Microbial DNA enrichment promotes liver steatosis and fibrosis in the course of non-alcoholic steatohepatitis.

AIM: Low-grade inflammation is the hallmark of non-alcoholic fatty liver diseases (NAFLD) and non-alcoholic steatohepatitis (NASH). The leakage of microbiota-derived products can contribute to liver inflammation during NAFLD/NASH development. Here, we assessed the roles of gut microbial DNA-containing extracellular vesicles (mEVs) in regulating liver cellular abnormalities in the course of NAFLD/NASH. METHODS: We performed studies with Vsig4-/- , C3-/- , cGAS-/- , and their wild-type littermate mice. Vsig4+ macrophage population and bacterial DNA abundance were examined in both mouse and human liver by either flow cytometric or immunohistochemistry analysis. Gut mEVs were adoptively transferred into Vsig4-/- , C3-/- , cGAS-/- , or littermate WT mice, and hepatocyte inflammation and HSC fibrogenic activation were measured in these mice. RESULTS: Non-alcoholic fatty liver diseases and non-alcoholic steatohepatitis development was concomitant with a diminished liver Vsig4+ macrophage population and a marked bacterial DNA enrichment in both hepatocytes and HSCs. In the absence of Vsig4+ macrophages, gut mEVs translocation led to microbial DNA accumulation in hepatocytes and HSCs, resulting elevated hepatocyte inflammation and HSC fibrogenic activation. In contrast, in lean WT mice, Vsig4+ macrophages remove gut mEVs from bloodstream through a C3-dependent opsonization mechanism and prevent the infiltration of gut mEVs into hepatic cells. Additionally, Vsig4-/- mice more quickly developed significant liver steatosis and fibrosis than WT mice after Western diet feeding. In vitro treatment with NASH mEVs triggered hepatocyte inflammation and HSC fibrogenic activation. Microbial DNAs are key cargo for the effects of gut mEVs by activating cGAS/STING. CONCLUSION: Accumulation of microbial DNAs fuels the development of NAFLD/NASH-associated liver abnormalities.

Microbial DNA Enrichment Promotes Adrenomedullary Inflammation, Catecholamine Secretion, and Hypertension in Obese Mice.

Background Obesity is an established risk factor for hypertension. Although obesity-induced gut barrier breach leads to the leakage of various microbiota-derived products into host circulation and distal organs, the roles of microbiota in mediating the development of obesity-associated adrenomedullary disorders and hypertension have not been elucidated. We seek to explore the impacts of microbial DNA enrichment on inducing obesity-related adrenomedullary abnormalities and hypertension. Methods and Results Obesity was accompanied by remarkable bacterial DNA accumulation and elevated inflammation in the adrenal glands. Gut microbial DNA containing extracellular vesicles (mEVs) were readily leaked into the bloodstream and infiltrated into the adrenal glands in obese mice, causing microbial DNA enrichment. In lean wild-type mice, adrenal macrophages expressed CRIg (complement receptor of the immunoglobulin superfamily) that efficiently blocks the infiltration of gut mEVs. In contrast, the adrenal CRIg+ cell population was greatly decreased in obese mice. In lean CRIg-/- or C3-/- (complement component 3) mice intravenously injected with gut mEVs, adrenal microbial DNA accumulation elevated adrenal inflammation and norepinephrine secretion, concomitant with hypertension. In addition, microbial DNA promoted inflammatory responses and norepinephrine production in rat pheochromocytoma PC12 cells treated with gut mEVs. Depletion of microbial DNA cargo markedly blunted the effects of gut mEVs. We also validated that activation of cGAS (cyclic GMP-AMP synthase)/STING (cyclic GMP-AMP receptor stimulator of interferon genes) signaling is required for the ability of microbial DNA to trigger adrenomedullary dysfunctions in both in vivo and in vitro experiments. Restoring CRIg+ cells in obese mice decreased microbial DNA abundance, inflammation, and hypertension. Conclusions The leakage of gut mEVs leads to adrenal enrichment of microbial DNA that are pathogenic to induce obesity-associated adrenomedullary abnormalities and hypertension. Recovering the CRIg+ macrophage population attenuates obesity-induced adrenomedullary disorders.

