The incretin hormones glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) have recently received much attention for their roles in type 2 diabetes therapy. GLP-1 stimulated insulin secretion in a glucose-dependent manner and is secreted by intestinal L cells. It also regulates blood glucose concentration, stomach motility, appetite, and body weight. These actions are mediated through G-protein-coupled receptors highly expressed on pancreatic beta cells and also exert indirect metabolic actions. Activation of GLP-1 receptors also produces nonglycemic effects in various tissues. The pleiotropic effects of GLP-1 have been recently reported. The mechanisms identified in preclinical studies have potential translational relevance for the treatment of disease. Here, the nonglycemic effects of GLP-1, especially those on the liver, central nervous system, and bone, were reviewed.
Appetite ; Blood Glucose ; Body Weight ; Central Nervous System ; Enteroendocrine Cells ; Glucagon ; Glucagon-Like Peptide 1 ; Incretins ; Insulin ; Insulin-Secreting Cells ; Liver ; Receptors, G-Protein-Coupled ; Stomach

BACKGROUND: Despite a recent breakthough in human islet transplantation for treating type 1 diabetes mellitus, the limited availability of donor pancreases remains a major obstacle. Endocrine cells within the gut epithelium (enteroendocrine cells) and pancreatic beta cells share similar pathways of differentiation during embryonic development. In particular, K-cells that secrete glucose-dependent insulinotropic polypeptide (GIP) have been shown to express many of the key proteins found in beta cells. Therefore, we hypothesize that K-cells can be transdifferentiated into beta cells because both cells have remarkable similarities in their embryonic development and cellular phenotypes. METHODS: K-cells were purified from heterogeneous STC-1 cells originating from an endocrine tumor of a mouse intestine. In addition, a K-cell subclone expressing stable Nkx6.1, called "Kn4-cells," was successfully obtained. In vitro differentiation of K-cells or Kn4-cells into beta cells was completed after exendin-4 treatment and serum deprivation. The expressions of insulin mRNA and protein were examined by RT-PCR and immunocytochemistry. The interacellular insulin content was also measured. RESULTS: K-cells were found to express glucokinase and GIP as assessed by RT-PCR and Western blot analysis. RT-PCR showed that K-cells also expressed Pdx-1, NeuroD1/Beta2, and MafA, but not Nkx6.1. After exendin-4 treatment and serum deprivation, insulin mRNA and insulin or C-peptide were clearly detected in Kn4-cells. The intracellular insulin content was also increased significantly in these cells. CONCLUSION: K-cells are an attractive potential source of insulin-producing cells for treatment of type 1 diabetes mellitus. However, more experiments are necessary to optimize a strategy for converting K-cells into beta cells.
Animals ; Blotting, Western ; C-Peptide ; Diabetes Mellitus, Type 1 ; Embryonic Development ; Endocrine Cells ; Enteroendocrine Cells ; Epithelium ; Female ; Glucokinase ; Humans ; Immunohistochemistry ; Insulin ; Insulin-Secreting Cells ; Intestines ; Islets of Langerhans Transplantation ; Mice ; Pancreas ; Peptides ; Phenotype ; Pregnancy ; Proteins ; RNA, Messenger ; Tissue Donors ; Venoms

A putative polypeptide hormone identified as amylin[islet amyloid polypeptide] is synthesized and co-localized with insulin in B cells of pancreatic islets in several animal species including man. However, there is growing evidence that somatostatin cells are also expressed and contained amylin in the pancreatic islets of the rat The aim of the present study was to investigate the immunocytochemical expression of the amylin within the endocrine pancreas of the man, rabbit and guinea pig, with special reference to the possible ability of islet cells other than insulin cells to synthesize amylin. For this purpose serial sections of the pancreatic islets were stainedimmunocytochemically using anti-amylin, anti-insulin, anti-glucagon, anti-somatostatin antisera. In serial sections of pancreatic islets of the man and rabbit, it was shown that amylin immunoreactivity occurred in insulin-reactive B cells predominantly located in interior of the islets. In contrast, amylin immunoreacivity appeared in glucagon-reactive A cells peripherally located in the islets of the guinea pig. These results suggest that in both the man and rabbit, amylin is synthesized by B cells for subsequent co-secretion with insulin, and that in guinea pig, amylin is synthesized by A cells for co-secretion with glucagon. It thus appears that amylin release may be mediated by different secretory mechanisms according to animal species.
Amyloid ; Animals ; B-Lymphocytes ; Glucagon ; Guinea Pigs* ; Guinea* ; Immune Sera ; Immunohistochemistry ; Insulin ; Islet Amyloid Polypeptide* ; Islets of Langerhans* ; Rats ; Somatostatin-Secreting Cells

