Leptin protects brain from ischemia/reperfusion-induced infarction by stabilizing the blood-brain barrier to block brain infiltration by the blood-borne neutrophils.

The cellular and molecular mechanisms underlying leptin-mediated brain protection against cerebral ischemia were investigated at the blood-brain barrier (BBB) and neutrophil level. Through the ischemia/reperfusion (I/R) animal model, we found that leptin expression level was significantly decreased in ischemic hemisphere. Brain injection with leptin (15 µg/kg, intracisternally) could block the I/R-increased BBB permeability, activation of matrix metallopeptidase 9 (MMP-9) and brain infiltration of blood-borne neutrophils to reduce the infarct volume of ischemic brain. The brain expression level of tight junction protein ZO-1 as well as number and motility of neutrophils in blood was all increased by the same injection, indicating BBB stability (rather than reduction in neutrophils) played a major role in the leptin-inhibited brain infiltration of neutrophils. Leptin-mediated protection of BBB was further confirmed in vitro, through a BBB cellular model under the in vitro ischemic condition (G/R: glucose-oxygen-serum deprivation followed by GOS restoration). The results showed that leptin again could block the G/R-increased neutrophil adherence to EC layer as well as BBB permeability, likely by stimulating the endothelial expression of ZO-1 and VE-Cadherin. The study has demonstrated that leptin could protect ischemic brain via multiple ways (other than neuronal protection), by inhibiting the BBB permeability, brain infiltration of the blood-borne neutrophils and neutrophil adherence to vascular ECs. The role of leptin in vascular biology of stroke could further support its therapeutic potential in other neurodegenerative diseases, associated with BBB disorder.

Involvement of Transcription Elongation Factor GreA in Mycobacterium Viability, Antibiotic Susceptibility, and Intracellular Fitness.

There is growing evidence that GreA aids adaptation to stressful environments in various bacteria. However, the functions of GreA among mycobacteria remain obscure. Here, we report on cellular consequences following deletion of greA gene in Mycobacterium spp. The greA mutant strain (ΔgreA) was generated in Mycobacterium smegmatis, Mycobacterium tuberculosis (MTB) H37Ra, and M. tuberculosis H37Rv. Deletion of greA results in growth retardation and poor survival in response to adverse stress, besides rendering M. tuberculosis more susceptible to vancomycin and rifampicin. By using RNA-seq, we observe that disrupting greA results in the differential regulation of 195 genes in M. smegmatis with 167 being negatively regulated. Among these, KEGG pathways significantly enriched for differentially regulated genes included tryptophan metabolism, starch and sucrose metabolism, and carotenoid biosynthesis, supporting a role of GreA in the metabolic regulation of mycobacteria. Moreover, like Escherichia coli GreA, M. smegmatis GreA exhibits a series of conservative features, and the anti-backtracking activity of C-terminal domain is indispensable for the expression of glgX, a gene was down-regulated in the RNA-seq data. Interestingly, the decrease in the expression of glgX by CRISPR interference, resulted in reduced growth. Finally, intracellular fitness significantly declines due to loss of greA. Our data indicates that GreA is an important factor for the survival and resistance establishment in Mycobacterium spp. This study provides new insight into GreA as a potential target in multi-drug resistant TB treatment.

Long non-coding RNA FLVCR1-AS1 sponges miR-155 to promote the tumorigenesis of gastric cancer by targeting c-Myc.

BACKGROUND: Gastric cancer (GC) is one of the most common digestive tract tumors, and a serious threat to human health. Long non-coding RNA (lncRNA) are involved in many cancers. However, the biological functions of most lncRNAs are unclear. In this study, we investigated the mechanisms by which FLVCR1-AS1 regulated GC progression. METHODS: FLVCR1-AS1 expression in GC tissues and 3 GC cell lines were measured by quantitative real-time PCR (qRT-PCR). Invasion, proliferation, and apoptosis profiles were analyzed by commercial assays to determine the biological functions of FLVCR1-AS1 in GC cells. The binding sites of micro RNA-155 (miR-155) on FLVCR1-AS1 were predicted using the miRDB program. Luciferase reporter assay was used to validate direct targeting of FLVCR1-AS1 by miR-155. The effects of FLVCR1-AS1 on expressions of c-Myc and p21 were assessed by western blotting. In vivo experiments were performed to analyze the effects of FLVCR1-AS1 on GC tumor growth. RESULTS: High expression of FLVCR1-AS1 correlated with poor clinical outcomes and prognosis in patients with GC. FLVCR1-AS1 promoted proliferation and invasion of GC cells by acting as a ceRNA to sponge miR-155. CONCLUSION: FLVCR1-AS1 acted as an oncogene in GC via FLVCR1-AS1-miR-155-c-Myc signaling and may serve as a novel therapeutic target for treatment of patients with GC.

