau) and monomeric heat-stable fraction (HS-tau) showed differences in truncation, hyperphosphorylation, and resistance to proteinase K. O-tau, SI₁-tau, and SI₂-tau, but not HS-tau, were hyperphosphorylated at multiple sites and contained SDS- and β-mercaptoethanol–resistant high molecular weight aggregates, which lacked the N-terminal portion of tau. O-tau and SI₂-tau displayed more truncation and less hyperphosphorylation than SI₁-tau. Resistance to proteinase K was increased from O-tau to SI₁-tau to SI₂-tau. O-tau and SI₁-tau, but not SI₂-tau or HS-tau, captured tau from cell lysates and seeded tau aggregation in cultured cells. Heat treatment could not kill the prion-like activity of O-tau to capture normal tau. Hippocampal injection of O-tau into 18-month-old FVB mice induced significant tau aggregation in both ipsilateral and contralateral hippocampi, but SI₁-tau only induced tau pathology in the ipsilateral hippocampus, and SI₂-tau and HS-tau failed to induce any detectable tau aggregation. These findings suggest that O-tau and SI₁-tau have prion-like activities and may serve as seeds to recruit tau and template tau to aggregate, resulting in the propagation of tau pathology. Heterogeneity of tau pathology within AD brain results in different fractions with different biological and prion-like properties, which may pose a major challenge in targeting tau for development of effective therapeutic treatments.

Seeding-Competent Tau in Gray Matter Versus White Matter of Alzheimer's Disease Brain

BACKGROUND

Neurofibrillary pathology of abnormally hyperphosphorylated tau spreads along neuroanatomical connections, underlying the progression of Alzheimer's disease (AD). The propagation of tau pathology to axonally connected brain regions inevitably involves trafficking of seeding-competent tau within the axonal compartment of the neuron.

OBJECTIVE

To determine the seeding activity of tau in cerebral gray and white matters of AD.

METHODS

Levels of total tau, hyperphosphorylation of tau, and SDS- and β-mercaptoethanol-resistant high molecular weight tau (HMW-tau) in crude extracts from gray and white matters of AD frontal lobes were analyzed by immuno-blots. Tau seeding activity was quantitatively assessed by measuring RIPA buffer-insoluble tau in HEK-293FT/tau151-391 cells treated with brain extracts.

RESULTS

We found a comparable level of soluble tau in gray matter versus white matter of control brains, but a higher level of soluble tau in gray matter than white matter of AD brains. In AD brains, tau is hyperphosphorylated in both gray and white matters, with a higher level in the former. The extracts of both gray and white matters of AD brains seeded tau aggregation in HEK-293FT/tau151-391 cells but the white matter showed less potency. Seeding activity of tau in brain extracts was positively correlated with the levels of tau hyperphosphorylation and HMW-tau. RIPA-insoluble tau, but not RIPA-soluble tau, was hyperphosphorylated tau at multiple sites.

CONCLUSION

Both gray and white matters of AD brain contain seeding-competent tau that can template aggregation of hyperphosphorylated tau, but the seeding potency is markedly higher in gray matter than in white matter.

[Diagnosis and follow-up of 2 cases of pediatric nephrogenic syndrome of inappropriate antidiuresis resulting from activating mutation in AVPR2 and literature review]

