Role of lysophosphatidic acid in proliferation and differentiation of intestinal epithelial cells.

Intestinal epithelial cells (IECs) are regenerated continuously from intestinal stem cells (ISCs) near the base of intestinal crypts in order to maintain homeostasis and structural integrity of intestinal epithelium. Epidermal growth factor (EGF) is thought to be important to drive the proliferation and differentiation of IECs from ISCs, it remains unknown whether other growth factors or lipid mediators are also important for such regulation, however. Here we show that lysophosphatidic acid (LPA), instead of EGF, robustly promoted the development of intestinal organoids prepared from the mouse small intestine. Indeed, LPA exhibited the proliferative activity of IECs as well as induction of differentiation of IECs into goblet cells, Paneth cells, and enteroendocrine cells in intestinal organoids. Inhibitors for LPA receptor 1 markedly suppressed the LPA-promoted development of intestinal organoids. LPA also promoted the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 in intestinal organoids, whereas inhibition of mitogen-activated protein kinase/ERK kinase (MEK) 1/2 significantly suppressed the development of, as well as the proliferative activity and differentiation of, intestinal organoids in response to LPA. Our results thus suggest that LPA is a key factor that drives the proliferation and differentiation of IECs.

Intracellular localization of GGA accessory protein p56 in cell lines and central nervous system neurons.

Adaptor protein complex-1 (AP-1) and Golgi associated, γ-adaptin ear containing, Arf binding proteins (GGAs) are clathrin adaptors that regulate membrane trafficking between the trans-Golgi network (TGN) and endosomes. p56 is a clathrin adaptor accessory protein that may modulate the function of GGAs in mammalian cell lines. However, the precise relationship between p56 and the three GGAs (GGA1-3), as well as the physiological role of p56 in tissue cells, remain unknown. To this end, we generated an antibody against p56 and determined its cellular localization. In ARPE-19 cells and mouse embryonic fibroblasts, p56 was found to be localized as fine puncta in the TGN. Interestingly, the depletion of each clathrin adaptor by RNAi revealed that this localization was dependent on the expression of GGA1, but not that of GGA2, GGA3, or AP-1. Using immunohistofluorescence microscopy in the mouse central nervous system (CNS), p56 was clearly detected as scattered cytoplasmic puncta in spinal motor neurons, cerebellar Purkinje cells, and pyramidal neurons of the hippocampus and cerebral cortex. Moreover, double labeling with organelle markers revealed that the majority of these puncta were closely associated with the TGN; however, a small fraction was associated with endosomes or lysosomes in spinal motor neurons. Collectively, these results indicate a functional association of p56 with GGA1, suggesting an important role of p56 in larger CNS neurons.

Quality-Quantity Control Culture Enhances Vasculogenesis and Wound Healing Efficacy of Human Diabetic Peripheral Blood CD34+ Cells.

Autologous endothelial progenitor cell (EPC) therapy is commonly used to stimulate angiogenesis in ischemic repair and wound healing. However, low total numbers and functional deficits of EPCs make autologous EPC therapy ineffective in diabetes. Currently, no known ex vivo culture techniques can expand and/or ameliorate the functional deficits of EPCs for clinical usage. Recently, we showed that a quality-quantity culture (QQc) system restores the vasculogenic and wound-healing efficacy of murine diabetic EPCs. To validate these results and elucidate the mechanism in a translational study, we evaluated the efficacy of this QQc system to restore the vasculogenic potential of diabetic human peripheral blood (PB) CD34+ cells. CD34+ cells purified from PB of diabetic and healthy patients were subjected to QQc. Gene expression, vascular regeneration, and expression of cytokines and paracrine mediators were analyzed. Pre- or post-QQc diabetic human PB-CD34+ cells were transplanted into wounded BALB/c nude mice and streptozotocin-induced diabetic mice to assess functional efficacy. Post-QQc diabetic human PB-CD34+ cell therapy significantly accelerated wound closure, re-epithelialization, and angiogenesis. The higher therapeutic efficacy of post-QQc diabetic human PB-CD34+ cells was attributed to increased differentiation ability of diabetic CD34+ cells, direct vasculogenesis, and enhanced expression of angiogenic factors and wound-healing genes. Thus, QQc can significantly enhance the therapeutic efficacy of human PB-CD34+ cells in diabetic wounds, overcoming the inherent limitation of autologous cell therapy in diabetic patients, and could be useful for treatment of not only wounds but also other ischemic diseases. Stem Cells Translational Medicine 2018;7:428-438.

