An observational study evaluating the efficacy of microfragmented adipose tissue in the treatment of osteoarthritis.

Aim: Osteoarthritis (OA) prevalence is increased in ageing and obese populations. This prospective single-arm cohort study aimed to investigate the efficacy of autologous microfragmented adipose tissue treatment of severe knee or shoulder OA. Materials & methods: Participants received an intra-articular microfragmented adipose tissue injection to the affected joint(s). Multiple patient reported outcome measures (PROMS) were recorded from 0 to 52 weeks for 63 consecutive joints. Results: Compared with baseline, there were significant improvements in all PROMS from 2 to 12 weeks and maintained at 52 weeks. Regression analysis revealed an inverse correlation with BMI and change in PROMS for knee joints. Conclusion: Our observed findings suggest this approach represents a safe, effective treatment for moderate-to-severe knee and shoulder OA, although efficacy may be reduced with increasing obesity.

Swelling and pain in the joints is common and found more often in older and overweight people. Osteoarthritis causes swelling and pain in joints because of a loss of tough, flexible tissue called cartilage. This study looks to see if injection of fat tissue into knee or shoulder joints can improve symptoms. The fat tissue used was called microfragmented adipose tissue (MFAT). This uses a technique to break down the fat tissue before injection. These cells were from the patient's own body. All patients had an injection of MFAT into their painful joints. In total, 59 patients took part. Reports were directly collected from the patient of how well they were doing. This was done before and after the injection at weeks 2, 6, 12, 24 and 52. There were three different types of report collected for knee joints and three for shoulder joints. Scores were then compared from these reports to see if there was a difference. An improvement was found in all three of the combined reports for both knees and shoulders. This stayed until 52 weeks. BMI is a measure of body weight in relation to height. Patients with a higher BMI were found to have had a smaller improvement in their scores. This study shows MFAT injections are safe and effective in treating painful joints.

The impact of obesity and uncontrolled asthma during pregnancy on metabolic and inflammatory pathways.

OBJECTIVE: Asthma and obesity are both inflammatory complications of pregnancy and when combined contribute to an increased risk of uncontrolled asthma during pregnancy and poor perinatal outcomes. Our previous work has identified the presence of maternal asthma is associated with a proinflammatory milieu in the placenta and reduced fetal growth. The current study was designed to determine the relationships between immunomodulatory metabolic pathways and inflammation and establish whether these pathways are associated with uncontrolled asthma in obese pregnant women. METHODS: Fifty-three obese (BMI >30) pregnant women were recruited prospectively. Participants were classified as having no asthma, controlled asthma, and uncontrolled asthma based on a doctor diagnosis and assessment using the Asthma Control Questionnaire (ACQ). Circulating plasma concentrations of metabolic hormones leptin, adiponectin, insulin, glucose, and extracellular vesicle (EVs) associated cytokines were measured at 18- and 36-weeks gestation. RESULTS: Concentrations of metabolic and inflammatory markers among obese participants with or without asthma were not significantly different throughout gestation. However total adiponectin concentrations increased as gestation progressed in obese, non-asthmatic women but did not increase in women with asthma. Plasma adiponectin and leptin levels in women with uncontrolled asthma were positively correlated with EV inflammatory markers including GM-CSF, IL-6, TNFα and IFNγ protein. CONCLUSIONS: This study demonstrated that most metabolic markers remain unchanged with the presence and severity of asthma in obese pregnant women. However, differences in the associations between metabolic and inflammatory pathways were observed in women with asthma and may be one of the mechanisms contributing to uncontrolled asthma in obese pregnant women.

Vitamin C protects against hypoxia, inflammation, and ER stress in primary human preadipocytes and adipocytes.

Dysregulation of adipose tissue involves increased cellular hypoxia, ER stress, and inflammation and altered adipokine production, contributing to the aetiology of obesity-related diseases including type 2 diabetes and cardiovascular disease. This study aimed to investigate the effects of Vitamin C supplementation on these processes in primary human preadipocytes and adipocytes. Treatment of preadipocytes and adipocytes with the proinflammatory cytokine TNFα and palmitic acid (PA), to mimic the obesogenic milieu, significantly increased markers of hypoxia, ER stress and inflammation and reduced secretion of high molecular weight (HMW) adiponectin. Importantly, Vitamin C abolished TNFα+PA induced hypoxia and significantly reduced the increases in ER stress and inflammation in both cell types. Vitamin C also significantly increased the secretion of HMW adiponectin from adipocytes. These findings indicate that Vitamin C can reduce obesity-associated cellular stress and thus provide a rationale for future investigations.