Objective: To analyze the clinical and genetic features, as well as the treatment outcomes of two boys with nephrogenic syndrome of inappropriate antidiuresis (NSIAD) caused by gain-of-function mutations in the V2 vasopressin receptor gene (AVPR2). Methods: The clinical manifestations, genetic testing, therapeutic interventions and the outcomes of two boys with NSIAD hospitalized in the Department of Endocrinology, Beijing Children's Hospital in April 2019 were reported. A literature search with "Nephrogenic syndrome of inappropriate antidiuresis" and "AVPR2 gene" as keywords was conducted at the China national knowledge infrastructure (CNKI), the Wanfang Data Knowledge Service Platform, PubMed and Springer Link up to May 2020. Relevant published articles were reviewed. Results: The two cases presented with chronic and severe hyponatremia with hypo-osmolality, inappropriately elevated urinary osmolality and urinary sodium levels. The onset age was 5.25-years and 2 months respectively. AVPR2 sequencing revealed a previously described hemizygous activating mutation (c.409C>T, p.R137C) in both of boys, each inherited the variant from their mother. Patient 1 limited fluid intake by himself in his daily life, intravenous and oral sodium supplementations showed no significant increase of serum sodium level. Oral furosemide increased the serum sodium level and maintained it within normal range. The serum sodium and potassium levels were in the normal range during the 1-year follow-up period with oral furosemide. The serum sodium level of Patient 2 increased with restricting fluid intake and with salt supplementation. However, after he experienced respiratory infection, the plasma sodium level decreased. Subsequently, oral anti-infection medicine and furosemide were applied. The serum sodium level increased two days later and remained at a normal range afterwards. The boy was 1 year old with normal growth. He stopped taking furosemide after 4 months while taking 1 gram of salt per day, the blood sodium level maintained at normal range. Literature search identified no reports in Chinese journals, whereas 50 publications were found in English journals. A total of 30 NSIAD probands were reported and 16 of those (53%) had childhood onset, most presented with seizures. The majority had a hotspot change at the nucleotide position of 409 in AVPR2. Nine cases had an amino acid change as R137C and five cases as R137L. Fluid restriction and oral urea intake were main treatment options, no report so far was found with oral furosemide treatment. Conclusions: NSIAD presented with hyponatremia without any other specific presentations. Genetic testing for variants in AVPR2 is helpful for early diagnosis and timely treatment. The first two cases of oral furosemide treatment were reported by the article which helped to maintain a normal serum sodium level after limiting fluid intake and supplementing sodium which showed limited effect.

Sevoflurane-induced neuronal apoptosis in neonatal mice is prevented with intranasal administration of insulin

Concerns about the potential neurotoxicity of general anesthesia to the developing brain have been increasing in recent years. Animal studies have shown that neonatal exposure to general anesthesia causes both acute neurotoxicity and behavioral abnormalities later in life. In the present study, we observed over-activation of neuronal apoptosis in the brain of neonatal mice after a single exposure to anesthesia with sevoflurane for 6 hours at the age of 7 days. More importantly, we found that insulin administered through intranasal delivery prior to anesthesia prevented anesthesia-induced over-activation of neuronal apoptosis. This study provides experimental evidence for a potential effective, yet simple, method to prevent anesthesia-induced neurotoxicity in children, especially in infants.

Intranasal Insulin Increases Synaptic Protein Expression and Prevents Anesthesia-Induced Cognitive Deficits Through mTOR-eEF2 Pathway

General anesthesia increases the risk for cognitive impairment and Alzheimer's disease (AD) in vulnerable individuals such as the elderly. We previously reported that prior administration of insulin through intranasal delivery can prevent the anesthesia-induced cognitive impairment and biochemical changes in the brain. However, little is known about the underlying molecular mechanisms. Here, we report that general anesthesia resulted in downregulation of mammalian/mechanistic target of rapamycin (mTOR) and eukaryotic elongation factor 2 (eEF2) in the brain along with reduction of presynaptic proteins and brain-derived neurotrophic factor and cognitive impairment in aged mice. Prior administration of intranasal insulin prevented these anesthesia-induced changes. These results suggest the involvement of the mTOR-eEF2 signaling pathway in the anesthesia-induced brain changes and cognitive impairment and in the prevention of these changes with insulin. Correlation analyses and the use of eEF2 kinase inhibitor further support our conclusions. These studies shed light on the molecular mechanism by which anesthesia and insulin could act on synaptic proteins and cognitive function.

Truncation of Tau selectively facilitates its pathological activities

Neurofibrillary tangles of abnormally hyperphosphorylated Tau are a hallmark of Alzheimer's disease (AD) and related tauopathies. Tau is truncated at multiple sites by various proteases in AD brain. Although many studies have reported the effect of truncation on the aggregation of Tau, these studies mostly employed highly artificial conditions, using heparin sulfate or arachidonic acid to induce aggregation. Here, we report for the first time the pathological activities of various truncations of Tau, including site-specific phosphorylation, self-aggregation, binding to hyperphosphorylated and oligomeric Tau isolated from AD brain tissue (AD O-Tau), and aggregation seeded by AD O-Tau. We found that deletion of the first 150 or 230 amino acids (aa) enhanced Tau's site-specific phosphorylation, self-aggregation, and binding to AD O-Tau and aggregation seeded by AD O-Tau, but deletion of the first 50 aa did not produce a significant effect. Deletion of the last 50 aa was found to modulate Tau's site-specific phosphorylation, promote its self-aggregation, and cause it to be captured by and aggregation seeded by AD O-Tau, whereas deletion of the last 20 aa had no such effects. Among the truncated Taus, Tau_151-391 showed the highest pathological activities. AD O-Tau induced aggregation of Tau_151-391 in vitro and in cultured cells. These findings suggest that the first 150 aa and the last 50 aa protect Tau from pathological characteristics and that their deletions facilitate pathological activities. Thus, inhibition of Tau truncation may represent a potential therapeutic approach to suppress Tau pathology in AD and related tauopathies.

