Cachexia is an extremely serious syndrome which occurs in most patients with different cancers, and it is characterized by systemic inflammation, a negative protein and energy balance, and involuntary loss of body mass. This syndrome has a dramatic impact on the patient's quality of life, and it is also associated with a low response to chemotherapy leading to a decrease in survival. Despite this, cachexia is still underestimated and often untreated. New research is needed in this area to understand this complex phenomenon and ultimately find treatment methods and therapeutic targets. The skeletal muscle can act as an endocrine organ. Signaling between muscles and other systems is done through myokines, cytokines, and proteins produced and released by myocytes. In this review, we would like to draw attention to some of the most important myokines that could have potential as biomarkers and therapeutic targets: myostatin, irisin, myonectin, decorin, <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em>, interleukin-6, interleukin-8, and interleukin-15.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF-<em>21</em>) is a secreted protein, which has anti-diabetic and lipocaic effects, but its ability to protect against hepatic fibrosis has not been studied. In this study, we investigated the ability of FGF-<em>21</em> to attenuate dimethylnitrosamine (DMN)-induced hepatic fibrogenesis in mice and the mechanism of its action. Hepatic fibrosis was induced by injection of DMN, FGF-<em>21</em> was administered to the mice once daily in association with DMN injection till the end of the experiment. Histopathological examination, tissue 4-hydroxyproline content and expressions of smooth muscle α-actin (α-SMA) and collagen I were measured to assess hepatic fibrosis. Ethanol/PDGF-BB-activated hepatic stellate cells (HSCs) were used to understand the mechanisms of FGF-<em>21</em> inhibited hepatic fibrogenesis. Results showed that FGF-<em>21</em> treatment attenuated hepatic fibrogenesis and was associated with a significant decrease in intrahepatic fibrogenesis, 4-hydroxyproline accumulation, α-SMA expression and collagen I deposition. FGF-<em>21</em> treatment inhibited the activation of HSCs via down-regulating the expression of TGF-β, NF-κB nuclear translocation, phosphorylation levels of smad2/3 and IκBα. Besides, FGF-<em>21</em> treatment caused activated HSC apoptosis with increasing expression of Caspase-3, and decreased the ratio of Bcl-2 to Bax. In conclusion, FGF-<em>21</em> attenuates hepatic fibrogenesis and inhibits the activation of HSC warranting the use of FGF-<em>21</em> as a potential therapeutic agent in the treatment of hepatic fibrosis.

Vascular endothelial <em>growth</em> <em>factor</em> (VEGF) plays an important role in angiogenesis by inducing endothelial cell proliferation, migration and survival. Direct pulp capping with an adhesive resin system was shown to induce local increase in blood vessel density and lack of dentin bridging. However, the mechanisms involved in the increase in blood vessel density observed near the pulp exposures capped with an adhesive resin are largely unknown. OBJECTIVES.: To investigate the effect of an adhesive resin or one of its hydrophilic monomers (HEMA), in the expression of VEGF by pulp cells. METHODS.: Mouse odontoblast-like cells (MDPC-23), undifferentiated pulp cells (OD-<em>21</em>), gingival <em>fibroblasts</em>, and macrophages were exposed to SingleBond (3M) or to 0-1000nM HEMA. VEGF expression was evaluated by ELISA and semi-quantitative RT-PCR. RESULTS AND SIGNIFICANCE.: VEGF expression was upregulated in MDPC-23 cells exposed to HEMA (p<0.001) or to SingleBond (p<0.018), and in macrophages exposed to HEMA (p<0.001) or SingleBond (p=0.001). In contrast, VEGF expression remained unchanged in undifferentiated pulp cells (OD-<em>21</em>), or <em>fibroblasts</em> exposed to either HEMA or Single Bond (p>0.05). Treatment with SingleBond or HEMA did not affect VEGF expression at the mRNA level of any cell type evaluated here, suggesting that the induction of VEGF expression in these cells is regulated primarily at the post-transcriptional level. These findings suggest that VEGF is involved in the regulation of pulp neovascularization observed in response to the application of adhesive resins at site of pulp exposure.

The nutritional environment to which animals are exposed in early life can lead to epigenetic changes in the genome that influence the risk of obesity in later life. Here, we demonstrate that the <em>fibroblast</em> <em>growth</em> <em>factor</em>-<em>21</em> gene (Fgf<em>21</em>) is subject to peroxisome proliferator-activated receptor (PPAR) α-dependent DNA demethylation in the liver during the postnatal period. Reductions in Fgf<em>21</em> methylation can be enhanced via pharmacologic activation of PPARα during the suckling period. We also reveal that the DNA methylation status of Fgf<em>21</em>, once established in early life, is relatively stable and persists into adulthood. Reduced DNA methylation is associated with enhanced induction of hepatic FGF<em>21</em> expression after PPARα activation, which may partly explain the attenuation of diet-induced obesity in adulthood. We propose that Fgf<em>21</em> methylation represents a form of epigenetic memory that persists into adulthood, and it may have a role in the developmental programming of obesity.