Accumulation of microbial DNAs promotes to islet inflammation and ß cell abnormalities in obesity in mice.

Various microbial products leaked from gut lumen exacerbate tissue inflammation and metabolic disorders in obesity. Vsig4+ macrophages are key players preventing infiltration of bacteria and their products into host tissues. However, roles of islet Vsig4+ macrophages in the communication between microbiota and ß cells in pathogenesis of obesity-associated islet abnormalities are unknown. Here, we find that bacterial DNAs are enriched in ß cells of individuals with obesity. Intestinal microbial DNA-containing extracellular vesicles (mEVs) readily pass through obese gut barrier and deliver microbial DNAs into ß cells, resulting in elevated inflammation and impaired insulin secretion by triggering cGAS/STING activation. Vsig4+ macrophages prevent mEV infiltration into ß cells through a C3-dependent opsonization, whereas loss of Vsig4 leads to microbial DNA enrichment in ß cells after mEV treatment. Removal of microbial DNAs blunts mEV effects. Loss of Vsig4+ macrophages leads to microbial DNA accumulation in ß cells and subsequently obesity-associated islet abnormalities.

Hepatocyte-derived exosomes from early onset obese mice promote insulin sensitivity through miR-3075.

In chronic obesity, hepatocytes become insulin resistant and exert important effects on systemic metabolism. Here we show that in early onset obesity (4 weeks high-fat diet), hepatocytes secrete exosomes that enhance insulin sensitivity both in vitro and in vivo. These beneficial effects were due to exosomal microRNA miR-3075, which is enriched in these hepatocyte exosomes. FA2H is a direct target of miR-3075 and small interfering RNA depletion of FA2H in adipocytes, myocytes and primary hepatocytes leads to increased insulin sensitivity. In chronic obesity (16-18 weeks of a high-fat diet), hepatocyte exosomes promote a state of insulin resistance. These chronic obese hepatocyte exosomes do not directly cause impaired insulin signalling in vitro but do promote proinflammatory activation of macrophages. Taken together, these studies show that in early onset obesity, hepatocytes produce exosomes that express high levels of the insulin-sensitizing miR-3075. In chronic obesity, this compensatory effect is lost and hepatocyte-derived exosomes from chronic obese mice promote insulin resistance.

Adipose Tissue Macrophages Modulate Obesity-Associated ß Cell Adaptations through Secreted miRNA-Containing Extracellular Vesicles.

Obesity induces an adaptive expansion of ß cell mass and insulin secretion abnormality. Expansion of adipose tissue macrophages (ATMs) is a hallmark of obesity. Here, we assessed a novel role of ATMs in mediating obesity-induced ß cell adaptation through the release of miRNA-containing extracellular vesicles (EVs). In both in vivo and in vitro experiments, we show that ATM EVs derived from obese mice notably suppress insulin secretion and enhance ß cell proliferation. We also observed similar phenotypes from human islets after obese ATM EV treatment. Importantly, depletion of miRNAs blunts the effects of obese ATM EVs, as evidenced by minimal effects of obese DicerKO ATM EVs on ß cell responses. miR-155 is a highly enriched miRNA within obese ATM EVs and miR-155 overexpressed in ß cells impairs insulin secretion and enhances ß cell proliferation. In contrast, knockout of miR-155 attenuates the regulation of obese ATM EVs on ß cell responses. We further demonstrate that the miR-155-Mafb axis plays a critical role in controlling ß cell responses. These studies show a novel mechanism by which ATM-derived EVs act as endocrine vehicles delivering miRNAs and subsequently mediating obesity-associated ß cell adaptation and dysfunction.

MiR-690, an exosomal-derived miRNA from M2-polarized macrophages, improves insulin sensitivity in obese mice.

