Implanted synthetic cells trigger tissue angiogenesis through de novo production of recombinant growth factors.

Progress in bottom-up synthetic biology has stimulated the development of synthetic cells (SCs), autonomous protein-manufacturing particles, as dynamic biomimetics for replacing diseased natural cells and addressing medical needs. Here, we report that SCs genetically encoded to produce proangiogenic factors triggered the physiological process of neovascularization in mice. The SCs were constructed of giant lipid vesicles and were optimized to facilitate enhanced protein production. When introduced with the appropriate genetic code, the SCs synthesized a recombinant human basic fibroblast growth factor (bFGF), reaching expression levels of up to 9⋅106 protein copies per SC. In culture, the SCs induced endothelial cell proliferation, migration, tube formation, and angiogenesis-related intracellular signaling, confirming their proangiogenic activity. Integrating the SCs with bioengineered constructs bearing endothelial cells promoted the remodeling of mature vascular networks, supported by a collagen-IV basement membrane-like matrix. In vivo, prolonged local administration of the SCs in mice triggered the infiltration of blood vessels into implanted Matrigel plugs without recorded systemic immunogenicity. These findings emphasize the potential of SCs as therapeutic platforms for activating physiological processes by autonomously producing biological drugs inside the body.

Pyruvate Upregulates Hepatic FGF21 Expression by Activating PDE and Inhibiting cAMP-Epac-CREB Signaling Pathway.

Fibroblast growth factor 21 (FGF21) functions as a polypeptide hormone to regulate glucose and lipid metabolism, and its expression is regulated by cellular metabolic stress. Pyruvate is an important intermediate metabolite that acts as a key hub for cellular fuel metabolism. However, the effect of pyruvate on hepatic FGF21 expression and secretion remains unknown. Herein, we examined the gene expression and protein levels of FGF21 in human hepatoma HepG2 cells and mouse AML12 hepatocytes in vitro, as well as in mice in vivo. In HepG2 and AML12 cells, pyruvate at concentrations above 0.1 mM significantly increased FGF21 expression and secretion. The increase in cellular cAMP levels by adenylyl cyclase activation, phosphodiesterase (PDE) inhibition and 8-Bromo-cAMP administration significantly restrained pyruvate-stimulated FGF21 expression. Pyruvate significantly increased PDE activities, reduced cAMP levels and decreased CREB phosphorylation. The inhibition of exchange protein directed activated by cAMP (Epac) and cAMP response element binding protein (CREB) upregulated FGF21 expression, upon which pyruvate no longer increased FGF21 expression. The increase in plasma pyruvate levels in mice induced by the intraperitoneal injection of pyruvate significantly increased FGF21 gene expression and PDE activity with a reduction in cAMP levels and CREB phosphorylation in the mouse liver compared with the control. In conclusion, pyruvate activates PDEs to reduce cAMP and then inhibits the cAMP-Epac-CREB signaling pathway to upregulate FGF21 expression in hepatocytes.

Lactic acid induces fibroblast growth factor 23 (FGF23) production in UMR106 osteoblast-like cells.

Endocrine and paracrine fibroblast growth factor 23 (FGF23) is a protein predominantly produced by bone cells with strong impact on phosphate and vitamin D metabolism by targeting the kidney. Plasma FGF23 concentration early rises in kidney and cardiovascular diseases correlating with progression and outcome. Lactic acid is generated in anaerobic glycolysis. Lactic acidosis is the consequence of various physiological and pathological conditions and may be fatal. Since FGF23 production is stimulated by inflammation and lactic acid induces pro-inflammatory signaling, we investigated whether and how lactic acid influences FGF23. Experiments were performed in UMR106 osteoblast-like cells, Fgf23 mRNA levels estimated from quantitative real-time polymerase chain reaction, and FGF23 protein determined by enzyme-linked immunosorbent assay. Lactic acid dose-dependently induced Fgf23 gene expression and up-regulated FGF23 synthesis. Also, Na+-lactate as well as formic acid and acetic acid up-regulated Fgf23. The lactic acid effect was significantly attenuated by nuclear factor kappa-light-chain enhancer of activated B-cells (NFκB) inhibitors wogonin and withaferin A. Lactic acid induces FGF23 production, an effect at least in part mediated by NFκB. Lactic acidosis may, therefore, be paralleled by a surge in plasma FGF23.

