参考文献

This study aimed to determine the association between non-high-fat diet-induced obesity- (non-DIO-) associated gut microbiome dysbiosis with gut abnormalities like cellular turnover of intestinal cells,tight junctions,and mucin formation that can impact gut permeability. We used leptin-deficient (Lepob/ob) mice in comparison to C57BL/6J control mice,which are fed on identical diets,and performed comparative and correlative analyses of gut microbiome composition,gut permeability,intestinal structural changes,tight junction-mucin formation,cellular turnover,and stemness genes. We found that obesity impacted cellular turnover of the intestine with increased cell death and cell survival/proliferation gene expression with enhanced stemness,which are associated with increased intestinal permeability,changes in villi/crypt length,and decreased expression of tight junctions and mucus synthesis genes along with dysbiotic gut microbiome signature. Obesity-induced gut microbiome dysbiosis is also associated with abnormal intestinal organoid formation characterized with decreased budding and higher stemness. Results suggest that non-DIO-associated gut microbiome dysbiosis is associated with changes in the intestinal cell death versus cell proliferation homeostasis and functions to control tight junctions and mucous synthesis-regulating gut permeability. View Publication

BACKGROUND Human microRNAs (miRNAs) have diverse functions in biology,and play a role in nearly every biological process. Here we report that miR-520d-5p (520d-5p) causes undifferentiated cancer cells to adopt benign or normal status in vivo in immunodeficient mice via demethylation and P53 upregulation. Further we found that 520-5p causes normal cells to elongate cellular lifetime and mesenchymal stem cell-like status with CD105 positivity. We hypothesized that ectopic 520d-5p expression reduced mutations in undifferentiated type of hepatoma (HLF) cells through synergistic modulation of methylation-related enzymatic expression. METHODS To examine whether there were any changes in mutation status in cells treated with 520d-5p,we performed next generation sequencing (NGS) in HLF cells and human iPSC-derivative cells in pre-mesenchymal stem cell status. We analyzed the data using both genome-wide and individual gene function approaches. RESULTS 520d-5p induced a shift towards a wild type or non-malignant phenotype,which was regulated by nucleotide mutations in both HLF cells and iPSCs. Further,520d-5p reduced mutation levels in both the whole genome and genomic fragment assemblies. CONCLUSIONS Cancer cell genomic mutations cannot be repaired in most contexts. However,these findings suggest that applied development of 520d-5p would allow new approaches to cancer research and improve the quality of iPSCs used in regenerative medicine. View Publication

Mesenchymal stromal cells (MSCs) are multipotent stem cells that participate in tissue repair and posses considerable immunomodulatory potential. MSCs have been shown to promote allograft survival,yet the mechanisms behind this phenomenon have not been fully defined. Here,we investigate the capacity of MSCs to suppress the allogeneic immune response by secreting the pleiotropic molecule hepatocyte growth factor (HGF). Using an in vivo mouse model of corneal transplantation,we report that MSCs promote graft survival in an HGF-dependent manner. Moreover,our data indicate that topically administered recombinant HGF (1) suppresses antigen-presenting cell maturation in draining lymphoid tissue,(2) limits T-helper type-1 cell generation,(3) decreases inflammatory cell infiltration into grafted tissue,and (4) is itself sufficient to promote transplant survival. These findings have potential translational implications for the development of HGF-based therapeutics. Stem Cells Translational Medicine 2019. View Publication

