BK Channel Depletion Promotes Adipocyte Differentiation by Activating the MAPK/ERK Pathway.

The expression of large conductance calcium-activated potassium channels (BK channels) in adipose tissue has been identified for years. BK channel deletion can improve metabolism in vivo, but the relative mechanisms remain unclear. Here, we examined the effects of BK channels on the differentiation of adipose-derived stem cells (ADSCs) and the related mechanisms. BKα and ß1 subunits were expressed on adipocytes. We found that both deletion of the KCNMA1 gene, encoding the pore forming α subunit of BK channels, and the BK channel inhibitor paxilline increased the expression of key genes in the peroxisome proliferator activated receptor (PPAR) pathway and promoted adipogenetic differentiation of ADSCs. We also observed that the MAPK-ERK pathway participates in BK channel deficiency-promoted adipogenic differentiation of ADSCs and that ERK inhibitors blocked the differentiation-promoting effect of BK channel deficiency. Hyperplasia of adipocytes is considered beneficial for metabolic health. These results indicate that BK channels play an important role in adipose hyperplasia by regulating the differentiation of ADSCs and may become an important target for studying the pathogenesis and treatment strategies of metabolic disorder-related diseases.

Deep neural network models for cell type prediction based on single-cell Hi-C data.

BACKGROUND: Cell type prediction is crucial to cell type identification of genomics, cancer diagnosis and drug development, and it can solve the time-consuming and difficult problem of cell classification in biological experiments. Therefore, a computational method is urgently needed to classify and predict cell types using single-cell Hi-C data. In previous studies, there is a lack of convenient and accurate method to predict cell types based on single-cell Hi-C data. Deep neural networks can form complex representations of single-cell Hi-C data and make it possible to handle the multidimensional and sparse biological datasets. RESULTS: We compare the performance of SCANN with existing methods and analyze the model by using five different evaluation metrics. When using only ML1 and ML3 datasets, the ARI and NMI values of SCANN increase by 14% and 11% over those of scHiCluster respectively. However, when using all six libraries of data, the ARI and NMI values of SCANN increase by 63% and 88% over those of scHiCluster respectively. These findings show that SCANN is highly accurate in predicting the type of independent cell samples using single-cell Hi-C data. CONCLUSIONS: SCANN enhances the training speed and requires fewer resources for predicting cell types. In addition, when the number of cells in different cell types was extremely unbalanced, SCANN has higher stability and flexibility in solving cell classification and cell type prediction using the single-cell Hi-C data. This predication method can assist biologists to study the differences in the chromosome structure of cells between different cell types.

[Effect of metabolic reprogramming on abdominal aortic aneurysm].

Abdominal aortic aneurysm (AAA) is a life-threatening disease that remains undetected until it acutely ruptures. Due to lack of effective pharmaceutic therapies, it is urgent to explore new prevention and treatment strategies. Metabolic reprogramming is a cellular process through which cells change their metabolic patterns to meet material and energy requirements, including glucose metabolism, lipid metabolism and amino acid metabolism. Recently, the regulatory role of metabolic reprogramming in cardiovascular diseases, especially AAA, has attracted significant attention. This review article focuses on the research progress regarding the effects of metabolic reprogramming of vascular smooth muscle cells (VSMCs) and macrophages on the occurrence and development of AAA, especially their roles in major pathological processes such as VSMCs apoptosis and phenotype transformation, extracellular matrix remodeling, oxidative stress, and inflammatory response. The aim is to provide new clues for the mechanism research and clinical treatment of AAA from the perspective of metabolism.

Mammalian sterile 20-like kinase 1 acts as a candidate biomarker of mortality of emergency surgical repair for acute type a aortic dissection.