Intermittent fasting promotes adult hippocampal neuronal differentiation by activating GSK-3β in 3xTg-AD mice

Moderate dietary restriction can ameliorate age-related chronic diseases such as Alzheimer's disease (AD) by increasing the expression of neurotrophic factors and promoting neurogenesis in the brain. Glycogen synthase kinase-3β (GSK-3β) signaling is essential for the coordination of progenitor cell proliferation and differentiation during brain development. The mechanisms by which GSK-3β is involved in dietary restriction-induced neurogenesis and cognitive improvement remain unclear. Six-month-old male 3xTg-AD and wild-type mice were fed on alternate days (intermittent fasting, IF) or ad libitum (AL) for 3 months. GSK-3β activity was regulated by bilaterally infusing lentiviral vectors carrying siRNA targeting GSK-3β into the dentate gyrus region of the hippocampus. Intermittent fasting promoted neuronal differentiation and maturation in the dentate gyrus and ameliorated recognized dysfunction in 3xTg-AD mice. These effects were reversed by siRNA targeting GSK-3β. After intermittent fasting, the insulin and protein kinase A signaling pathways were inhibited, while the adenosine monophosphate-activated protein kinase and brain-derived neurotrophic factor pathways were activated. These findings suggest that intermittent fasting can promote neuronal differentiation and maturation in the hippocampus by activating GSK-3β, thus improving learning and memory.

Young blood plasma reduces Alzheimer's disease-like brain pathologies and ameliorates cognitive impairment in 3×Tg-AD mice

Background

Recent studies indicated that circulatory factors in blood plasma from young animals can reactivate neurogenesis, restore synaptic plasticity, and improve cognitive function in aged animals. Here, we investigated if young plasma could have a possible therapeutic effect for treatment of Alzheimer’s disease (AD)-like pathologies and cognitive impairment in triple-transgenic AD (3×Tg-AD) mice.

Methods

We intravenously injected plasma from 2- to 3-month-old C57BL/6 J wild-type mice into 16–17-month-old 3×Tg-AD mice twice a week for 8 weeks. The behavioral tests including open field, novel object recognition, Morris water maze, and reversal Morris water maze were conducted after 4-week plasma injections. The effect of young plasma on tau and Aβ pathologies and on the levels of synaptic proteins and neuroinflammation were assessed by Western blots and immunohistochemical staining.

Results

Young plasma treatment improved short-term memory in the novel object recognition test and enhanced the spatial learning and memory in Morris water maze test and reversal Morris water maze test. Biochemical studies revealed that young plasma treatment reduced both tau and Aβ pathologies, as well as neuroinflammation in the mouse brain. However, we did not detect any significant changes in levels of synaptic proteins or the dentate gyrus neurogenesis in the mouse brain after the treatment with young plasma.

Conclusions

These data indicate that young blood plasma not only ameliorates tau and Aβ pathologies but also enhances the cognitive function in 3×Tg-AD mice. These findings suggest that transfusion with young blood plasma could be a potentially effective treatment for AD.

