[Clinical characteristics and labial gland pathological features in children with systemic lupus erythematosus complicated by Sjögren's syndrome]. / å„¿ç«¥ç³»ç»Ÿæ€§çº¢æ–‘ç‹¼ç–®åˆå¹¶å¹²ç‡¥ç»¼åˆå¾çš„ä¸´åºŠç‰¹ç‚¹åŠå”‡è ºç— ç†ç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical manifestations, laboratory features, and labial gland pathological features in children with systemic lupus erythematosus (SLE) complicated by Sjögren's syndrome (SS). METHODS: A retrospective analysis was conducted on 102 children with SLE who underwent labial gland biopsies at Renji Hospital, Shanghai Jiao Tong University School of Medicine from January 2013 to December 2022. The children were divided into two groups based on the presence of SS: the SLE with SS group (SLE-SS; 60 children) and the SLE-only group (42 children). According to the focus score (FS) of the labial glands, children in the SLE-SS group were further subdivided into FS≥4 subgroup (26 children) and FS<4 subgroup (34 children). The clinical data of the groups were compared. RESULTS: Compared to the SLE-only group, children in the SLE-SS group had less skin and mucosal involvement, were more likely to have positive anti-SSA and anti-SSB antibodies, and had higher levels of rheumatoid factor (P<0.05). There was no significant difference in treatment protocols between the two groups (P>0.05). Compared to the FS<4 subgroup, the FS≥4 subgroup had more frequent musculoskeletal involvement (P<0.05), but there was no significant difference in SLE disease activity or other major organ involvement between the subgroups (P>0.05). CONCLUSIONS: Children with SLE complicated by SS are less likely to have skin and mucous membrane involvement and exhibit specific serological characteristics. The SLE-SS children with an FS≥4 are more likely to experience musculoskeletal involvement. However, FS is not associated with disease activity or other significant organ damage.

Discovery of novel glucosinolates inhibiting advanced glycation end products: Virtual screening and molecular dynamic simulation.

Protein glycation can result in the formation of advanced glycation end products (AGEs), which pose a potential health risk due to their association with diabetic complications. Natural products are a source of drugs discovery and the search for potential natural inhibitors of AGEs is of great significance. Glucosinolates (GSLs) mainly from cruciferous plants have potential antioxidant, anti-inflammatory, and anti-glycation activities. In this study, the inhibitory activity of GSLs on bovine serum albumin (BSA) along with its mechanism was investigated by virtual screening and various computational simulation techniques. Virtual screening revealed that 174 GSLs were screened using Maestro based on the glide score and 89% of the compounds were found to have potential anti-glycation ability with the docking scores less than -5 kcal/mol. Molecular docking showed that the top 10 GSLs were bound to the IIA structural domain of BSA. Among them, glucohesperin (1) and 2-hydroxyethyl glucosinolate (2) had the lowest docking scores of -9.428 and -9.333 kcal/mol, respectively, reflecting their good binding affinity. Molecular dynamics simulations of 1 (ΔG = -43.46 kcal/mol) and 2 (ΔG = -43.71 kcal/mol) revealed that the complexes of these two compounds with proteins had good stability. Further binding site analysis suggested that the mechanism of inhibition of protein glycation by these two active ingredients might be through competitive hydrogen bonding to maintain the structural integrity of the protein, thus inhibiting glycation reaction. Moreover, the ADMET values and CYP450 metabolism prediction data were within the recommended values. Therefore, it can be concluded that 1 and 2 may act as potential anti-glycation agents.

A risk-based approach for cell line development, manufacturing and characterization of genetically engineered, induced pluripotent stem cell-derived allogeneic cell therapies.

Advances in cellular reprogramming and gene-editing approaches have opened up the potential for a new class of ex vivo cell therapies based on genetically engineered, induced pluripotent stem cell (iPSC)-derived allogeneic cells. While these new therapies share some similarities with their primary cell-derived autologous and allogeneic cell therapy predecessors, key differences exist in the processes used for generating genetically engineered, iPSC-derived allogeneic therapies. Specifically, in iPSC-derived allogeneic therapies, donor selection and gene-editing are performed once over the lifetime of the product as opposed to as part of the manufacturing of each product batch. The introduction of a well-characterized, fully modified, clonally derived master cell bank reduces risks that have been inherent to primary-cell derived autologous and allogeneic therapies. Current regulatory guidance, which was largely developed based on the learnings gained from earlier generation therapies, leaves open questions around considerations for donor eligibility, starting materials and critical components, cell banking and genetic stability. Here, a risk-based approach is proposed to address these considerations, while regulatory guidance continues to evolve.