BACKGROUND: Acute type A aortic dissection (ATAAD) is a life-threatening pathological change of the aorta. Patients who have undergone aortic surgery are usually at high risk of mortality. AIM: We investigated the predictive value of serum Mammalian sterile 20-like kinase 1 (MST1) as a biomarker for the risk of mortality of ATAAD patients. METHODS: In this retrospective cohort study, we analyzed 160 consecutive ATAAD patients who had undergone emergency surgery from July 2016 to April 2017. Medical records and blood samples were collected and analyzed. ELISA assays were performed to detect the concentrations of several proteins including MST1. The relationship between these potential biomarkers and the primary endpoint of death was evaluated using Cox proportional hazard regression analysis. RESULTS: Compared with a low level (< 1330.8 ng/L), high serum MST1 level (≥ 1330.8 ng/L) was positively associated with the 30-day mortality (OR = 5.233, 95%CI, 1.843-14.862, P < 0.01) and retained predictive after adjustment for sex, age, BMI, nasopharyngeal temperature and deep hypothermia circulatory arrest time (OR = 4.628 95% CI, 1.572-13.625, P < 0.01). A pre-existing basic clinical prediction model was improved with the inclusion of preoperative serum MST1. Specifically, the area under the ROC curve for base model (history of cerebrovascular disease, creatinine, time of operation) was 0.708 (95%CI, 0.546-0.836) and markedly increased to 0.823 when taking MST1 into consideration (95%CI, 0.700-0.912, P = 0.02). CONCLUSION: Our study suggests that high preoperative circulating MST1, with a concentration greater than 1330.8 ng/L, was correlated with the 30-day mortality of ATAAD patients who underwent emergency surgery.

Transposon insertions regulate genome-wide allele-specific expression and underpin flower colour variations in apple (Malus spp.).

Allele-specific expression (ASE) can lead to phenotypic diversity and evolution. However, the mechanisms regulating ASE are not well understood, particularly in woody perennial plants. In this study, we investigated ASE genes in the apple cultivar 'Royal Gala' (RG). A high quality chromosome-level genome was assembled using a homozygous tetra-haploid RG plant, derived from anther cultures. Using RNA-sequencing (RNA-seq) data from RG flower and fruit tissues, we identified 2091 ASE genes. Compared with the haploid genome of 'Golden Delicious' (GD), a parent of RG, we distinguished the genomic sequences between the two alleles of 817 ASE genes, and further identified allele-specific presence of a transposable element (TE) in the upstream region of 354 ASE genes. These included MYB110a that encodes a transcription factor regulating anthocyanin biosynthesis. Interestingly, another ASE gene, MYB10 also showed an allele-specific TE insertion and was identified using genome data of other apple cultivars. The presence of the TE insertion in both MYB genes was positively associated with ASE and anthocyanin accumulation in apple petals through analysis of 231 apple accessions, and thus underpins apple flower colour evolution. Our study demonstrated the importance of TEs in regulating ASE on a genome-wide scale and presents a novel method for rapid identification of ASE genes and their regulatory elements in plants.

Targeted lipidomics analysis of lysine 179 acetylation of ACSF2 in rat hepatic stellate cells.

Activation of hepatic stellate cells (HSCs) is generally recognized as a central driver of liver fibrosis. Metabolism of fatty acids (FA) plays a critical role in the activation of HSCs. Proteomics analysis on lysine acetylation of proteins in activated HSCs in our previous study indicated that acetylation of the lysine residues on ACSF2 is one of the most significantly upregulated sites in activated-HSCs and K179 is its important acetylation site. However, the role of acetylation at K179 of ACSF2 on activation of HSCs and free fatty acids (FFA) metabolism remains largely unknown. The reported study demonstrates that acetylation at K179 of ACSF2 promoted HSCs activation. The targeted lipidomic analysis indicated K179 acetylation of ACSF2 mainly affected long chain fatty acids (LCFA) metabolism, especially oleic acid, elaidic acid and palmitoleic acid. And the liquid chromatography mass spectrometry (LC-MS) analysis further demonstrated the formation of many long-chain acyl-CoAs were catalyzed by acetylation at K179 of ACSF2 including oleic acid, elaidic acid and palmitoleic acid. In conclusion, this study indicated that ACSF2 may be a potential therapeutic targets by regulating the metabolism of LCFA for liver fibrosis.

C/EBP-α induces autophagy by binding to Beclin1 through its own acetylation modification in activated hepatic stellate cells.