BACKGROUND AND OBJECTIVES: Type 1 Diabetes Mellitus (T1DM) is an autoimmune disorder resulting out of T cell mediated destruction of pancreatic beta cells. Immunomodulatory properties of mesenchymal stem cells may help to regenerate beta cells and/or prevent further destruction of remnant, unaffected beta cells in diabetes. We have assessed the ability of umbilical cord derived MSCs (UCMSCs) to differentiate into functional islet cells in vitro. METHODS AND RESULTS: We have isolated UCMSCs and allowed sequential exposure of various inducing agents and growth factors. We characterized these cells for confirmation of the presence of islet cell markers and their functionality. The spindle shaped undifferentiated UCMSCs, change their morphology to become triangular in shape. These cells then come together to form the islet like structures which then grow in size and mature over time. These cells express pancreatic and duodenal homeobox -1 (PDX-1), neurogenin 3 (Ngn-3), glucose transporter 2 (Glut 2) and other pancreatic cell markers like glucagon, somatostatin and pancreatic polypeptide and lose expression of MSC markers like CD73 and CD105. They were functionally active as demonstrated by release of physiological insulin and C-peptide in response to elevated glucose concentrations. CONCLUSIONS: Pancreatic islet like cells with desired functionality can thus be obtained in reasonable numbers from undifferentiated UCMSCs in vitro. This could help in establishing a "very definitive source" of islet like cells for cell therapy. UCMSCs could thus be a game changer in treatment of diabetes.
C-Peptide ; Cell- and Tissue-Based Therapy* ; Diabetes Mellitus, Type 1 ; Genes, Homeobox ; Glucagon ; Glucose ; Glucose Transport Proteins, Facilitative ; Insulin* ; Insulin-Secreting Cells ; Intercellular Signaling Peptides and Proteins ; Islets of Langerhans ; Mesenchymal Stromal Cells* ; Pancreatic Polypeptide ; Somatostatin ; Stem Cells ; Umbilical Cord*

Sex cord tumors with annular tubules are known to originate from the sex cord of embryonic gonads that synthesize Sertoli cells, Leydig cells, granulosa cells, and theca cells of the ovarian stroma, while ovarian small cell carcinoma of the hypercalcemic type is a type of neuroendocrine tumor. Both these tumors are uncommon, potentially malignant neoplasms in children. We report the case of a sex cord tumor with annular tubules in an 11-year-old girl and a case of small cell carcinoma of the hypercalcemic type in a 10-year-old girl. We also discuss the prognosis and management of these tumors.
Carcinoma, Small Cell ; Child* ; Female ; Gonads ; Granulosa Cells ; Humans ; Hypercalcemia ; Leydig Cells ; Male ; Neuroendocrine Tumors ; Ovary* ; Prognosis ; Sertoli Cells ; Theca Cells

Type 2 diabetes (T2D) has been known as 'bi-hormonal disorder' since decades ago, the role of glucagon from alpha-cell has languished whereas beta-cell taking center stage. Recently, numerous findings indicate that the defects of glucagon secretion get involve with development and exacerbation of hyperglycemia in T2D. Aberrant alpha-cell responses exhibit both fasting and postprandial states: hyperglucagonemia contributes to fasting hyperglycemia caused by inappropriate hepatic glucose production, and to postprandial hyperglycemia owing to blunted alpha-cell suppression. During hypoglycemia, insufficient counter-regulation response is also observed in advanced T2D. Though many debates still remained for exact mechanisms behind the dysregulation of alpha-cell in T2D, it is clear that the blockade of glucagon receptor or suppression of glucagon secretion from alpha-cell would be novel therapeutic targets for control of hyperglycemia. Whereas there have not been remarkable advances in developing new class of drugs, currently available glucagon-like peptide-1 and dipeptidyl peptidase-IV inhibitors could be options for treatment of hyperglucagonemia. In this review, we focus on alpha-cell dysfunction and therapeutic potentials of targeting alpha-cell in T2D.
Diabetes Mellitus, Type 2 ; Fasting ; Glucagon ; Glucagon-Like Peptide 1 ; Glucagon-Secreting Cells ; Glucose ; Hyperglycemia ; Hypoglycemia ; Insulin ; Insulin-Secreting Cells ; Receptors, Glucagon