Muscle-specific overexpression of AdipoR1 or AdipoR2 gives rise to common and discrete local effects whilst AdipoR2 promotes additional systemic effects.

Hypoadiponectinemia and adiponectin resistance are implicated in the aetiology of obesity-related cardiometabolic disorders, hence represent a potential therapeutic axis. Here we characterised the effects of in vivo electrotransfer-mediated overexpression of the adiponectin receptors, AdipoR1 or AdipoR2, into tibialis anterior muscle (TAM) of lean or obese mice. In lean mice, TAM-specific overexpression of AdipoR1 (TAMR1) or AdipoR2 (TAMR2) increased phosphorylation of AMPK, AKT and ERK and expression of the insulin responsive glucose transporter glut4. In contrast, only TAMR2 increased pparα and a target gene acox1. These effects were decreased in obese mice despite no reduction in circulating adiponectin levels. TAMR2 also increased expression of adipoQ in TAM of lean and obese mice. Furthermore, in obese mice TAMR2 promoted systemic effects including; decreased weight gain; reduced epididymal fat mass and inflammation; increased epididymal adipoQ expression; increased circulating adiponectin. Collectively, these results demonstrate that AdipoR1 and AdipoR2 exhibit overlapping and distinct effects in skeletal muscle consistent with enhanced adiponectin sensitivity but these appear insufficient to ameliorate established obesity-induced adiponectin resistance. We also identify systemic effects upon TAMR2 in obese mice and postulate these are mediated by altered myokine production. Further studies are warranted to investigate this possibility which may reveal novel therapeutic approaches.

Ectodermal-Neural Cortex 1 Isoforms Have Contrasting Effects on MC3T3-E1 Osteoblast Mineralization and Gene Expression.

The importance of Wnt pathway signaling in development of bone has been well established. Here we investigated the role of a known Wnt target, ENC1 (ectodermal-neural cortex 1; NRP/B), in osteoblast differentiation. Enc1 expression was detected in mouse osteoblasts, chondrocytes, and osteocytes by in situ hybridization, and osteoblastic expression was verified in differentiating primary cultures and MC3T3-E1 pre-osteoblast cells, with 57 kDa and 67 kDa ENC1 protein isoforms detected throughout differentiation. Induced knockdown of both ENC1 isoforms reduced alkaline phosphatase staining and virtually abolished MC3T3-E1 mineralization. At culture confluence, Alpl (alkaline phosphatase liver/bone/kidney) expression was markedly reduced compared with control cells, and there was significant and coordinated alteration of other genes involved in cellular phosphate biochemistry. In contrast, with 67 kDa-selective knockdown mineralized nodule formation was enhanced and there was a two-fold increase in Alpl expression at confluence. There was enhanced expression of Wnt/ß-catenin target genes with knockdown of both isoforms at this time-point and a five-fold increase in Frzb (Frizzled related protein) with 67 kDa-selective knockdown at mineralization, indicating possible ENC1 interactions with Wnt signaling in osteoblasts. These results are the first to demonstrate a role for ENC1 in the control of osteoblast differentiation. Additionally, the contrasting mineralization phenotypes and transcriptional patterns seen with coordinate knockdown of both ENC1 isoforms vs selective knockdown of 67 kDa ENC1 suggest opposing roles for the isoforms in regulation of osteoblastic differentiation, through effects on Alpl expression and phosphate cellular biochemistry. This study is the first to report differential roles for the ENC1 isoforms in any cell lineage. J. Cell. Biochem. 118: 2141-2150, 2017. © 2016 Wiley Periodicals, Inc.

Identification of carboxypeptidase X (CPX)-1 as a positive regulator of adipogenesis.