Regulation by commensal bacteria of neurogenesis in the subventricular zone of adult mouse brain.

In the mouse olfactory bulb (OB), interneurons such as granule cells and periglomerular cells are continuously replaced by adult-born neurons, which are generated in the subventricular zone (SVZ) of the brain. We have now investigated the role of commensal bacteria in regulation of such neuronal cell turnover in the adult mouse brain. Administration of mixture of antibiotics to specific pathogen-free (SPF) mice markedly attenuated the incorporation of bromodeoxyuridine (BrdU) into the SVZ cells. The treatment with antibiotics also reduced newly generated BrdU-positive neurons in the mouse OB. In addition, the incorporation of BrdU into the SVZ cells of germ-free (GF) mice was markedly reduced compared to that apparent for SPF mice. In contrast, the reduced incorporation of BrdU into the SVZ cells of GF mice was recovered by their co-housing with SPF mice, suggesting that commensal bacteria promote the incorporation of BrdU into the SVZ cells. Finally, we found that administration of ampicillin markedly attenuated the incorporation of BrdU into the SVZ cells of SPF mice. Our results thus suggest that ampicillin-sensitive commensal bacteria regulate the neurogenesis in the SVZ of adult mouse brain.

Kinetic Analysis of the Solvent Extraction of Cadmium(II) Complexes Using a Cadmium-deposited Recessed Microelectrode and Confocal Fluorescence Microscope.

Using a Cd-deposited microelectrode, an electrochemically generated Cd(II) ion in a micro-water phase was reacted with 5-octyloxymethyl-8-quinolinol (HC8Q) in 1,6-dichlorohexane. The fluorescence intensity of Cd(C8Q)2 near the water/oil interface (IF) was analyzed under a confocal fluorescence microscope. The rate of decrease of IF was independent of the HC8Q concentration and pH, but was influenced by the phase-boundary potential between the water and oil phases, suggesting that Cd(II) extraction is governed by Cd(C8Q)+ desorption at the interface.

Metabolic Regulation of Angiogenesis in Diabetes and Aging.

Impaired angiogenesis and endothelial dysfunction are hallmarks of diabetes and aging. Clinical efforts at promoting angiogenesis have largely focused on growth factor pathways, with mixed results. Recently, a new repertoire of endothelial intracellular molecules critical to endothelial metabolism has emerged as playing an important role in regulating angiogenesis. This review thus focuses on the emerging importance and therapeutic potential of these proteins and of endothelial bioenergetics in diabetes and aging.

Deletion of the transcriptional coactivator PGC1α in skeletal muscles is associated with reduced expression of genes related to oxidative muscle function.

The expression of the transcriptional coactivator PGC1α is increased in skeletal muscles during exercise. Previously, we showed that increased PGC1α leads to prolonged exercise performance (the duration for which running can be continued) and, at the same time, increases the expression of branched-chain amino acid (BCAA) metabolism-related enzymes and genes that are involved in supplying substrates for the TCA cycle. We recently created mice with PGC1α knockout specifically in the skeletal muscles (PGC1α KO mice), which show decreased mitochondrial content. In this study, global gene expression (microarray) analysis was performed in the skeletal muscles of PGC1α KO mice compared with that of wild-type control mice. As a result, decreased expression of genes involved in the TCA cycle, oxidative phosphorylation, and BCAA metabolism were observed. Compared with previously obtained microarray data on PGC1α-overexpressing transgenic mice, each gene showed the completely opposite direction of expression change. Bioinformatic analysis of the promoter region of genes with decreased expression in PGC1α KO mice predicted the involvement of several transcription factors, including a nuclear receptor, ERR, in their regulation. As PGC1α KO microarray data in this study show opposing findings to the PGC1α transgenic data, a loss-of-function experiment, as well as a gain-of-function experiment, revealed PGC1α's function in the oxidative energy metabolism of skeletal muscles.