Mullerian inhibiting substance (MIS) is a glycoprotein hormone produced by fetal Sertoli cells that causes regression of the Mullerian ducts in males during sexual differentiation. Cell lines derived from human ovarian epithelium and rodent Leydig cell tumors, which respond to MIS in growth inhibition assays and express the MIS type II receptors (MISR II). But the pathophysiological role of MIS in human ovarian neoplasia development has not yet been fully established. In order to understand its role in pathogenesis of ovarian neoplasia, the expression and localization of the MIS and MISR II were studied in 5 normal ovaries, 11 benign tumors, 9 borderline ovarian malignancies, 40 ovarian malignancies in paraffin embedded tissue and tissue microarrays by using immunohistochemical stain. The results were as follows; 1. The first staining for MIS and MISR II were detected in granulosa cells in primary follicles of normal ovary. Among the growing follicles, larger developing follicles stained more intensely than smaller follicles. 2. In benign ovarian tumors, 8 (72.73%) in MIS and 5 (45.45%) in MISR II out of 11 cases were stained. The intensity scores of staining were 1.18 in MIS and 0.64 in MISR II. 3. In borderline malignancies, 6 (66.67%) in MIS and 7 (77.78%) in MISR II out of 9 cases were stained. The intensity scores of staining were 0.89 in MIS and 1.22 in MISR II. 4. In ovarian malignancies, the expression of MIS and MISR II were 50% (9/18) and 50% (9/18) in epithelial, 92.30% (12/13) and 76.72% (10/13) in germ cell, and 88.9% (8/9) and 100% (9/9) in sex-cord stromal tumors. The intensity scores of MIS and MISR II expression were 0.72 and 0.72 in epithelial, 1.45 and 1.62 in germ cell, and 1.78 and 1.67 in sex-cord stromal tumors. 5. There was significant high expression of MIS and MISR II in non-epithelial (90.91%, 86.36%) than epithelial ovarian cancers (50%, 50%). The scores of expression intensity was also higher in non-elithelial cancers (MIS: 1.67 +/- 0.16 vs 0.72 +/- 0.20, p=0.003, MISR II: 1.64 +/- 0.20 vs 0.72 +/- 0.21, p=0.022). In conlusion, the expression of MIS and MISR II were not different according to the differentiation, but tissue type specific. The frequency of MIS and MISR II expression was higher in non-epithelial cancers, especially in sex-cord stromal tumors. The results of this experiment could be utilized as scientific basis of researches, furthermore clinical applications in diagnosis and treatment of non-epithelial ovarian malignancies.
Anti-Mullerian Hormone* ; Cell Line ; Diagnosis ; Epithelium ; Female ; Germ Cells ; Glycoproteins ; Granulosa Cells ; Humans ; Leydig Cell Tumor ; Male ; Mullerian Ducts ; Ovarian Neoplasms ; Ovary ; Paraffin ; Rodentia ; Sertoli Cells ; Sex Differentiation

The purpose of this study was to examine the ultrastructural characteristic of the normal pylorus mucosa, and their structural changes induced by the ligation of common bile duct of the male rabbits weighing about 1.5 kg each. Experiment animals were divided into normal, sham operation, and experimental groups. Common bile duct ligation was performed under ether anesthesia and anjmals were sacrificed on the 1st, 3rd, 5th, 7th and 14th day after operation. The mucosal specimen of the pylorus, were fixed and embedded with common method. The sections were cut on a LKB-V ultratome, and observed under a JEM 100CX II electron microscope. The results were as follow : 1. In the early stages (1st, 3rd, 5th day groups) following the ligation, surface mucous cells have the various electron densities and shape of the mucous granules. In the late stages (7th, 14th day groups) following the ligation, many surface mucose cells containing numerous electron dense mucous granules are seen. 2. In the early stage of the ligation of bile duct, secretory function of EC cells was depressed, but in the later stage, the cells showed recovered secretory activity. 3. Secretory function of D cells was depressed on the early groups after the ligation of common bile duct, but they showed recovered secretory activity from the late groups after the ligation of the common bile duct. 4. Secretory function of G cells was activated on the early groups after the ligation of common bile duct, but they showed depressed secretory activity from the late groups after the ligation of the common bile duct. Considering the above findings, common bile duct ligation probably causes the dysfunction of the pyloric surface mucous cells that results in delayed mucous formation and secretion, and recovered mucous secretory function on the late stages. EC cells and G cells, depressed the secretory activities on the early stages and recovered on the late stages of the ligation of common bile duct. But D cells in the pyloric mucosa was activated on the early groups after the ligation of common bile duct ligation, but they was depressed secretory activities on the late groups.
Anesthesia ; Animals ; Bile Ducts ; Common Bile Duct* ; Ether ; Gastrin-Secreting Cells ; Humans ; Ligation* ; Male ; Mucous Membrane* ; Pylorus ; Rabbits ; Somatostatin-Secreting Cells