Antagonists of the 5-hydroxytryptamine (serotonin) 3 receptor (5-HT3R) have anti-inflammatory and anti-apoptotic activities,but the detailed,underlying mechanisms are not well understood. We focused on anti-apoptotic activities via 5-HT3R signaling to clarify the underlying mechanisms. Mice were administered 5-fluorouracil (5-FU),which induced apoptosis in intestinal epithelial cells. Coadministration with 5-HT3R antagonists or agonists tended to decrease or increase the number of apoptotic cells,respectively. In serotonin 3A receptor (5-HT3AR) null (HTR3A-/-) mice,the number of apoptotic cells induced by 5-FU was decreased compared with that in wild-type (WT) mice. Bone marrow (BM) transplantation was performed to determine if BM-derived immune cells regulated 5-FU-induced apoptosis,but they were found to be unrelated to this process. Data from 5-HT3AR/enhanced green fluorescent protein reporter mice revealed that 50{\%} of enterochromaffin (EC) cells expressed 5-HT3AR,but the number of apoptotic cells induced by 5-FU in the intestinal crypt organoids of HTR3A-/- mice was not altered compared with WT mice. In contrast,plasma 5-HT concentrations in WT mice but not in HTR3A-/- mice administered 5-FU were increased significantly. In conclusion,5-HT3R signaling may enhance 5-HT release,possibly from EC cells intravascularly,or paracrine,resulting in increases in plasma 5-HT concentration,which in turn,enhances apoptotic activities induced by 5-FU.-Mikawa,S.,Kondo,M.,Kaji,N.,Mihara,T.,Yoshitake,R.,Nakagawa,T.,Takamoto,M.,Nishimura,R.,Shimada,S.,Ozaki,H.,Hori,M. Serotonin 3 receptor signaling regulates 5-fluorouracil-mediated apoptosis indirectly via TNF-alpha production by enhancing serotonin release from enterochromaffin cells. View Publication

Metabolic health depends on the capacity of adipose tissue progenitor cells to undergo de novo adipogenesis. The cellular hierarchy and mechanisms governing adipocyte progenitor differentiation are incompletely understood. Through single-cell RNA sequence analyses,we show that the lineage hierarchy of adipocyte progenitors consists of distinct mesenchymal cell types that are present in both mouse and human adipose tissues. Cells marked by dipeptidyl peptidase-4 (DPP4)/CD26 expression are highly proliferative,multipotent progenitors. During the development of subcutaneous adipose tissue in mice,these progenitor cells give rise to intercellular adhesion molecule-1 (ICAM1)/CD54-expressing (CD54+) committed preadipocytes and a related adipogenic cell population marked by Clec11a and F3/CD142 expression. Transforming growth factor-beta maintains DPP4+ cell identity and inhibits adipogenic commitment of DPP4+ and CD142+ cells. Notably,DPP4+ progenitors reside in the reticular interstitium,a recently appreciated fluid-filled space within and between tissues,including adipose depots. View Publication

The complex process of platelet formation originates with the hematopoietic stem cell,which differentiates through the myeloid lineage,matures,and releases proplatelets into the BM sinusoids. How formed platelets maintain a low basal activation state in the circulation remains unknown. We identify Lepr+ stromal cells lining the BM sinusoids as important contributors to sustaining low platelet activation. Ablation of murine Lepr+ cells led to a decreased number of platelets in the circulation with an increased activation state. We developed a potentially novel culture system for supporting platelet formation in vitro using a unique population of CD51+PDGFRalpha+ perivascular cells,derived from human umbilical cord tissue,which display numerous mesenchymal stem cell (MSC) properties. Megakaryocytes cocultured with MSCs had altered LAT and Rap1b gene expression,yielding platelets that are functional with low basal activation levels,a critical consideration for developing a transfusion product. Identification of a regulatory cell that maintains low baseline platelet activation during thrombopoiesis opens up new avenues for improving blood product production ex vivo. View Publication

Tumors are composed of phenotypically heterogeneous cancer cells that often resemble various differentiation states of their lineage of origin. Within this hierarchy,it is thought that an immature subpopulation of tumor-propagating cancer stem cells (CSCs) differentiates into non-tumorigenic progeny,providing a rationale for therapeutic strategies that specifically eradicate CSCs or induce their differentiation. The clinical success of these approaches depends on CSC differentiation being unidirectional rather than reversible,yet this question remains unresolved even in prototypically hierarchical malignancies,such as acute myeloid leukemia (AML). Here,we show in murine and human models of AML that,upon perturbation of endogenous expression of the lineage-determining transcription factor PU.1 or withdrawal of established differentiation therapies,some mature leukemia cells can de-differentiate and reacquire clonogenic and leukemogenic properties. Our results reveal plasticity of CSC maturation in AML,highlighting the need to therapeutically eradicate cancer cells across a range of differentiation states. View Publication

