Rotavirus and Norovirus Infections in Children Under 5 Years Old with Acute Gastroenteritis in Southwestern China, 2018-2020.

OBJECTIVE: Rotaviruses and noroviruses are important causes of acute gastroenteritis in children. While previous studies in China have mainly focused on rotavirus, we investigated the incidence of norovirus in addition to rotavirus in Southwestern China. METHODS: From January 2018 to December 2020, cases of rotavirus or norovirus infections among children under five ages with acute gastroenteritis were evaluated retrospectively. RESULTS: The detection rate of rotavirus was 24.5% (27,237/111,070) and norovirus was 26.1% (4649/17,797). Among 17,113 cases submitted for dual testing of both rotavirus and norovirus, mixed rotavirus/norovirus infections were detected in 5.0% (859/17,113) of cases. While there was no difference in norovirus incidence in outpatient compared to hospitalized cases, rotavirus was detected two times more in outpatients compared to hospitalized cases (26.6% vs.13.6%; P < 0.001). Both rotavirus and norovirus infections peaked in children aged 12-18 months seeking medical care with acute gastroenteritis (35.6% rotavirus cases; 8439/23,728 and 32.5% norovirus cases; 1660/5107). Rotavirus infections were frequent between December and March of each year while norovirus was detected earlier from October to December. Our results showed significant correlation between virus detection and environmental factors such as average monthly temperature but not relative humidity. In addition, we observed a reduction in the detection rates of rotavirus and norovirus at the beginning of the SARS-CoV-2 pandemic in 2020. CONCLUSION: Our results indicate that rotavirus and norovirus are still important viral agents in pediatric acute gastroenteritis in Southwestern China.

Porphyrin-based covalent organic framework as bioplatfrom for detection of vascular endothelial growth factor 165 through fluorescence resonance energy transfer.

A fluorescent aptasensor based on porphyrin-based covalent organic framework (p-COF) and carbon dots (CDs) was constructed for detecting vascular endothelial growth factor 165 (VEGF165) and for imaging of the breast cancer cell line Michigan cancer foundation-7 (MCF-7). CDs synthesized with strong photoluminescence at λ∼380 nm were used as donors to label the VEGF165-targeted aptamers (AptVEGF/CDs). Additionally, the p-COF nanostructure comprised rich functional groups of CN on the surface and π-stacking planar nanostructure, resulting in the CDs adsorption via weakly π-π stacking, hydrogen bond and the Van der Waals force. Thereby, the fluorescence resonance energy transfer (FRET) occurred due to the close distance between the p-COF network and CDs, leading to the quenching of the fluorescence feature of CDs and p-COF. In the presence of VEGF165, the G-quadruplex was formed via the specific binding between VEGF165 and aptamer. It impelled that the release of partial VEGF165-AptVEGF/CDs complex, affording the fluorescence recovery of the sensing system to some extent. Consequently, the proposed AptVEGF/CDs/p-COF fluorescence biosensor offered excellent analytical performances for the VEGF165 detection, displaying a detection limit of 20.9 fg mL-1 within a wide linear range of the VEGF165 concentration of 1.0 pg mL-1-100 ng mL-1. The developed fluorescence biosensor was also used to determine VEGF165-overexpressed in MCF-7 cancer cells. Thereby, the present work can greatly widen the application of COFs in the development of aptasensors and cancer diagnosis.

Quantification of EGFR and EGFR-overexpressed cancer cells based on carbon dots@bimetallic CuCo Prussian blue analogue.

A new bimetallic CuCo Prussian blue analogue (CuCo PBA) loaded with carbon dots (CDs) was prepared (represented by CD@CuCoPBA) and developed as a scaffold for anchoring the epidermal growth factor receptor (EGFR) aptamer to detect EGFR and living EGFR-overexpressed cancer cells. The basic characterizations revealed CuCo PBA exhibited nanocube shape and still remained its nanostructure and physical/chemical properties after coupling with large amounts of CDs. As compared with the pristine CuCo PBA, the CD@CuCoPBA displayed good electrochemical activity, strong binding interaction toward aptamer, and high stability of aptamer-EGFR G-quadruplex in aqueous solution. As such, the results of electrochemical impedance spectroscopy measurements indicated that the CD@CuCoPBA-based aptasensor displayed an ultra-low detection limit toward EGFR (0.42 fg mL-1) and living EGFR-overexpressed MCF-7 cancer cells (80 cell per mL), as well as high selectivity, good reproducibility, high stability, repeatability, and acceptable applicability. Consequently, the constructed CD@CuCoPBA-based aptasensor can be extended to be a promising universal method for early diagnosis of cancers.