The activation of hepatic stellate cells (HSCs) plays a key role in the occurrence of liver fibrosis，and promoting the apoptosis of activated HSCs or reducing the number of activated HSCs can reverse the development of liver fibrosis. In our previous studies, we have demonstrated that the CCAAT/enhancer binding protein α (C/EBP-α) played an important role in promoting the apoptosis of activated HSCs, thereby exerting an anti-liver fibrosis effect. Unlike apoptosis, autophagy, as a caspase-independent programmed cell death, can promptly remove the abnormal accumulation of substances or damaged organelles in cells and play a key role in regulating the homeostasis of intracellular environment. However, it is still unclear whether C/EBP-α participates in the occurrence of autophagy in HSCs. Therefore, in this study, we firstly used the methods of Western blot and immunofluorescence to characterize the consequence of C/EBP-α overexpression on the expression of proteins LC3B, P62, ATG5 and Beclin1 which were related to autophagy in HSCs. Subsequently, we performed Western blot and site-directed mutagenesis methods to clarify the type and related mechanism of autophagy which was induced by C/EBP-α. Here we show that C/EBP-α promotes the occurrence of autophagy in HSCs and the autophagy induced by C/EBP-α belongs to mitophagy. The stability of C/EBP-α protein regulates the level of autophagy in HSCs. In addition, acetylation of C/EBP-α also regulates the occurrence of autophagy in HSCs. Acetylation of lysine at positions K298, K302 and K326 of C/EBP-α promotes its binding to Beclin1. In conclusion, our study uncovers the role of C/EBP-α in regulating autophagy in HSCs, thereby providing a new strategy for clinical treatment of liver fibrosis.

RACGAP1 modulates ECT2-Dependent mitochondrial quality control to drive breast cancer metastasis.

Most cancer deaths are due to the colonization of tumor cells in distant organs. More evidence indicates that overexpression of RACGAP1 plays a critical role in cancer metastasis. However, the underlying mechanism still remains poorly understood. Here we found that RACGAP1 promoted breast cancer metastasis through regulating mitochondrial quality control. Overexpression of RACGAP1 in breast cancer cells led to the fragmentation of mitochondria, increased mitophagy intensity, mitochondrial turnover, and aerobic glycolysis ATP production. We showed that RACGAP1 promoted mitochondrial fission through recruiting ECT2 during anaphase and subsequently had activated ERK-DRP1 pathway. We further demonstrated the phosphorylation of RACGAP1 is essential for its ability of binding with ECT2 and its downstream effects. RACGAP1 overexpression also increased the expression of PGC-1a, a key mitochondrial biogenesis regulator, presumably by the increased mitophagy intensity induced by RACGAP1. PGC-1a increased the enrichment of DNMT1 in mitochondria, mitochondrial DNMT1 augmented mitochondrial DNA methylation and upregulated mitochondrial genome transcription. Our data indicated that RACGAP1 simultaneously facilitated mitophagy and mitochondrial biogenesis through regulating DRP1 phosphorylation and PGC-1a expression, eventually improved mitochondrial quality control in breast cancer cells. Our study provided a new angle in understanding the RACGAP1-overexpression related malignancy in breast cancer patients.

Deletion of large-conductance calcium-activated potassium channels promotes vascular remodelling through the CTRP7-mediated PI3K/Akt signaling pathway.

The large-conductance calcium-activated potassium (BK) channel is a critical regulator and potential therapeutic target of vascular tone and architecture, and abnormal expression or dysfunction of this channel is linked to many vascular diseases. Vascular remodelling is the early pathological basis of severe vascular diseases. Delaying the progression of vascular remodelling can reduce cardiovascular events, but the pathogenesis remains unclear. To clarify the role of BK channels in vascular remodelling, we use rats with BK channel α subunit knockout (BK α ‒/‒). The results show that BK α ‒/‒ rats have smaller inner and outer diameters, thickened aortic walls, increased fibrosis, and disordered elastic fibers of the aortas compared with WT rats. When the expression and function of BK α are inhibited in human umbilical arterial smooth muscle cells (HUASMCs), the expressions of matrix metalloproteinase 2 (MMP2), MMP9, and interleukin-6 are enhanced, while the expressions of smooth muscle cell contractile phenotype proteins are reduced. RNA sequencing, bioinformatics analysis and qPCR verification show that C1q/tumor necrosis factor-related protein 7 ( CTRP7) is the downstream target gene. Furthermore, except for that of MMPs, a similar pattern of IL-6, smooth muscle cell contractile phenotype proteins expression trend is observed after CTRP7 knockdown. Moreover, knockdown of both BK α and CTRP7 in HUASMCs activates PI3K/Akt signaling. Additionally, CTRP7 is expressed in vascular smooth muscle cells (VSMCs), and BK α deficiency activates the PI3K/Akt pathway by reducing CTRP7 level. Therefore, we first show that BK channel deficiency leads to vascular remodelling. The BK channel and CTRP7 may serve as potential targets for the treatment of cardiovascular diseases.