Associations of FGF21 and GDF15 with mitochondrial dysfunction in children living with perinatally-acquired HIV: A cross-sectional evaluation of pediatric AIDS clinical trials group 219/219C.

BACKGROUND: In persons living with HIV, mitochondrial disease (MD) is difficult to diagnose, as clinical signs are non-specific with inconsistent patterns. Fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15) are mitokines elevated in MD patients without HIV, and associated with cardiometabolic comorbidities in adults living with HIV. We assessed relationships of these biomarkers with MD in children living with perinatally-acquired HIV infection (CPHIV). SETTING: Cross-sectional study of CPHIV from Pediatric ACTG 219/219C classified by Mitochondrial Disease Criteria (MDC) that defines scores 2-4 as "possible" MD. METHODS: Each case with MDC equaling 4 (MDC4; n = 23) was matched to one randomly selected control displaying no MDC (MDC0; n = 23) based on calendar date. Unmatched cases with MDC equaling 3 (MDC3; n = 71) were also assessed. Plasma samples proximal to diagnoses were assayed by ELISA. Mitokine distributions were compared using Wilcoxon tests, Spearman correlations were calculated, and associations with MD status were assessed by conditional logistic regression. RESULTS: Median FGF21 and GDF15 concentrations, respectively, were highest in MDC4 (143.9 and 1441.1 pg/mL), then MDC3 (104.0 and 726.5 pg/mL), and lowest in controls (89.4 and 484.7 pg/mL). Distributions of FGF21 (paired Wilcoxon rank sum p = 0.002) and GDF15 (paired Wilcoxon rank sum p<0.001) differed in MDC4 vs MDC0. Mitokine concentrations were correlated across all participants (r = 0.33; p<0.001). Unadjusted odds ratios of being MDC4 vs MDC0 were 5.2 [95% confidence interval (CI): 1.06-25.92] for FGF21 and 3.5 (95%CI: 1.19-10.25) for GDF15. Relationships persisted after covariate adjustments. CONCLUSION: FGF21 and GDF15 levels may be useful biomarkers to screen for CPHIV with mitochondrial dysfunction.

Activation of activator protein-1-fibroblast growth factor 21 signaling attenuates Cisplatin hepatotoxicity.

Fibroblast growth factor (Fgf/FGF) 21, which plays important roles in sugar, lipid and energy metabolism, has been accepted as a mito-stress marker gene. We recently reported that FGF21 expression can be up-regulated via activation of aryl hydrocarbon receptor (AhR) or glucocorticoid receptor (GR) and that FGF21 plays important cytoprotective roles. Cisplatin (cis-diamminedichloroplatinum, CDDP) is a widely used chemotherapeutic drug. Numerous adverse effects including hepatotoxicity have been noted during CDDP therapy. It is known that CDDP can induce mitochondrial dysfunction. The studies were designed to determine the regulation of Fgf/FGF21 expression by CDDP, and to characterize the underlying mechanisms of its regulation, as well as to determine the impact of gain or loss of Fgf/FGF21 function on the progression of CDDP hepatotoxicity. Our results showed that CDDP and phorbol ester induced mRNA and protein expression of Fgf/FGF21 and ß-Klotho, two essential components of Fgf21 signaling, in mouse livers and cultured mouse/human hepatocytes. Luciferase reporter assays and ChIP-qPCR assays demonstrated that the cJun-AP-1 activation is responsible for CDDP- and phorbol ester-induced Fgf/FGF21 expression. Such induction is abolished after cotreated with AP-1 inhibitor SR11302. In addition, CDDP produces more severe liver injury in Fgf21-null than wild-type mice. Pre-treatment of GR activator dexamethasone or AhR activator ß-Naphthoflavone, both of which can induce Fgf21 expression, attenuated CDDP-induced hepatotoxicity in vivo and in vitro. In conclusion, Fgf/FGF21-ß-Klotho signaling can be activated via AP-1 activation. Gain of Fgf/FGF21 function attenuates the progression of CDDP hepatotoxicity, which may be considered clinically to improve CDDP therapy.