Microglia-Derived Adiposomes are Potential Targets for the Treatment of Ischemic Stroke.

It is known that cerebral ischemia can cause brain inflammation and adiposome can serve as a depot of inflammatory mediators. In the study, the pro-inflammatory and pro-death role of adiposome in ischemic microglia and ischemic brain was newly investigated. The contribution of PPARγ to adiposome formation was also evaluated for the first time in ischemic microglia. Focal cerebral ischemia/reperfusion (I/R) animal model and the in vitro glucose-oxygen-serum deprivation (GOSD) cell model were both applied in the study. GOSD- or I/R-induced adiposome formation, inflammatory activity, cell death of microglia, and brain infarction were, respectively, determined, in the absence or presence of NS-398 (adiposome inhibitor) or GW9662 (PPARγ antagonist). GOSD-increased adiposome formation played a critical role in stimulating the inflammatory activity (production of TNF-α and IL-1ß) and cell death of microglia. Similar results were also found in ischemic brain tissues. GOSD-induced PPARγ partially contributed to the increase of adiposomes and adiposome-mediated inflammatory responses of microglia. Blockade of adiposome formation with NS-398 or GW9662 significantly reduced not only the inflammatory activity and death rate of GOSD-treated microglia but also the brain infarct volume and motor function deficit of ischemic rats. The pathological role of microglia-derived adiposome in cerebral ischemia has been confirmed and attributed to its pro-inflammatory and/or pro-death effect upon ischemic brain cells and tissues. Adiposome and its upstream regulator PPARγ were therefore as potential targets for the treatment of ischemic stroke. Therapeutic values of NS-398 and GW9662 have been suggested.

Up-regulated long noncoding RNA AB073614 modulates the tumor cell proliferation, invasion and migration in human colorectal cancer.

Colorectal cancer (CRC) is a common cancer and the function of long noncoding RNA (lncRNA) AB073614 in CRC mainly unclear. Here, the expression of lncRNA AB073614 in CRC tissues was evaluated by quantitative real-time PCR (qRT-PCR). CCK-8 assays were conducted to explore the impact of AB073614 on cell proliferation. The effects of AB073614 on cell migration, invasion and apoptosis were evaluated by a Transwell in vitro assay. Apoptosis-related molecular marker expression levels were detected by Western blot analysis. In the present study, we confirmed that AB073614 was significantly upregulated in CRC tissues. A difference analysis in the lncRNA AB073614 expression in CRC patient group suggested that the expression of lncRNA AB073614 was independently associated with higher possibilities of high grade (P = 0.0005), tumor size (> 5 cm) (P = 0.0001), distant metastasis (P = 0.0009), and differentiation level (P = 0.0037). In vitro studies demonstrated that the knockdown of {"type": "entrez-nucleotide", "attrs":{"text": "AB073614", "term_id": "51555790", "term_text": "AB073614"}}AB073614 suppressed SW480 cell proliferation. Meanwhile, the overexpression of {"type": "entrez-nucleotide", "attrs":{"text": "AB073614", "term_id": "51555790", "term_text": "AB073614"}}AB073614 in SW480 cells accelerated cell growth and invasion, and suppressed cell apoptosis. In conclusion, our results suggest that AB073614 may function as a tumor promoter in CRC. Our findings may provide a therapeutic approach for the future treatment of CRC.

LncRNA AB073614 induces epithelial- mesenchymal transition of colorectal cancer cells via regulating the JAK/STAT3 pathway.

BACKGROUND: LncRNAs are involved in the metastasis and recurrence of human tumors, including colorectal cancer (CRC). We previously reported that lncRNA AB073614 promotes tumor proliferation and metastasis and predicted a poor clinical outcome of CRC patients. Herein, we investigated the underlying mechanism of lncRNA AB073614-related metastasis in CRC. MATERIAL AND METHODS: The expression of lncRNA AB073614 in CRC tissues were evaluated by quantitative real-time PCR (qRT-PCR). Transwell assay was performed to detect the effects of lncRNA AB073614 on cell migration and invasion. Epithelial-mesenchymal transition (EMT) molecular markers and Janus kinase/signal transducer and activator of transcription (JAK/STAT3) pathway proteins expression levels were detected by Western blot and Immunofluorescence. RESULTS: We confirmed that lncRNA AB073614 was highly expressed in the colorectal cancer tissues. LncRNA AB073614 knockdown in SW480 and HCT116 cells significantly promoted the protein expression levels of E-cadherin and Occludin, and decreased the expressions of N-cadherin and Vimentin, then further decreased the cell migration and invasion ability. Interestingly, the expression of phosphorylated STAT3 was also down-regulated. Furthermore, SW480 and HCT116 cells were transfected with lncRNA AB073614 vector and treated with a JAK inhibitor, AT9283. The results showed that lncRNA AB073614 regulated EMT through JAK-STAT3 signaling pathway. CONCLUSION: All these results indicate that lncRNA AB073614 can induce the expression of EMT cell markers and regulate the process of EMT of CRC cells through regulating the JAK/STAT3 pathway activation.