Adipose tissue expansion occurs through a combination of hypertrophy of existing adipocytes and generation of new adipocytes via the process of hyperplasia, which involves the proliferation and subsequent differentiation of preadipocytes. Deficiencies in hyperplasia contribute to adipose tissue dysfunction and the association of obesity with chronic cardiometabolic diseases. Thus, increased understanding of hyperplastic pathways may be expected to afford novel therapeutic strategies. We have reported that fibroblast growth factor (FGF)-1 promotes proliferation and differentiation of human preadipocytes and recently demonstrated that bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) is a central, proximal effector. Herein, we describe the identification and characterization of carboxypeptidase X (CPX)-1, a secreted collagen-binding glycoprotein, as a novel downstream effector in human primary and Simpson-Golabi-Behmel syndrome preadipocytes. CPX-1 expression increased after treatment of preadipocytes with FGF-1, BAMBI knockdown, or induction of differentiation. CPX-1 knockdown compromised preadipocyte differentiation coincident with reduced collagen expression. Furthermore, preadipocytes differentiated on matrix derived from CPX-1 knockdown cells exhibited reduced Glut4 expression and insulin-stimulated glucose uptake. Finally, CPX-1 expression was increased in adipose tissue from obese mice and humans. Collectively, these findings establish CPX-1 as a positive regulator of adipogenesis situated downstream of FGF-1/BAMBI that may contribute to hyperplastic adipose tissue expansion via affecting extracellular matrix remodeling.-Kim, Y.-H., Barclay, J. L., He, J., Luo, X., O'Neill, H. M., Keshvari, S., Webster, J. A., Ng, C., Hutley, L. J., Prins, J. B., Whitehead, J. P. Identification of carboxypeptidase X (CPX)-1 as a positive regulator of adipogenesis.

Development of an enzyme-linked immunosorbent assay for thrombospondin-1 and comparison of human plasma and serum concentrations.

BACKGROUND: Thrombospondin-1 (TSP-1) is a circulating matricellular glycoprotein produced from many cell types including platelets. Currently TSP-1 is measured in either plasma or serum, using expensive commercial assays. AIM: To develop and validate a cost effective in-house immunoassay for human TSP-1 suitable for quantitating levels from both plasma and serum. METHODS: An in-house enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of human TSP-1. Sixteen healthy volunteers (8 male and 8 female), mean age 29 years (range 21-49), body mass index (BMI) mean 23.3 kg/m(2) (range 17.3-26.7) had non-fasted venous blood sampled at 0800 h and 1600 h for both plasma and serum TSP-1. RESULTS: The assay limit of quantitation was 7.8 µg/L, inter assay CV was 17-31%, intra assay CV was 3-4% for plasma and <9% for serum. Plasma TSP-1 ranged from 133 to 478 µg/L (mean concentration 290 µg/L) in normal volunteers. Serum TSP-1 was approximately 100-fold higher, ranging from 13,700 to 44,400 µg/L (mean concentration 257,00 µg/L). There was no correlation between plasma and serum TSP-1. CONCLUSIONS: TSP-1 can be readily measured in human plasma using ELISA. Serum concentrations are 100-fold higher, reflecting documented TSP-1 release by platelets, and does not provide a meaningful measure of circulating concentrations.

Thrombospondin-1 is a glucocorticoid responsive protein in humans.

OBJECTIVE: Thrombospondin-1 (TSP1) is a matricellular protein whose gene expression has previously been shown to increase acutely after exposure to dexamethasone in vitro. The aim of this study was to determine if TSP1 is altered by acute and chronic states of glucocorticoid excess in human subjects. DESIGN AND METHODS: Three studies have been undertaken to assess the difference or change in TSP1 in response to altered glucocorticoid activity: i) an acute interventional study assessed the effects of a single 4 mg dose of dexamethasone in 20 healthy volunteers; ii) a cross-sectional study compared plasma TSP1 in 20 healthy volunteers and eight patients with Cushing's syndrome; iii) an interventional study assessed the effect on plasma TSP1 of an increase in hydrocortisone dose from ≤20 mg/day to 30 mg/day for 7 days in 16 patients with secondary adrenal insufficiency. RESULTS: In healthy volunteers, 4 mg dexamethasone significantly increased peripheral blood mononuclear cell (PBMC) TSP1 mRNA levels (P<0.0001) and plasma TSP1 concentrations (P<0.0001), peaking at 12 h. Median (interquartile range) plasma TSP1 was higher in Cushing's, 638 (535-756) ng/ml, than in healthy volunteers, 272 (237-336) ng/ml (P<0.0001). Plasma TSP1 >400 ng/ml diagnosed Cushing's syndrome with sensitivity of 100% and specificity of 85%. The higher hydrocortisone dose increased plasma TSP1 from 139 (86-199) to 256 (133-516) ng/ml, (P<0.01) in patients with secondary adrenal insufficiency. CONCLUSIONS: TSP1 is a glucocorticoid responsive protein in humans. Further research is required to determine if plasma TSP1 has a role as a glucocorticoid biomarker.

