Myostatin inhibits proliferation and insulin-stimulated glucose uptake in mouse liver cells

Myostatin: a potential therapeutic target for metabolic syndrome

Metabolic syndrome is a complex metabolic disorder, its main clinical manifestations are obesity, hyperglycemia, hypertension and hyperlipidemia. Although metabolic syndrome has been the focus of research in recent decades, it has been proposed that the occurrence and development of metabolic syndrome is related to pathophysiological processes such as insulin resistance, adipose tissue dysfunction and chronic inflammation, but there is still a lack of favorable clinical prevention and treatment measures for metabolic syndrome. Multiple studies have shown that myostatin (MSTN), a member of the TGF-β family, is involved in the development and development of obesity, hyperlipidemia, diabetes, and hypertension (clinical manifestations of metabolic syndrome), and thus may be a potential therapeutic target for metabolic syndrome. In this review, we describe the transcriptional regulation and receptor binding pathway of MSTN, then introduce the role of MSTN in regulating mitochondrial function and autophagy, review the research progress of MSTN in metabolic syndrome. Finally summarize some MSTN inhibitors under clinical trial and proposed the use of MSTN inhibitor as a potential target for the treatment of metabolic syndrome.

LncRNAs and Cardiovascular Disease

A novel class of RNA molecule emerged from human transcriptome sequencing studies termed long non-coding RNAs. These RNA molecules differ from other classes of non-coding RNAs such as microRNAs in their sizes, sequence motifs and structures. Studies have demonstrated that long non-coding RNAs play a prominent role in the development and progression of cardiovascular disease. They provide the cell with tiered levels of gene regulation interacting with DNA, other RNA molecules or proteins acting in various capacities to control a variety of cellular mechanisms. Cell specificity is a hallmark of lncRNA studies and they have been identified in macrophages, smooth muscle cells, endothelial cells and hepatocytes. Recent lncRNA studies have uncovered functional micropeptides encoded within lncRNA genes that can have a different function to the lncRNA. Disease associated mutations in the genome tend to occur in non-coding regions signifying the importance of non-coding genes in disease associations. There is a great deal of work to be done in the non-coding RNA field and tremendous therapeutic potential due to their cell type specificity. A better understanding of the functions and interactions of lncRNAs will inevitably have clinical implications.

Myostatin Knockout Regulates Bile Acid Metabolism by Promoting Bile Acid Synthesis in Cattle

Myostatin (MSTN) is a major negative regulator of skeletal muscle mass and causes a variety of metabolic changes. However, the effect of MSTN knockout on bile acid metabolism has rarely been reported. In this study, the physiological and biochemical alterations of serum in MSTN^+/- and wild type (WT) cattle were investigated. There were no significant changes in liver and kidney biochemical indexes. However, compared with the WT cattle, lactate dehydrogenase, total bile acid (TBA), cholesterol, and high-density lipoprotein (HDL) in the MSTN^+/- cattle were significantly increased, and glucose, low-density lipoprotein (LDL), and triglycerides (TG) were significantly decreased, indicating that MSTN knockout affected glucose and lipid metabolism and total bile acids content. Targeted metabolomic analysis of the bile acids and their derivatives was performed on serum samples and found that bile acids were significantly increased in the MSTN^+/- cattle compared with the WT cattle. As the only bile acid synthesis organ in the body, we performed metabolomic analysis on the liver to study the effect of MSTN knockout on hepatic metabolism. Metabolic pathway enrichment analysis of differential metabolites showed significant enrichment of the primary bile acid biosynthesis and bile secretion pathway in the MSTN^+/- cattle. Targeted metabolomics data further showed that MSTN knockout significantly increased bile acid content in the liver, which may have resulted from enhanced bile acid synthesis due to the expression of bile acid synthesis genes, cholesterol 7 alpha-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1), and upregulation in the liver of the MSTN^+/- cattle. These results indicate that MSTN knockout does not adversely affect bovine fitness but regulates bile acid metabolism via enhanced bile acid synthesis. This further suggests a role of MSTN in regulating metabolism.