Insulin resistance is a major pathophysiologic defect in type 2 diabetes and obesity, while anti-inflammatory M2-like macrophages are important in maintaining normal metabolic homeostasis. Here, we show that M2 polarized bone marrow-derived macrophages (BMDMs) secrete miRNA-containing exosomes (Exos), which improve glucose tolerance and insulin sensitivity when given to obese mice. Depletion of their miRNA cargo blocks the ability of M2 BMDM Exos to enhance insulin sensitivity. We found that miR-690 is highly expressed in M2 BMDM Exos and functions as an insulin sensitizer both in vivo and in vitro. Expressing an miR-690 mimic in miRNA-depleted BMDMs generates Exos that recapitulate the effects of M2 BMDM Exos on metabolic phenotypes. Nadk is a bona fide target mRNA of miR-690, and Nadk plays a role in modulating macrophage inflammation and insulin signaling. Taken together, these data suggest miR-690 could be a new therapeutic insulin-sensitizing agent for metabolic disease.

CRIg+ Macrophages Prevent Gut Microbial DNA-Containing Extracellular Vesicle-Induced Tissue Inflammation and Insulin Resistance.

BACKGROUND & AIMS: Liver CRIg+ (complement receptor of the immunoglobulin superfamily) macrophages play a critical role in filtering bacteria and their products from circulation. Translocation of microbiota-derived products from an impaired gut barrier contributes to the development of obesity-associated tissue inflammation and insulin resistance. However, the critical role of CRIg+ macrophages in clearing microbiota-derived products from the bloodstream in the context of obesity is largely unknown. METHODS: We performed studies with CRIg-/-, C3-/-, cGAS-/-, and their wild-type littermate mice. The CRIg+ macrophage population and bacterial DNA abundance were examined in both mouse and human liver by either flow cytometric or immunohistochemistry analysis. Gut microbial DNA-containing extracellular vesicles (mEVs) were adoptively transferred into CRIg-/-, C3-/-, or wild-type mice, and tissue inflammation and insulin sensitivity were measured in these mice. After coculture with gut mEVs, cellular insulin responses and cGAS/STING-mediated inflammatory responses were evaluated. RESULTS: Gut mEVs can reach metabolic tissues in obesity. Liver CRIg+ macrophages efficiently clear mEVs from the bloodstream through a C3-dependent opsonization mechanism, whereas obesity elicits a marked reduction in the CRIg+ macrophage population. Depletion of CRIg+ cells results in the spread of mEVs into distant metabolic tissues, subsequently exacerbating tissue inflammation and metabolic disorders. Additionally, in vitro treatment of obese mEVs directly triggers inflammation and insulin resistance of insulin target cells. Depletion of microbial DNA blunts the pathogenic effects of intestinal EVs. Furthermore, the cGAS/STING pathway is crucial for microbial DNA-mediated inflammatory responses. CONCLUSIONS: Deficiency of CRIg+ macrophages and leakage of intestinal EVs containing microbial DNA contribute to the development of obesity-associated tissue inflammation and metabolic diseases.

Relationship Between Visceral Metastases and Survival in Patients with Metastasis-related Spinal Cord Compression.