Neonatal Exposure to Anesthesia Leads to Cognitive Deficits in Old Age: Prevention with Intranasal Administration of Insulin in Mice

Recent pre-clinical and clinical studies suggest that general anesthesia in infants and children may increase the risk of learning disabilities. Currently, there is no treatment for preventing anesthesia-induced neurotoxicity and potential long-term functional impairment. Animal studies have shown that neonatal exposure to anesthesia can induce acute neurotoxicity and long-term behavioral changes that can be detected a few months later. It is currently unknown whether neonatal exposure, especially repeated exposures, to general anesthesia can induce or increase the risk for cognitive impairment during aging. Here, we report that repeated exposures of neonatal mice (P7-9 days old) to anesthesia with sevoflurane (3 h/day for 3 days) led to cognitive impairment that was detectable at the age of 18-19 months, as assessed by using novel object recognition, Morris water maze, and fear conditioning tests. The repeated neonatal exposures to anesthesia did not result in detectable alterations in neurobehavioral development, in tau phosphorylation, or in the levels of synaptic proteins in the aged mouse brains. Importantly, we found that treatment with intranasal insulin prior to anesthesia exposure can prevent mice from anesthesia-induced cognitive impairment. These results suggest that neonatal exposure to general anesthesia could increase the risk for cognitive impairment during aging. This study also supports pre-treatment with intranasal administration of insulin to be a simple, effective approach to prevent infants and children from the increased risk for age-related cognitive impairment induced by neonatal exposure to general anesthesia.

Effect of Peripheral Insulin Administration on Phosphorylation of Tau in the Brain

BACKGROUND

Abnormally hyperphosphorylated tau is the major protein of neurofibrillary tangles in Alzheimer's disease. Insulin activates PI3K-AKT signaling and regulates tau phosphorylation. Impaired brain insulin signaling is involved in Alzheimer's disease pathogenesis. However, the effect of peripheral insulin on tau phosphorylation is controversial.

OBJECTIVE

In the present study, we determined the effect of peripheral insulin administration on tau phosphorylation in brain.

METHODS

We intraperitoneally injected a super physiological dose of insulin to mice and analyzed PI3K-AKT signaling and tau phosphorylation in brains by western blots.

RESULTS

We found that peripherally administered insulin activated the PI3K-AKT signaling pathway immediately in the liver, but not in the brain. Tau phosphorylation in the mouse brain was found to be first decreased (15 min) and then increased (30 min and 60 min) after peripheral insulin administration and these changes correlated inversely with body temperature and the level of brain protein O-GlcNAcylation. Maintaining body temperature of mice post peripheral insulin administration prevented the insulin/hypoglycemia-induced tau hyperphosphorylation after peripheral insulin administration.

CONCLUSION

These findings suggest that peripheral insulin can induce tau hyperphosphorylation through both hypothermia and downregulation of brain protein O-GlcNAcylation during hypoglycemia.

Anesthesia with sevoflurane or isoflurane induces severe hypoglycemia in neonatal mice

Sevoflurane and isoflurane are among the most commonly used general anesthetics for children including infants, but their impact on metabolism, especially on blood glucose level, in children is not well understood. We investigated the impacts of anesthesia of neonatal (7–8 days old) and adult (2–3 months old) mice with the inhalational anesthetics 2.5% sevoflurane or 1.5% isoflurane, or the injectable anesthetics propofol (150 mg/kg) or avertin (375 mg/kg), for up to 6 hours. We found that sevoflurane and isoflurane induced severe hypoglycemia in neonatal mice and that this phenomenon was specific to the inhalational anesthetics because the injectable anesthetics propofol and avertin did not induce hypoglycemia. Surprisingly, the inhalational anesthesia induced hyperglycemia instead in adult mice. We also demonstrated that the inhalational anesthesia-induced hypoglycemia was a major cause of death for the neonatal mice receiving intranasal administration of saline prior to anesthesia. These studies revealed severe hypoglycemia in neonatal mice during anesthesia with sevoflurane or isoflurane. If this phenomenon also occurs in human, our findings would warrant closely monitoring blood glucose level and maintaining it in the normal range in infants receiving inhalational anesthesia.

Age-Dependent Changes in the Plasma Proteome of Healthy Adults

OBJECTIVE

Human blood plasma is a complex that communicates with most parts of the body and reflects the changes in the state of an organism. Identifying age-related biomarkers can help predict and monitor age-related physiological decline and diseases and identify new treatments for diseases.

METHODS AND PARTICIPANTS

In this study, TMT-LC-MS/MS was utilized to screen differentially expressed plasma proteins in 118 healthy adults of different ages. Participants were divided into three groups: 21-30 years of age (Young), 41-50 years of age (Middle) and ≥60 years of age (Old).