Fibroblast growth factor-1 (FGF-1) promotes adipogenesis by downregulation of carboxypeptidase A4 (CPA4) - a negative regulator of adipogenesis implicated in the modulation of local and systemic insulin sensitivity.

Fibroblast growth factor-1 (FGF-1) promotes differentiation of human preadipocytes into mature adipocytes via modulation of a BMP and Activin Membrane-Bound Inhibitor (BAMBI)/Peroxisome proliferator-activated receptor (PPARγ)-dependent network. Here, we combined transcriptomic and functional investigations to identify novel downstream effectors aligned with complementary analyses of gene expression in human adipose tissue to explore relationships with insulin sensitivity. RNA-Seq and qRT-PCR analysis revealed significant down-regulation of carboxypeptidase A4 (CPA4) following FGF-1 treatment or induction of differentiation of human preadipocytes in a BAMBI/PPARγ-independent manner. siRNA-mediated knockdown of CPA4 resulted in enhanced differentiation of human preadipocytes. Furthermore, expression of CPA4 in subcutaneous adipose tissue correlated negatively with indices of local and systemic (liver and muscle) insulin sensitivity. These results identify CPA4 as a negative regulator of adipogenesis that is down-regulated by FGF-1 and a putative deleterious modulator of local and systemic insulin sensitivity. Further investigations are required to define the molecular mechanism(s) involved and potential therapeutic opportunities.

Carboxypeptidase X-1 (CPX-1) is a secreted collagen-binding glycoprotein.

Carboxypeptidase X-1 (CPX-1) is an atypical member of the carboxypeptidase (CP) family of proteins involved in a variety of physiological and pathological processes. However, unlike most other family members CPX-1 lacks catalytic activity making its biological function unclear. CPX-1 contains a 160 amino acid discoidin domain (DSD) that serves as a binding domain in other proteins prompting us to investigate a putative functional role for this domain in CPX-1. Sequence alignment confirmed the overarching homology between the DSD of CPX-1 and other DSDs whilst more detailed analysis revealed conservation of the residues known to form the collagen-binding trench within the DSD of the discoidin domain receptors (DDRs) 1 and 2. Biochemical characterisation of transiently expressed human CPX-1 revealed that CPX-1 was secreted in an N-glycosylation-dependent manner as treatment with the N-glycosylation inhibitor tunicamycin inhibited secretion concomitant with a reduction in CPX-1 mobility on Western blot. Using a collagen pull-down assay we found that secreted CPX-1 bound collagen and this appeared independent of N-glycosylation as treatment with PNGaseF did not affect binding. Further analysis under non-reducing and reducing (+DTT) conditions revealed that CPX-1 was secreted in both monomeric and dimeric forms and only the former bound collagen. Finally, mutation of a key residue situated within the putative collagen-binding trench within the DSD of CPX-1 (R192A) significantly reduced secretion and collagen-binding by 40% and 60%, respectively. Collectively these results demonstrate that CPX-1 is a secreted collagen-binding glycoprotein and provide a foundation for future studies investigating the function of CPX-1.

Induction of heme-oxygenase-1 (HO-1) does not enhance adiponectin production in human adipocytes: Evidence against a direct HO-1 - Adiponectin axis.

Adiponectin is a salutary adipokine and hypoadiponectinemia is implicated in the aetiology of obesity-related inflammation and cardiometabolic disease making therapeutic strategies to increase adiponectin attractive. Emerging evidence, predominantly from preclinical studies, suggests induction of heme-oxygenase-1 (HO-1) increases adiponectin production and reduces inflammatory tone. Here, we aimed to test whether induction of HO-1 enhanced adiponectin production from mature adipocytes. Treatment of human adipocytes with cobalt protoporphyrin (CoPP) or hemin for 24-48 h increased HO-1 expression and activity without affecting adiponectin expression and secretion. Treatment of adipocytes with TNFα reduced adiponectin secretion and increased expression and secretion of additional pro-inflammatory cytokines, IL-6 and MCP-1, as well as expression of sXBP-1, a marker of ER stress. HO-1 induction failed to reverse these effects. These results demonstrate that induction of HO-1 does not directly enhance adiponectin production or ameliorate the pro-inflammatory effects of TNFα and argue against a direct HO-1 - adiponectin axis.

Nutrient and immune sensing are obligate pathways in metabolism, immunity, and disease.