Most hormones secreted from specific organs of the body in response to diverse stimuli contribute to the homeostasis of the whole organism. <em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>), a hormone induced by a variety of environmental or metabolic stimuli, plays a crucial role in the adaptive response to these stressful conditions. In addition to its role as a stress hormone, FGF<em>21</em> appears to function as a mediator of the therapeutic effects of currently available drugs and those under development for treatment of metabolic diseases. In this review, we highlight molecular mechanisms and the functional importance of FGF<em>21</em> induction in response to diverse stress conditions such as changes of nutritional status, cold exposure, and exercise. In addition, we describe recent findings regarding the role of FGF<em>21</em> in the pathogenesis and treatment of diabetes associated with obesity, liver diseases, pancreatitis, muscle atrophy, atherosclerosis, cardiac hypertrophy, and diabetic nephropathy. Finally, we discuss the current understanding of the actions of FGF<em>21</em> as a crucial regulator mediating beneficial metabolic effects of therapeutic agents such as metformin, glucagon/glucagon-like peptide 1 analogues, thiazolidinedione, sirtuin 1 activators, and lipoic acid.

Rheumatoid arthritis (RA) is characterized by the infiltration of a number of pro-inflammatory cytokines into synovial fluid and patients with RA often develop joint destruction and deficits in muscle mass. The <em>growth</em> <em>factor</em> myostatin is a key regulator linking muscle mass and bone structure. We sought to determine whether myostatin regulates rheumatoid synovial <em>fibroblast</em> activity and inflammation in RA. We found that levels of myostatin and interleukin (IL)-1β (a key pro-inflammatory cytokine in RA) in synovial fluid from RA patients were overexpressed and positively correlated. In in vitro investigations, we found that myostatin dose-dependently regulated IL-1β expression through the ERK, JNK, and AP-1 signal-transduction pathways. Computational analysis confirmed that miR-<em>21</em>-5p directly targets the expression of the 3' untranslated region (3' UTR) of IL-1β. Treatment of cells with myostatin inhibited miR-<em>21</em>-5p expression and miR-<em>21</em>-5p mimic prevented myostatin-induced enhancement of IL-1β expression, showing an inverse correlation between miR-<em>21</em>-5p and IL-1β expression during myostatin treatment. We also found significantly increased paw swelling in an animal model of collagen-induced arthritis (CIA), compared with controls; immunohistochemistry staining revealed substantially higher levels of myostatin and IL-1β expression in CIA tissue. Our evidence indicates that myostatin regulates IL-1β production. Thus, targeting myostatin may represent a potential therapeutic target for RA.

BACKGROUND

Diagnosis of mitochondrial disorders is challenging, because of their highly variable clinical manifestations and age-of-onset and the shortage of specific diagnostic tools. Recent molecular studies have found that serum <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) has potential to be a biomarker for muscle-manifesting mitochondrial disease, as well as for follow-up of disease progression and effect of intervention.

METHODS

Serum FGF<em>21</em> as a biomarker is compared to conventional serum diagnostic tools for mitochondrial disorders.

CONCLUSIONS

Mitochondrial disorders are a large group of different progressive disorders, with the age-of-onset from neonatal life to late adulthood, and symptoms originating from any organ system but sharing an underlying cause of mitochondrial dysfunction. The prevalence of these disorders is about 1:2000, varying somewhat between different countries. Serum diagnostic tools include lactate, pyruvate, their ratio, creatine kinase and amino acids. However, none of these markers are both sensitive and specific. Increased levels of FGF<em>21</em> cytokine were recently found in the serum of patients, who have a muscle-manifesting mitochondrial disease, thus providing a promising, novel, sensitive and specific biomarker for these disorders.