RESULTS

The number of differentially expressed proteins in the comparisons of Young vs Middle, Middle vs Old and Young vs Old were 82, 22 and 99, respectively. These proteins were involved in numerous physiological processes, such as "negative regulation of smooth muscle cell proliferation" and "blood coagulation". Moreover, when Young was compared with Middle or Old, "complement and coagulation cascades" was the top enriched pathway by KEGG pathway enrichment analysis. Functional phenotyping of the proteome demonstrated that the plasma proteomic profiles of young adults were strikingly dissimilar to those of the middle-aged or older adults.

CONCLUSIONS

The results of this study mapped the variation in the expression of plasma proteins and provided information about possible biomarkers/treatments for different age-related functional disorders.

Rbfox3/NeuN Regulates Alternative Splicing of Tau Exon 10

Alternative splicing of tau exon 10 generates tau isoforms with three or four microtubule-binding repeats, 3R-tau or 4R-tau, which are under developmental regulation. Dysregulation of tau exon 10 splicing is sufficient to cause neurodegenerative disorders. The RNA-binding Fox3 (Rbfox3), identified as NeuN, regulates RNA processing. However, whether Rbfox3/NeuN regulates tau exon 10 splicing is unknown. In the present study, we found that the developmental expression of 4R-tau coincided with the expression of Rbfox3 in rat brains. Rbfox3 enhanced tau exon 10 inclusion. Tau intron 10 contains UGCAUG, the conservative binding sequence of Rbfox3. Intron 10 of tau pre-mRNA was co-immunoprecipitated by Rbfox3/NeuN. Deletion mutants of the RNA recognition motif (RRM) or three RNA-binding sites of the RRM in Rbfox3/NeuN failed to enhance tau exon 10 inclusion. Rbfox3, specifically expressed in the fetal brain, did not affect tau exon 10 splicing. The level of Rbfox3/NeuN was reduced and was associated with the ratio of 4R-tau/3R-tau in the excitotoxic mouse brains induced by kainic acid. These findings suggest that Rbfox3/NeuN regulates the alternative splicing of tau exon 10 and that decreased Rbfox3/NeuN may lower the ratio of 4R-tau/3R-tau.

Glycogen synthase kinase-3β suppresses the expression of protein phosphatase methylesterase-1 through β-catenin

Protein phosphatase 2A (PP2A) is the major tau phosphatase. Its activity toward tau is regulated by the methylation of PP2A catalytic subunit (PP2Ac) at Leu309. Protein phosphatase methylesterase-1 (PME-1) demethylates PP2Ac and suppresses its activity. We previously found that glycogen synthase kinase-3β (GSK-3β) suppresses PME-1 expression. However, the underlying molecular mechanism is unknown. In the present study, we analyzed the promoter of PME-1 gene and found that human PME-1 promoter contains two lymphoid enhancer binding factor-1/T-cell factor (LEF1/TCF) cis-elements in which β-catenin serves as a co-activator. β-catenin acted on these two cis-elements and promoted PME-1 expression. GSK-3β phosphorylated β-catenin and suppressed its function in promoting PME-1 expression. Inhibition and activation of GSK-3β by PI3K-AKT pathway promoted and suppressed, respectively, PME-1 expression in primary cultured neurons, SH-SY5Y cells and in the mouse brain. These findings suggest that GSK-3β phosphorylates β-catenin and suppresses its function on PME-1 expression, resulting in an increase of PP2Ac methylation.

[Clinical phenotype and gene analysis of 86 cases of 5 alpha reductase deficiency]

