Nicotinamide protects human beta cells against chemically-induced necrosis, but not against cytokine-induced apoptosis

• Published in: Diabetologia Vol. 42; no. 1; pp. 55 - 59
• Main Authors: Hoorens, A., Pipeleers, D.
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.01.1999
• Subjects: Animals; Apoptosis - drug effects; Apoptosis - physiology; Biological and medical sciences; Cell Survival - drug effects; Cells, Cultured; Cytokines - pharmacology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Humans; Hydrogen Peroxide - pharmacology; Interferon-gamma - pharmacology; Interleukin-1 - pharmacology; Islets of Langerhans - cytology; Islets of Langerhans - drug effects; Islets of Langerhans - pathology; Male; Medical sciences; Necrosis; Niacinamide - pharmacology; Rats; Rats, Wistar; Recombinant Proteins - pharmacology; Streptozocin - toxicity; Tumor Necrosis Factor-alpha - pharmacology; Endocrinopathy; Human; Immunopathology; Cytokine; Langerhans islet; Autoimmune disease; B-Vitamins; In vitro; Necrosis; B-Cell; Cell death; Insulin dependent diabetes; Nicotinamide; Protection; Endocrine pancreas; Apoptosis
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s001250051113

Nicotinamide intervention trials are presently undertaken to prevent Type I (insulin-dependent) diabetes in high risk subjects. They are based on studies in rodents reporting nicotinamide protection against beta-cell injury in vitro and in vivo. This study examines whether nicotinamide can protect human beta cells in vitro. At concentrations (2 and 5 mmol/l) to protect rat beta cells against necrosis by streptozotocin or hydrogen peroxide, nicotinamide prevents hydrogen peroxide-induced necrosis of human beta cells. As with rat beta cells, nicotinamide fails to protect human beta cells against apoptosis induced by a combination of the cytokines interleukin-1beta, interferon-gamma and tumour necrosis factor-alpha. In rat beta cells, nicotinamide (2 to 20 mmol/l) was also found to induce apoptosis, in particular during the days following its protection against necrosis; this cytotoxic effect was not observed with human beta cells. These data demonstrate that nicotinamide can protect human beta cells against radical-induced necrosis, but not against cytokine-induced apoptosis. This effect is not associated with a delayed apoptosis as in rat beta cells.