Diabetes mellitus (DM) is a major endocrine metabolic disease and is marked by a lack of insulin. The complication of DM is one of the most difficult problems in medicine. The initial translational studies revealed that <em>growth</em> <em>factors</em> have a major role in integrating tissue physiology and in embryology as well as in <em>growth</em>, maturation and tissue repair. In some tissues affected by diabetes, <em>growth</em> <em>factors</em> are induced by a relative deficit or excess. <em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a promising regulator of glucose and lipid metabolism with multiple beneficial effects including hypoglycemic and lipid-lowering. Vascular endothelial <em>growth</em> <em>factor</em> (VEGF) is a potent angiogenic and vascular permeability <em>factor</em> and is implicated in both of these complications in diabetes. Increase or decrease in the production of transforming <em>growth</em> <em>factor</em>-β1 (TGF-β1) has been associated with diabetic nephropathy and retinopathy. The insulin-like <em>growth</em> <em>factor</em>-I (IGF-I) is a naturally-occurring single chain polypeptide which has been widely used in the treatment of diabetic glomerular and renal tubular injuries. This review summarizes the recent evidences for an involvement of <em>growth</em> <em>factors</em> in diabetic complications, focusing on their emergence in sequence of events leading to vascular complications or their potential therapeutic role in these diseases. <em>Growth</em> <em>factor</em> therapy in diabetic foot ulcers is already a clinical reality. As methods to finely regulate <em>growth</em> <em>factors</em> in a tissue and time-specific manner are further developed and tested, regulation of the <em>growth</em> <em>factor</em> to normal level in vivo may well become a therapy to prevent and treat diabetic complications.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> (FGF) <em>21</em> belongs to the FGF superfamily that is involved in cell proliferation and differentiation, neural development, angiogenesis, and metabolism. FGF<em>21</em> requires β-Klotho as a co-receptor. Tissues involved in metabolism such as the liver, adipose tissues, skeletal muscle, and pancreas express FGF<em>21</em>. Starvation increases hepatic expression of FGF<em>21</em>, which then acts centrally to increase hepatic gluconeogenesis. FGF<em>21</em> also increases fatty acid oxidation. This may be relevant in cold exposure, when expression of FGF<em>21</em> is induced. Chronic treatment with recombinant FGF<em>21</em> reduces serum and hepatic triglyceride levels and ameliorates fatty liver in obese mice, through the suppression of the lipogenic gene, Srebp-1. FGF<em>21</em> reduces hepatic cholesterol production by inhibiting Srebp-2, a transactivator of proprotein convertase subtilisin/kexin type 9 (PCSK9). LY2045319, an FGF<em>21</em> analog, reduces LDL-C and triglycerides and increases HDL-C in obese human subjects with type 2 diabetes. FGF<em>21</em> does not seem to lower blood pressure acutely. In rats fed with high-fructose water to induce mild hypertension, 4-week treatment with recombinant FGF<em>21</em> led to normalization of systolic blood pressure and improved serum lipid profile. FGF receptors and β-Klotho are expressed on the nucleus tractus solitarii and nodose ganglion in the baroreflex afferent pathway. Moreover, FGF<em>21</em> acts on the hypothalamus to release corticosterone and induces in adipocytes the production of adiponectin, an adipokine with antihypertensive activities. Therefore, FGF<em>21</em> may decrease blood pressure indirectly, through its actions in the liver, brain, and adipose tissues.

The objectives of this study were to develop an in vitro culture system to optimize germ cell proliferation and to measure the potential of the cultured germ cells to produce mature spermatozoa after transplantation into a recipient. Donor germ cells isolated from ROSA26 male mice were cultured with a STO feeder cell layer in Dulbecco's minimal essential medium (DMEM) supplemented with fetal bovine serum (FBS), stem cell <em>factor</em>, leukemia inhibitory <em>factor</em>, basic <em>fibroblast</em> <em>growth</em> <em>factor</em>, insulin-like <em>growth</em> <em>factor</em> 1, interleukin-11, L-glutamine, sodium pyruvate, 2-mercaptoethanol, murine oncostatin M, and platelet-derived <em>growth</em> <em>factor</em>. Donor germ cells formed colonies in the primary cultures after 8-<em>21</em> days. These cultured colonies were maintained for 4 weeks or longer without subculture and proliferated for up to 8 passages over a period of 3 months. These colonies had alkaline phosphatase activity and incorporated 5-bromo-2'-deoxyuridine. These colonies were positive partially when screened with antibody for germ cell nuclear antigen and c-kit. Germ cells cultured with this supplemented medium showed enhanced colonization vs controls cultured with DMEM and FBS. Cultured germ cells from Rosa26 donors were transplanted into testes and were identified by X-gal staining and histological screening. The cells cultured in the supplemented medium colonized the tubules and initiated spermatogenesis in the recipient mice. This is an improved method for culturing germ cells and may be useful in gene therapy and the production of transgenic animals.