Polymorphisms in miRNA genes play roles in the initiation and development of cervical cancer.

MicroRNA deregulation is crucial for cancer development. Studies showed that polymorphisms in miRNA genes could affect miRNA expression, which might be associated with cancer development. In the current study, we investigated the association of seven single nucleotide polymorphisms (SNPs) in seven miRNA genes with the initiation and development of cervical cancer in a Chinese Han population. The SNPs of 358 cervical intraepithelial neoplasia (CIN) patients, 547 cervical cancer patients and 567 healthy individuals were genotyped using TaqMan assays. Moreover, we evaluated the association of the seven SNPs with the different stages of cervical cancer. Our results showed that rs4636297 in miR-126 was associated with susceptibility to CIN and cervical cancer (P=0.019 and 0.019, respectively) and that the T allele was associated with a higher risk of CIN (OR=1.334, 95% CI: 1.049-1.698) and cervical cancer (OR=1.296, 95% CI: 1.044-1.609). Similarly, rs11614913 in miR-125a was associated with CIN and cervical cancer (P=0.025 and 0.015, respectively), and the T allele might be the protective factor for CIN (OR=0.807, 95% CI: 0.669-0.974) and cervical cancer (OR=0.814, 95% CI: 0.689-0.961). Our results indicated that rs4636297 in miR-126 and rs11614913 in miR-196a2 play an important role only in the initiation of cervical cancer not in the development of CIN to cervical cancer.

Molecular cloning and functional characterization of chalcone isomerase from Carthamus tinctorius.

Flavonoid is one of the widespread groups of plant secondary metabolites that provide several health benefits. However, the explicit mechanism of flavonoid biosynthesis in plants largely remains unclear. Chalcone isomerase an important class of enzyme presents crucial role during flavonoid metabolism in many plants. Here, we isolated the full-length cDNA (1161 bp) of a novel Chalcone Isomerase from safflower encoding 217 amino acid polypeptide using oligos from 5' and 3' ends. The result of Sanger sequencing and phylogenetic analysis revealed that CtCHI is highly homologous to other plants, including typical polyadenylation signals AATAA and Poly A tail. The transient expression in tobacco mesophyll cells using Green Fluorescent Protein tagging determined the subcellular localization of CtCHI in cell membrane and nucleus. The CtCHI ectopic expression in different safflower varieties at different flowering stages showed that CtCHI were found in abundance at the bud stage of Jihong No. 1. Further correlation analysis between CtCHI expression and flavonoid accumulation at various flowering phases suggested that CtCHI might play a potential role during flavonoid biosynthesis in safflower. In addition, the overexpression of pBASTA-CtCHI in transgenic Arabidopsis infiltrated with floral dip transformation showed relatively higher expression level and increased flavonoid accumulation than wild type. Moreover, the in vitro enzymatic activity and HPLC analysis of transgenic Arabidopsis confirmed the de novo biosynthesis of Rutin. Taken together, our findings laid the foundation of identifying an important gene that might influence flavonoid metabolism in safflower.

Human Papillomavirus Type 16 E1 Mutations Associated with Cervical Cancer in a Han Chinese Population.