A comprehensive review of long non-coding RNAs in the pathogenesis and development of non-alcoholic fatty liver disease

One of the most prevalent diseases worldwide without a fully-known mechanism is non-alcoholic fatty liver disease (NAFLD). Recently, long non-coding RNAs (lncRNAs) have emerged as significant regulatory molecules. These RNAs have been claimed by bioinformatic research that is involved in biologic processes, including cell cycle, transcription factor regulation, fatty acids metabolism, and-so-forth. There is a body of evidence that lncRNAs have a pivotal role in triglyceride, cholesterol, and lipoprotein metabolism. Moreover, lncRNAs by up- or down-regulation of the downstream molecules in fatty acid metabolism may determine the fatty acid deposition in the liver. Therefore, lncRNAs have attracted considerable interest in NAFLD pathology and research. In this review, we provide all of the lncRNAs and their possible mechanisms which have been introduced up to now. It is hoped that this study would provide deep insight into the role of lncRNAs in NAFLD to recognize the better molecular targets for therapy.

Long noncoding RNAs in nonalcoholic fatty liver disease and liver fibrosis: state-of-the-art and perspectives in diagnosis and treatment

Nonalcoholic fatty liver disease (NAFLD) significantly impacts global health. Despite considerable research, its pathophysiology remains partially unclear. In addition, selective serum biomarkers of disease diagnosis and progression are missing. Long noncoding RNAs (lncRNAs) are a heterogeneous group of ncRNAs with crucial roles in biological processes underlying the pathophysiology of different human diseases. Recent studies have shown that lncRNA could be associated with the genesis and progression of NAFLD towards the most severe forms. Although the field is still in its infancy, it is tempting to speculate that these transcripts could be used as both diagnostic and therapeutic targets. In this review, we summarize recent findings on lncRNAs in the complex research field of NAFLD.

Effects of dapagliflozin on the serum levels of fibroblast growth factor 21 and myokines and muscle mass in Japanese patients with type 2 diabetes: A randomized, controlled trial

AIMS/INTRODUCTION

Our aims were to examine the add-on effects of a sodium-glucose cotransporter 2 inhibitor, dapagliflozin, compared with existing antidiabetes treatments, on anthropometric/metabolic parameters, the levels of an endocrine regulator, fibroblast growth factor 21 (FGF21); a skeletal muscle mass (SMM) negative regulator, myostatin; and a metabolic regulator, irisin, in patients with type 2 diabetes.

MATERIALS AND METHODS

A total of 54 patients with type 2 diabetes were randomly divided into dapagliflozin and control groups. The dapagliflozin group received dapagliflozin 5 mg/day in addition to conventional therapy for 24 weeks. The primary outcome was the change in the level of serum FGF21 from baseline. The secondary outcomes included changes from baseline in anthropometric/metabolic parameters and serum levels of myostatin and irisin.

RESULTS

Bodyweight decreased in the dapagliflozin group compared with the control group (P < 0.001), but the changes in SMM were not significant between the groups (P = 0.611), thereby elevating the ratio of SMM-to-bodyweight in the dapagliflozin group (P = 0.028). Myostatin levels were significantly decreased (P = 0.010), and irisin levels showed a nearly significant reduction (P = 0.052) in the dapagliflozin group compared with the control group, whereas FGF21 levels did not change significantly from baseline to the end of the intervention in both the dapagliflozin (P = 0.673) and the control (P = 0.823) groups.

CONCLUSIONS

Dapagliflozin add-on therapy in patients with type 2 diabetes reduced myostatin levels significantly and maintained SMM, without significant changes in FGF21 levels.

AdipoRon prevents myostatin-induced upregulation of fatty acid synthesis and downregulation of insulin activity in a mouse hepatocyte line

Liver diseases such as non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are characterized by excess hepatic accumulation of lipid droplets and triglycerides which are associated with defective insulin action. Myostatin (Mstn) and adiponectin, secreted by muscle cells and adipocytes, respectively, play important roles in regulating insulin signaling and energy metabolism. The mechanisms underlying the actions of Mstn and adiponectin remain largely unknown. Moreover, the interactions between Mstn and adiponectin in regulating gene expression critical for fatty acid metabolism and insulin action in hepatocytes have not been investigated. The effects of Mstn and AdipoRon, a synthetic adiponectin receptor agonist that is orally active, alone or in combination, on hepatic gene expression and function was investigated. While Mstn increased fatty acid (FA) accumulation and desensitized cellular responses to insulin, AdipoRon protected against Mstn-induced defects in hepatic gene expression and function. In addition, these effects of Mstn were associated with reduced AMPK and PPARα activities which were reversed by AdipoRon. Finally, AdipoRon was able to prevent Mstn-induced activation of the Smad2/3 pathway. These data suggest crosstalk between Mstn-induced Smad2/3 and adiponectin-induced AMPK/PPARα pathways, which may play important roles in the regulation of hepatic gene expression critical for FA metabolism and insulin signaling. In addition, the data suggest that AdipoRon, as an adiponectin receptor agonist, may serve a therapeutic role to reduce the hepatic contribution to the disorders of fat metabolism and insulin action.