Objective: Molecular genetics and clinical phenotypic characteristics of 5 alpha reductase deficiency were analyzed. Methods: The genetic results and clinical features classied as Prader grade of external genitalia of 86 children with SRD5A2 mutation seen from 2007 to 2017 at Department of Endocrinology of Beijing Children's Hospital were analyzed, and the mutation differences in different were compared regions according to the literatures. Results: Among the 86 children, 15 had were homozygous mutations, accounting for 17%, and 71 cases of compound heterozygous mutations accounted for 83%. Totally 172 alleles mutations in this series. The mutation was mainly located on exon 1 and exon 4, in which the mutation frequency of exon 1 was 23.8% (41/172), and the frequency of exon 4 mutation was 55.8% (96/172). A total of 19 mutation types of the SRD5A2 gene in this group were detected, of which 5 were new mutations (p.A228F, p.E57D, p.V124D, p.A117D, p.E197K); 65 patients had p.R227Q mutation, accounting for 76%, while 31 had p.Q6* mutation, accounting for 36%. Other rare types such as p.R246W, p.R103* and so on were also seen in the present study, there was no significant difference between north China and south China (P>0.05). The clinical phenotypes of p.R227Q variation varied, mainly in Prader 3-4, accounting for 82%, while (Prader 0-1) were less, accounting only 2%. The variation of p.Q6* was mainly manifested in Prader 3, accounting for 50%. p.R246Q mainly presented Prader 3. The variation of p.G203S appeared to have Prader 2 and Prader 4-5, accounting for 20% and 73% respectively. There was no significant difference in clinical phenotype corresponding to each protein type (P>0.05) . Conclusion: Among the 86 children have identified 19 SRD5A2 mutation types, p.R227Q is a hotspot mutation in Chinese. Variations at different types may have different clinical phenotypes, while the same variations may have different clinical features. There was no significance different in the variation types between the north and the south.

Elevation of casein kinase 1ε associated with TDP-43 and tau pathologies in Alzheimer's disease

Alzheimer's disease (AD) is characterized by the presence of extracellular amyloid β plaques and intraneuronal neurofibrillary tangles of hyperphosphorylated microtubule-associated protein tau in the brain. Aggregation of transactive response DNA-binding protein of 43 kDa (TDP-43) in the neuronal cytoplasm is another feature of AD. However, how TDP-43 is associated with AD pathogenesis is unknown. Here, we found that casein kinase 1ε (CK1ε) phosphorylated TDP-43 at Ser403/404 and Ser409/410. In AD brains, the level of CK1ε was dramatically increased and positively correlated with the phosphorylation of TDP-43 at Ser403/404 and Ser409/410. Overexpression of CK1ε promoted its cytoplasmic aggregation and suppressed TDP-43-promoted tau mRNA instability and tau exon 10 inclusion, leading to an increase of tau and 3R-tau expressions. Levels of CK1ε and TDP-43 phosphorylation were positively correlated with the levels of total tau and 3R-tau in human brains. Furthermore, we observed, in pilot immunohistochemical studies, that the severe tau pathology was accompanied by robust TDP-43 pathology and a high level of CK1ε. Taken together, our findings suggest that the elevation of CK1ε in AD brain may phosphorylate TDP-43, promote its cytoplasmic aggregation and suppress its function in tau mRNA processing, leading to acceleration/exacerbation of tau pathology. Thus, the elevation of CK1ε may link TDP-43 to tau pathogenesis in AD brain.

Intranasal Administration of Insulin Reduces Chronic Behavioral Abnormality and Neuronal Apoptosis Induced by General Anesthesia in Neonatal Mice

Children, after multiple exposures to general anesthesia, appear to be at an increased risk of developing learning disabilities. Almost all general anesthetics—including sevoflurane, which is commonly used for children—are potentially neurotoxic to the developing brain. Anesthesia exposure during development might also be associated with behavioral deficiencies later in life. To date, there is no treatment to prevent anesthesia-induced neurotoxicity and behavioral changes. In this study, we anesthetized 7-day-old neonatal mice with sevoflurane for 3 h per day for three consecutive days and found that the anesthesia led to mild behavioral abnormalities later in life that were detectable by using the novel object recognition test, Morris water maze, and fear conditioning test. Biochemical and immunohistochemical studies indicate that anesthesia induced a decrease in brain levels of postsynaptic density 95 (PSD95), a postsynaptic marker, and marked activation of neuronal apoptosis in neonatal mice. Importantly, insulin administered through intranasal delivery prior to anesthesia was found to prevent the anesthesia-induced long-term behavioral abnormalities, reduction of PSD95, and activation of neuronal apoptosis. These findings suggest that intranasal insulin administration could be an effective approach to prevent the increased risk of neurotoxicity and chronic damage caused by anesthesia in the developing brain.