The growth and survival of multicellular organisms depend upon their abilities to acquire and metabolize nutrients, efficiently store and harness energy, and sense and fight infection. Systems for sensing and using nutrients have consequently coevolved alongside systems for sensing and responding to danger signals, including pathogens, and share many of the same cell signaling proteins and networks. Diets rich in carbohydrates and fats can overload these systems, leading to obesity, metabolic dysfunction, impaired immunity, and cardiovascular disease. Excessive nutrient intake promotes adiposity, typically altering adipocyte function and immune cell distribution, both of which trigger metabolic dysfunction. Here, we discuss novel mechanistic links between metabolism and immunity that underlie metabolic dysfunction in obesity. We aim to stimulate debate about how the endocrine and immune systems are connected through autocrine, paracrine, and neuroendocrine signaling in sophisticated networks that are only now beginning to be resolved. Understanding the expression and action of signaling proteins, together with modulating their receptors or pattern recognition using agonists or antagonists, will enable rational intervention in immunometabolism that may lead to novel treatments for obesity and metabolic dysfunction.

Characterisation of the adiponectin receptors: Differential cell-surface expression and temporal signalling profiles of AdipoR1 and AdipoR2 are regulated by the non-conserved N-terminal trunks.

The adiponectin axis regulates cardiometabolic and inflammatory tone making it an attractive therapeutic focus. Rudimentary understanding of the adiponectin receptors, AdipoR1 and AdipoR2, constrains our ability to target these atypical seven trans-membrane proteins. Here, we aimed to further elaborate the molecular details governing cell-surface expression and signal transduction by transient expression of AdipoR1 or AdipoR2 in HEK293 cells. Following serum starvation, adiponectin reduced cell-surface expression of both receptors, consistent with internalisation, and promoted phosphorylation of downstream effectors. Temporal phosphorylation profiles differed with AdipoR1 and AdipoR2 transduced signals peaking at 15 min and 24 h. Analysis of receptor chimeras showed that the non-conserved N-terminal trunks (AdipoR1(1-70) and AdipoR2(1-81)) define the temporal signalling profiles and contain multiple regions that promote or inhibit cell-surface expression, respectively. These findings highlight the importance of the non-conserved N-terminal trunks and demonstrate that cell-surface expression of AdipoR1 and AdipoR2 is required for effective coupling to downstream effectors.

The feasibility of an exercise intervention in males at risk of oesophageal adenocarcinoma: a randomized controlled trial.

OBJECTIVE: To investigate the feasibility and safety of a 24-week exercise intervention, compared to control, in males with Barrett's oesophagus, and to estimate the effect of the intervention, compared to control, on risk factors associated with oesophageal adenocarcinoma development. METHODS: A randomized controlled trial of an exercise intervention (60 minutes moderate-intensity aerobic and resistance exercise five days/week over 24 weeks; one supervised and four unsupervised sessions) versus attention control (45 minutes stretching five days/week over 24 weeks; one supervised and four unsupervised sessions) in inactive, overweight/obese (25.0-34.9 kg/m2) males with Barrett's oesophagus, aged 18-70 years. Primary outcomes were obesity-associated hormones relevant to oesophageal adenocarcinoma risk (circulating concentrations of leptin, adiponectin, interleukin-6, tumour necrosis factor-alpha, C-reactive protein, and insulin resistance [HOMA]). Secondary outcomes included waist circumference, body composition, fitness, strength and gastro-oesophageal reflux symptoms. Outcomes were measured at baseline and 24-weeks. Intervention effects were analysed using generalised linear models, adjusting for baseline value. RESULTS: Recruitment was difficult in this population with a total of 33 participants recruited (target sample size: n = 80); 97% retention at 24-weeks. Adherence to the exercise protocol was moderate. No serious adverse events were reported. A statistically significant intervention effect (exercise minus control) was observed for waist circumference (-4.5 [95% CI -7.5, -1.4] cm; p < 0.01). Effects on primary outcomes were not statistically significant. CONCLUSION: This small, exploratory trial provides important information to inform future trial development including recruitment rates and estimates of effect sizes on outcomes related to oesophageal adenocarcinoma risk. Future trials should investigate a combined dietary and exercise intervention to achieve greater weight loss in this population and relax inclusion criteria to maximize recruitment. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12609000401257.

[Differential expression of bone morphogenetic protein and activin membrane-bound inhibitor in mouse adipose tissues and primary preadipocytes].