Parallel comparative proteomics and phosphoproteomics reveal that cattle myostatin regulates phosphorylation of key enzymes in glycogen metabolism and glycolysis pathway

MSTN-encoded myostatin is a negative regulator of skeletal muscle development. Here, we utilized the gluteus tissues from MSTN gene editing and wild type Luxi beef cattle which are native breed of cattle in China, performed tandem mass tag (TMT) -based comparative proteomics and phosphoproteomics analyses to investigate the regulatory mechanism of MSTN related to cellular metabolism and signaling pathway in muscle development. Out of 1,315 proteins, 69 differentially expressed proteins (DEPs) were found in global proteomics analysis. Meanwhile, 149 differentially changed phosphopeptides corresponding to 76 unique phosphorylated proteins (DEPPs) were detected from 2,600 identified phosphopeptides in 702 phosphorylated proteins. Bioinformatics analyses suggested that majority of DEPs and DEPPs were closely related to glycolysis, glycogenolysis, and muscle contractile fibre processes. The global discovery results were validated by Multiple Reaction Monitoring (MRM)-based targeted peptide quantitation analysis, western blotting, and muscle glycogen content measurement. Our data revealed that increase in abundance of key enzymes and phosphorylation on their regulatory sites appears responsible for the enhanced glycogenolysis and glycolysis in MSTN-/- . The elevated glycogenolysis was assocaited with an enhanced phosphorylation of Ser1018 in PHKA1, and Ser641/Ser645 in GYS1, which were regulated by upstream phosphorylated AKT-GSK3β pathway and highly consistent with the lower glycogen content in gluteus of MSTN-/- . Collectively, this study provides new insights into the regulatory mechanisms of MSTN involved in energy metabolism and muscle growth.

Sarcopenia in Liver Disease: Current Evidence and Issues to Be sResolved

Sarcopenia is a common clinical symptom in aging and patients with wasting diseases, characterized by a decreased skeletal muscle mass. As a consequence of lifestyle change, the nonalcoholic fatty liver disease (NAFLD) presents a rising trend. In the past three decades, increasing evidence has proved that sarcopenia is related to NAFLD. In this chapter, we will summarize the emerging evidence of the predictive role of sarcopenia in NAFLD and review the diagnosis value, feasible mechanism, and therapy strategies of sarcopenia in NAFLD. Sarcopenia is a potential risk factor for NAFLD, and targeting sarcopenia can benefit NAFLD to some extent.

Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management

An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.

Micromanagement of Immune System: Role of miRNAs in Helminthic Infections

Helminthic infections fall under neglected tropical diseases, although they inflict severe morbidity to human and causes major economic burden on health care system in many developing countries. There is increased effort to understand their immunopathology in recent days due to their immuno-modulatory capabilities. Immune response is primarily controlled at the transcriptional level, however, microRNA-mediated RNA interference is emerging as important regulatory machinery that works at the translation level. In the past decade, microRNA (miRNA/miR) research has advanced with significant momentum. The result is ever increasing list of curated sequences from a broad panel of organisms including helminths. Several miRNAs had been discovered from trematodes, nematodes and cestodes like let-7, miR155, miR-199, miR-134, miR-223, miR-146, and fhe-mir-125a etc., with potential role in immune modulation. These miRs had been associated with TGF-β, MAPK, Toll-like receptor, PI3K/AKT signaling pathways and insulin growth factor regulation. Thus, controlling the immune cells development, survival, proliferation and death. Apart from micromanagement of immune system, they also express certain unique miRNA also like cis-miR-001, cis-miR-2, cis-miR-6, cis-miR-10, cis-miR-18, cis-miR-19, trs-mir-0001, fhe-miR-01, fhe-miR-07, fhe-miR-08, egr-miR-4988, egr-miR-4989 etc. The specific role played by most of these species specific unique miRs are yet to be discovered. However, these newly discovered miRNAs might serve as novel targets for therapeutic intervention or biomarkers for parasitic infections.