Little regeneration of transected axons occurs after the damage caused by traumatic spinal cord injury (SCI), and unidirectional and irreversible fibrotic scars are thought to be the main chemical and physical obstacle for axonal re<em>growth</em> in SCI pathology. We previously demonstrated that microRNA (miR)-<em>21</em>-5p and transforming <em>growth</em> <em>factor</em> (TGF)-β1, a central pathological mediator of fibrotic diseases, were significantly up-regulated in the lesion epicenter after SCI. Here, we found that TGF-β1 enhanced miR-<em>21</em>-5p expression in primary spinal <em>fibroblasts</em>, and regulated the expression of fibrosis-related genes. The overexpression of miR-<em>21</em>-5p promoted the pro-fibrogenic activity of TGF-β1 in spinal <em>fibroblasts</em>, while miR-<em>21</em>-5p knockdown attenuated this activity. We identified Smad7 as a target gene of miR-<em>21</em>-5p, suggesting a potential mechanism for the role of miR-<em>21</em>-5p in spinal fibrosis through regulating Smad7 expression. Furthermore, miR-<em>21</em>-5p knockdown in a mouse model significantly improved motor functional recovery after spinal cord injury. These data demonstrate that miR-<em>21</em>-5p functions in an amplifying circuit to enhance TGF-β signaling events in the activation of spinal <em>fibroblasts</em> and suggest that miR-<em>21</em>-5p is a potential therapeutic target in the treatment of fibrotic scar formation after SCI.

Skeletal muscle androgen receptor (AR) expression at the onset of functional overload (OV) has not been well described. It is also not known if overload and/or anabolic steroid differentially regulate AR expression. The purpose of this study was to examine AR gene expression at the onset of functional OV in rat plantaris muscle with and without nandrolone decanoate (ND) administration. The functional significance of AR protein induction was examined using skeletal alpha-actin promoter activity in transiently transfected CV-1 <em>fibroblast</em> cells. Male Sprague-Dawley rats ( approximately 125 g) were functionally overloaded for 1, 3, 7, or <em>21</em> days. A subset of animals was given an ND (6 mg/kg) injection at day 0 and then overloaded for 3 days. Control animals underwent sham surgeries. AR protein concentration increased 106 and 279% after 7 and <em>21</em> days of OV, respectively. AR mRNA increased 430% after 7 days of OV. AR protein expression in C2C12 murine myotubes subjected to 1% chronic radial stretch for 18 h was elevated 101% compared with control. ND treatment increased AR protein concentration 1,300% compared with controls, and there was no additional effect when ND and OV were combined. ND with 3 days of OV treatment increased AR mRNA expression 50% compared with control. AR overexpression in transiently transfected CV-1 <em>fibroblast</em> cells increased -424 bp skeletal alpha-actin promoter activity 80 to 1,800% in a dose-dependent fashion. Co-overexpression of either serum response <em>factor</em> (SRF) or active RhoA with AR overexpression induced a synergistic 36- and 28-fold induction of skeletal alpha-actin promoter. Cotransfection of AR, SRF, and active RhoA induced 180-fold increase in skeletal alpha-actin promoter activity. In conclusion, AR protein expression is increased after 7 days of functional OV, and this induction is regulated pretranslationally. AR induction in conjunction with SRF and RhoA signaling may be an important regulator of gene expression during overload-induced muscle <em>growth</em>.