Using ultrasound radiomics analysis to diagnose cervical lymph node metastasis in patients with nasopharyngeal carcinoma.

OBJECTIVE: This study aimed to explore the clinical value of ultrasound radiomics analysis in the diagnosis of cervical lymph node metastasis (CLNM) in patients with nasopharyngeal carcinoma (NPC). METHODS: A total of 205 cases of NPC CLNM and 284 cases of benign lymphadenopathy with pathologic diagnosis were retrospectively included. Grayscale ultrasound (US) images of the largest section of every lymph node underwent feature extraction. Feature selection was done by maximum relevance minimum redundancy (mRMR) algorithm and multivariate logistic least absolute shrinkage and selection operator (LASSO) regression. Logistic regression models were developed based on clinical features, radiomics features, and the combination of those features. The AUCs of models were analyzed by DeLong's test. RESULTS: In the clinical model, lymph nodes in the upper neck, larger long axis, and unclear hilus were significant factors for CLNM (p < 0.001). MRMR and LASSO regression selected 7 significant features for the radiomics model from the 386 radiomics features extracted. In the validation dataset, the AUC value was 0.838 (0.776-0.901) in the clinical model, 0.810 (0.739-0.881) in the radiomics model, and 0.880 (0.826-0.933) in the combined model. There was not a significant difference between the AUCs of clinical models and radiomics models in both datasets. DeLong's test revealed a significantly larger AUC in the combined model than in the clinical model in both training (p = 0.049) and validation datasets (p = 0.027). CONCLUSION: Ultrasound radiomics analysis has potential value in screening meaningful ultrasound features and improving the diagnostic efficiency of ultrasound in CLNM of patients with NPC. KEY POINTS: • Radiomics analysis of gray-scale ultrasound images can be used to develop an effective radiomics model for the diagnosis of cervical lymph node metastasis in nasopharyngeal carcinoma patients. • Radiomics model combined with general ultrasound features performed better than the clinical model in differentiating cervical lymph node metastases from benign lymphadenopathy.

Oocyte meiosis-coupled poly(A) polymerase α phosphorylation and activation trigger maternal mRNA translation in mice.

Mammalian oocyte maturation is driven by strictly regulated polyadenylation and translational activation of maternal mRNA stored in the cytoplasm. However, the poly(A) polymerase (PAP) that directly mediates cytoplasmic polyadenylation in mammalian oocytes has not been determined. In this study, we identified PAPα as the elusive enzyme that catalyzes cytoplasmic mRNA polyadenylation implicated in mouse oocyte maturation. PAPα was mainly localized in the germinal vesicle (GV) of fully grown oocytes but was distributed to the ooplasm after GV breakdown. Inhibition of PAPα activity impaired cytoplasmic polyadenylation and translation of maternal transcripts, thus blocking meiotic cell cycle progression. Once an oocyte resumes meiosis, activated CDK1 and ERK1/2 cooperatively mediate the phosphorylation of three serine residues of PAPα, 537, 545 and 558, thereby leading to increased activity. This mechanism is responsible for translational activation of transcripts lacking cytoplasmic polyadenylation elements in their 3'-untranslated region (3'-UTR). In turn, activated PAPα stimulated polyadenylation and translation of the mRNA encoding its own (Papola) through a positive feedback circuit. ERK1/2 promoted Papola mRNA translation in a 3'-UTR polyadenylation signal-dependent manner. Through these mechanisms, PAPα activity and levels were significantly amplified, improving the levels of global mRNA polyadenylation and translation, thus, benefiting meiotic cell cycle progression.

Transcriptomic and metabolomic insights into the defense response to HFRs in Arabidopsis.