Protein-carbohydrate interaction effects on energy balance, FGF21, IGF-1, and hypothalamic gene expression in rats.

Amino acids are involved in energy homeostasis, just as are carbohydrates and lipids. Therefore, mechanisms controlling protein intake should operate independently and in combination with systems controlling overall energy intake to coordinate appropriate metabolic and behavioral responses. The objective of this study was to quantify the respective roles of dietary protein and carbohydrate levels on energy balance, plasma fibroblast growth factor 21 (FGF21) and insulin growth factor 1 (IGF-1) concentrations, and hypothalamic neurotransmitters (POMC, NPY, AgRP, and CART). In a simplified geometric framework, 7-wk-old male Wistar rats were fed 12 diets containing 3%-30% protein for 3 wk, in which carbohydrates accounted for 30%-75% of the carbohydrate and fat part of the diet. As a result of this study, most of the studied parameters (body composition, energy expenditure, plasma FGF21 and IGF-1 concentrations, and Pomc/Agrp ratio) responded mainly to the protein content and to a lesser extent to the carbohydrate content in the diet.NEW & NOTEWORTHY As mechanisms controlling protein intake can operate independently and in combination with those controlling energy intakes, we investigated the metabolic and behavioral effects of the protein-carbohydrate interaction. With a simplified geometric framework, we showed that body composition, energy balance, plasma FGF21 and IGF-1 concentrations, and hypothalamic Pomc/Agrp ratio were primarily responsive to protein content and, to a lesser extent, to carbohydrate content of the diet.

Periodontitis is associated to increased systemic inflammation in postmyocardial infarction patients.

OBJECTIVE: Periodontitis has been independently associated to cardiovascular disease. However, the biological mechanisms underlying such association are still partially unknown. Thus, this study aimed to discover immunological clues accounting for the increased risk of myocardial infarction (MI) in patients having periodontitis. METHODS: We included 100 patients with a first MI, 50 with and 50 without severe periodontitis, and 100 age-matched, sex-matched and area-matched controls from the Periodontitis and Its Relation to Coronary Artery Disease Study. Participants underwent comprehensive clinical and laboratory examinations 6-10 weeks after the MI and plasma expression of 92 inflammation-related markers was assessed through proximity extension assay. RESULTS: Patients who had an MI displayed altered expression of CCL19, TNFRSF9 and LAP TGF-ß1 in comparison with controls. TNFRSF9 correlated significantly with the amount of alveolar bone loss. MI patients with deep periodontal pockets showed increased white cell count and higher expression of FGF-21, HGF, OSM, CCL20 and IL-18R1 than patients without. White cell count correlated significantly with four of these proteins. CONCLUSIONS: Collectively, our results indicate molecular markers that could be responsible for the increased systemic inflammatory activity in patients with MI with periodontitis.

The miR-182-5p/FGF21/acetylcholine axis mediates the crosstalk between adipocytes and macrophages to promote beige fat thermogenesis.