MicroRNAs (miRNAs) play important roles in the fibrosis of systemic sclerosis (SSc). However, the underlying miRNA-mRNA regulatory network is not fully understood. A systemic investigation of the role of miRNAs would be very valuable for increasing our knowledge of the pathogenesis of SSc. Here, we combined miRNA and mRNA expression profiles and bioinformatics analyses and then performed validation experiments. we identified <em>21</em> miRNAs and 2698 mRNAs that were differentially expressed in SSc. Among these, 17 miRNAs and their 33 target mRNAs (55 miRNA-mRNA pairs) were involved in Toll-like receptor, transforming <em>growth</em> <em>factor</em> β and Wnt signalling pathways. Validation experiments revealed that miR-146b, miR-130b, miR-<em>21</em>, miR-31 and miR-34a levels were higher whereas miR-145 levels were lower in SSc skin tissues and <em>fibroblasts</em>, normal <em>fibroblasts</em> and endothelial cells that were stimulated with SSc serum. ACVR2B, FZD2, FZD5 and SOX2 levels were increased in SSc skin <em>fibroblasts</em>, normal <em>fibroblasts</em> and endothelial cells that were stimulated with SSc serum. We did not identify any negative correlations among these miRNA-mRNA pairs. miR-<em>21</em> was specifically expressed at higher levels in SSc serum. Six miRNAs and 4 mRNAs appear to play important roles in the pathogenesis of SSc are worth investigating in future functional studies.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF-<em>21</em>) is an endocrine <em>factor</em> that can be secreted into circulation by the liver. FGF-<em>21</em> takes part in metabolic actions and is thought to be a promising candidate for the treatment of diabetes. However, the role of FGF-<em>21</em> in atherosclerosis is unknown. In this study, apoE(-/-) mice were fed an atherogenic diet for 4 weeks with and without subcutaneous injections of FGF-<em>21</em>. ApoE(-/-) mice fed an atherogenic diet showed hyperlipidemia, a large plaque area in aortas and increased vessel wall thickness. Plasma FGF-<em>21</em> content and protein level of FGF receptor 1 (FGFR1) in aortas was greater in apoE(-/-) than C57BL/6J mice. Exogenous FGF-<em>21</em> treatment significantly ameliorated dyslipidemia in apoE(-/-) mice. FGF-<em>21</em>-treated apoE(-/-) mice showed reduced number of aortic plaques and plaque area as well as reduced number of TUNEL-positive cells. Protein levels of the endoplasmic reticulum stress markers glucose-regulated protein 94, caspase-12 and C/EBP homologous protein were reduced by 34.5, 31.4 and 26.5 %, respectively, in apoE(-/-) mice. Endogenous expression of FGF-<em>21</em> and its receptor FGFR1 were upregulated in apoE(-/-) mice, and exogenous administration of FGF-<em>21</em> ameliorated the atherogenic-induced dyslipidemia and vascular atherosclerotic lesions. FGF-<em>21</em> protecting against atherosclerosis might be in part by its inhibitory effects on endoplasmic reticulum stress-mediated apoptosis.

Peroxisome proliferator-activated receptor α (PPARα) is a key transcriptional <em>factor</em> that regulates hepatic lipid catabolism by stimulating fatty acid oxidation and ketogenesis in an adaptive response to nutrient starvation. However, how PPARα is regulated by posttranslational modification is poorly understood. In this study, we identified that progestin and adipoQ receptor 3 (PAQR3) promotes PPARα ubiquitination through the E3 ubiquitin ligase HUWE1, thereby negatively modulating PPARα functions both in vitro and in vivo. Adenovirus-mediated Paqr3 knockdown and liver-specific deletion of the Paqr3 gene reduced hepatic triglyceride levels while increasing fatty acid oxidation and ketogenesis upon fasting. PAQR3 deficiency enhanced the fasting-induced expression of PPARα target genes, including those involved in fatty acid oxidation and <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em>, a key molecule that mediates the metabolism-modulating effects of PPARα. PAQR3 directly interacted with PPARα and increased the polyubiquitination and proteasome-mediated degradation of PPARα. Furthermore, the E3 ubiquitin ligase HUWE1 was identified to mediate PPARα polyubiquitination. Additionally, PAQR3 enhanced the interaction between HUWE1 and PPARα.

CONCLUSIONS

Ubiquitination modification through the coordinated action of PAQR3 with HUWE1 plays a crucial role in regulating the activity of PPARα in response to starvation. (Hepatology 2018;68:289-303).

Regional and temporal patterns of the expression of basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), and two of its high affinity receptors (FGFR1 and FGFR2), were examined in the male rat brain during early postnatal development; the reverse transcription-polymerase chain reaction (RT-PCR) was used to obtain mRNA measurements which were expressed relative to mRNA for GAPDH as a constant. In the rat cerebrum, the mRNAs for bFGF and for FGFR2 were relatively low in amount within the first postnatal week, but by 28 days, they were as high as in the 1-year-old rat cerebrum. In contrast, the expression of FGFR1 was biphasic: mRNA levels were higher at postnatal days 1 and 28 than at day <em>21</em>. Quantitation of mRNA from microdissected regions of 28-day-old rat brain revealed that the expression of bFGF and of FGFR2 showed a marked variation between regions but the expression of FGFR1 appeared less variable between the regions that were analyzed. For all three genes the hippocampus appeared to have high relative amounts of mRNA. The temporal patterns of expression of bFGF, FGFR1 and FGFR2 also differed with brain region during early postnatal development. In the occipital cortex and inferior colliculus, the mRNAs for bFGF and FGFR2 both increased in amount during the first month, unlike that for FGFR1. However, in the cerebellum, the highest expression of bFGF and FGFR1 mRNAs occurred at postnatal day 1; FGFR2 expression apparently showed less change with age. The temporal changes in bFGF, FGFR1 and FGFR2 expression in different brain regions during early postnatal development suggest that receptor regulation may permit different physiological effects of bFGF according to brain region and developmental age.