Tetrabromobisphenol A (TBBPA), Tetrachlorobisphenol A (TCBPA), Tetrabromobisphenol S (TBBPS) and their derivatives as the most widely used halogenated flame retardants (HFR), had been employed in the manufacturing industry to raise fire safety. HFRs have been shown to be developmentally toxic to animals and also affect plant growth. However, little was known about the molecular mechanism responded by when plants were treated with these compounds. In this study, when Arabidopsis was exposed to four HFRs (TBBPA, TCBPA, TBBPS-MDHP, TBBPS), the stress of these compounds had different inhibitory effects on seed germination and plant growth. Transcriptome and metabolome analysis showed that all four HFRs could influence the expression of transmembrane transporters to affect ion transport, Phenylpropanoid biosynthesis, Plant-pathogen interaction, MAPK signalling pathway and other pathways. In addition, the effects of different kinds of HFR on plants also have variant characteristics. It is very fascinating that Arabidopsis shows the response of biotic stress after exposure to these kinds of compounds, including the immune mechanism. Overall, the findings of the mechanism recovered by methods of transcriptome and metabolome analysis supplied a vital insight into the molecular perspective for Arabidopsis response to HFRs stress.

Chemical Composition Analysis and Discrimination of Essential Oils of Artemisia Argyi Folium from Different Germplasm Resources Based on Electronic Nose and GC/MS Combined with Chemometrics.

In this study, the electronic nose and GC/MS were used to analyze the chemical components of essential oils from different germplasm resources of Artemisia argyi Folium (A. argyi), in order to quickly identify essential oils of A. argyi from different germplasm resources and clarify the differences among different A. argyi samples. The essential oils of A. argyi were extracted by steam distillation. This article describes for the first time that electronic nose combined with chemometrics can distinguish the essential oils of A. argyi from different germplasm, which proves the reliability and potential of this technology. GC/MS was used to identify 134 volatile components from the essential oil of A. argyi. The main bioactive components were cineole, thujarone, artemisia ketone, ß-caryophyllene, (-)-4-terpinol, 3,3,6-trimethyl-1,5-heptadien-4-ol, (-)-α-thujone, camphor, borneol. In addition, the results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that there were significant differences in the essential oils of A. argyi from different germplasm resources, terpenes, alcohols and ketones played an important role in identifying the essential oils of A. argyi from different germplasm resources. This indicates that electronic nose and GC/MS combined with chemometrics can be used as reliable techniques to identify different germplasm resources of A. argyi, and provide certain reference value for quality evaluation, selection of high-quality varieties and rational development of resources of A. argyi.

Comparative analyses of five complete chloroplast genomes from the endemic genus Cremanthodium (Asteraceae) in Himalayan and adjacent areas.

Cremanthodium Benth. is an endemic genus in the Himalayas and adjacent areas. Some plants of the genus are traditional medicinal plants in Tibetan medicine. In this study, the chloroplast genomes of five species (Cremanthodium arnicoides (DC. ex Royle) Good, Cremanthodium brunneopilosum S. W. Liu, Cremanthodium ellisii (Hook. f.) Kitam., Cremanthodium nervosum S. W. Liu, and Cremanthodium rhodocephalum Diels) were collected for sequencing. The sequencing results showed that the size of the chloroplast genome ranged from 150,985 to 151,284 bp and possessed a typical quadripartite structure containing one large single copy (LSC) region (83,326-83,369 bp), one small single copy (SSC) region (17,956-18,201 bp), and a pair of inverted repeats (IR) regions (24,830-24,855 bp) in C. arnicoides, C. brunneopilosum, C. ellisii, C. nervosum, and C. rhodocephalum. The chloroplast genomes encoded an equal number of genes, of which 88 were protein-coding genes, 37 were transfer ribonucleic acid genes, and eight were ribosomal ribonucleic acid genes, and were highly similar in overall size, genome structure, gene content, and order. In comparison with other species in the Asteraceae family, their chloroplast genomes share similarities but show some structural variations. There was no obvious expansion or contraction in the LSC, SSC or IR regions among the five species, indicating that the chloroplast gene structure of the genus was highly conserved. Collinearity analysis showed that there was no gene rearrangement. The results of the phylogenetic tree showed that the whole chloroplast genomes of the five species were closely related, and the plants of this genus were grouped into one large cluster with Ligularia Cass. and Farfugium Lindl.