A dynamically regulated microenvironment, which is mediated by crosstalk between adipocytes and neighboring cells, is critical for adipose tissue homeostasis and function. However, information on key molecules and/or signaling pathways regulating the crosstalk remains limited. In this study, we identify adipocyte miRNA-182-5p (miR-182-5p) as a crucial antiobesity molecule that stimulated beige fat thermogenesis by promoting the crosstalk between adipocytes and macrophages. miR-182-5p was highly enriched in thermogenic adipocytes, and its expression was markedly stimulated by cold exposure in mice. In contrast, miR-182-5p expression was significantly reduced in adipose tissues of obese humans and mice. Knockout of miR-185-5p decreased cold-induced beige fat thermogenesis whereas overexpression of miR-185-5p increased beiging and thermogenesis in mice. Mechanistically, miR-182-5p promoted FGF21 expression and secretion in adipocytes by suppressing nuclear receptor subfamily 1 group D member 1 (Nr1d1) at 5'-UTR, which in turn stimulates acetylcholine synthesis and release in macrophages. Increased acetylcholine expression activated the nicotine acetylcholine receptor in adipocytes, which stimulated PKA signaling and consequent thermogenic gene expression. Our study reveals a key role of the miR-182-5p/FGF21/acetylcholine/acetylcholine receptor axis that mediates the crosstalk between adipocytes and macrophages to promote beige fat thermogenesis. Activation of the miR-182-5p-induced signaling pathway in adipose tissue may be an effective approach to ameliorate obesity and associated metabolic diseases.

Evaluation of testicular glycogen storage, FGF21 and LDH expression and physiological parameters of sperm in hyperglycemic rats treated with hydroalcoholic extract of Securigera Securidaca seeds, and Glibenclamide.

Structural and physiological changes in sperm and semen parameters reduce fertility in diabetic patients. Securigera Securidaca (S. Securidaca) seed is a herbal medicine with hypoglycemic, antioxidant, and anti-hypertensive effects. The question now is whether this herbal medicine improves fertility in diabetic males. The study aimed to evaluate the effects of hydroalcoholic extract of S. Securidaca seeds (HESS), glibenclamide and a combination of both on fertility in hyperglycemic rats by comparing histological and some biochemical changes in testicular tissue and sperm parameters. The treatment protocol included administration of three doses of HESS and one dose of glibenclamide, as well as treatment with both in diabetic Wistar diabetic rats and comparison of the results with untrated groups. The quality of the testicular tissue as well as histometric parameters and spermatogenesis indices were evaluated during histopathological examination. Epididymal sperm analysis including sperm motility, viability, abnormalities, maturity, and chromatin structure were studied. The effect of HESS on the expression of LDH and FGF21 genes and tissue levels of glycogen, lactate, and total antioxidant capacity in testicular tissue was investigated and compared with glibenclamide. HESS improved sperm parameters in diabetic rats but showed little restorative effect on damaged testicular tissue. In this regard, glibenclamide was more effective than the highest dose of HESS and its combination with HESS enhanced its effectiveness so that histological tissue characteristics and sperm parameters were were comparable to those of healthy rats. The expression level of testicular FGF21 gene increased in diabetic rats, which intensified after treatment with HESS as well as glibenclamide. The combination of HESS and glibenclamide restored the expression level of testicular LDH gene, as well as tissue storage of glycogen, lactate and LDH activity, and serum testosterone to the levels near healthy control. S. Securidaca seeds can be considered as an effective supplement in combination with hypoglycemic drugs to prevent infertility complications in diabetes.

Anterograde regulation of mitochondrial genes and FGF21 signaling by hepatic LSD1.

Mitochondrial biogenesis and function are controlled by anterograde regulatory pathways involving more than 1000 nuclear-encoded proteins. Transcriptional networks controlling the nuclear-encoded mitochondrial genes remain to be fully elucidated. Here, we show that histone demethylase LSD1 KO from adult mouse liver (LSD1-LKO) reduces the expression of one-third of all nuclear-encoded mitochondrial genes and decreases mitochondrial biogenesis and function. LSD1-modulated histone methylation epigenetically regulates nuclear-encoded mitochondrial genes. Furthermore, LSD1 regulates gene expression and protein methylation of nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1), which controls the final step of NAD+ synthesis and limits NAD+ availability in the nucleus. Lsd1 KO reduces NAD+-dependent SIRT1 and SIRT7 deacetylase activity, leading to hyperacetylation and hypofunctioning of GABPß and PGC-1α, the major transcriptional factor/cofactor for nuclear-encoded mitochondrial genes. Despite the reduced mitochondrial function in the liver, LSD1-LKO mice are protected from diet-induced hepatic steatosis and glucose intolerance, partially due to induction of hepatokine FGF21. Thus, LSD1 orchestrates a core regulatory network involving epigenetic modifications and NAD+ synthesis to control mitochondrial function and hepatokine production.