Human papillomavirus type 16 (HPV16) is a high-risk HPV type and a potent carcinogen. HPV E1 is one of the most highly conserved proteins and it plays a central role in initiating HPV DNA replication. In current study, we enrolled 161 HPV16-positive cervical cancer patients (case group) and 171 HPV16-positive asymptomatic individuals (control group) in a study to analyse the association between HPV16 E1 genetic mutations and cervical cancer. The samples of case group were cervical cancer tissues and the samples of control group were cervical exfoliated cells. Three variants (A4, A1-A3 and D3) were found in the case group, 68.3% of the HPV16 E1 sequences belonged to the A4 (As) sub-lineage, 29.2% belonged to the A1-A3 (EUR) sub-lineage, and 2.5% belonged to the D3 (AA1) sub-lineage. Two variants (A4 and A1-A3) occurred in the control group. The A4 (As) sub-lineage was predominant in this group as well (66.1%), followed by the A1-A3 (EUR) sub-lineage (33.9%), but the D3 (AA1) sub-lineage was not found in the control group. The distribution of the HPV16 variants between the case and control groups was significantly different (P<0.05). When the distribution of the HPV16 E1 gene mutations was compared, the distribution of twenty-seven mutations was significantly different between the case and control groups (P<0.05), and twenty-two mutations occurred only in the D3 (AA1) sub-lineage, two were found only in the A4 (As) sub-lineage, one was found in the A1-A3 (EUR) sub-lineage, two was found in both the A4 (As) and A1-A3 (EUR) sub-lineages. In the sub-lineage analysis, the differences in the T933A (A23A), T1014G (D50E) and G2160A (R432R) mutations were statistically significant between the case and control groups for the A4 (As) sub-lineage (P<0.05), and the differences in the T2232C (F456F), G2337A (M491I) and A2547G (P561P) mutations were statistically significant between the case and control groups for the A1-A3 (EUR) sub-lineage (P<0.05). In the current study, we describe specific mutations in the HPV16 E1 gene associated with cervical cancer, and our study will provide a good reference for further functional studies of the relationship between cervical cancer carcinogenesis and HPV genes.

A bimetallic (Cu-Co) Prussian Blue analogue loaded with gold nanoparticles for impedimetric aptasensing of ochratoxin a.

Bimetallic (Cu-Co) Prussian Blue analogs (PBAs) were coupled to gold nanoparticles to give a nanocomposite of type AuNP@CuCoPBA. It is shown to be a viable material for the impedimetric aptamer-based determination of ochratoxin A (OTA). Basic characterizations revealed that the chemical composition and crystal structure of AuNP@CuCoPBA is similar to that of pristine CuCo PBA. Nevertheless, the nanocube shape of CoCu PBA is converted to small nanoparticles on addition of AuNPs. Compared with CuCoPBA-based aptasensor, the AuNP@CuCoPBA-based assay exhibits excellent electrochemical conductivity, strong aptamer binding interaction, and high G-quadruplex stability. Electrochemical impedance spectroscopy revealed that the assay has limits of detection as low as 5.2 fg mL-1 of OTA, a response in the 50 fg mL-1 to 10 ng mL-1 concentration range, high selectivity, good reproducibility, repeatability, and acceptable applicability. In our perception, it represents a universal and powerful method for aptamer strand immobilization. It may be applied to the determination of various other analytes for which aptamers are available. Graphical abstract Schematic presentation of the preparation of a novel bimetallic Cu-Co PBAs coupling with gold nanoparticles (AuNPs) was supplied. The AuNP@CuCoPBA composite was applied for the sensitive detection of ochratoxin A (OTA). The impedimetric aptasensensor based on AuNP@CuCoPBA displays extremely low limits of detection toward OTA (5.2 fg mL-1), along with high selectivity, good reproducibility, high stability, repeatability, and acceptable applicability.

Human papillomavirus type 16 E6 and E7 gene variations associated with cervical cancer in a Han Chinese population.