BKCa channel participates in insulin-induced lipid deposition in adipocytes by increasing intracellular calcium.

Storing energy in the form of triglyceride (TG) is one of the basic functions of adipose tissue. Large-conductance calcium-activated potassium channels (BKCa channels) are expressed in adipose tissue and adipocyte-specific BKCa deficiency resists obesity in mice, but the role of BKCa channels in lipid deposition and the underlying mechanisms have not been elucidated. In the present study, we generated BKCa knockout (KO) rats and performed a transcriptome analysis of adipose tissue. We found that the phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway, which is important for lipid deposition, exhibited the most notable reduction among various signaling pathways in BKCa KO rats compared to wild-type rats. Insulin-induced TG deposition, glucose uptake, and Akt (Ser473) phosphorylation were significantly reduced in cultured adipocytes differentiated from adipose-derived stem cells of BKCa KO rats. Furthermore, we found that the insulin-induced increase of intracellular calcium resulting from extracellular calcium influx was significantly impaired in BKCa KO adipocytes. Finally, insulin activated BKCa currents through PI3K, which was independent of Akt and intracellular calcium. The results of this study suggested that BKCa channels participate in the insulin signaling pathway and promote TG deposition by increasing extracellular calcium influx in adipocytes.

Deletion of BK channels decreased skeletal and cardiac muscle function but increased smooth muscle contraction in rats.

Large conductance calcium-activated potassium channel (BK channel) is widely expressed in skeletal muscle, myocardium, smooth muscle and other muscle tissues. Mutation, abnormal expression and altered activity of BK channel are linked to muscle-related diseases such as dyskinesia, epilepsy and erectile dysfunction. In order to compare the effects of BK channel on different muscle tissues, we constructed BK channel gene knockout rats||||||| (BK-/- rats). HE staining, open field and grip strength tests, ultrasound, blood pressure measurement and vascular tension test were utilized to explore the effects of BK channel deletion on the structure and function changes in skeletal muscle, myocardium, and vascular smooth muscle (VSM). It was found that compared with wild-type rats, the BK-/- rats showed decreased skeletal muscle fiber area, grip, movement distance and speed at 2 and 12 months of ages. At heart, the muscle fiber area, cardiac systolic/diastolic function and heart rate decreased in BK-/- rats. The wall of the left ventricle became thin. However, the vascular wall of BK-/- rats thickened, the pulse wave velocity was increased, and the VSM contraction was enhanced. Unexpectedly, both systolic and diastolic blood pressure were reduced in BK-/- rats, while pulse pressure difference was increased. These results suggest that BK channel may have different effects on different types of muscle tissue, and it should be noted that different parts of muscle tissue may have different effects when BK channel-related drugs are used.

A mobile health application to support self-management in patients with chronic obstructive pulmonary disease: a randomised controlled trial.

OBJECTIVE: To investigate the effects of a mobile health smartphone application to support self-management programmes on quality of life, self-management behaviour and exercise and smoking cessation behaviour in patients with chronic obstructive pulmonary disease (COPD). DESIGN: A randomised controlled, single-blind trial, was carried out from November 2017 to February 2019, which included 78 participants admitted with COPD to the Affiliated Hospital of Zunyi Medical University in Guizhou. The study participants were randomised into intervention (n = 39) and control groups (n = 39). METHODS: Participants in the intervention group undertook a mobile medical application-based programme in addition to routine care, and participants in the control group received only routine care. The outcome measures were health-related quality of life evaluated by the COPD Assessment-Test, self-management behaviour using the COPD Self-Management Scale and physical activity and smoking behaviour were measured using a self-designed questionnaire. Data collection was conducted at baseline, third month, sixth month and 12th months. RESULTS: Thirty-five participants in the intervention group and 33 in the control group completed the study. Compared to the control group, participants in the intervention group showed statistically significant improvement in the COPD -Assessment -Test scores (P < 0.01) and in all domains of the COPD Self-Management Scale scores (P < 0.01) at 12th 12 months. Improvements in the COPD -Assessment -Test scores by 4.3 and 0.3 units, and in the total scores of the COPD Self-Management Scale total score by 23.01 and 2.28 units, respectively, were observed in the intervention and control groups, respectively over the 12-month study period. Meanwhile, the mobile health application programme also improved participants' exercise and smoking cessation behaviour. CONCLUSIONS: The mobile health smartphone application to support self-management programmes was effective in improving health-related quality of life and self-management behaviour in patients with COPD. TRIAL REGISTRATION: This study was registered in Chinese clinicaltrials.gov.