OBJECTIVE: To investigate whether visceral metastases have a significant impact on survival in patients with metastasis-related spinal cord compression (MSCC), and to determine the difference in prognosis between patients with and without visceral metastases. METHODS: Three institutional databases were searched to identify all patients who had undergone spinal surgery for spinal metastases between March 2002 and June 2010. Data on patient characteristics including pre- and post-operative medical conditions, were collected from medical records or by telephone follow-up. Survival data were obtained either from medical records or by searching a governmental cancer registry. RESULTS: The mean age of study patients was 59.6 ± 10.5 years (range, 18-84 years), of whom 102 were male and 67 female. The median and mean postoperative survival times were 7.0 ± 0.5 (95% CI 6.0-8.0) months and 12.6 ± 1.2 (95% CI 10.1-15.0) months, respectively, in all patients, being 5.0 ± 0.5 (95% CI 4.0-6.0) months and 10.8 ± 2.4 (95% CI 6.1-15.5) months, respectively, for patients with visceral metastases and 7.0 ± 0.8 (95% CI 5.4-8.6) months and 13.0 ± 1.4 (95%CI 10.3-15.6) months, respectively, for patients without visceral metastases (P = 0.87). These survival times did not differ significantly between groups. Multivariate Cox proportional hazard regressions showed that visceral metastases had no statistically significant association with survival (P = 0.277), whereas rate of growth of primary tumor (P = 0.003), preoperative Karnofsky performance status (KPS) (P < 0.001), change in KPS (P < 0.001), and Frankel grade (P = 0.091) were independent prognostic factors in the whole cohort (P = 0.005). Changes in KPS (P = 0.001) and major complications (P = 0.003) were significantly associated with survival in patients with visceral metastases, whereas rate of growth of primary tumor (P = 0.016), change in KPS (P = 0.001), and preoperative KPS (P < 0.001) were significantly associated with survival in patients without visceral metastases. CONCLUSIONS: Visceral metastases do not appear to predict the prognosis of patients with MSCC; thus, more aggressive surgery should be considered in patients with MSCC who have visceral metastases. Additionally, prognostic factors differ according to visceral metastases status in these patients.

BML-111 suppresses TGF-ß1-induced lung fibroblast activation in vitro and decreases experimental pulmonary fibrosis in vivo.

Pulmonary fibrosis is an aggressive end­stage disease. Transforming growth factor­ß1 (TGF­ß1) mediates lung fibroblast activation and is essential for the progress of pulmonary fibrosis. BML­111, a lipoxinA4 (LXA4) receptor (ALX) agonist, has been reported to possess anti­ï¬brotic properties. The present study aimed to elucidate whether BML­111 inhibits TGF­ß1­induced mouse embryo lung fibroblast (NIH3T3 cell line) activation in vitro and bleomycin (BLM)­induced pulmonary fibrosis in vivo. In vitro experiments demonstrated that BML­111 treatment inhibits TGF­ß1­induced NIH3T3 cell viability and the expression of smooth muscle α actin (α­SMA), fibronectin and total collagen. Furthermore, this suppressive effect was associated with mothers against decapentaplegic homolog (Smad)2/3, extracellular signal­regulated kinase (ERK) and Akt phosphorylation interference. In vivo experiments revealed that BML­111 treatment markedly improved survival rate and ameliorated the destruction of lung tissue structure. It also reduced interleukin­1ß (IL­1ß), tumor necrosis factor­α (TNF­α) and TGF­ß1 expression in the BLM intratracheal mouse model. In addition, the expression ofα­SMA and extracellular matrix (ECM) deposition (total collagen, hydroxyproline and fibronectin) were also suppressed following BML­111 treatment. However, BOC­2, an antagonist of ALX, partially weakened the effects of BML­111. In conclusion, these results indicated that BML­111 inhibits TGF­ß1­induced fibroblasts activation and alleviates BLM­induced pulmonary fibrosis. Therefore, BML­111 may be used as a potential therapeutic agent for pulmonary fibrosis treatment.

Galectin-7 promotes proliferation and Th1/2 cells polarization toward Th1 in activated CD4+ T cells by inhibiting The TGFß/Smad3 pathway.