Myokine Responses to Exercise in a Rat Model of Low/High Adaptive Potential.

Introduction: Assuming myokines underlie some of the health benefits of exercise, we hypothesised that 'high responder trainer' (HRT) rats would exhibit distinct myokine profiles to 'low responder trainers' (LRT), reflecting distinct health and adaptive traits. Methods: Blood was collected from LRT and HRT (N=8) rats at baseline (BL), immediately (0h), 1h, and 3h after running; repeated after 3-wks training. Myokines were analysed by ELISA (i.e. BDNF/Fractalkine/SPARC/Irisin/FGF21/Musclin/IL-6). Results: At baseline, Musclin (LRT: 84 ± 24 vs HRT: 26 ± 3 pg/ml, P=0.05) and FGF21 (LRT: 133 ± 34 vs HRT: 63.5 ± 13 pg/ml, P=0.08) were higher in LRT than HRT. Training increased Musclin in HRT (26 ± 3 to 54 ± 9 pg/ml, P<0.05) and decreased FGF21 in LRT (133 ± 34 to 60 ± 28 pg/ml, P<0.05). Training increased SPARC (LRT: 0.8 ± 0.1 to 2.1 ± 0.6 ng/ml, P<0.05; HRT: 0.7 ± 0.06 to 1.8 ± 0.3 ng/ml, P=0.06) and Irisin (LRT 0.62 ± 0.1 to 2.6 ± 0.4 ng/ml, P<0.01; HRT 0.53 ± 0.1 to 2.8 ± 0.7 ng/ml, P<0.01) while decreasing BDNF (LRT: 2747 ± 293 to 1081 ± 330 pg/ml, P<0.01; HRT: 1976 ± 328 to 797 ± 160 pg/ml, P<0.05). Acute exercise response of Musclin (AUC) was higher in LRT vs HRT (306 ± 74 vs. 88 ± 12 pg/ml×3h-1, P<0.01) and elevated in HRT after training (221 ± 31 pg/ml×3h-1, P<0.01). Training elevated SPARC (LRT: 2.4 ± 0.1 to 7.7 ± 1.3 ng/ml×3h-1, P<0.05; HRT: 2.5 ± 0.13 to 11.2 ± 2.2 ng/ml×3h-1, P<0.001) and Irisin (LRT: 1.34 ± 0.3 to 9.6 ± 1.7 ng/ml×3h-1, P<0.001; HRT: 1.5 ± 0.5 to 12.1 ± 1.9 ng/ml×3h-1, P<0.0001). Conclusion: Exercise training alters how myokines are secreted in response to acute exercise. Myokine responses were not robustly linked to adaptive potential in aerobic capacity, making them an unlikely regulator of adaptive traits.

Parenteral iron therapy and phosphorus homeostasis: A review.

Phosphorus has an essential role in cellular and extracellular metabolism; maintenance of normal phosphorus homeostasis is critical. Phosphorus homeostasis can be affected by diet and certain medications; some intravenous iron formulations can induce renal phosphate excretion and hypophosphatemia, likely through increasing serum concentrations of intact fibroblast growth factor 23. Case studies provide insights into two types of hypophosphatemia: acute symptomatic and chronic hypophosphatemia, while considering the role of pre-existing conditions and comorbidities, medications, and intravenous iron. This review examines phosphorus homeostasis and hypophosphatemia, with emphasis on effects of iron deficiency and iron replacement using intravenous iron formulations.

lncRNA LINC00963 downregulation regulates colorectal cancer tumorigenesis and progression via the miR­10b/FGF13 axis.