Phosphorylation of 4EBP by oral leucine administration was suppressed in the skeletal muscle of PGC-1α knockout mice.

Leucine is known to increase mTOR-mediated phosphorylation of 4EBP. In this study, leucine was administered to skeletal muscle-PGC-1α knockout mice. We observed attenuated 4EBP phosphorylation in the skeletal muscle, but not in the liver, of the PGC-1α knockout mice. These data suggest that skeletal muscle-PGC-1α is important for leucine-mediated mTOR activation and protein biosynthesis.

Parathyroid adenoma causing spontaneous cervical hematoma: two case reports.

BACKGROUND: Although spontaneous rupture of a cervical parathyroid adenoma with extracapsular hemorrhage is rare, it may cause cervical and mediastinal hematoma, leading to potentially fatal consequences. CASE PRESENTATION: The first case was a 76-year-old Asian female who presented with pharyngeal discomfort and anterior chest ecchymosis. Endoscopic investigation showed submucosal hemorrhage in the pharynx and larynx. The second case was a 62-year-old Asian male who presented with anterior chest ecchymosis and suspected of a ruptured blood vessel. Both cases were diagnosed parathyroid adenoma with extracapsular bleeding by hypercalcemia, high levels of intact parathyroid hormone and presence of a nodule behind the thyroid. Both cases were treated with excision of tumor 7 months after initial presentation. After surgery, serum calcium and parathyroid hormone levels had decreased to normal level in both cases. CONCLUSION: Extracapsular bleeding of a parathyroid adenoma should be considered in the differential diagnosis of non-traumatic neck hematoma.

PGC-1α-mediated changes in phospholipid profiles of exercise-trained skeletal muscle.

Exercise training influences phospholipid fatty acid composition in skeletal muscle and these changes are associated with physiological phenotypes; however, the molecular mechanism of this influence on compositional changes is poorly understood. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a nuclear receptor coactivator, promotes mitochondrial biogenesis, the fiber-type switch to oxidative fibers, and angiogenesis in skeletal muscle. Because exercise training induces these adaptations, together with increased PGC-1α, PGC-1α may contribute to the exercise-mediated change in phospholipid fatty acid composition. To determine the role of PGC-1α, we performed lipidomic analyses of skeletal muscle from genetically modified mice that overexpress PGC-1α in skeletal muscle or that carry KO alleles of PGC-1α. We found that PGC-1α affected lipid profiles in skeletal muscle and increased several phospholipid species in glycolytic muscle, namely phosphatidylcholine (PC) (18:0/22:6) and phosphatidylethanolamine (PE) (18:0/22:6). We also found that exercise training increased PC (18:0/22:6) and PE (18:0/22:6) in glycolytic muscle and that PGC-1α was required for these alterations. Because phospholipid fatty acid composition influences cell permeability and receptor stability at the cell membrane, these phospholipids may contribute to exercise training-mediated functional changes in the skeletal muscle.

Endothelial PGC-1α mediates vascular dysfunction in diabetes.

Endothelial dysfunction is a central hallmark of diabetes. The transcriptional coactivator PGC-1α is a powerful regulator of metabolism, but its role in endothelial cells remains poorly understood. We show here that endothelial PGC-1α expression is high in diabetic rodents and humans and that PGC-1α powerfully blocks endothelial migration in cell culture and vasculogenesis in vivo. Mechanistically, PGC-1α induces Notch signaling, blunts activation of Rac/Akt/eNOS signaling, and renders endothelial cells unresponsive to established angiogenic factors. Transgenic overexpression of PGC-1α in the endothelium mimics multiple diabetic phenotypes, including aberrant re-endothelialization after carotid injury, blunted wound healing, and reduced blood flow recovery after hindlimb ischemia. Conversely, deletion of endothelial PGC-1α rescues the blunted wound healing and recovery from hindlimb ischemia seen in type 1 and type 2 diabetes. Endothelial PGC-1α thus potently inhibits endothelial function and angiogenesis, and induction of endothelial PGC-1α contributes to multiple aspects of vascular dysfunction in diabetes.