Galectin-7 (Gal-7) has been associated with cell proliferation and apoptosis. It is known that Gal-7 antagonises TGFß-mediated effects in hepatocytes by interacting with Smad3. Previously, we have demonstrated that Gal-7 is related to CD4+ T cells responses; nevertheless, its effect and functional mechanism on CD4+ T cells responses remain unclear. The murine CD4+ T cells were respectively cultured with Gal-7, anti-CD3/CD28 mAbs, or with anti-CD3/CD28 mAbs & Gal-7. The effects of Gal-7 on proliferation and the phenotypic changes in CD4+ T cells were assessed by flow cytometry. The cytokines from CD4+ T cells were analysed by quantitative real-time PCR. Subcellular localisation and expression of Smad3 were determined by immunofluorescence staining and Western blot, respectively. Gal-7 enhanced the proliferation of activated CD4+ T cells in a dose- and ß-galactoside-dependent manner. Additionally, Gal-7 treatment did not change the ratio of Th2 cells in activated CD4+ T cells, while it increased the ratio of Th1 cells. Gal-7 also induced activated CD4+ T cells to produce a higher level of IFN-γ and TNF-α and a lower level of IL-10. Moreover, Gal-7 treatment significantly accelerated nuclear export of Smad3 in activated CD4+ T cells. These results revealed a novel role of Gal-7 in promoting proliferation and Th1/2 cells polarization toward Th1 in activated CD4+ T cells by inhibiting the TGFß/Smad3 pathway.

Maresin 1 Inhibits Epithelial-to-Mesenchymal Transition in Vitro and Attenuates Bleomycin Induced Lung Fibrosis in Vivo.

Lung fibrosis is an aggressive disease with uncontrolled fibrotic response and no effective therapeutic treatment. Epithelial-to-mesenchymal transition (EMT) has been proved to be an important pathological feature in lung fibrosis. In this study, we investigated whether MaR1, a kind of proresolving lipid mediators, could inhibit TGF-ß1-induced EMT in vitro and lung fibrosis in vivo. In vitro study, mouse type II alveolar epithelial cells were treated with different does of MaR1 for 30 min and were exposed to TGF-ß1 for 48 h. In vivo study, C57BL/6 mice were administered bleomycin intratracheally. After 14 days, MaR1 was injected intraperitoneally daily for 7 days. In day 28, mice were sacrificed. The results demonstrate that treatment of mouse type II alveolar epithelial cells with MaR1 (10 nM) significantly prevents TGF-ß1-induced fibronectin and α-SMA expression and restores E-Cadherin level. The down-regulation of profibrotic molecules of MaR1 is associated with suppression of Smad2/3 and Akt phosphorylation. In vivo, MaR1 treatment significantly prolongs survival rate and attenuates destruction of lung architecture, as well as collagen deposition after bleomycin inhalation. TGF-ß1 concentration in bronchoalveolar lavage and fibrotic markers (fibronectin and α-SMA) in lung tissues are inhibited by MaR1 administration. These data indicate that MaR1 inhibits TGF-ß1-induced EMT and attenuates bleomycin-induced pulmonary fibrosis. MaR1 may be a promising strategy for alleviation of lung fibrosis.

MARESIN 1 PREVENTS LIPOPOLYSACCHARIDE-INDUCED NEUTROPHIL SURVIVAL AND ACCELERATES RESOLUTION OF ACUTE LUNG INJURY.

Acute lung injury (ALI) is characterized by lung inflammation and diffuse infiltration of neutrophils. Neutrophil apoptosis is recognized as an important control point in the resolution of inflammation. Maresin 1 (MaR1) is a new docosahexaenoic acid-derived proresolving agent that promotes the resolution of inflammation. However, its function in neutrophil apoptosis is unknown. In this study, isolated human neutrophils were incubated with MaR1, the pan-caspase inhibitor z-VAD-fmk, and lipopolysaccharide (LPS) to determine the mechanism of neutrophil apoptosis. Acute lung injury was induced by intratracheal instillation of LPS. In addition, mice were treated with MaR1 intravenously at the peak of inflammation and administered z-VAD-fmk intraperitoneally. We found that culture of isolated human neutrophils with LPS dramatically delayed neutrophil apoptosis through the phosphorylation of AKT, ERK, and p38 to upregulate the expression of the antiapoptotic proteins Mcl-1 and Bcl-2, which was blocked by pretreatment with MaR1 in vitro. In mice, MaR1 accelerated the resolution of inflammation in LPS-induced ALI through attenuation of neutrophil accumulation, pathohistological changes, and pulmonary edema. Maresin 1 promoted resolution of inflammation by accelerating caspase-dependent neutrophil apoptosis. Moreover, MaR1 also reduced the LPS-induced production of proinflammatory cytokines and upregulated the production of the anti-inflammatory cytokine interleukin-10. In contrast, treatment with z-VAD-fmk inhibited the proapoptotic action of MaR1 and attenuated the protective effects of MaR1 in LPS-induced ALI. Taken together, MaR1 promotes the resolution of LPS-induced ALI by overcoming LPS-mediated suppression of neutrophil apoptosis.