Long non-coding RNAs (lncRNAs) serve a key role in different types of cancer, including colorectal cancer (CRC). The exact roles and mechanisms underlying lncRNA00963 [long intergenic non­protein coding RNA 963 (LINC00963)] in CRC are not completely understood. The present study aimed to identify the effects and mechanisms underlying LINC00963 in CRC. Firstly, the LINC00963 expression was detected using reverse transcription­quantitative PCR and the results demonstrated that LINC00963 expression levels were significantly increased in CRC tissues and cell lines compared with healthy tissues and HpoEpiC cells, respectively. Online database analysis indicated that high levels of LINC00963 were associated with low survival rates. The results of functional experiments, such as CCK­8 assay, colony formation assay, wound healing assay and Transwell invasion assay, indicated that LINC00963 knockdown significantly inhibited CRC cell proliferation, colony formation, migration and invasion compared with the small interfering RNA (si)­negative control (NC) group. Furthermore, the luciferase reporter indicated that LINC00963 competitively regulated microRNA (miR)­10b by targeting fibroblast growth factor 13 (FGF13). Compared with si­NC, LINC00963 knockdown decreased the expression levels of FGF13, vimentin and N­cadherin, and increased the expression of E­cadherin as detecting by western blotting. miR­10b inhibitors partly attenuated si­LINC00963­induced inhibition of CRC cell proliferation, migration and invasion. Collectively, the results of the present study suggested a potential role of the LINC00963/miR-10b/FGF13 axis in the tumorigenesis and progression of CRC, indicating a novel lncRNA-based diagnostic or therapeutic target for CRC.

Production of active human FGF21 using tobacco mosaic virus-based transient expression system.

Fibroblast growth factor (FGF) family has a wide range of metabolic processes. FGF21 exerts critical physiological functions in clinical application. This study aimed to explore a convenient and highly efficient approach for rhFGF21 expression using TMV-TES. Firstly, the vector pTTEV-GFP was constructed, followed by optimisation of the expression parameters in Nicotiana benthamiana. Then, the rhFGF21 encoding gene harbouring vector pTTEV-rhFGF21 was constructed. Agrobacterium-mediated vacuum infiltration was performed with the optimised parameters and the expression of rhFGF21 was confirmed by the immunoblotting analysis. ELISA revealed that the protein accumulation of rhFGF21 accounts for 0.11% of total soluble proteins. The biological activity was evaluated and the results suggested that tobacco-expressed rhFGF21 could stimulate the glucose uptake in swiss 3T3-L1 adipocytes, which was similar to the activity of commercial products, suggesting its native biological activity. Therefore, using TMV-TES to express rhFGF21 will be a feasible approach for the mass production of rhFGF21.

DPP-4 inhibitor induces FGF21 expression via sirtuin 1 signaling and improves myocardial energy metabolism.

Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used incretin-based therapy for the treatment of type 2 diabetes. We investigated the cardioprotective effect of a DPP-4 inhibitor, vildagliptin (vilda), on myocardial metabolism and cardiac performance under pressure overload. Mice were treated with either vehicle or vilda, followed by transverse aortic constriction (TAC). After 3 weeks of TAC, cardiac hypertrophy and impairment of systolic function were attenuated in vilda-treated mice. Pressure-volume analysis showed that vilda treatment significantly improved left-ventricular contractile efficiency in TAC heart. Myocardial energy substrate analysis showed that vilda treatment significantly increased glucose uptake as well as fatty acid uptake. Fibroblast growth factor 21 (FGF21), a peptide involved in the regulation of energy metabolism, increased in TAC heart and was further increased by vilda treatment. FGF21 was strongly expressed in cardiac fibroblasts than in cardiomyocytes in mouse heart after TAC with vilda treatment. Vilda treatment markedly induced FGF21 expression in human cardiac fibroblasts through a sirtuin (Sirt) 1-mediated pathway, suggesting that fibroblast-mediated FGF21 expression may regulate energy metabolism and exert vilda-mediated beneficial effects in stressed heart. Vilda induced a metabolic regulator, FGF21 expression in cardiac fibroblasts via Sirt1, and increased contractile efficiency in murine pressure-overloaded heart.