BACKGROUD: Human papillomavirus type 16 (HPV16) is a high-risk HPV subtype and a potent carcinogen. The HPV16 E6 and E7 genes are considered oncogenes that play a core role in the development of cervical cancer. METHODS: In the current study, we enrolled 97 HPV16-positive cervical cancer patients (case group) and 136 HPV16-positive asymptomatic individuals (control group) in a study to analyse the association between HPV16 E6 and E7 gene variations and cervical cancer. RESULTS: Our results showed that three HPV16 sub-lineages (A1-A3, A4 and D3) were present; the distribution of these variants between the case and control group was not significantly different (P = 0.178). When the distribution of the HPV16 E6 and E7 gene variations was compared, the distribution of only A131C (R10R) in the E6 gene showed a different trend between the case and control groups and C749T (S63F) in the E7 gene was significantly different between the case and control groups (P = 0.071 and P = 4.861 × 10-10, respectively). Regarding the sub-lineages, no variations in the E6 gene were significantly different between the case and control group for the A4 (As) and A1-A3 (EUR) sub-lineages. However, the distribution of C749T (S63F) in the E7 gene was significantly different between the case and control groups for the A4 (As) and A1-A3 (EUR) sub-lineages (P = 1.815 × 10-8 and P = 0.008). In the current study, we found that the C749T (S63F) variation in the HPV16 E7 gene was associated with cervical cancer not only in the A4 (As) sub-lineage but also in the A1-A3 (EUR) sub-lineage. CONCLUSION: Our study will provide a good reference for further functional studies of the relationship between cervical cancer carcinogenesis and the HPV16 E6 and E7 genes.

NiCo2O4 spinel embedded with carbon nanotubes derived from bimetallic NiCo metal-organic framework for the ultrasensitive detection of human immune deficiency virus-1 gene.

A bimetallic NiCo-based metal-organic framework (NiCo-MOF) was pyrolyzed into a novel composite comprising NiCo2O4 spinel, CoO, and metallic Co/Ni nanoparticles embedded with carbon nanotubes at high temperature 700 °C under N2 atmosphere (represented by NiCo2O4/CoO@CNTs), whereas organic ligands were almost decomposed in H2 atmosphere, leading to absence of carbon nanotubes (denoted by NiCo2O4/CoO). The feasibility of using the composite as efficient bioplatform for immobilizing the probe DNA of human immune deficiency virus-1 (HIV-1) in the electrochemical detection of the HIV-1 DNA was explored. Compared with the pristine NiCo-MOF and NiCo2O4/CoO, the NiCo2O4/CoO@CNTs composite exhibited high electrochemical activity, good biocompatibility, and strong bioaffinity toward the probe DNA. Electrochemical measurements demonstrated that the NiCo2O4/CoO@CNTs-based bioassay displayed superior sensing performances, giving an ultralow detection limit of 16.7 fM toward HIV-1 DNA over the linear range of 0.1 pM to 20 nM; possessing high selectivity even against noncomplementary and two-base mismatch sequences; exhibiting good stability, reproducibility, repeatability and applicability in the application of detecting human serum samples. Thus, the present strategy can broaden the application of MOFs and their derivatives in various fields of biosensing.

Upconversion of transparent glass ceramics containing ß-NaYF4:Yb3+, Er3+ nanocrystals for optical thermometry.

ß-NaYF4 nanocrystal embedded glass ceramics were fabricated by a melt-quenching method with subsequent heat-treatment. Structural characterizations and spectrographic techniques were performed to verify the successful precipitation of ß-NaYF4 nanocrystals and partition of dopants. Upon excitation of 980 nm, bright green upconversion emission could be achieved in Yb3+, Er3+ codoped ß-NaYF4 nanocrystal embedded glass ceramics. Furthermore, the temperature-dependent upconversion behaviour based on thermally coupled energy levels was also examined in the range of 300-773 K with the maximum relative sensitivity of 1.24% K-1 at 300 K. Accordingly, it has been proved to be a promising candidate for application in optical thermometry.

Core-Shell Heterostructured CuFe@FeFe Prussian Blue Analogue Coupling with Silver Nanoclusters via a One-Step Bioinspired Approach: Efficiently Nonlabeled Aptasensor for Detection of Bleomycin in Various Aqueous Environments.