TTK predicts triple positive breast cancer prognosis and regulates tumor proliferation and invasion.

This study was conducted to investigate the expression of the spindle assembly checkpoint kinase tyrosine/threonine kinase (TTK) in triple positive breast cancer (TPBC) and its effect on TPBC cells. We analyzed the status of TTK in 69 TPBC samples using immunohistochemistry. The correlation between TTK and clinicopathological parameters was analyzed using a chi-squared test. The prognostic value of TTK was evaluated using Kaplan-Meier survival curves. We analyzed the role of TTK in the invasion and proliferation of TPBC cells in vitro and in vivo. The mean age of the 69 patients with TPBC enrolled in this study was 53 years (range: 29-86 years). TTK expression was positively correlated with tumor size (p=0.034), p53 status (p=0.023), TNM stage ([p=0.023), and Ki-67 index (p<0.001). The Kaplan-Meier curves revealed that TTK expression was correlated with poor disease-free survival (p=0.001) and overall survival (p=0.050). Multivariate proportional hazard regression analyses showed that TTK and TNM staging were significant independent predictors of disease-free survival (p=0.007 and p=0.034, respectively). Additionally, TTK knockdown inhibited the invasion and proliferation of the BT474 TPBC cell line. The findings of this study indicate that TTK overexpression is associated with cancer progression and prognosis in patients with TPBC, whereas TTK knockdown inhibits the invasion and proliferation of TPBC cells. Thus, TTK might serve as a prognostic marker for TPBC.

Carpelipines C and D, Two Anti-Inflammatory Germacranolides from the Flowers of Carpesium lipskyi Winkl. (Asteraceae).

Two new germacranolides, carpelipine C (1) and carpelipine D (2), together with four known ones (3-6), were isolated from Carpesium lipskyi Winkl. flowers, a folk Tibetan herbal medicine with antipyretic-analgesic and anti-inflammatory effects. The chemical structures of new structure were illuminated by diversified spectroscopic and X-ray crystallographic analyses. Compounds 1 and 3 dramatically suppressed the synthesis of NO and decreased pre-inflammatory protein expression of iNOS and COX-2 in LPS-induced RAW264.7 cells. Furthermore, it was revealed that NF-κB/MAPK signaling pathway were involved in the anti-inflammatory process of 1 and 3, and their effects on reducing oxidative stress by activating Nrf2/HO-1 pathway were also measured. This article indicated that the traditional use of C. lipskyi to treat inflammatory diseases has a certain rationality.

Lipskynoids A-G, New Acyclic Diterpenes from the Flowers of Carpesium lipskyi.

Seven new acyclic diterpenes, namely lipskynoids A-G (1-7), were isolated from the flowers of Carpesium lipskyi, a traditional Tibetan herbal medicine with anti-inflammatory and antipyretic-analgesic effects. These new compounds were elucidated by analysis of extensive spectroscopic data including ESI-MS, 1D, 2D NMR, and DP4+ analyses. Biological assays showed that 1-7 display significant inhibitory effects against the NO production in LPS-induced RAW264.7 cells with its IC50 values from 9.9 to 18.47 µM, however, no cytotoxicity effect was observed of these isolates against the growth of HePG2, PC3, DU145, and A549 cells.

Genomic Elucidation of a COVID-19 Resurgence and Local Transmission of SARS-CoV-2 in Guangzhou, China.

While China experienced a peak and decline in coronavirus disease 2019 (COVID-19) cases at the start of 2020, regional outbreaks continuously emerged in subsequent months. Resurgences of COVID-19 have also been observed in many other countries. In Guangzhou, China, a small outbreak, involving less than 100 residents, emerged in March and April 2020, and comprehensive and near-real-time genomic surveillance of SARS-CoV-2 was conducted. When the numbers of confirmed cases among overseas travelers increased, public health measures were enhanced by shifting from self-quarantine to central quarantine and SARS-CoV-2 testing for all overseas travelers. In an analysis of 109 imported cases, we found diverse viral variants distributed in the global viral phylogeny, which were frequently shared within households but not among passengers on the same flight. In contrast to the viral diversity of imported cases, local transmission was predominately attributed to two specific variants imported from Africa, including local cases that reported no direct or indirect contact with imported cases. The introduction events of the virus were identified or deduced before the enhanced measures were taken. These results show the interventions were effective in containing the spread of SARS-CoV-2, and they rule out the possibility of cryptic transmission of viral variants from the first wave in January and February 2020. Our study provides evidence and emphasizes the importance of controls for overseas travelers in the context of the pandemic and exemplifies how viral genomic data can facilitate COVID-19 surveillance and inform public health mitigation strategies.