Systematic profiling of early regulators during tissue regeneration using zebrafish model.

Great progresses have been made in comprehension of tissue regeneration process. However, one of the central questions in regeneration research remains to be deciphered is what factors initiate regenerative process. In present study, we focused on systematic profiling of early regulators in tissue regeneration via high-throughput screening on zebrafish caudal fin model. Firstly, 53 GO-annotated regeneration-related genes, which were specifically activated upon fin amputation, were identified according to the transcriptomic analysis. Moreover, qRT-PCR analysis of a couple of randomly selected genes from the aforementioned gene list validated our sequencing results. These studies confirmed the reliability of transcriptome sequencing analysis. Fibroblast growth factor 20a (fgf20a) is a key initial factor in the regeneration of zebrafish. Through a gene expression correlation analysis, we discovered a collection of 70 genes correlating with fgf20a, whose expression increased promptly at 2 days post amputation (dpa) and went down to the basal level until the completion of fin regeneration. In addition, two genes, socs3b and nppc, were chosen to investigate their functions during the fin regeneration. Inhibition of either of those genes significantly delayed the regenerative process. Taken together, we provided a simple and effective time-saving strategy that may serve as a tool for identifying early regulators in regeneration and identified 71 genes as early regulators of fin regeneration.

Apical ectodermal ridge regulates three principal axes of the developing limb.

Understanding limb development not only gives insights into the outgrowth and differentiation of the limb, but also has clinical relevance. Limb development begins with two paired limb buds (forelimb and hindlimb buds), which are initially undifferentiated mesenchymal cells tipped with a thickening of the ectoderm, termed the apical ectodermal ridge (AER). As a transitional embryonic structure, the AER undergoes four stages and contributes to multiple axes of limb development through the coordination of signalling centres, feedback loops, and other cell activities by secretory signalling and the activation of gene expression. Within the scope of proximodistal patterning, it is understood that while fibroblast growth factors (FGFs) function sequentially over time as primary components of the AER signalling process, there is still no consensus on models that would explain proximodistal patterning itself. In anteroposterior patterning, the AER has a dual-direction regulation by which it promotes the sonic hedgehog (Shh) gene expression in the zone of polarizing activity (ZPA) for proliferation, and inhibits Shh expression in the anterior mesenchyme. In dorsoventral patterning, the AER activates Engrailed-1 (En1) expression, and thus represses Wnt family member 7a (Wnt7a) expression in the ventral ectoderm by the expression of Fgfs, Sp6/8, and bone morphogenetic protein (Bmp) genes. The AER also plays a vital role in shaping the individual digits, since levels of Fgf4/8 and Bmps expressed in the AER affect digit patterning by controlling apoptosis. In summary, the knowledge of crosstalk within AER among the three main axes is essential to understand limb growth and pattern formation, as the development of its areas proceeds simultaneously.

Propofol Improved Glucose Tolerance Associated with Increased FGF-21 and GLP-1 Production in Male Sprague-Dawley Rats.