microRNA-1297 Inhibits the Growth and Metastasis of Colorectal Cancer by Suppressing Cyclin D2 Expression.

microRNAs (miR) can potentially be used for categorizing the various subtypes of colorectal cancer (CRC) and predicting a patient's response to treatment with traditional anti-CRC therapies. We investigated how miR-1297 and its potential target molecule cyclin D2 (CCND2) might affect the progression of CRC. Thirty-two pairs of CRC specimens and corresponding samples of para-tumor tissue were collected and examined for their levels of miR-1297 and CCND2 expression. We also examined miR-1297 and CCND2 expression in cultured SW480 cells. The effects of modulated levels of miR-1297 and CCND2 on cell viability, anchorage-independent growth ability, proliferation, apoptosis, cell cycle distribution, migration, and invasion were detected using specific techniques. The possible regulatory effect of miR-1297 on CCND2 was investigated using dual luciferase assays. Our results showed that miR-1297 expression was downregulated in clinical CRC specimens, and such downregulation was associated with upregulated levels of CCND2 expression. Upregulation of miR-1297 and downregulation of CCND2 reduced the proliferation and metastasis potential of SW480 cells, but did not affect the apoptotic process. In addition, miR-1297 regulated CCND2 function by directly binding to the promoter sequence of the CCND2 gene, which would block CCND2-related signaling at the transcription level. Our findings validate the anti-CRC function of miR-1297 and pro-CRC function of CCND2. Our findings may assist in developing miR-based therapies against CRC.

Therapeutic Effect of Sodium Glucose Co-Transporter 2 Inhibitor Dapagliflozin on Renal Cell Carcinoma.

BACKGROUND Patients with type 2 diabetes mellitus (T2DM) have a high incidence of renal cell carcinoma (RCC) and high sodium glucose co-transporters 2 (SGLT2) expressions. The purpose of this study was to evaluate the anticancer activity of dapagliflozin as an SGLT2 inhibitor on RCC cell lines in vitro and in vivo. MATERIAL AND METHODS qRT-PCR and Western blot were used to detect SGLT2 expression on different human renal cells. Then, flow cytometry and immunofluorescence were used to investigate the effects of dapagliflozin on cell cycle, apoptosis, and SGLT2 expression of CaKi-1 cells. Finally, a xenograft model and immunohistochemical staining were used to investigate the function of dapagliflozin in nude mice. RESULTS We proved that SGLT2 is highly expressed in RCC cell lines. We found that dapagliflozin exerts a higher cytotoxic effect on human RCC than on normal human renal cells, regulates the cell cycle and apoptosis, and reduces the glucose uptake and SGLT2 expression of CaKi-1 cells. Moreover, dapagliflozin inhibits tumor growth and reduces SGLT2 expression in vivo. CONCLUSIONS Our results indicate that dapagliflozin has high efficiency and low toxicity and could be a new therapeutic target for RCC.

LncRNA AB073614 regulates proliferation and metastasis of colorectal cancer cells via the PI3K/AKT signaling pathway.

The expression profiles of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC) have remained unclear. LncRNA AB073614 is known to be upregulated in ovarian cancer and glioma tissues, and is associated with the occurrence and progression of those cancers. In the present study, we investigated the lncRNA AB073614 gene expression patterns in CRC cell lines and tissue samples from CRC patients, and then analyzed them for possible associations with various clinicopathological characteristics. Furthermore, the roles played by lncRNA AB073614 in CRC cell proliferation, apoptosis, cell cycle progression, migration, and invasion were examined in vitro by using gene knockdown and overexpression techniques. We detected the levels of lncRNA AB073614 in 28 paired CRC tissues and adjacent normal tissues by qRT-PCR, and our results revealed that AB073614 expression in 85.7% (24/28) of the CRC tissues was significantly higher than those in the paired normal tissues. Furthermore, the levels of AB073614 were closely related to tumor grade, size, cell differentiation status, and the presence of distant metastases. Knockdown of AB073614 expression significantly inhibited the proliferation, migration, and invasion of SW480 cells, and resulted in their increased rates of apoptosis and G1 phase cell cycle arrest, whereas overexpression of AB073614 produced the opposite effects. Finally, results of studies which used an agonist (740Y-P) and an inhibitor (LY294002) of the PI3K/AKT signaling pathway, as well as the results of western blot assays, indicated that lncRNA AB073614 exerts its effects by targeting the PI3K/AKT-mediated signaling pathway. Taken together, our data indicate that lncRNA AB073614 acts to prevent CRC progression by affecting the PI3K/AKT signaling pathway, and may be useful as a novel prognostic or treatment agent for CRC.