Rho/Rho-associated coiled-coil forming kinase pathway as therapeutic targets for statins in atherosclerosis.

SIGNIFICANCE: The 3-hydroxy-methylglutaryl coenzyme A reductase inhibitors or statins are important therapeutic agents for lowering serum cholesterol levels. However, recent studies suggest that statins may exert atheroprotective effects beyond cholesterol lowering. These so-called "pleiotropic effects" include effects of statins on vascular and inflammatory cells. Thus, it is important to understand whether other signaling pathways that are involved in atherosclerosis could be targets of statins, and if so, whether individuals with "overactivity" of these pathways could benefit from statin therapy, regardless of serum cholesterol level. RECENT ADVANCES: Statins inhibit the synthesis of isoprenoids, which are important for the function of the Rho/Rho-associated coiled-coil containing kinase (ROCK) pathway. Indeed, recent studies suggest that inhibition of the Rho/ROCK pathway by statins could lead to improved endothelial function and decreased vascular inflammation and atherosclerosis. Thus, the Rho/ROCK pathway has emerged as an important target of statin therapy for reducing atherosclerosis and possibly cardiovascular disease. CRITICAL ISSUES: Because atherosclerosis is both a lipid and an inflammatory disease, it is important to understand how inhibition of Rho/ROCK pathway could contribute to statins' antiatherosclerotic effects. FUTURE DIRECTIONS: The role of ROCKs (ROCK1 and ROCK2) in endothelial, smooth muscle, and inflammatory cells needs to be determined in the context of atherogenesis. This could lead to the development of specific ROCK1 or ROCK2 inhibitors, which could have greater therapeutic benefits with less toxicity. Also, clinical trials will need to be performed to determine whether inhibition of ROCKs, with and without statins, could lead to further reduction in atherosclerosis and cardiovascular disease.

Persistent petrosquamosal sinus: underlying cause of otitic hydrocephalus with lateral sinus thrombosis.

Lateral sinus thrombosis (LST) occurs when a middle ear infection disseminates directly via bone erosion or disseminates indirectly through the venous networks. The petrosquamosal sinus (PSS) is the residual accessory dural sinus connecting intracranial to extracranial drainage. This report describes a case of a patient with persistent PSS running through the mastoid in context of otitic hydrocephalus with LST. To identify PSS, enhanced CT and reconstructed image from CT venography were more useful than MRI. The possibility of persistent PSS running through the mastoid should be considered if LST without marked inflammation and bone erosion is noted.

Glucose-independent persistence of PAI-1 gene expression and H3K4 tri-methylation in type 1 diabetic mouse endothelium: implication in metabolic memory.

Clinical trials with type 1 and type 2 diabetes have identified a phenomenon known as "metabolic memory" in which previous periods of hyperglycemia result in the long-lasting deleterious impact on cardiovascular events. Emerging evidence shows that transient hyperglycemic exposure of human endothelial cells induces histone 3 lysine 4 mono-methylation (H3K4me1) on the promoter and persistent mRNA expression of RelA and IL-8 genes, suggesting that epigenetic histone modification and chromatin structure remodeling is a key event underlying metabolic memory. This burgeoning hypothesis, however, critically remains to be tested for relevance in the disease process of diabetes in vivo, and for broader applicability to an array of genes involved in endothelial dysfunction. To address this, we used type 1 diabetes mouse model induced by streptozocin to be hyperglycemic for 8 weeks, and isolated endothelial cells that were used either freshly after isolation or after 2 to 3-week cell culture in normoglycemic conditions. mRNA expression profiling in diabetic mouse endothelial cells revealed significant and persistent up-regulation of Serpine1 encoding PAI-1, the hypo-fibrinolytic mediator leading to thrombotic diseases in diabetes, along with Rock2, Fn1 and Ccl2, whereas only Serpine 1 was persistently elevated in high glucose-treated mouse endothelial cells. Chromosome immunoprecipitation assay in type 1 diabetic mouse endothelial cells showed predominant enrichment of H3K4 tri-methylation on Serpine1 promoter, suggesting a unique epigenetic regulation in diabetic mice as opposed to high glucose-treated human ECs. Our study demonstrates the importance of combining in vivo models of diabetes with high glucose-treated cell culture to better assess the epigenetic mechanisms relevant to disease.