[Gender selection and postoperative follow-up analysis in 85 children with 46, XY disorders of sex development]

Objective: To understand the gender selection and prognosis of children with 46, XY disorders of sex development (DSD) after surgery, and to provide reference for future clinical decision-making. Methods: Data of 85 (80 males and 5 females) postoperative patients with 46, XY DSD with follow-up age of 6(4,11) years who were treated at the Department of Endocrinology, Genetics and Metabolism of Beijing Children's Hospital Affiliated to Capital Medical University during the period from September 2009 to April 2018 were retrospectively analyzed. The patients were grouped based on diagnosis. The basis of postoperative gender selection, patient satisfaction and related factors, gender characteristics, and adolescent development were analyzed. The Pre-school Activities Inventory or the Children's Sex Role Inventory were used in the analysis of gender tendency. Mann-Whitney U test was used to compare postoperative gender satisfaction of different factors. The Kruskal-Wallis method was used to compare the postoperative gender satisfaction of each group. Fisher's test was used to compare the follow-up status of male children over 11 years old in each group. Results: Among the 85 patients, 62 individuals were raised as girls after birth, 9 were facultative and 14 as boys. According to the diagnosis, there were 31 individuals in group 1 (with 5α-reductase deficiency), 11 individuals in group 2 (with androgen insensitivity syndrome), 9 individuals in group 3 (with NR5A1 gene mutation), 4 individuals in group 4 (with hypergonadotropic gonadal dysplasia), and 30 indiviudals in group 5 (with unclear diagnosis and normal human choionic gonadotophin test). Among the 71 children who were raised as girls or facultative children after birth, 66 selected as boys, and 5 continued as girls (among them, 3 individuals were female with passive selection, and 2 individuals of testicular dysplasia with uterus in group 4 and 5 were female with active selection). Among the 71 patients faced with gender selection, only one was unsatisfied, that was a postoperative female. There was no significant difference in postoperative gender satisfaction among different disease diagnoses, surgical age and penis length (χ(2)(H)=6.007, P=0.199; Z=-0.860, P=0.390; Z=-0.438, P=0.661). Fifty-nine of the 85 cases completed the gender tendency scale test and 46 cases (78%) were consistent. In the male patients, 45 cases were consistent. Thirteen inconsistent patients (22%) were female or facultative after birth who were 5 years old or older. There was no stigmatization noticed in the inconsistent patients' daily life and school social settings. There were 22 male patients aged 11 years and older. They were 13(12,16) years old. Fourteen (64%) individuals' penile length reached the normal minimum, 15 (68%) individuals' testicular volume were equal or more than 4 ml, 16 (73%) individuals' sex hormones entered puberty levels, 12 (55%) individuals had been spermatorrhea, the age of first spermatorrhea was (13.3±2.4) years. They were satisfied and adaptable after surgery. There was no significant difference in the above indicators among the groups (χ²=2.999, P=0.694; χ²=7.278, P=0.086; χ²=5.597, P=0.358; χ²=6.904, P=0.127). Conclusions: The appropriate gender of 46, XY DSD patients was selected according to gonadal status after diagnosis. Regardless the diagnosis, the age of operation and the length of the penis at the first diagnosis, male patients were satisfied with the gender after the operation. A few of patients were inconsistent with the results of gender tendency scale test who were raised as girls or facultative children after birth, and they required sustained special attention. Some of the children showed natural adolescent development in males, and the prognosis may be ideal.

Calpain I Activation Causes GLUT3 Proteolysis and Downregulation of O-GlcNAcylation in Alzheimer's Disease Brain

Impairment of cerebral glucose uptake/metabolism in individuals with Alzheimer's disease (AD) is believed to lead to downregulation of protein O-GlcNAcylation, which contributes to tau pathogenesis through tau hyperphosphorylation. Level of glucose transporter 3 (GLUT3), a neuronal specific glucose transporter, is decreased in AD brain, which may contribute to impaired brain glucose uptake/metabolism. However, what causes the reduction of GLUT3 in AD brain is not fully understood. Here, we report 1) that decrease of GLUT3 is associated with the reduction of protein O-GlcNAcylation in AD brain, 2) that GLUT3 level is negatively correlated with calpain I activation in human brain, 3) that calpain I proteolyzes GLUT3 at the N-terminus in vitro, and 4) that activation of calpain I is negatively correlated with protein O-GlcNAcylation in AD brain. Furthermore, we found that overexpression of GLUT3 enhances protein O-GlcNAcylation in N2a cells. Overexpression of calpain I suppresses protein O-GlcNAcylation in these cells. These findings suggest a novel mechanism by which calpain I overactivation leads to GLUT3 degradation and the consequent down-regulation of protein O-GlcNAcylation in AD brain.