Laminin and fibronectin are glycoproteins that influence cell behavior and mediate cell/substratum adhesion. We have examined the interaction of these macromolecules with the serine protease plasminogen activator (PA) in two types of extracellular matrices; one produced by the murine Engelbreth-Holm-Swarm (EHS) tumor (Matrigel),and another by normal kidney epithelial cells in culture. Matrigel was found to contain significant quantities of tissue-type PA (tPA). Two of the major components of Matrigel,laminin and type IV collagen,were also examined. Tissue-type PA was associated with purified preparations of laminin; however,it was not found associated with type IV collagen. Normal kidney epithelial cells in culture secrete large amounts of urokinase (UK) and deposit a subepithelial matrix containing both laminin and fibronectin. These matrix macromolecules were isolated from the deposited matrix by immunoprecipitation,examined by zymography,and found to contain UK. The potential role of this interaction in the mechanisms of cell migration and matrix remodeling is discussed. View Publication

Inflammatory bowel disease (IBD) is characterized by severe and recurrent inflammation of the gastrointestinal tract,associated with altered patterns of cytokine synthesis,excessive reactive oxygen species (ROS) production,and high levels of the innate immune protein,lipocalin-2 (LCN-2),in the mucosa. The major source of ROS in intestinal epithelial cells is the NADPH oxidase NOX1,which consists of the transmembrane proteins,NOX1 and p22PHOX,and the cytosolic proteins,NOXO1,NOXA1,and Rac1. Here,we investigated whether NOX1 activation and ROS production induced by key inflammatory cytokines in IBD causally affects LCN-2 production in colonic epithelial cells. We found that the combination of TNFalpha and IL-17 induced a dramatic upregulation of NOXO1 expression that was dependent on the activation of p38MAPK and JNK1/2,and resulted into an increase of NOX1 activity and ROS production. NOX1-derived ROS drive the expression of LCN-2 by controlling the expression of IkappaBzeta,a master inducer of LCN-2. Furthermore,LCN-2 production and colon damage were decreased in NOX1-deficient mice during TNBS-induced colitis. Finally,analyses of biopsies from patients with Crohn's disease showed increased JNK1/2 activation,and NOXO1 and LCN-2 expression. Therefore,NOX1 might play a key role in mucosal immunity and inflammation by controlling LCN-2 expression. View Publication

Soybeans are a rich source of isoflavones that have been linked with anti-inflammatory processes and various health benefits. However,specific mechanisms whereby soy bioactives impact immune cell subsets are unclear. Isoflavones,such as genistein and daidzein,are metabolized by microbes to bioactive metabolites as O-desmethylangolensin (O-DMA) and equol,whose presence has been linked to health benefits. We examined how soy isoflavones and metabolites impact natural killer (NK) cell signaling and function. We observe no impact of isoflavones on viability of healthy donor peripheral blood mononuclear cells (PBMCs) or NK cells,even at high (25 µM) concentrations. However,pre-treatment of PBMCs with physiologically-relevant concentrations of genistein (p = 0.0023) and equol (p = 0.006) decreases interleukin (IL)-12/IL-18-induced interferon-gamma (IFN-gamma) production versus controls. Detailed cellular analyses indicate genistein and equol decrease IL-12/IL-18-induced IFN-gamma production by human NK cell subsets,but do not consistently alter cytotoxicity. At the level of signal transduction,genistein decreases IL-12/IL-18-induced total phosphorylated tyrosine,and phosphorylation MAPK pathway components. Further,genistein limits IL-12/IL-18-mediated upregulation of IL-18Ralpha expression on NK cells (p = 0.0109). Finally,in vivo studies revealed that C57BL/6 mice fed a soy-enriched diet produce less plasma IFN-gamma following administration of IL-12/IL-18 versus control-fed animals (p {\textless} 0.0001). This study provides insight into how dietary soy modulates NK cell functions. View Publication