Metals of Deep Ocean Water Increase the Anti-Adipogenesis Effect of Monascus-Fermented Product via Modulating the Monascin and Ankaflavin Production.

Deep ocean water (DOW) obtained from a depth of more than 200 m includes abundant nutrients and minerals. DOW was proven to positively increase monascin (MS) and ankaflavin (AK) production and the anti-adipogenesis effect of Monascus-fermented red mold dioscorea (RMD). However, the influences that the major metals in DOW have on Monascus secondary metabolite biosynthesis and anti-adipogenesis remain unknown. Therefore, the major metals in DOW were used as the culture water to produce RMD. The secondary metabolites production and anti-adipogenesis effect of RMD cultured with various individual metal waters were investigated. In the results, the addition of water with Mg, Ca, Zn, and Fe increased MS and AK production and inhibited mycotoxin citrinin (CT). However, the positive influence may be contributed to the regulation of pigment biosynthesis. Furthermore, in the results of cell testing, higher lipogenesis inhibition was seen in the treatments of various ethanol extracts of RMD cultured with water containing Mg, K, Zn, and Fe than in those of RMD cultured with ultra-pure water. In conclusion, various individual metals resulted in different effects on MS and AK productions as well as the anti-adipogenesis effect of RMD, but the specific metals contained in DOW may cause synergistic or comprehensive effects that increase the significantly positive influence.

Molecular Mechanisms Responsible for Neuron-Derived Conditioned Medium (NCM)-Mediated Protection of Ischemic Brain.

The protective value of neuron-derived conditioned medium (NCM) in cerebral ischemia and the underlying mechanism(s) responsible for NCM-mediated brain protection against cerebral ischemia were investigated in the study. NCM was first collected from the neuronal culture growing under the in vitro ischemic condition (glucose-, oxygen- and serum-deprivation or GOSD) for 2, 4 or 6 h. Through the focal cerebral ischemia (bilateral CCAO/unilateral MCAO) animal model, we discovered that ischemia/reperfusion (I/R)-induced brain infarction was significantly reduced by NCM, given directly into the cistern magna at the end of 90 min of CCAO/MCAO. Immunoblocking and chemical blocking strategies were applied in the in vitro ischemic studies to show that NCM supplement could protect microglia, astrocytes and neurons from GOSD-induced cell death, in a growth factor (TGFß1, NT-3 and GDNF) and p-ERK dependent manner. Brain injection with TGFß1, NT3, GDNF and ERK agonist (DADS) alone or in combination, therefore also significantly decreased the infarct volume of ischemic brain. Moreover, NCM could inhibit ROS but stimulate IL-1ß release from GOSD-treated microglia and limit the infiltration of IL-ß-positive microglia into the core area of ischemic brain, revealing the anti-oxidant and anti-inflammatory activities of NCM. In overall, NCM-mediated brain protection against cerebral ischemia has been demonstrated for the first time in S.D. rats, due to its anti-apoptotic, anti-oxidant and potentially anti-glutamate activities (NCM-induced IL-1ß can inhibit the glutamate-mediated neurotoxicity) and restriction upon the infiltration of inflammatory microglia into the core area of ischemic brain. The therapeutic potentials of NCM, TGFß1, GDNF, NT-3 and DADS in the control of cerebral ischemia in human therefore have been suggested and require further investigation.

Molecular epidemiology and population dynamics of hepatitis B virus in Dianjiang County, Chongqing, China.

Hepatitis B virus infection is highly endemic in China, especially in rural areas such as Dianjiang County with poor-quality health care and little local HBV information. Therefore, for the first time, the present study was carried out to investigate the molecular epidemiology, phylogeny and population dynamics of HBV based on 146 HBV-infected patients. A 435-bp portion of the HBV S region was sequenced, and the phylogeny was reconstructed, indicating that three genotypes, B, C and D of HBV were distributed in Dianjiang County. The predominant genotype is B (67.12 %), followed by C (32.19 %) and D (0.68 %). Patient demographic information and clinical outcomes were examined by genotypes, and no significant association was found. Population dynamics analysis suggested that both genotype B and C have experienced a tenfold expansion during the last five years for reasons that are unclear. Thus, a thorough molecular epidemiology investigation is strongly recommended in the future.