Comparison of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy for Kidney Stones: A Meta-Analysis.

BACKGROUND: Advances in micro-percutaneous nephrolithotomy (PCNL) for kidney stones have made it an alternative approach to the retrograde intrarenal surgery (RIRS) approach. Nevertheless, the superiority of micro-PCNL over RIRS is still under debate. The results are controversial. OBJECTIVES: The purpose of this study was to systematically evaluate the clinical results in patients presenting with kidney stones treated with micro-PCNL or RIRS. METHODS: A literature search was done for electronic databases to identify researches that compared micro-PCNL and RIRS till December 2019. The clinical outcome included complications, stone-free rates (SFRs), hemoglobin reduction, length of hospital stay, and operative time. RESULTS: Five articles were included in our study. The pooled results revealed no statistical difference in the rate of complications (OR = 0.99, 95% CI = 0.57-1.74, p = 0.99), length of hospital stay (MD = -0.29, 95% CI = -0.82 to 0.24, p = 0.28), and operative time (MD = -6.63, 95% CI = -27.34 to 14.08, p = 0.53) between the 2 groups. However, significant difference was present in hemoglobin reduction (MD = -0.43, 95% CI = -0.55 to 0.30, p < 0.001) and the SFRs (OR = 0.59, 95% CI = 0.36-0.98, p = 0.04) when comparing RIRS with micro-PCNL. CONCLUSIONS: Compared with micro-PCNL to treat kidney stones, RIRS is associated with better stone clearance and bearing higher hemoglobin loss. As the advantages of both technologies have been shown in some fields, the continuation of well-designed clinical trials may be necessary.

AT1-receptor autoantibody exposure in utero contributes to cardiac dysfunction and increased glycolysis in fetal mice.

Exposure to adverse factors in utero may lead to adaptive changes in cardiac structure and metabolism, which increases the risk of chronic cardiovascular disease later in life. Studies showed that the angiotensin II type 1 receptor autoantibodies (AT1-AAs) are able to cross the placenta into the circulation of pregnant rodents' embryo, which adversely affects embryogenesis. However, the effects of AT1-AA exposure on the fetal heart in utero are still unknown. In this study, we investigated whether intrauterine AT1-AA exposure has adverse effects on fetal heart structure, function and metabolism. AT1-AA-positive pregnant mouse models were successfully established by passive immunity, evidenced by increased AT1-AA content. Morphological and ultrasonic results showed that the fetal mice on embryonic day 18 (E18) of AT1-AA group have loose and disordered myocardial structure, and decreased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), compared with control groups. The myocardium of AT1-AA group fetal mice on E18 exhibited increased expression of the key molecules in the glycolytic pathway, pyruvate and lactic acid content and ATP production, suggesting that the glycolysis rate was enhanced. Furthermore, the enhanced effect of glycolysis caused by AT1-AA is mainly through the PPARß/δ pathway. These data confirmed that fetus exposure to AT1-AA in utero developed left ventricular dysfunction, myocardial structural arrangement disorders, and enhanced glycolysis on E18. Our results support AT1-AA being a potentially harmful factor for cardiovascular disease in fetal mice.

LOXL2 promotes vasculogenic mimicry and tumour aggressiveness in hepatocellular carcinoma.