We synthesized novel core-shell heterostructured Prussian blue analogue (PBA) nanospheres coupled with silver nanoclusters (AgNCs) via a one-step bioinspired approach and further exploited these as aptasensors for the detection of a trace antibiotic, bleomycin (BLM). Using FeFe Prussian blue (FeFe PB) as the core, a bimetallic CuFe@FeFe PBA layer was prepared by coupling with AgNCs synthesized by taking the BLM-targeted aptamer as a template (denoted by AgNCs/Apt@CuFe@FeFe). The coupling of AgNCs/Apt via a one-step bioinspired approach not only can improve the sensing performance of CuFe@FeFe-based aptasensors but also can shorten the aptasensor fabrication procedure. Due to the strong coordination interaction between abundant Fe(II) ions contained in CuFe@FeFe PBA nanospheres and BLM (represented by Fe(II)·BLM), the Fe(II)·BLM complex formed enables aptamer strands to undergo an irreversible cleavage event that can result in a significant change in electrochemical activity. Electrochemical results displayed that both CuFe@FeFe- and AgNCs/Apt@CuFe@FeFe-based aptasensors exhibited high sensitivity and selectivity, good stability and reproducibility, and acceptable applicability toward BLM. In comparison with the pristine CuFe@FeFe-based aptasensor (limit of detection (LOD) = 0.49 fg mL-1 within the BLM concentration from 1.0 to 2.0 ng mL-1), the as-prepared AgNCs/Apt@CuFe@FeFe-based aptasensor gave a extremely lower LOD value of 0.0082 fg mL-1 within a relatively narrow BLM concentration range (0.01 fg mL-1 to 0.1 pg mL-1). The proposed method can broaden the application of PBA nanomaterials in food safety and biosensing fields and provides a potential determination method for rapidly detecting BLM in various aqueous environments.

Bifunctional aptasensor based on novel two-dimensional nanocomposite of MoS2 quantum dots and g-C3N4 nanosheets decorated with chitosan-stabilized Au nanoparticles for selectively detecting prostate specific antigen.

A novel nanostructured biosensing platform was designed based on two-dimensional (2D) nanocomposite of graphitic carbon nitride (g-C3N4) nanosheets and MoS2 quantum dots (MoS2 QDs), followed by decoration with chitosan-stabilized Au nanoparticles (CS-AuNPs) (denoted as MoS2QDs@g-C3N4@CS-AuNPs), of which CS-AuNPs were prepared by plasma enhanced-chemical vapor deposition. Owning to the good surface plasmon performance of the CS-AuNPs and excellent electrochemical activity of MoS2QDs@g-C3N4 nanosheets, the as-obtained 2D MoS2QDs@g-C3N4@CS-AuNPs nanocomposite was simultaneously explored to construct both surface plasmon resonance spectroscopy (SPR) sensor and electrochemical aptasensor. The MoS2QDs@g-C3N4@CS-AuNPs-based aptasensor shows strong bio-binding affinity toward the prostate specific antigen (PSA) targeted aptamer strands as compared to the individual component, including MoS2 QDs, g-C3N4, and CS-AuNPs. When detecting PSA, the low limit of detection (LOD) of 0.71 pg mL-1 deduced by electrochemical aptasensor is three orders of magnitude lower than that deduced by SPR sensor (0.77 ng mL-1). As expected, both SPR sensor and electrochemical aptasensor demonstrate good selectivity, highly stability, acceptable reproducibility, and well consistent applicability in human serum. The satisfactory results suggest potential application of the MoS2QDs@g-C3N4@CS-AuNPs in bifunctional biosensing fields and clinical monitoring of cancer markers.

Bimetallic NiFe oxide structures derived from hollow NiFe Prussian blue nanobox for label-free electrochemical biosensing adenosine triphosphate.

We designed and constructed a novel aptasensor based on the porous nanostructured bimetallic NiFe-oxides embedded with the mesoporous carbon (represented by NiOxFeOy@mC) for sensitively detecting adenosine triphosphate (ATP), of which the porous NiOxFeOy@mC was derived from the hollow NiFe Prussian blue analogue (hollow NiFe PBA) by calcinating under high temperature. Owning to the excellent electrochemical activity originated from the metal oxides and mesoporous carbon and the strong binding interaction between the aptamer strands and the nanostructure hybrid, the formed porous NiOxFeOy@mC composite calcinated at 900 °C exhibited superior sensitivity toward ATP determination in comparison with other porous nanocubes obtained at 500 and 700 °C. The proposed aptasensor not only revealed a wide linear range from 5.0 fg·mL-1 to 5.0 ng mL-1 with a extremely low detection limit of 0.98 fg·mL-1 (1.62 fM) (S/N = 3), but also displayed high selectivity towards other interferences, good stability and reproducibility, and acceptable applicability. Therefore, this proposed approach provides a promising platform for ultra-sensitive detection of ATP, further having the potential applications on diagnosis of ATP-related diseases.