Long noncoding RNA expression profile of infantile hemangioma identified by microarray analysis

Infantile hemangioma (IH) is one of the most common vascular tumors of childhood. Long noncoding RNAs (lncRNAs) play a critical role in angiogenesis, but their involvement in hemangioma remains unknown. This study aimed to assess the expression profiles of lncRNAs in IH and adjacent normal tissue samples, exploring the biological functions of lncRNAs as well as their involvement in IH pathogenesis. The lncRNA expression profiles were determined by lncRNA microarrays. A total of 1259 and 857 lncRNAs were upregulated and downregulated in IH, respectively, at a fold change cutoff of 2.0 (p < 0.05); in addition, 1469 and 1184 messenger RNAs (mRNAs) were upregulated and downregulated, respectively (fold change cutoff of 2.0; p < 0.05). A total of 292 differentially expressed mRNAs were targeted by the lncRNAs with altered expression in hemangioma, including 228 and 64 upregulated and downregulated, respectively (cutoff of 2.0, p < 0.05). Gene ontology (GO) analyses revealed several angiogenesis-related pathways. An lncRNA-mRNA co-expression network for differentially expressed lncRNAs revealed significant associations of the lncRNAs MEG3, MEG8, FENDRR, and Linc00152 with their related mRNAs. The validation results of nine differentially expressed lncRNAs (MALAT1, MEG3, MEG8, p29066, p33867, FENDRR, Linc00152, p44557_v4, p8683) as well as two mRNAs (FOXF1, EGFL7) indicated that the microarray data correlated well with the QPCR results. Interestingly, MALAT1 knockdown induced apoptosis and S-phase cell cycle arrest in human umbilical vein endothelial cells (HUVECs). Overall, this study revealed the lncRNA expression profile of IH and that lncRNAs likely regulate several genes with important roles in angiogenesis.

2-Deoxyglucose Reverses the Promoting Effect of Insulin on Colorectal Cancer Cells In Vitro

An increased risk of colorectal cancer is related to the development of metabolic syndromes including hyperglycemia, and hyperinsulinemia. The high circulatory levels of glucose and/or insulin or the application of exogenous insulin may promote carcinogenesis, cancer progression and metastasis, which can be attributed to the Warburg effect or aerobic glycolysis. We attempted to resolve these existing questions by applying the glucose analog 2-deoxyglucose (2DG). According to the in vitro studies we performed, the glycolysis of colorectal cancer cells could be interrupted by 2DG as it decreased the cellular productions of ATP and lactate. In addition, 2DG induced apoptosis and cell cycle arrest, and inhibited proliferation, migration and invasion of these cells. Since insulin can stimulate the cellular uptake of hexose, including 2DG, the combination of 2DG and insulin improved the cytotoxicity of 2DG and meanwhile overcame the cancer-promoting effects of insulin. This in vitro study provided a viewpoint of 2DG as a potential therapeutic agent against colorectal cancer, especially for patients with concomitant hyperinsulinemia or treated with exogenous insulin.

Long noncoding RNA MALAT1 promotes hepatic steatosis and insulin resistance by increasing nuclear SREBP-1c protein stability

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is implicated in liver cell proliferation. However, its role in hepatic steatosis and insulin resistance remain poorly understood. The aim of this study was to investigate the effects of MALAT1 on hepatic lipid accumulation and its potential targets. As expected, MALAT1 expression is increased in hepatocytes exposed to palmitate and livers of ob/ob mice. Knockdown of MALAT1 expression dramatically suppressed palmitate-induced lipid accumulation and the increase of nuclear SREBP-1c protein in HepG2 cells. In addition, RNA immunoprecipitation and RNA pull-down assay confirmed that MALAT1 interacted with SREBP-1c to stabilize nuclear SREBP-1c protein. Finally, injection of si-MALAT1 prevented hepatic lipid accumulation and insulin resistance in ob/ob mice. In conclusion, our observations suggest that MALAT1 promotes hepatic steatosis and insulin resistance by increasing nuclear SREBP-1c protein stability.

