Basics about insulin and dedicated research tools

Diabetes is a major health concern. And its research can be a nightmare sometimes. tebu-bio strive to offer a comprehensive range of research tools and services to study Obesity, Diabetes, and Metabolic syndrome (including pancreatic islet cells), and tools to unravel signaling mechanisms in insulin secretion. Anyhow, it might be good, though, to go back to the basics from time to time. Let’s remember our graduate courses (more or less years ago) about Insulin and its biological roles.

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20S Proteasome inhibitors and Leptin against obesity

The World Health Organization (WHO) estimated in 2008 that 1.4 billion adults worldwide were overweight and of these 500 million were obese with risks for developing type 2 diabetes, hypertension and cardio-vascular diseases. The discovery of the adipocyte hormone, Leptin, brought to light the possibility that its anorectic effect could be harnessed for treating the epidemic of obesity. However up until now Leptin resistance has been an unsurmountable problem and the use of this adipokine for suppressing food intake has failed. In a recent issue of Cell, Junli Liu and coworkers at Harvard Medical School report that Celastrol, a natural product isolated from the Thunder God Vine (Tripterygium Wilfordi), is a powerful antiobesity agent.

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Biomarkers of micronutrient malnutrition

Unfortunately, and still in the XXIst century, micronutrient (MN) malnutrition is a problem in all countries, in all segments of society. While part of the world starves, another part is obese. And a balanced diet is still far from being real for many people. Something to think about…

This is a real public health concern, and policies in this area are aimed at preventing, among others, mild, moderate an severe MN malnutrition. Deficiencies in MNs such as iron, vitamin A (VA), iodine, zinc and folic acid are associated with adverse health outcomes, especially in pregnant women and children. For example, VA is critical for embryonic development, adult growth and development, cellular differentiation, immune function, reproduction and vision. On the other hand, low iron levels lead to reduced physical activity in adults and impaired brain development in children. [Read more…]

miRNA and cytokine profiling in hypoxic adipose tissue

In a recent publication, Mennesson E. et al. have developped a smart approach to perform both adipokine protein and miRNA profilings in in vitro adipocyte models mimicking the physiological state of adipose tissues. Adipokines and miRNAs are now known to be involved in adipose tissue metabolism in obesity during which hypoxic adipose tissue development is seen due to tissue mass expansion. Such Cytokine and miRNA profilings are thus needed to better decipher the physiopathology of obesity and to identify new biomarkers.

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Adipokine monitoring during Hunger and Satiety balance

Cytokines and growth factors that are produced by or have an effect on adipocytes and related peptide neuro-transmitters are central players in hunger vs. satiety balance and in eating behavior (1). Recent evidence shows that adipokines, and more generally mediators or indicators of inflammation (2), play roles in the development of insulin resistance (3), diabetes (4) and many other concomittant health problems associated with obesity, including hypertension, dyslipidemia and atherosclerosis (5).

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RhoA/ROCK and F-actin modeling involved in Insulin secretion

This is the conclusion of Liu X. et al. who demonstrated, in a mouse model, that RhoA/ROCK signaling pathway modulates insulin secretion of 3D cultured islet pancreatic ß-cells. This modulation is made through the regulation of Connexin 36.

Cell-permeable C3 transferase (C3T; Cytoskeleton Inc.) and the small molecule Y-27632 ROCK inhibitor (Stemgent-Asterand) were used in these studies.

External links regarding RhoA/ROCK in insulin secretion of pancreatic ß-cells

  • Liu X. et al. “Involvement of RhoA/ROCK in insulin secretion of pancreatic ß-cells in 3D
    Anti RhoA Human in WB analysis Cytoskeleton tebu-bio ARH03

    Western blot detection of RhoA (cat. nr ARH03) in cell extracts (50 µg each) of rat NRK cells (lane 1), human HeLa cells (lane 2), bovine brain extract (lane 3), and human platelet cell extract (lane 4).

    culture” (2014) Cell Tissue Res. DOI: 10.1007/s00441-014-1961-2

  • Cell permeable C3 transferase (cat. nr CT04), inhibits cellular Rho within 2-4h
  • Selective Rho Kinase (ROCK) inhibitors and anti Human RhoA antibody (a Mouse monoclonal that only recognizes RhoA, not RhoB, RhoC, Rac1, Rac2, Rac3, Cdc42 or H-Ras).

I hope you will enjoy this new publication. Don’t hesitate to leave your comments or remarks regarding the use of bioactive small molecules in signal transduction studies.

Adipokines in obesity and glucose homeostasis

Obesity is the abnormal increase in adipose tissue mass. This phenomenon increases the likelyhood of a number of diseases such as heart disease, high blood pressure, type 2 diabetes, obstructive sleep apnea, osteoarthritis, and some kinds of cancer.

Obesity is probably the leading preventable cause of death worldwide. People are considered to be obese if their body mass index (BMI) exceeds a value of 30. The mainstays of treatment of obesity remain dieting and physical exercise.

Nevertheless, adipose tissue (fat) cannot be considered a worthless batch of “lard”, but rather a fascinating vital tissue that in addition to being the body’s major energy reservoir, plays a central role as a secretory organ. Research in this field has already lead to exciting results related to both fat reduction, insulin resistance and to the development of robust tools to study diabetes / obesity.

Adipokines are factors secreted by adipose tissue which carry messages to other parts of the body. I would like to briefly introduce the role of adipokines in the regulation of body weight and glucose homeostasis. [Read more…]

Obesity, Diabetes, Metabolic syndrome new research tools

Insulin and Glucagon are involved in glucose homeostasis in addition to other factors secreted by the adipose tissue (adipokines). Insulin and Glucagon are produced by the endocrine pancreas. While Glucagon is released by alpha-cells of the islets of Langerhans to raise glycemia when blood glucose levels fall too low, Insulin has the opposite effectInsulin is produced by beta-cells of the islets of Langerhans. It allows glucose to be taken up from the bloodstream when blood glucose levels are high and to be used by insulin-dependent tissues (liver, skeletal muscles, fat tissue…).

Let’s take a look at a selection of immuno-assays and primary cells for analysing these two hormones and the recentlly launched primary Human Islet cells.

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