Heterostructured Bi2S3@NH2-MIL-125(Ti) nanocomposite as a bifunctional photocatalyst for Cr(vi) reduction and rhodamine B degradation under visible light.

A series of bismuth sulfide (Bi2S3) nanorods and amine-functionalized Ti-based metal-organic framework heterojunctions [denoted by Bi2S3@NH2-MIL-125(Ti)] were constructed and explored as bifunctional photocatalysts for Cr(vi) reduction and rhodamine B (RhB) degradation under visible light illumination. Compared with the individual NH2-MIL-125(Ti) and Bi2S3, the as-synthesized Bi2S3@NH2-MIL-125(Ti) photocatalyst exhibited an enhanced photocatalytic activity toward Cr(vi) and RhB owning to the synergetic effect between Bi2S3 and NH2-MIL-125(Ti). Moreover, the Bi2S3@NH2-MIL-125(Ti) heterojunctions showed increased Cr(vi) removal efficiency by adding RhB in the system. The photocatalytic mechanism was proposed based on the analysis of different scavenger for active species and electron spin resonance spectrometry. The introduction of Bi2S3 into NH2-MIL-125(Ti) can extend the light adsorption and improve the transfer and separation of photogenerated charge carriers through the Bi2S3@NH2-MIL-125(Ti) heterojunction with unique band gap structure. The synthesized Bi2S3@NH2-MIL-125(Ti) photocatalyst also exhibited good reusability and stability.

Aptamer-Embedded Zirconium-Based Metal-Organic Framework Composites Prepared by De Novo Bio-Inspired Approach with Enhanced Biosensing for Detecting Trace Analytes.

A series of Zr-based metal-organic framework (MOF) composites embedded with three kinds of aptamer strands (509-MOF@Apt) were achieved by a one-step de novo synthetic approach. A platform for ultrasensitive detection of analytes, namely, thrombin, kanamycin, and carcinoembryonic antigen (CEA), was also established. Considering the conformational changes caused by the binding interactions between aptamer strands and targeted molecules, the label-free electrochemical aptasensors based on 509-MOF@Apt composites could be developed to detect various target molecules. By comparing the common fabrication approaches of aptasensors, a distinct determination mechanism was presented through analysis of the electrochemical measurements on different interaction behaviors between probe aptamer strands and 509-MOF materials. The optimized aptasensors based on 509-MOFs@Apt demonstrated excellent sensitivity (with the detection limit of 0.40, 0.37, and 0.21 pg mL-1 for CEA, thrombin, and kanamycin, respectively), stability, repeatability, and applicability. This work will provide a new platform for direct and feasible detection in biosensing related to clinical diagnostics and therapeutics, and further, extend the scope of potential applications for MOF materials.

Subacute ibuprofen treatment rescues the synaptic and cognitive deficits in advanced-aged mice.

Aging is accompanied by increased neuroinflammation, synaptic dysfunction, and cognitive deficits both in rodents and humans, yet the onset and progression of these deficits throughout the life span remain unknown. These aging-related deficits affect the quality of life and present challenges to our aging society. Here, we defined age-dependent and progressive impairments of synaptic and cognitive functions and showed that reducing astrocyte-related neuroinflammation through anti-inflammatory drug treatment in aged mice reverses these events. By comparing young (3 months), middle-aged (18 months), aged (24 months), and advanced-aged wild-type mice (30 months), we found that the levels of an astrocytic marker, glial fibrillary acidic protein, progressively increased after 18 months of age, which preceded the decreases of the synaptic marker PSD-95. Hippocampal long-term potentiation was also suppressed in an age-dependent manner, where significant deficits were observed after 24 months of age. Fear conditioning tests demonstrated that associative memory in the context and cued conditions was decreased starting at the ages of 18 and 30 months, respectively. When the mice were tested on hidden platform water maze, spatial learning memory was significantly impaired after 24 months of age. Importantly, subacute treatment with the anti-inflammatory drug ibuprofen suppressed astrocyte activation and restored synaptic plasticity and memory function in advanced-aged mice. These results support the critical contribution of aging-related inflammatory responses to hippocampal-dependent cognitive function and synaptic plasticity, in particular during advanced aging. Our findings provide strong evidence that suppression of neuroinflammation could be a promising treatment strategy to preserve cognition during aging.