Lysyl oxidase-like 2 (LOXL2) has shown to promote metastasis and poor prognosis in hepatocellular carcinoma (HCC). Also, we have previously reported that vasculogenic mimicry (VM) is associated with invasion, metastasis and poor survival in HCC patients. In the present study, we investigated molecular function of LOXL2 in HCC and VM. We used the immunohistochemical and CD31/periodic acid-Schiff double staining to detect the relationship between LOXL2 and VM formation. We performed the gain and loss of function studies and analysed the migratory, invasion and tube formation in HCC cell lines. We analysed the function of LOXL2 in VM formation and HCC metastasis both in vitro and in vivo. We have showed that LOXL2 was overexpression in HCC and was positively correlated with tumour grade, metastasis, VM formation and poor survival in 201 HCC patients. Secondly, our studies have showed that LOXL2 overexpression in HCC cells significantly promoted migration, invasion and tube formation. Finally, we found that LOXL2 may increase SNAIL expression, thereby enabling VM. Our study indicated that LOXL2 may promote VM formation and tumour metastasis by collaborating with SNAIL in HCC. What's more, the overexpression of LOXL2 indicated a poor prognosis in HCC patients.

Isolation and culture of vascular smooth muscle cells from rat placenta.

We developed a new separation method for isolating placental vascular smooth muscle cells (PVSMCs) from a rat in this study. Our method used the magnetic force between a magnet and ferrous ferric oxide (Fe3 O 4 ) to make the separation and extraction processes easier and more efficient. From the first to sixth generation, the cells isolated using this protocol were identified as smooth muscle cells (SMCs) by their immunoreactivity to the SMC markers and by the "hill and valley" morphology. PVSMCs were exposed to angiotensin II (1 µmol/L) and resulted in sharply increased intracellular Ca 2+ concentration. Furthermore, activation of protein kinase C (PKC) increased concomitantly with a decrease in calponin expression. These results indicate that the isolated cells had biological activity. Our method of isolating PVSMCs from rat leads to isolation of cultured cells with activity and high purity. The approach will be useful in research studies on placental vascular diseases.

High glucose-induced defective thrombospondin-1 release from astrocytes via TLR9 activation contributes to the synaptic protein loss.

Diabetes, characterized by chronic hyperglycemia, is known to induce synaptic degeneration in the brain, thereby resulting in cognitive dysfunction. Thrombospondin-1(TSP-1), the secreted protein produced by astrocytes, plays a crucial role in promoting synapse formation. Toll-like receptor 9 (TLR9) has been widely known to initiate the innate immune response. We recently reported TLR9 activation in neurons results in tau hyperphosphorylation induced by HG in vitro. Its activation has been also considered to mediate oxidative stress and astrocytic dysfunction under pathological circumstance. However, whether astrocytic TSP-1 alteration plays a role in synaptic protein loss under high glucose condition and whether TLR9 activation is involved in this process have not been reported. In this study, we found that primary mouse astrocytes incubated in high glucose (30mM) induced a significant decreased TSP-1 secretion and increased intracellular contents of TSP-1 without affecting transcription level. Addition of conditioned medium from high glucose (30mM) treated astrocytes to the primary neurons exhibited reduced synaptic proteins expression, which was attenuated by treatment with exogenous rTSP-1. In addition, we demonstrated that TLR9 activation along with reactive oxygen species (ROS) generation in astrocytes was induced by high glucose (30mM). Furthermore, we explored the relationship between TLR9 activation and TSP-1 production. Both TLR9 deficiency and the antioxidant N-acetyl-L-cysteine treatment improved altered intra- and extracellular TSP-1 levels under high glucose condition. Together, our findings suggest that high glucose (30mM) impairs TSP-1 secretion from astrocytes, which depends on astrocytic dysfunction associated with TLR9 activation mediated ROS signaling, ultimately contributing to the synaptic proteins loss.

High glucose-induced complement component 3 up-regulation via RAGE-p38MAPK-NF-κB signalling in astrocytes: In vivo and in vitro studies.