[Clinical outcomes of mini-invasive transforaminal lumbar interbody fusion under Quadrant system for upper lumbar disc herniation].

OBJECTIVE: To evaluate the treatment outcomes of mini-invasive transforaminal lumbar interbody fusion by Quadrant system for upper lumbar disc herniation. METHODS: Between February 2008 and June 2011, 21 patients with upper lumbar disc herniation underwent mini-invasive transforaminal lumbar interbody fusion under Quadrant system at our institution. The relevant patient data included visual analogue scale (VAS) and Oswestry disability index (ODI) scores before and after operation 1 week, 3 months and last follow-up. And all data were collected retrospectively. RESULTS: No operation-related complications occurred. The mean operative duration was 2.8 (2.5-3) hours. The average blood loss volume was 430 (350-500) ml. Preoperative VAS was 7.3 ± 0.8 and 2.1 ± 0.9, 1.3 ± 0.6, 0.6 ± 0.5 after operation 1 week, 3 months and last follow-up respectively. Statistically significant differences were demonstrated between each group. Preoperative ODI was 43.7 ± 12.9 and 22.5 ± 10.4, 16.2 ± 8.5, 11.3 ± 7.2 after operation 1 week, 3 months and last follow up. Significant differences existed in preoperative and postoperative ODI scores respectively. CONCLUSION: Mini-invasive transforaminal lumbar interbody fusion using Quadrant system and special osteotome is safe and efficacious for upper lumbar disc herniation.

BML-111 attenuates hemorrhagic shock-induced acute lung injury through inhibiting activation of mitogen-activated protein kinase pathway in rats.

BACKGROUND: Hemorrhagic shock activates cellular stress signals and can lead to systemic inflammatory response, organ injury, and death. Mitogen-activated protein kinase (MAPK) acts as a sensor of tissue injury in models of ischemia-reperfusion injury. Lipoxins are endogenous lipid mediators with potent anti-inflammatory and pro-resolving actions. We hypothesized that BML-111 (a lipoxin A4-receptor agonist) attenuates hemorrhagic shock-induced acute lung injury (ALI) through inhibiting activation of the MAPK pathway. METHODS: We randomized Sprague-Dawley rats into four groups: sham, hemorrhagic shock-resuscitation (HS), HS plus BML-111 (BML-111), and HS plus BML-111 and BOC-2 (BOC-2). Two hours after resuscitation, we collected samples of lung. We obtained bronchoalveolar lavage fluid for neutrophil count. We performed optical microscopy to examine pathologic changes in lungs. Wet/dry ratios, myeloperoxidase expression, interleukin (IL)-1ß and IL-6 levels in lung were measured. We evaluated MAPK activation and the DNA binding activity of activator protein-1 in lung. RESULTS: Treatment with BML-111 reduced the lung damage and wet/dry ratio, neutrophil count in bronchoalveolar lavage fluid, expression of myeloperoxidase, and production of IL-1ß and IL-6 in lung. Phosphorylation of MAPK was also decreased by BML-111 in lung. Furthermore, the DNA binding activity of activator protein-1 was blocked by BML-111. An antagonist of the lipoxin A4-receptor, BOC-2, reversed the protective effect of BML-111 on ALI induced by hemorrhagic shock. CONCLUSIONS: This study indicates that BML-111 attenuated hemorrhagic shock-induced ALI via the MAPK/activator protein-1 signaling pathway. Therefore, BML-111 may have therapeutic potential for hemorrhagic shock-induced ALI.