OBJECTIVE

Resolution of venous thrombi is accompanied by an ingrowth of capillaries, which appears to be analogous to angiogenesis in other tissues. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are major regulators of angiogenesis. The aim of this study was to determine the temporal changes and the location of VEGF and bFGF expression in a rat model of venous thrombus resolution.

METHODS

Thrombi were induced in the inferior venae cavae of rats by creating a stenosis to reduce blood flow by 80% to 90%. Thrombi, adjacent inferior vena cava wall, and systemic blood were collected at 1, 3, 7, 14, 21, and 28 days after thrombus generation (n = 9). Sham operations were performed (n = 5), and blood was collected at 1, 3, and 7 days. VEGF and bFGF were measured with specific immunoassays, and levels in tissues were expressed as picogram per milligram soluble protein. Tissues from two animals that were humanely killed 7 days after thrombus formation were prepared for histological examination. Immunohistochemistry was performed by the use of antibodies against VEGF, bFGF, and ED-1 (a monocyte/macrophage marker).

RESULTS

Laminated thrombi were reliably produced with a median weight at 1 day of 39 mg (range, 23-63 mg). There was a significant increase in thrombus VEGF concentration between 1 day (median, 247; range, 0-514) and 7 days (median, 556; range, 254-1741) (P =.02). There was no difference between the seventh day and subsequent days. There was a positive linear correlation between thrombus bFGF concentration and time (R = 0.74, P <.0001), with a more than 300-fold increase in bFGF concentration over the 28 days of the study. VEGF and bFGF concentrations in the adjacent vena caval wall did not change significantly with time. The serum VEGF was significantly raised at 1 day (median, 5520 pg/mL; range, 4040-7912 pg/mL) and 3 days (median, 3880 pg/mL; range, 2564-7232 pg/mL) compared with 7 days (median, 1790 pg/mL; range, 232-3228 pg/mL) (P <.0001). Similar changes in the serum VEGF also developed in the sham-operated animals. The serum bFGF (day 1 median, 15.5 pg/mL; range, 1-42 pg/mL) did not change with time. Immunohistochemistry showed that the VEGF antigen was localized to monocytes, endothelial cells, and spindle-shaped cells within the thrombus. The bFGF antigen was localized to mononuclear cells and spindle-shaped cells and was also present in the extracellular matrix.

CONCLUSIONS

VEGF and bFGF are found in organizing thrombi and have characteristic temporal expression patterns, which suggest that they have a role in thrombus resolution. Augmenting angiogenic growth factor expression may enhance thrombus recanalization, thus reducing long-term complications.

Social isolation contributes to the development of obesity and insulin-independent diabetes in KKA(y) mice. Here we show that systemic administration of liraglutide, a long-acting human glucagon-like peptide-1 (GLP-1) analog, significantly decreased food intake, body weight, and blood glucose levels at 24 h after its administration while having no significant effects on plasma insulin and glucagon levels in individually housed KKA(y) mice. In addition, the systemic administration of liraglutide significantly increased plasma <em>fibroblast</em> <em>growth</em> <em>factor</em> (Fgf) <em>21</em> levels (1.8-fold increase) associated with increases in the expression of hepatic Fgf<em>21</em> (1.9-fold increase) and Pparγ (1.8-fold increase), while having no effects on the expression of hepatic Pparα and Fgf<em>21</em> in white adipose tissue. Moreover, systemic administration of liraglutide over 3 days significantly suppressed food intake, body weight gain, and hyperglycemia in KKA(y) mice. On the other hand, despite remarkably increased plasma active GLP-1 levels (4.2-fold increase), the ingestion of alogliptin, a selective dipeptidyl peptidase-4 inhibitor, over 3 days had no effects on food intake, body weight, blood glucose levels, and plasma Fgf<em>21</em> levels in KKA(y) mice. These findings suggest that systemic administration of liraglutide induces hepatic Fgf<em>21</em> production and suppresses the social isolation-induced obesity and diabetes independently of insulin, glucagon, and active GLP-1 in KKA(y) mice.

BACKGROUND

The fibroblast growth factor 23 (FGF23) is the most important hormonal regulator of circulating phosphate levels. Apart from this essential role, it may also act as a 'hormone-like' factor involved in glucose and lipid metabolism. It is believed to have a potential role in the development of insulin resistance.

OBJECTIVE

The aim of the study was to compare FGF23 levels between two groups of obese adolescents: insulin resistant and non-insulin resistant.