Anesthetics, particularly volatile anesthetics, have been shown to impair glucose metabolism and cause hyperglycemia, closely linking them with mortality and morbidity as related to surgery. Beyond being an anesthetic used for general anesthesia and sedation, intravenous hypnotic propofol displays an effect on glucose metabolism. To extend the scope of propofol studies, its effects on glucose metabolism were evaluated in male Sprague-Dawley rats of various ages. Unlike chloral hydrate and isoflurane, propofol had little effect on basal glucose levels in rats at 2 months of age, although it did reduce chloral hydrate- and isoflurane-induced hyperglycemia. Propofol reduced postload glucose levels after either intraperitoneal or oral administration of glucose in both 7- and 12-month-old rats, but not those at 2 months of age. These improved effects regarding propofol on glucose metabolism were accompanied by an increase in insulin, fibroblast growth factor-21 (FGF-21), and glucagon-like peptide-1 (GLP-1) secretion. Additionally, an increase in hepatic FGF-21 expression, GLP-1 signaling, and FGF-21 signaling, along with a decrease in endoplasmic reticulum (ER) stress, were noted in propofol-treated rats at 7 months of age. Current findings imply that propofol may turn into insulin-sensitizing molecules during situations of existing insulin resistance, which involve FGF-21, GLP-1, and ER stress.

CREBH knockout accelerates hepatic fibrosis in mouse models of diet-induced nonalcoholic fatty liver disease.

AIMS: The primary focus of this study was to explore the effects of cyclic AMP response element-binding protein H (CREBH) on the development of nonalcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS: CREBH knockout (KO) and wildtype (WT) mice were averagely divided into a methionine and choline-deficient (MCD) or high fat (HF) diet group and respective chow diet (CD) groups. Mice were sacrificed after 4-week treatment for MCD model and 24-week treatment for HF model. KEY FINDINGS: Characteristics of nonalcoholic steatohepatitis-related liver fibrosis in KO-MCD/HF group were verified by hepatic histological analyses. Compared with WT-MCD/HF group, levels of plasma ALT and hepatic hydroxyproline increased in KO-MCD/HF group. Significantly higher levels of MCP-1, αSMA, Desmin, COL-1, TIMP-1, TGF-ß1, TGF-ß2 were found while MMP-9 and FGF21 mRNA levels decreased in KO-MCD/HF group. There was also a distinct difference of mRNA levels of TNFα, CTGF and CCND1 in KO-HF group compared with controls. Protein levels of MCP-1, BAX, αSMA, COL-1, TGF-ß1 and SMAD2/3 significantly increased in KO-MCD/HF group and CCND1 was also upregulated in KO-HF group compared to their counterparts. SIGNIFICANCE: CREBH knockout may primarily regulate the TGF-ß1 signaling pathway via TGF-ß2 and FGF21 resulting in more severe inflammation and fibrosis in NAFLD.

Characterization of gene expression changes in human neural stem cells and endothelial cells modeling a neurovascular microenvironment.

Angiogenesis-mediated neovascularization correlates with recovery after intracerebral implantation of neural stem cells (NSCs) in stroke. To elucidate NSCs' mechanism of action, it is essential to understand how these interact with the brain's vasculature after implantation. Using an all-human endothelial cell (EC, D3 cell line) and NSC (STROC05 and CTXOE03) co-culture model, fluorescently activated cell sorting (FACS) was used to isolate each cell type for a comparison of gene expression between monocultures of undifferentiated proliferating and differentiated non-proliferating cells. Gene expression for angiogenic factors (vascular endothelial growth factor, platelet derived growth factor, angiopoietin), as well as cell survival (brain derived neurotrophic factor, fibroblast growth factor) and migration (stromal cell-derived factor-1a) were measured and contrasted with the corresponding receptors on each cell type. The cellular source of extracellular matrix defining the basement membrane (vitronectin, fibronectin, laminin, collagen I and IV) and neuropil (hyaluronic acid, aggrecan, neurocan, thrombospondin, nidogen and brain associated link protein-1) was evaluated for NSCs and ECs. Co-culturing dramatically changed the expression profiles of each cell type in comparison to undifferentiated, but also differentiated cells. These results indicate that monocultures provide a poor model to investigate the cellular signaling involved in a tissue repair response. Co-cultures of NSCs and ECs forming vasculature-like structures (VLS) provide a more complex model to investigate NSC-induced neovascularization. These in vitro studies are essential to tease out individual cell signaling in NSCs and ECs to develop a mechanistic understanding of the efficacy of NSCs as a therapeutic for stroke.