Endocrine disruptors (e.g., polychlorinated biphenyls [PCBs], dichlorodiphenyl-trichloroethane [DDT], dioxin, and some pesticides) are estrogen-like and anti-androgenic chemicals in the environment. They mimic natural hormones, inhibit the action of hormones, or alter the normal regulatory function of the endocrine system and have potential hazardous effects on male reproductive axis causing infertility. Although testicular and prostate cancers, abnormal sexual development, undescended testis, chronic inflammation, Sertoli-cell-only pattern, hypospadias, altered pituitary and thyroid gland functions are also observed, the available data are insufficient to deduce worldwide conclusions. The development of intra-cytoplasmic sperm injection (ICSI) is beyond doubt the most important recent breakthrough in the treatment of male infertility, but it does not necessarily treat the cause and may inadvertently pass on adverse genetic consequences. Many well-controlled clinical studies and basic scientific discoveries in the physiology, biochemistry, and molecular and cellular biology of the male reproductive system have helped in the identification of greater numbers of men with male factor problems. Newer tools for the detection of Y-chromosome deletions have further strengthened the hypothesis that the decline in male reproductive health and fertility may be related to the presence of certain toxic chemicals in the environment. Thus the etiology, diagnosis, and treatment of male factor infertility remain a real challenge. Clinicians should always attempt to identify the etiology of a possible testicular toxicity, assess the degree of risk to the patient being evaluated for infertility, and initiate a plan to control and prevent exposure to others once an association between occupation/toxicant and infertility has been established.
Endocrine Disruptors ; pharmacology ; toxicity ; Environmental Pollutants ; Estrogens ; pharmacology ; toxicity ; Humans ; Infertility, Male ; chemically induced ; epidemiology ; Leydig Cells ; drug effects ; Male ; Reproduction ; drug effects ; Sertoli Cells ; drug effects ; Spermatogenesis ; drug effects

The present study was performed to corroborate our hypothesis that soybean diet or SBTI treatment could stimulate neogenic regeneration of pancreatic beta cells, but also increase insulin synthesis and secretion from the beta cells for correction of hyperglycemia and diabetic symptoms. We, thus, monitored the beta cell regeneration in the neogenic pancreas as well as the changes of the blood glucose and insulin levels after subtotal pancreatectomy. The diabetic animals with hyperglycemia induced by the subtotal pancreatectomy showed recovery of blood glucose level toward the normal range (<150 mg/dl) by giving raw soybean for 3~4 weeks. Most animals treated with SBTI remained in euglycemic condition in spite of diabetic induction by subtotal pancreatectomy. Their serum insulin level was also recovered to the level of normal control, indicating the increased insulin synthesis and secretion from the neogenic beta cells. Neogenic area was enlarged at least 2 times in the pancreatectomized rats with dietary soybean or SBTI treatment, when compared with their pancreatectomized controls without any dietary treatment. In neogenic tissue, few endocrine cells were detected as a single cell or cell cluster at 3 days, and they formed primitive islet at 7 days after pancreatectomy in non-treated controls. The numbers of beta cells as well as alpha cells were considerably increased in the SBTI treated rats, and early formation of primitive islets were found in the neogenic tissue of those animals at 3 days after pancreatectomy. Those beta cells demonstrated a strong immunoreactivity for insulin, indicating their bioactive insulin secretion. Clusterin, a marker protein for pancreatic neogenesis, was expressed in the wider pancreatic area and at earlier stage after pancreatectomy when compared with non-treated control rats, indicating acceleration and stimulation of neogenesis of pancreas by stimulating proliferation and differentiation of the functional pancreatic cells. Taken together, we concluded that dietary soybean and SBTI could stimulate beta cell neogenesis and induce activation of insulin synthesis and secretion from the neogenic beta cells for correction of glucose homeostasis in diabetic subjects.
Acceleration ; Animals ; Blood Glucose ; Clusterin ; Diet* ; Endocrine Cells ; Glucose ; Homeostasis ; Hyperglycemia ; Insulin ; Insulin-Secreting Cells ; Pancreas ; Pancreatectomy* ; Rats ; Reference Values ; Regeneration ; Soybeans* ; Trypsin*