Validation of American College of Radiology Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US): Analysis on 1054 adnexal masses.

OBJECTIVE: To assess the diagnostic performance and inter-observer agreement of the American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US). METHODS: From January 2016 to December 2018 a total of 1054 adnexal lesions in 1035 patients with pathologic results from two hospitals were retrospectively included. Each lesion was assigned to an O-RADS US category according to the criteria. Kappa (κ) statistics were applied to assess inter-observer agreement between a less experienced and an expert radiologist. RESULTS: Of the 1054 adnexal lesions, 750 were benign and 304 were malignant. The malignancy rates of O-RADS 5, O-RADS 4, O-RADS 3, and O-RADS 2 lesions were 89.57%, 34.46%, 1.10%, and 0.45% respectively. Area under the receiver operating characteristic curve was 0.960 (95% CI, 0.947-0.971). The optimal cutoff value for predicting malignancy was >O-RADS 3 with a sensitivity and specificity of 98.7% (95% CI, 0.964-0.996) and 83.2% (95% CI, 0.802-0.858) respectively. When sub-classifying multilocular cysts and smooth solid lesions in O-RADS 4 lesions as O-RADS 4a lesions and the rest cystic lesions with solid components as O-RADS 4b lesions, the malignancy rate were 17.02% and 42.57% respectively, which showed better risk stratification (P < 0.001). The inter-observer agreement between a less-experienced and an expert radiologist of O-RADS categorization was good (κ = 0.714). CONCLUSIONS: The ACR O-RADS US provides effective malignancy risk stratification for adnexal lesions with high reliability for radiologists with different experience. Sub-grouping of O-RADS 4 lesions into two groups facilitated better stratification of the intermediate risk.

Community evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through air.

BACKGROUND: Nine COVID-19 (Corona Virus Disease, 2019) cases were observed in one community in Guangzhou. All the cases lived in three vertically aligned units of one building sharing the same piping system, which provided one unique opportunity to examine the transmission mode of SARS-CoV-2. METHODS: We interviewed the cases on the history of travelling and close contact with the index patients. Respiratory samples from all the cases were collected for viral phylogenetic analyses. A simulation experiment in the building and a parallel control experiment in a similar building were then conducted to investigate the possibility of transmission through air. RESULTS: Index patients living in Apartment 15-b had a travelling history in Wuhan, and four cases who lived in Apartment 25-b and 27-b were subsequently diagnosed. Phylogenetic analyses showed that virus of all the patients were from the same strain of the virus. No close contacts between the index cases and other families indicated that the transmission might not occur through droplet and close contacts. Airflow detection and simulation experiment revealed that flushing the toilets could increase the speed of airflow in the pipes and transmitted the airflow from Apartment 15-b to 25-b and 27-b. Reduced exhaust flow rates in the infected building might have contributed to the outbreak. CONCLUSIONS: The outbreak of COVID-19 in this community could be largely explained by the transmission through air, and future efforts to prevent the infection should take the possibility of transmission through air into consideration. A disconnected drain pipe and exhaust pipe for toilet should be considered in the architectural design to help prevent possible virus spreading through the air.

Evaluation of a multiplex PCR assay for detection of respiratory viruses and Mycoplasma pneumoniae in oropharyngeal swab samples from outpatients.