Nasopharyngeal tuberculosis.

Today, the opportunity to see tuberculosis is decreasing. Nasopharyngeal tuberculosis is a rare entity, even in endemic tuberculosis areas. A case of nasopharyngeal tuberculosis is described. A 28-year-old woman presented with a sore throat. Irregular mucosal thickening was seen in the nasopharynx. Staining for acid-fast bacilli was positive (Gaffky 1), and the PCR test was positive for Mycobacterium tuberculosis from pharyngeal mucus. Computed tomography showed mucosal thickening in the pharynx and old pulmonary tuberculosis in the right upper lobe. Multiple anti-tuberculosis drug therapy was performed for 6 months. A few days after the initiation of therapy, the pharyngeal pain subsided. The irregular mucosal thickening was quite thin after 1 month of multidrug therapy and was no longer observed after 2 months. A case of nasopharyngeal tuberculosis is reported. A good result was obtained with multiple anti-tuberculous drug therapy for 6 months. Nasopharyngeal tuberculosis should be considered in the differential diagnosis of a white nasopharyngeal coating, especially in a patient with a history of pulmonary tuberculosis.

Cathepsin L is highly expressed in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract that are diagnosed by c-kit staining in most cases. A lysosomal cysteine proteinase termed cathepsin L has been commonly associated with malignancy in several cancer types, but this finding has not been reported for GISTs. We analyzed the cathepsin L mRNA and protein expression in GISTs. Real-time reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that cathepsin L levels were higher in GISTs than those in gastric or colorectal tumors; this finding was supported by results of the Western blot analysis. Immunohistochemistry revealed that cathepsin L was localized to the cytoplasm of GIST cells as an intense granular signal, which was not observed in the cells of leiomyoma, a mesenchymal tumor that was analyzed as a control specimen. Double immunofluorescence microscopy revealed that a portion of the granular signal colocalized with lysosome-associated membrane protein-1 (LAMP-1), which is a lysosomal marker. Moreover, immunohistochemical analysis of 43 tumor specimens revealed that 86.0% (n=37) were cathepsin-L positive, and this positivity was significantly correlated with c-kit positivity but not with other clinicopathological factors, including gender, age, region, size, mitosis and risk of recurrence. From these results, we conclude that cathepsin L is highly expressed in GISTs compared to its expression in other cancerous lesions; this identifies cathepsin-L as a new diagnostic marker for GISTs.

Role of transient receptor potential vanilloid 2 in LPS-induced cytokine production in macrophages.

There is considerable evidence indicating that intracellular Ca2+ participates as a second messenger in TLR4-dependent signaling. However, how intracellular free Ca2+ concentrations ([Ca2+]i) is increased in response to LPS and how they affect cytokine production are poorly understood. Here we examined the role of transient receptor potential (TRP), a major Ca2+ permeation pathway in non-excitable cells, in the LPS-induced cytokine production in macrophages. Pharmacologic experiments suggested that TRPV family members, but neither TRPC nor TRPM family members, are involved in the LPS-induced TNFalpha and IL-6 production in RAW264 macrophages. RT-PCR and immunoblot analyses showed that TRPV2 is the sole member of TRPV family expressed in macrophages. ShRNA against TRPV2 inhibited the LPS-induced TNFalpha and IL-6 production as well as IkappaBalpha degradation. Experiments using BAPTA/AM and EGTA, and Ca2+ imaging suggested that the LPS-induced increase in [Ca2+]i involves both the TRPV2-mediated intracellular and extracellular Ca2+ mobilizations. BAPTA/AM abolished LPS-induced TNFalpha and IL-6 production, while EGTA only partially suppressed LPS-induced IL-6 production, but not TNFalpha production. These data indicate that TRPV2 is involved in the LPS-induced Ca2+ mobilization from intracellular Ca2+ store and extracellular Ca2+. In addition to Ca2+ mobilization through the IP3-receptor, TRPV2-mediated intracellular Ca2+ mobilization is involved in NFkappaB-dependent TNFalpha and IL-6 expression, while extracellular Ca2+ entry is involved in NFkappaB-independent IL-6 production.