METHODS

The study included 36 obese, insulin-resistant adolescents (21 boys and 15 girls) of pubertal age (mean age, 13.95 years; Tanner stage IV or V). The control group consisted of 21 obese peers with normal HOMA-IR values.

METHODS

FGF23 levels were measured in a fasting blood sample by Human Intact FGF-23 ELISA Kit (Immunotopics Inc., San Clemente, CA, USA). A standard oral glucose tolerance test was performed, which assessed fasting and 120 min postload plasma glucose and serum insulin levels; the insulin resistance index HOMA-IR was calculated. The definition of insulin resistance was based on a HOMA-IR threshold set for adolescents >> or = 3.16).

RESULTS

There was a significant inverse correlation between FGF23 levels and HOMA-IR (R = -0.26, p < 0.05) in the study group. FGF23 levels were also significantly lower in the study group (9.8 vs. 11.9 pg/mL, p = 0.026).

CONCLUSIONS

In adolescents with simple obesity and insulin resistance, FGF23 levels are lower compared with obese adolescents with normal HOMA-IR.

OBJECTIVE

To identify pathogenic and/or disease-specific short peptides in sera from patients with systemic sclerosis (SSc).

METHODS

Serum samples from 40 patients with SSc, 30 patients with systemic lupus erythematosus, <em>21</em> patients with rheumatoid arthritis, 30 patients with osteoarthritis, and 26 healthy donors were tested. Short peptides with molecular weights of smaller than approximately 3 kd, purified from the sera by magnetic bead-based hydrophobic interaction chromatography 18, were detected and their amino acid sequences determined using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Effects of the identified peptides on <em>fibroblasts</em> and microvascular endothelial cells were tested using synthesized peptides and sera containing the peptides.

RESULTS

A group of peptides with mass/charge (m/z) values of 1,865, 1,778, 1,691, 1,563, and 1,450 were detected predominantly in the SSc sera. These peptides were identified as family members of complement C3f-des-arginine (DRC3f) derived from C3b. The level of DRC3f (m/z 1,865) was related to vascular involvement in SSc and to SSc disease activity. The synthesized peptides of DRC3f and C3f, as well as the filtrated sera containing DRC3f, enhanced proliferation of microvascular endothelial cells, but not fibroblasts. Both DRC3f and C3f increased production of transforming growth factor beta1 by dermal microvascular endothelial cells.

CONCLUSIONS

This comprehensive peptidomics analysis revealed the predominance of DRC3f in the sera of patients with SSc. Investigation of DRC3f may be a useful tool for the diagnosis and evaluation of disease activity in SSc. Moreover, its demonstrated effects on endothelial cells suggest a potential role for DRC3f in the pathophysiologic mechanisms of SSc.

The objectives of this investigation were (1) to characterize the <em>growth</em> <em>factor</em> release profile of a basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF)-coated three-dimensional (3D) polymer scaffold under static and cyclically strained conditions, and (2) to delineate the individual and collective contributions of locally released bFGF and mechanical strain on cellular morphology and gene expression in this 3D system. Scaffolds were treated with I(125)-bFGF and subjected to mechanical strain or maintained in a static environment and the media sampled for <em>factor</em> release over a period of 6 days. Over the first 10 hours, a burst release of 25% of the incorporated <em>growth</em> <em>factor</em> into the surrounding media was noted. At 24 hours, approximately 40% of the bFGF was released into the media, after which steady state was achieved and minimal subsequent release was noted. Mechanical stimulation had no effect on <em>growth</em> <em>factor</em> release from the scaffold in this system. To test the concerted effects of bFGF and mechanical stimulation on bone marrow stromal cells (BMSCs), scaffolds were loaded with 0, 100, or 500 ng of bFGF, seeded with cells, and subjected to mechanical strain or maintained in a static environment. Scaffolds were harvested at 1, 7, and <em>21</em> days for RT-PCR and histomorphometry. All scaffolds subjected to <em>growth</em> <em>factor</em> and/or mechanical stimulation demonstrated cellular adherence and spreading at <em>21</em> days. Conversely, in the absence of both bFGF and mechanical stimulation, cells demonstrated minimal cytoplasmic spread. Moreover, at <em>21</em> days, cells subjected to both mechanical stimulation and bFGF (500 ng) demonstrated the highest upregulation of stress-resistive (collagen I, III) and stress-responsive proteins (tenascin-C). The effect of <em>growth</em> <em>factor</em> may be dose sensitive, however, as unstrained scaffolds treated with 100 ng of bFGF demonstrated upregulation of gene expression comparable to strained scaffolds treated with lower doses of bFGF (0 or 100 ng). In conclusion, results from this study suggest that the stimulatory effects of bFGF are dose sensitive and appear to be influenced by the addition of mechanical strain. The concurrent application of biochemical and mechanical stimuli may be important in promoting the adaptation of BMSCs and driving the transcription of genes essential for synthesis of a functional ligament replacement tissue.