Diabetes is considered as a risk for cognitive decline, which is characterized by neurodegenerative alteration and innate immunity activation. Recently, complement 3 (C3), the critical central component of complement system, has been reported to play a key role in neurodegenerative alterations under pathological condition. Receptor for advanced glycation end products (RAGE) activation is confirmed to mediate several inflammatory cytokines production. However, whether C3 activation participates in the diabetic neuropathology and whether this process is regulated by RAGE activation remains unknown. The present study aimed to investigate the role of C3 in streptozotocin-induced diabetic mice and high glucose-induced primary astrocytes and the underlying modulatory mechanisms. The decreased synaptophysin density and increased C3 deposition at synapses were observed in the diabetic brain compared to the control brain. Furthermore, the elevated C3 was co-localized with GFAP-positive astrocytes in the diabetic brain slice in vivo and high glucose-induced astrocytes culture in vitro. Diabetes/high glucose-induced up-regulation of C3 expression at gene, protein and secretion levels, which were attenuated by pre-treatment with RAGE, p38MAPK and NF-κB inhibitors separately. These results demonstrate that high glucose induces C3 up-regulation via RAGE- p38MAPK-NF-κB signalling in vivo and in vitro, which might be associated with synaptic protein loss.

Shift of Macrophage Phenotype Due to Cartilage Oligomeric Matrix Protein Deficiency Drives Atherosclerotic Calcification.

RATIONALE: Intimal calcification is highly correlated with atherosclerotic plaque burden, but the underlying mechanism is poorly understood. We recently reported that cartilage oligomeric matrix protein (COMP), a component of vascular extracellular matrix, is an endogenous inhibitor of vascular smooth muscle cell calcification. OBJECTIVE: To investigate whether COMP affects atherosclerotic calcification. METHODS AND RESULTS: ApoE(-/-)COMP(-/-) mice fed with chow diet for 12 months manifested more extensive atherosclerotic calcification in the innominate arteries than did ApoE(-/-) mice. To investigate which origins of COMP contributed to atherosclerotic calcification, bone marrow transplantation was performed between ApoE(-/-) and ApoE(-/-)COMP(-/-) mice. Enhanced calcification was observed in mice transplanted with ApoE(-/-)COMP(-/-) bone marrow compared with mice transplanted with ApoE(-/-) bone marrow, indicating that bone marrow-derived COMP may play a critical role in atherosclerotic calcification. Furthermore, microarray profiling of wild-type and COMP(-/-) macrophages revealed that COMP-deficient macrophages exerted atherogenic and osteogenic characters. Integrin ß3 protein was attenuated in COMP(-/-) macrophages, and overexpression of integrin ß3 inhibited the shift of macrophage phenotypes by COMP deficiency. Furthermore, adeno-associated virus 2-integrin ß3 infection attenuated atherosclerotic calcification in ApoE(-/-)COMP(-/-) mice. Mechanistically, COMP bound directly to ß-tail domain of integrin ß3 via its C-terminus, and blocking of the COMP-integrin ß3 association by ß-tail domain mimicked the COMP deficiency-induced shift in macrophage phenotypes. Similar to COMP deficiency in mice, transduction of adeno-associated virus 2-ß-tail domain enhanced atherosclerotic calcification in ApoE(-/-) mice. CONCLUSIONS: These results reveal that COMP deficiency acted via integrin ß3 to drive macrophages toward the atherogenic and osteogenic phenotype and thereby aggravate atherosclerotic calcification.

High-glucose induces tau hyperphosphorylation through activation of TLR9-P38MAPK pathway.

Diabetic encephalopathy (DE) is one of the most common complications of diabetes. The major pathological variations include neurofibrillary tangles (NFTs), which are caused by tau hyperphosphorylation, and senile plaques (SPs) consisting of amyloid ß- protein(Aß) deposits. In recent years, DE research studies have focused on exploring the activation of the inflammatory signaling pathway in immune cells. Toll-like receptor 9 (TLR9) is well known to regulate the inflammatory reactions in immune processes. During the tau hyperphosphorylation process, TLR9 in microglia plays bidirectional roles. However, no studies have clearly demonstrated the relationship between TLR9 and tau hyperphosphorylation in neurons. Based on our experiments, we found significant increase in TLR9 expression in neurons and an increase in tau hyperphosphorylation in high-glucose media. However, these alterations can be reversed by TLR9 inhibitor. Furthermore, we specifically inhibited the activation of P38mitogenactivated protein kinase(P38MAPK) and found an effective decrease in tau hyperphosphorylation. This effect is likely related to Unc93b1. Meanwhile, High glucose levels can induce neuronal apoptosis via the TLR9 signaling pathway. Our studies are the first to reveal that high glucose can regulate tau hyperphosphorylation and neuronal apoptosis via TLR9-P38MAPK signaling pathway. These findings provide a new method for studying the mechanism underlying DE.