Novel aspects of the roles of Rac1 GTPase in the cardiovascular system.

Rac1 GTPase is an established master regulator of cell motility through cortical actin re-organization and of reactive oxygen species generation through regulation of NADPH oxidase activity. Numerous molecular and cellular studies have implicated Rac1 in various cardiovascular pathologies: vascular smooth muscle proliferation, cardiomyocyte hypertrophy, and endothelial cell shape change. The physiological relevance of these in vitro findings, however, is just beginning to be reassessed with the newly developed, conditional mouse mutagenesis technology. Conditional gene targeting has also revealed unexpected, cell type-specific roles of Rac1. The aim of this review is to summarize the recent advance made in Rac1 research in the cardiovascular system, with special focus on its novel roles in the regulation of endothelial function, angiogenesis, and endothelium-mediated neuroprotection.

Functional characterization of protein-sorting machineries at the trans-Golgi network in Drosophila melanogaster.

Targeting of proteins to their final destination is a prerequisite for living cells to maintain their homeostasis. Clathrin functions as a coat that forms transport carriers called clathrin-coated vesicles (CCVs) at the plasma membrane and post-Golgi compartments. In this study, we established an experimental system using Schneider S2 cells derived from the fruit fly, Drosophila melanogaster, as a model system to study the physiological roles of clathrin adaptors, and to dissect the processes of CCV formation. We found that a clathrin adaptor Drosophila GGA (dGGA), a homolog of mammalian GGA proteins, localizes to the trans-Golgi network (TGN) and is capable of recruiting clathrin from the cytosol onto TGN membranes. dGGA itself is recruited from the cytosol to the TGN in an ARF1 small GTPase (dARF79F)-dependent manner. dGGA recognizes the cytoplasmic acidic-cluster-dileucine (ACLL) sorting signal of Lerp (lysosomal enzyme receptor protein), a homolog of mammalian mannose 6-phosphate receptors. Moreover, both dGGA and another type of TGN-localized clathrin adaptor, AP-1 (adaptor protein-1 complex), are shown to be involved in the trafficking of Lerp from the TGN to endosomes and/or lysosomes. Taken together, our findings indicate that the protein-sorting machinery in fly cells is well conserved relative to that in mammals, enabling the use of fly cells to dissect CCV biogenesis and clathrin-dependent protein trafficking at the TGN of higher eukaryotes.

The transcriptional coactivator PGC-1alpha mediates exercise-induced angiogenesis in skeletal muscle.

Peripheral arterial disease (PAD) affects 5 million people in the US and is the primary cause of limb amputations. Exercise remains the single best intervention for PAD, in part thought to be mediated by increases in capillary density. How exercise triggers angiogenesis is not known. PPARgamma coactivator (PGC)-1alpha is a potent transcriptional co-activator that regulates oxidative metabolism in a variety of tissues. We show here that PGC-1alpha mediates exercise-induced angiogenesis. Voluntary exercise induced robust angiogenesis in mouse skeletal muscle. Mice lacking PGC-1alpha in skeletal muscle failed to increase capillary density in response to exercise. Exercise strongly induced expression of PGC-1alpha from an alternate promoter. The induction of PGC-1alpha depended on beta-adrenergic signaling. beta-adrenergic stimulation also induced a broad program of angiogenic factors, including vascular endothelial growth factor (VEGF). This induction required PGC-1alpha. The orphan nuclear receptor ERRalpha mediated the induction of VEGF by PGC-1alpha, and mice lacking ERRalpha also failed to increase vascular density after exercise. These data demonstrate that beta-adrenergic stimulation of a PGC-1alpha/ERRalpha/VEGF axis mediates exercise-induced angiogenesis in skeletal muscle.