We reported induction of broad-spectrum chemoresistance by acidic and basic <em>fibroblast</em> <em>growth</em> <em>factors</em> and chemosensitization by their nonspecific inhibitor suramin at nontoxic and subtherapeutic doses. This study evaluated whether low-dose suramin enhances paclitaxel activity in chemotherapy-naïve and paclitaxel-pretreated human MCF7 breast xenograft tumors in mice. Suramin, 10 mg/kg, and/or paclitaxel, 15 mg/kg, were administered intravenously, twice weekly for 2 to 3 weeks. In addition to conventional end points [tumor size change, median survival time (MST)], we also used clinically relevant end points [partial (PR) and complete response rates (CR); progressive disease (PD); stable disease (SD); time to tumor progression (TTP)]. In chemotherapy-naïve mice, the control and suramin groups showed identical TTP (3 days) and MST (<em>21</em> days). Single-agent paclitaxel produced 47% PR and 24% CR, and prolonged both TTP and MST to 73 days. The addition of suramin further improved the total response rate to 100% with a dramatically greater 63% CR, shortened the time to attain PR and CR, and prolonged TTP and MST to>> or =136 days. In the paclitaxel-pretreated group, single-agent paclitaxel resulted in 67% SD and 33% PD, whereas the combination produced 50% PR and 50% SD. Suramin also significantly enhanced the apoptotic effect of paclitaxel in tumors. In conclusion, suramin improved the activity of paclitaxel in both chemotherapy-naïve and paclitaxel-pretreated animals, without enhancing host toxicity (< or =10% body weight loss in all groups). These data have led to the initiation of phase I/II trials of paclitaxel and low-dose suramin combination in advanced metastatic breast cancer patients.

Mesangial cells in diabetic mice and human kidneys with diabetic nephropathy exhibit increased type VIII collagen, a nonfibrillar protein that exists as a heterodimer composed of α1(VIII) and α2(VIII), encoded by Col8a1 and Col8a2, respectively. Because TGF-β1 promotes the development of diabetic glomerulosclerosis, we studied whether type VIII collagen modulates the effects of TGF-β1 in mesangial cells. We obtained primary cultures of mesangial cells from wild-type, doubly heterozygous (Col8a1(+/-)/Col8a2(+/-)), and double-knockout (Col8a1(-/-)/Col8a2(-/-)) mice. TGF-β1 bound normally to double-knockout mesangial cells. In wild-type mesangial cells, TGF-β1 inhibited proliferation, but in double-knockout cells, it stimulated proliferation, promoted cell cycle progression, and reduced apoptosis; we could reverse this effect by reconstituting α1(VIII). Furthermore, in wild-type cells, TGF-β1 mainly stimulated the Smad pathways, whereas in double-knockout cells, it activated the MAPK and PI3K/Akt pathways and induced expression of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>). Inhibiting FGF<em>21</em> expression by either interfering with activation of the MAPK and PI3K/Akt pathways or by FGF<em>21</em> siRNA attenuated the TGF-β1-induced proliferation of double-knockout mesangial cells. In vivo, diabetic double-knockout mice had significantly higher expression of renal FGF<em>21</em> mRNA and protein compared with diabetic wild-type mice. Immunohistochemistry revealed strong expression of FGF<em>21</em> in both glomerular (mesangial) and tubular cells of diabetic mice. Taken together, these data suggest that type VIII collagen significantly modulates the effect of TGF-β1 on mesangial cells and may therefore play a role in the pathogenesis of diabetic nephropathy.

Loss of intestinal CD4(+) T cells was associated with decreased production of several T-helper 1 (TH1) and TH2 cytokines and increased production of interleukin 17 (IL-17), gamma interferon (IFN-γ), CCL4, and granulocyte-macrophage colony-stimulating <em>factor</em> (GM-CSF) by CD8(+) T cells <em>21</em> days after simian immunodeficiency virus (SIV) infection in rhesus macaques. Shifting of mucosal TH1 to TH2 or T-cytotoxic 1 (TC1) to TC2 cytokine profiles was not evident. Additionally, both CD4(+) and CD8(+) T cells showed upregulation of macrophage migration inhibition <em>factor</em> (MIF) and basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF-basic) cytokines that have been linked to HIV disease progression.