Novel insight into MALAT-1 in cancer: Therapeutic targets and clinical applications

Long non-protein-coding RNAs (lncRNAs) are emerging as important gene expression regulators that are linked to various biological processes at the post-transcriptional and transcriptional levels. lncRNAs are known to be important in cell proliferation, cell differentiation, apoptosis and metastasis. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1), a novel lncRNA, is highly conserved amongst mammals. In addition, it has been considered to act as an oncogene, depending on the tumor system. An increasing number of studies have indicated that MALAT-1 may be detected in certain types of human tumors, including lung and bladder cancer and hepatocellular carcinoma. MALAT-1 silencing may be an effective therapeutic approach against tumors. The present study reviews the current knowledge on the functional role of MALAT-1 in the control of various cancers.

Malat1 as an evolutionarily conserved lncRNA, plays a positive role in regulating proliferation and maintaining undifferentiated status of early-stage hematopoietic cells

Background

The metastasis-associated lung adenocarcinoma transcription 1 (Malat1) is a highly conserved long non-coding RNA (lncRNA) gene. Previous studies showed that Malat1 is abundantly expressed in many tissues and involves in promoting tumor growth and metastasis by modulating gene expression and target protein activities. However, little is known about the biological function and regulation mechanism of Malat1 in normal cell proliferation.

Results

In this study we conformed that Malat1 is highly conserved across vast evolutionary distances amongst 20 species of mammals in terms of sequence, and found that mouse Malat1 expresses in tissues of liver, kidney, lung, heart, testis, spleen and brain, but not in skeletal muscle. After treating erythroid myeloid lymphoid (EML) cells with All-trans Retinoic Acid (ATRA), we investigated the expression and regulation of Malat1 during hematopoietic differentiation, the results showed that ATRA significantly down regulates Malat1 expression during the differentiation of EML cells. Mouse LRH (Lin-Rhodamine^low Hoechst^low) cells that represent the early-stage progenitor cells show a high level of Malat1 expression, while LRB (Lin − Hoechst^Low Rhodamine^Bright) cells that represent the late-stage progenitor cells had no detectable expression of Malat1.

Knockdown experiment showed that depletion of Malat1 inhibits the EML cell proliferation. Along with the down regulation of Malat1, the tumor suppressor gene p53 was up regulated during the differentiation. Interestingly, we found two p53 binding motifs with help of bioinformatic tools, and the following chromatin immunoprecipitation (ChIP) test conformed that p53 acts as a transcription repressor that binds to Malat1’s promoter. Furthermore, we testified that p53 over expression in EML cells causes down regulation of Malat1.

Conclusions

In summary, this study indicates Malat1 plays a critical role in maintaining the proliferation potential of early-stage hematopoietic cells. In addition to its biological function, the study also uncovers the regulation pattern of Malat1 expression mediated by p53 in hematopoietic differentiation. Our research shed a light on exploring the Malat1 biological role including therapeutic significance to inhibit the proliferation potential of malignant cells.

The ACTN3 R577X Polymorphism Is Associated with Cardiometabolic Fitness in Healthy Young Adults

Homozygosity for a premature stop codon (X) in the ACTN3 “sprinter” gene is common in humans despite the fact that it reduces muscle size, strength and power. Because of the close relationship between skeletal muscle function and cardiometabolic health we examined the influence of ACTN3 R577X polymorphism over cardiovascular and metabolic characteristics of young adults (n = 98 males, n = 102 females; 23 ± 4.2 years) from our Assessing Inherent Markers for Metabolic syndrome in the Young (AIMMY) study. Both males and females with the RR vs XX genotype achieved higher mean VO₂ peak scores (47.8 ± 1.5 vs 43.2 ±1.8 ml/O₂/min, p = 0.002) and exhibited higher resting systolic (115 ± 2 vs 105 ± mmHg, p = 0.027) and diastolic (69 ± 3 vs 59 ± 3 mmHg, p = 0.005) blood pressure suggesting a role for ACTN3 in the maintenance of vascular tone. We subsequently identified the expression of alpha-actinin 3 protein in pulmonary artery smooth muscle, which may explain the genotype-specific differences in cardiovascular adaptation to acute exercise. In addition, we utilized targeted serum metabolomics to distinguish between RR and XX genotypes, suggesting an additional role for the ACTN3 R577X polymorphism in human metabolism. Taken together, these results identify significant cardiometabolic effects associated with possessing one or more functional copies of the ACTN3 gene.