TREM2 Promotes Microglial Survival by Activating Wnt/ß-Catenin Pathway.

Triggering Receptor Expressed on Myeloid cells 2 (TREM2), which is expressed on myeloid cells including microglia in the CNS, has recently been identified as a risk factor for Alzheimer's disease (AD). TREM2 transmits intracellular signals through its transmembrane binding partner DNAX-activating protein 12 (DAP12). Homozygous mutations inactivating TREM2 or DAP12 lead to Nasu-Hakola disease; however, how AD risk-conferring variants increase AD risk is not clear. To elucidate the signaling pathways underlying reduced TREM2 expression or loss of function in microglia, we respectively knocked down and knocked out the expression of TREM2 in in vitro and in vivo models. We found that TREM2 deficiency reduced the viability and proliferation of primary microglia, reduced microgliosis in Trem2-/- mouse brains, induced cell cycle arrest at the G1/S checkpoint, and decreased the stability of ß-catenin, a key component of the canonical Wnt signaling pathway responsible for maintaining many biological processes, including cell survival. TREM2 stabilized ß-catenin by inhibiting its degradation via the Akt/GSK3ß signaling pathway. More importantly, treatment with Wnt3a, LiCl, or TDZD-8, which activates the ß-catenin-mediated Wnt signaling pathway, rescued microglia survival and microgliosis in Trem2-/- microglia and/or in Trem2-/- mouse brain. Together, our studies demonstrate a critical role of TREM2-mediated Wnt/ß-catenin pathway in microglial viability and suggest that modulating this pathway therapeutically may help to combat the impaired microglial survival and microgliosis associated with AD.SIGNIFICANCE STATEMENT Mutations in the TREM2 (Triggering Receptor Expressed on Myeloid cells 2) gene are associated with increased risk for Alzheimer's disease (AD) with effective sizes comparable to that of the apolipoprotein E (APOE) ε4 allele, making it imperative to understand the molecular pathway(s) underlying TREM2 function in microglia. Our findings shed new light on the relationship between TREM2/DNAX-activating protein 12 (DAP12) signaling and Wnt/ß-catenin signaling and provide clues as to how reduced TREM2 function might impair microglial survival in AD pathogenesis. We demonstrate that TREM2 promotes microglial survival by activating the Wnt/ß-catenin signaling pathway and that it is possible to restore Wnt/ß-catenin signaling when TREM2 activity is disrupted or reduced. Therefore, we demonstrate the potential for manipulating the TREM2/ß-catenin signaling pathway for the treatment of AD.

LRP1 modulates the microglial immune response via regulation of JNK and NF-κB signaling pathways.

BACKGROUND: Neuroinflammation is characterized by microglial activation and the increased levels of cytokines and chemokines in the central nervous system (CNS). Recent evidence has implicated both beneficial and toxic roles of microglia when over-activated upon nerve injury or in neurodegenerative diseases, including Alzheimer's disease (AD). The low-density lipoprotein receptor-related protein 1 (LRP1) is a major receptor for apolipoprotein E (apoE) and amyloid-ß (Aß), which play critical roles in AD pathogenesis. LRP1 regulates inflammatory responses in peripheral tissues by modulating the release of inflammatory cytokines and phagocytosis. However, the roles of LRP1 in brain innate immunity and neuroinflammation remain unclear. METHODS: In this study, we determined whether LRP1 modulates microglial activation by knocking down Lrp1 in mouse primary microglia. LRP1-related functions in microglia were also assessed in the presence of LRP1 antagonist, the receptor-associated protein (RAP). The effects on the production of inflammatory cytokines were measured by quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Potential involvement of specific signaling pathways in LRP1-regulated functions including mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) were assessed using specific inhibitors. RESULTS: We found that knocking down of Lrp1 in mouse primary microglia led to the activation of both c-Jun N-terminal kinase (JNK) and NF-κB pathways with corresponding enhanced sensitivity to lipopolysaccharide (LPS) in the production of pro-inflammatory cytokines. Similar effects were observed when microglia were treated with LRP1 antagonist RAP. In addition, treatment with pro-inflammatory stimuli suppressed Lrp1 expression in microglia. Interestingly, NF-κB inhibitor not only suppressed the production of cytokines induced by the knockdown of Lrp1 but also restored the down-regulated expression of Lrp1 by LPS. CONCLUSIONS: Our study uncovers that LRP1 suppresses microglial activation by modulating JNK and NF-κB signaling pathways. Given that dysregulation of LRP1 has been associated with AD pathogenesis, our work reveals a critical regulatory mechanism of microglial activation by LRP1 that could be associated with other AD-related pathways thus further nominating LRP1 as a potential disease-modifying target for the treatment of AD.