OBJECTIVE: To investigate the expression profiles of bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) during the development of mouse adipose tissue. METHODS: The total RNA was extracted for real-time PCR for amplification of BAMBI mRNA from the suprascapular brown adipose tissue (BAT) and subcutaneous (inguinal) and visceral (gonadal) white adipose tissue (sWAT and vWAT, respectively) of mice at various embryonic and postnatal stages, as well as from isolated primary preadipocytes during differentiation. RESULTS: In BAT, BAMBI mRNA levels exhibited a transient increase, peaking at day 0 (D0) and declined thereafter. sWAT and vWAT could be isolated from mice from postnatal D21 onwards, in which BAMBI mRNA levels were the highest and decreased at 8 weeks and 6 months. BAMBI mRNA levels were also significantly reduced in primary preadipocytes isolated from vWAT after induced differentiation. BAMBI mRNA expression level was higher in vWAT than in sWAT and BAT at the same developmental stages. CONCLUSION: BAMBI is differentially expressed in different adipose tissues and developmental stages, which supports the hypothesis that BAMBI plays a pivotal role in the development of adipose tissues.

Glycemic control in diabetes is restored by therapeutic manipulation of cytokines that regulate beta cell stress.

In type 2 diabetes, hyperglycemia is present when an increased demand for insulin, typically due to insulin resistance, is not met as a result of progressive pancreatic beta cell dysfunction. This defect in beta cell activity is typically characterized by impaired insulin biosynthesis and secretion, usually accompanied by oxidative and endoplasmic reticulum (ER) stress. We demonstrate that multiple inflammatory cytokines elevated in diabetic pancreatic islets induce beta cell oxidative and ER stress, with interleukin-23 (IL-23), IL-24 and IL-33 being the most potent. Conversely, we show that islet-endogenous and exogenous IL-22, by regulating oxidative stress pathways, suppresses oxidative and ER stress caused by cytokines or glucolipotoxicity in mouse and human beta cells. In obese mice, antibody neutralization of IL-23 or IL-24 partially reduced beta cell ER stress and improved glucose tolerance, whereas IL-22 administration modulated oxidative stress regulatory genes in islets, suppressed ER stress and inflammation, promoted secretion of high-quality efficacious insulin and fully restored glucose homeostasis followed by restitution of insulin sensitivity. Thus, therapeutic manipulation of immune regulators of beta cell stress reverses the hyperglycemia central to diabetes pathology.

GLP-1(28-36)amide, the Glucagon-like peptide-1 metabolite: friend, foe, or pharmacological folly?

The glucagon-like peptide-1 (GLP-1) axis has emerged as a major therapeutic target for the treatment of type 2 diabetes. GLP-1 mediates its key insulinotropic effects via a G-protein coupled receptor expressed on ß-cells and other pancreatic cell types. The insulinotropic activity of GLP-1 is terminated via enzymatic cleavage by dipeptidyl peptidase-4. Until recently, GLP-1-derived metabolites were generally considered metabolically inactive; however, accumulating evidence indicates some have biological activity that may contribute to the pleiotropic effects of GLP-1 independent of the GLP-1 receptor. Recent reports describing the putative effects of one such metabolite, the GLP-1-derived nonapeptide GLP-1(28-36) amide, are the focus of this review. Administration of the nonapeptide elevates cyclic adenosine monophosphate (cAMP) and activates protein kinase A, ß-catenin, and cAMP response-element binding protein in pancreatic ß-cells and hepatocytes. In stressed cells, the nonapeptide targets the mitochondria and, via poorly defined mechanisms, helps to maintain mitochondrial membrane potential and cellular adenosine triphosphate levels and to reduce cytotoxicity and apoptosis. In mouse models of diet-induced obesity, treatment with the nonapeptide reduces weight gain and ameliorates associated pathophysiology, including hyperglycemia, hyperinsulinemia, and hepatic steatosis. Nonapeptide administration in a streptozotocin-induced model of type 1 diabetes also improves glucose disposal concomitant with elevated insulin levels and increased ß-cell mass and proliferation. Collectively, these results suggest some of the beneficial effects of GLP-1 receptor analogs may be mediated by the nonapeptide. However, the concentrations required to elicit some of these effects are in the micromolar range, leading to reservations about potentially related therapeutic benefits. Moreover, although controversial, concerns have been raised about the potential for incretin-based therapies to promote pancreatitis and pancreatic and thyroid cancers. The effects ascribed to the nonapeptide make it a potential contributor to such outcomes, raising additional questions about its therapeutic suitability. Notwithstanding, the nonapeptide, like other GLP-1 metabolites, appears to be biologically active. Increasing understanding of such noncanonical GLP-1 activities should help to improve future incretin-based therapeutics.