A soluble activin receptor type IIB does not improve blood glucose in streptozotocin-treated mice

Type 1 diabetes mellitus (T1DM), or insulin dependent DM, is accompanied by decreased muscle mass. The growth factor myostatin (MSTN) is a negative regulator of muscle growth, and a loss of MSTN signaling has been shown to increase muscle mass and prevent the development of obesity, insulin resistance and lipodystrophic diabetes in mice. The effects of MSTN inhibition in a T1DM model on muscle mass and blood glucose are unknown. We asked whether MSTN inhibition would increase muscle mass and decrease hyperglycemia in mice treated with streptozotocin (STZ) to destroy pancreatic beta cells. After diabetes developed, mice were treated with a soluble MSTN/activin receptor fused to Fc (ACVR2B:Fc). ACVR2B:Fc increased body weight and muscle mass compared to vehicle treated mice. Unexpectedly, ACVR2B:Fc reproducibly exacerbated hyperglycemia within approximately one week of administration. ACVR2B:Fc treatment also elevated serum levels of the glucocorticoid corticosterone. These results suggest that although MSTN/activin inhibitors increased muscle mass, they may be counterproductive in improving health in patients with T1DM.

Myostatin in the placentae of pregnancies complicated with gestational diabetes mellitus

INTRODUCTION

Gestational diabetes mellitus (GDM) is characterised by maternal glucose intolerance and insulin resistance during pregnancy. Myostatin, initially identified as a negative regulator of muscle development may also function in the regulation of placental development and glucose uptake. Myostatin expression in placentae of GDM complicated pregnancies is unknown. However, higher myostatin levels occur in placentae of pregnancies complicated with preeclampsia. We hypothesise that myostatin will be differentially expressed in GDM complicated pregnancies.

METHODS

Myostatin concentrations (ELISA) were evaluated in plasma of presymptomatic women who later developed GDM and compared to plasma of normal glucose tolerant (NGT) women. Furthermore, myostatin protein expression (Western blot) was studied in placentae of pregnant women with GDM (treated with diet or insulin) compared to placentae of NGT women.

RESULTS

No significant difference in myostatin concentration was seen in plasma of pre-symptomatic GDM women compared to NGT women. In placenta significant differences in myostatin protein expressions (higher precursor; p < 0.05and lower dimer: p < 0.005) were observed in GDM complicated compared to NGT pregnancies. Furthermore, placentae of GDM women treated with insulin compared to diet have higher dimer (p < 0.005) and lower precursor (p < 0.05). Compared to lean women, placentae of obese NGT women were lower in myostatin dimer expression (p < 0.05).

DISCUSSION

Myostatin expression in placental tissue is altered under stress conditions (e.g. obesity and abnormal glucose metabolism) found in pregnancies complicated with GDM. We hypothesise that myostatin is active in these placentae and could affect glucose homoeostasis and/or cytokine production thereby altering the function of the placenta.

Novel detection method for chemiluminescence derived from the Kinase-Glo luminescent kinase assay platform: Advantages over traditional microplate luminometers

The efficacy of cellular signal transduction is of paramount importance for the proper functioning of a cell and an organism as a whole. Protein kinases are responsible for much of this transmission and thus have been the focal point of extensive research. While there are numerous commercially available protein kinase assays, the Kinase-Glo luminescent kinase assay (Promega) provides an easy-to-use and high throughput platform for determining protein kinase activity. This assay is said to require the use of a microplate spectrophotometer capable of detecting a luminescent signal. This study shows that:•

The ChemiGenius Bioimaging system (Syngene), typically used for visualizing chemiluminescence from Western blots, provides an alternative detection system for Kinase-Glo luminescence.

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The novel detection system confers an advantage over traditional luminometers, in that it allows visualization of the luminescent wells, which allows for the real-time analysis and correction of experimental errors (i.e. bubble formation).

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Determining kinase kinetics using this detection system produced comparable results to previous studies on the same enzyme (i.e. glycogen synthase kinase 3).