Tryptophan for the sleeping disorder and mental symptom of new-type drug dependence: A randomized, double-blind, placebo-controlled trial.

INTRODUCTION: New-type drugs are popular with adolescents and could lead to psychiatry disorders, but no medications have been proven to be effective for these disorders of new-type drug dependence. We aimed to evaluate the efficacy of tryptophan on sleeping disorders and mental symptoms in detoxified individuals with new-type drug dependence. METHODS: This randomized, placebo-controlled trial included 80 detoxified individuals with new-type drug dependence, recruited successively from a Compulsory Residential Drug Abstinence Institution in Wuhan, China, from April 2012 to November 2012. Eligible participants were randomly allocated to be treated with tryptophan (1000 mg/d, n = 40) or placebo (n = 40) for 2 weeks. The sleeping disorders and mental symptoms were assessed using Athens Insomnia Scale and Symptom Check-List-90 at baseline and 2 weeks. Results were analyzed according to the "intention-to-treat" approach. RESULTS: Forty-five participants completed the 2-week study, 24 in the tryptophan group and 21 in the placebo group. There were no statistically significant differences in baseline characteristics between groups and the treatment adherence was similar between groups. The reduction in the Athens Insomnia Scale score in the tryptophan group was significantly greater than that in the placebo group (P = 0.017). However, no significant differences were found in Symptom Check-List-90 scores (either by individual dimension or the overall score) between groups (all P > 0.05). The frequency of adverse events was similar and no serious adverse events were reported during the study. CONCLUSION: Tryptophan was unlikely to be effective for mental symptoms, but could alleviate sleep disorders in short term among detoxified individuals with new-type drug dependence. Future large-scale trials are required to confirm findings from this study.

Opposing roles of the triggering receptor expressed on myeloid cells 2 and triggering receptor expressed on myeloid cells-like transcript 2 in microglia activation.

Mutations in triggering receptor expressed on myeloid cells 2 (TREM2), which has been proposed to regulate the inflammatory responses and the clearance of apoptotic neurons and/or amyloid-ß, are genetically linked to increased risk for late-onset Alzheimer's disease (AD). Interestingly, a missense variant in TREM-like transcript 2 (TREML2), a structurally similar protein encoded by the same gene cluster with TREM2 on chromosome 6, has been shown to protect against AD. However, the molecular mechanisms by which TREM2 and TREML2 regulate the pathogenesis of AD, and their functional relationship, if any, remain unclear. Here, we show that lipopolysaccharide (LPS) stimulation significantly suppressed TREM2 but increased TREML2 expression in mouse brain. Consistent with this in vivo result, LPS or oligomeric amyloid-ß treatment down regulated TREM2 but up-regulated TREML2 expression in primary microglia. Most important, modulation of TREM2 or TREML2 levels had opposing effects on inflammatory responses with enhancement or suppression of LPS-induced proinflammatory cytokine gene expression observed on TREM2 or TREML2 down regulation, respectively. In addition, the proliferation of primary microglia was significantly decreased when TREM2 was down regulated, whereas it was increased on TREML2 knockdown. Together, our results suggest that several microglial functions are strictly regulated by TREM2 and TREML2, whose dysfunctions likely contribute to AD pathogenesis by impairing brain innate immunity. Our findings provide novel mechanistic insights into the functions of TREM2 and TREML2 in microglia and have implications on designing new therapeutic strategies to treat AD.