BACKGROUND: Respiratory viruses, such as influenza viruses, initially infect the upper airways but can manifest as severe lower respiratory tract infections in high-risk patients with significant morbidity and mortality. For syndromic diagnosis, several multiplex nucleic acid amplification tests have been developed for clinics, of which SureX 13 Respiratory Pathogen Multiplex Kit (ResP) can simultaneously detect 13 pathogens directly from airway secretion specimens. The organisms identified are influenza virus A, influenza virus A pdmH1N1 (2009), influenza virus A H3N2, influenza virus B, adenovirus, boca virus, rhinovirus, parainfluenza virus, coronavirus, respiratory syncytial virus, human metapneumovirus, Mycoplasma pneumoniae, and Chlamydia. METHODS: This study provides performance evaluation data of this assay by comparing with pathogen-specific PCRs from oropharyngeal swab samples. RESULTS: Ten pathogens were detected in this assay, of which rhinovirus, adenovirus, and influenza virus A pdmH1N1 (2009) were the most common. The overall agreement between the ResP and the comparator tests was 93.8%. The ResP demonstrated 86.5% agreement for positive results and 97.8% agreement for negative results. CONCLUSION: The ResP assay demonstrated a highly concordant performance comparing with pathogen-specific PCRs for detection of respiratory pathogens in oropharyngeal swabs from outpatients and could aid in the diagnosis of respiratory infections in a variety of clinical scenarios.

Telomere length and type 2 diabetes: Mendelian randomization study and polygenic risk score analysis.

Recent epidemiological studies suggest an association between shorter telomere length and higher risk for type 2 diabetes (T2D). However, results from observational studies are susceptible to confounding and reverse causation, and it is not clear whether there is a causal association between telomere length and T2D. Using Mendelian randomization (MR) and polygenic risk score (PRS) approaches, we had evaluated the causal effect of telomere length on T2D in the Chinese Han population. Using 8 telomere-length associated genetic variants as instrumental variables, an analysis of genetically predicted telomere length and T2D risk was performed in the MR study based on data from a T2D genome-wide association study (GWAS) in 2632 individuals (1318 cases and 1314 controls). We also applied a PRS approach to investigate the causal relationship using Chinese GWAS data. The inverse-variance weighted, MR-Egger regression, simple median, and weighted median methods yielded no evidence of association between genetically predicted longer telomere length and risk of T2D (OR = 0.78, 95% CI: 0.36 ~ 1.68, P = 0.522; OR = 0.23, 95% CI: 0.01 ~ 7.64, P = 0.412; OR = 0.60, 95% CI: 0.28 ~ 1.28, P = 0.185; OR = 0.64, 95% CI: 0.31 ~ 1.33,P = 0.233; respectively). Further, PRS analysis did not produce consistent genetic overlap between telomere length and T2D. Accordingly, this study found no evidence supporting a causal association between telomere length and T2D. Further studies with larger cohorts could yield more reliable results and conclusions.

Maternal DCAF2 is crucial for maintenance of genome stability during the first cell cycle in mice.

Precise regulation of DNA replication and genome integrity is crucial for gametogenesis and early embryogenesis. Cullin ring-finger ubiquitin ligase 4 (CRL4) has multiple functions in the maintenance of germ cell survival, oocyte meiotic maturation, and maternal-zygotic transition in mammals. DDB1-cullin-4-associated factor-2 (DCAF2, also known as DTL or CDT2) is an evolutionarily conserved substrate receptor of CRL4. To determine whether DCAF2 is a key CRL4 substrate adaptor in mammalian oocytes, we generated a novel mouse strain that carries a Dcaf2 allele flanked by loxP sequences, and specifically deleted Dcaf2 in oocytes. Dcaf2 knockout in mouse oocytes leads to female infertility. Although Dcaf2-null oocytes were able to develop and mature normally, the embryos derived from them were arrested at one- to two-cell stage, owing to prolonged DNA replication and accumulation of massive DNA damage. These results indicate that DCAF2 is a previously unrecognized maternal factor that safeguards zygotic genome stability. Maternal DCAF2 protein is crucial for prevention of DNA re-replication in the first and unique mitotic cell cycle of the zygote.This article has an associated First Person interview with the first author of the paper.

Involvement of RhoA/ROCK Signaling in Aß-Induced Chemotaxis, Cytotoxicity and Inflammatory Response of Microglial BV2 Cells.