A randomized trial of sodium-restriction on kidney function, fluid volume and adipokines in CKD patients.

BACKGROUND: Dietary sodium restriction is a key management strategy in chronic kidney disease (CKD). Recent evidence has demonstrated short-term reduction in blood pressure (BP) and proteinuria with sodium restriction, however the effect on other cardiovascular-related risk factors requires investigation in CKD. METHODS: The LowSALT CKD study involved 20 hypertensive Stage III-IV CKD patients counselled by a dietitian to consume a low-sodium diet (<100 mmol/day). The study was a randomised crossover trial comparing 2 weeks of high-sodium (additional 120 mmol sodium tablets) and low-sodium intake (placebo). Measurements were taken after each crossover arm including BP (peripheral and central), adipokines (inflammation markers and adiponectin), volume markers (extracellular-to-intracellular [E/I] fluid ratio; N-terminal pro-brain natriuretic peptide [NT-proBNP]), kidney function (estimated Glomerular Filtration Rate [eGFR]) and proteinuria (urine protein-creatinine ratio [PCR] and albumin-creatinine ratio [ACR]). Outcomes were compared using paired t-test for each cross-over arm. RESULTS: BP-lowering benefits of a low-sodium intake (peripheral BP (mean ± SD) 148/82 ± 21/12 mmHg) from high-sodium (159/87 ± 15/10 mmHg) intake were reflected in central BP and a reduction in eGFR, PCR, ACR, NTproBNP and E/I ratio. There was no change in inflammatory markers, total or high molecular weight adiponectin. CONCLUSIONS: Short-term benefits of sodium restriction on BP were reflected in significant change in kidney function and fluid volume parameters. Larger, long-term adequately powered trials in CKD are necessary to confirm these results. TRIAL REGISTRATION: Universal Trial Number U1111-1125-2149 registered on 13/10/2011; Australian New Zealand Clinical Trials Registry Number ACTRN12611001097932 registered on 21/10/2011.

Resveratrol does not benefit patients with nonalcoholic fatty liver disease.

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD), characterized by accumulation of hepatic triglycerides (steatosis), is associated with abdominal obesity, insulin resistance, and inflammation. Although weight loss via calorie restriction reduces features of NAFLD, there is no pharmacologic therapy. Resveratrol is a polyphenol that prevents high-energy diet-induced steatosis and insulin resistance in animals by up-regulating pathways that regulate energy metabolism. We performed a placebo-controlled trial to assess the effects of resveratrol in patients with NAFLD. METHODS: Overweight or obese men diagnosed with NAFLD were recruited from hepatology outpatient clinics in Brisbane, Australia from 2011 through 2012. They were randomly assigned to groups given 3000 mg resveratrol (n = 10) or placebo (n = 10) daily for 8 weeks. Outcomes included insulin resistance (assessed by the euglycemic-hyperinsulinemic clamp), hepatic steatosis, and abdominal fat distribution (assessed by magnetic resonance spectroscopy and imaging). Plasma markers of inflammation, as well as metabolic, hepatic, and antioxidant function, were measured; transcription of target genes was measured in peripheral blood mononuclear cells. Resveratrol pharmacokinetics and safety were assessed. RESULTS: Eight-week administration of resveratrol did not reduce insulin resistance, steatosis, or abdominal fat distribution when compared with baseline. No change was observed in plasma lipids or antioxidant activity. Levels of alanine and aspartate aminotransferases increased significantly among patients in the resveratrol group until week 6 when compared with the placebo group. Resveratrol did not significantly alter transcription of NQO1, PTP1B, IL6, or HO1 in peripheral blood mononuclear cells. Resveratrol was well-tolerated. CONCLUSIONS: Eight weeks administration of resveratrol did not significantly improve any features of NAFLD, compared with placebo, but it increased hepatic stress, based on observed increases in levels of liver enzymes. Further studies are needed to determine whether agents that are purported to mimic calorie restriction, such as resveratrol, are safe and effective for complications of obesity. Clinical trials registration no: ACTRN12612001135808.