Reactive microglia clustering around amyloid plaques in brain is a histopathological feature of Alzheimer's disease (AD) and reflects the contribution of neuroinflammation in AD pathogenesis. ß-Amyloid peptide (Aß) has been shown to induce a range of microglial responses including chemotaxis, cytotoxicity and inflammation, but the underlying mechanism is poorly understood. Considering the fundamental role of RhoA/ROCK signaling in cell migration and its broad implication in AD and neuroinflammation, we hypothesized that RhoA/ROCK signaling might be involved in Aß-induced microglial responses. From in vivo mouse models including APP/PS1 transgene and fibrillar Aß stereotactic injection, we observed the elevated expression level of RhoA in reactive microglia. Through a series in vitro cell migration, cytotoxicity and biochemistry assays, we found that RhoA/ROCK signaling plays an essential role in Aß-induced responses of microglial BV2 cells. Small molecular agents Fasudil and Y27632 showed prominent beneficial effects, which implies the therapeutic potential of RhoA/ROCK signaling inhibitors in AD treatment.

Pseudo-phosphorylation at AT8 epitopes regulates the tau truncation at aspartate 421.

Tau pathology in Alzheimer's disease (AD) includes hyperphosphorylation and truncation of tau. Phosphorylation at S422 is found to suppress truncation of tau at D421 that leading to the generation of ΔTau. However, the interrelation between hyperphosphorylation and generation of ΔTau in AD remains elusive. In current study, staurosporine (Stau) induced ΔTau generation by caspases in SH-SY5Y cells with tau overexpression was found to be accompanied by a dramatic dephosphorylation at S422 and the epitope of the diagnostic antibody AT8 (S199 + S202 + T205), but a moderate dephosphorylation of PHF1 (S396 + S404) epitope. Therefore, to explore the effect of AT8 epitope on tau truncation, the residues in AT8 epitope were mutated to produce "pseudo-phosphorylated" (AT8E) or "pseudo-unphosphorylated" (AT8A) tau constructs. With Stau treatment, the generation of ΔTau from tau-AT8E was significantly attenuated comparing with that from tau-AT8A, which was S422-independent in that addition of S422A mutation still preserved this effect. Interestingly, this modulatory effect was able to be reversed by addition of PHF1E mutation. Moreover, treating the crude tau extracts with recombinant caspase-3 in vitro, also showed that ΔTau level was suppressed by AT8E, and potentiated by AT8E + PHF1E. The results primarily revealed the modulating effects of phosphorylation on ΔTau generation which may have potential implications in tau pathological processes and therapeutic intervention.

Memantine Differentially Regulates Tau Phosphorylation Induced by Chronic Restraint Stress of Varying Duration in Mice.

Exposure to chronic psychiatric stress has been linked to Alzheimer's disease-related tau hyperphosphorylation and abnormalities in glutamate neurotransmission. However, the pathological relationship between glutamatergic dysfunction and tau phosphorylation in the cerebral cortex under chronic psychiatric stress is not fully understood. The present study investigated the effects of memantine (MEM, 5 and 10 mg/kg), an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, on chronic restraint stress- (CRS-) induced tau phosphorylation in mice. CRS administered for 16 or 28 consecutive days (1 h daily) induced significant tau phosphorylation in the brain. MEM treatment suppressed the elevation of phosphorylated tau (P-tau) levels induced by 16-day CRS in a dose-dependent manner. P-tau reduction was accompanied by the attenuation of the upregulation of GSK3ß and CDK5 expression and the downregulation of PP2A activity induced by CRS. Additionally, MEM reduced CRS-induced upregulation of NMDA receptor subunit levels (GluN2A, GluN2B) in the frontal cortex. However, MEM markedly enhanced tau phosphorylation in the frontal cortex and other cerebral cortical regions following 28 days of CRS. The stimulatory effect of MEM on CRS-induced tau phosphorylation was correlated with increased activities of AKT, JNK, and GSK3ß, inactivation of PP2A, and downregulation of Pin1 and HSP70. Moreover, MEM did not effectively reverse the NMDA receptor upregulation induced by 28-day CRS and even increased GluN2B subunit levels. In contrast to the duration-dependent effects of MEM on P-tau levels, MEM produced an anxiolytic effect in both regimens as revealed by elevated plus maze testing. However, MEM did not affect the body weight reduction induced by CRS. Thus, MEM exerts distinctive effects on CRS-induced tau phosphorylation, which might be related to the expression of GluN2B. The differential effects of MEM on P-tau levels have crucial implications for its clinical application.