Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies using adult human islets and mouse embryonic stem cells have suggested that the neurepithelial precursor cell marker nestin also identifies and can be used to purify beta-cell precursors. To determine whether nestin can be used to identify beta-cell progenitors in the developing human pancreas, we characterized nestin expression from 12 to 24 gestational weeks, purified nestin+ cells using an enhancer/promoter-driven selection plasmid, and determined whether nestin+ cells can differentiate into beta-cells. Nestin was visualized in the platelet endothelial cell adhesion molecule and alpha smooth muscle actin-positive blood vessels and colocalized with vimentin in the interstitium. Nestin was not observed in pan cytokeratin (pCK)-positive ductal epithelium or insulin cells. Purified nestin+ cells also coexpressed vimentin and lacked pCK immunoreactivity. Purified adult and fetal pancreatic fibroblasts also expressed nestin. The nestin enhancer/promoter used in the selection plasmid was sufficient to drive reporter gene expression, green fluorescent protein, in human fetal pancreatic tissue. Exposure of selected nestin+ cells to nicotinamide, hepatocyte growth factor/scatter factor, betacellulin, activin A, or exendin-4 failed to induce pancreatic and duodenal homeobox gene-1 or insulin message as determined by RT-PCR. Transplantation of nestin+ cells and fetal pancreatic fibroblasts into athymic mice also failed to result in the development of beta-cells, whereas nestin- fetal pancreatic epithelial cells gave rise to functional insulin-secreting beta-cells. We conclude that nestin is not a specific marker of beta-cell precursors in the developing human pancreas.
Diabetes 2003 Oct
PMID:Characterization and isolation of promoter-defined nestin-positive cells from the human fetal pancreas. 1451 35

Diabetics suffer from both more frequent bacterial infections and greater consequences of infection. However, bacteria-induced tissue destruction and the subsequent response in diabetics have received relatively little attention. To investigate this issue, we inoculated the scalp of control or db/db diabetic mice, with the pathogen Porphyromonas gingivalis, which causes connective tissue destruction in humans. Both bacteria-induced cytokine expression and tissue loss were similar in diabetic and control mice. However, there was a significantly higher rate of fibroblast-specific apoptosis in the diabetic group, which was measured as cells that were double positive for the terminal deoxynucleotidyltransferase-mediated deoxy-UTP nick end labeling assay and expression of vimentin. The higher rate of fibroblast apoptosis could be explained in the diabetic group by enhanced levels of activated caspase-3. Apoptosis was evident during the peak healing period and coincided with reduced numbers of fibroblasts, diminished collagen I and III expression, and significantly reduced formation of new connective tissue matrix in diabetic mice. Thus, diabetes may impair the healing response to bacteria-induced connective tissue loss by increasing the number of caspase-3-activated fibroblasts, leading to greater apoptosis and reduced numbers of fibroblastic cells.
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PMID:Diabetes alters the response to bacteria by enhancing fibroblast apoptosis. 1503 11

Type I diabetes is characterized by destruction of insulin-producing beta-islet cells in the pancreas resulting in hyperglycemia and associated morbidity. The successful treatment of diabetes by transplanted islets has resulted in renewed efforts to identify methods to augment islet availability. One approach is to identify and expand islet precursor cells able to later differentiate into functional endocrine cells. A population of cytokeratin 19-negative, vimentin-positive, insulin-negative, glucagon-negative, and nestin-positive cells was cultured from human fetal pancreas and passaged for over 20 population doublings. These cells were stimulated to form cell aggregates when grown on poly-D-lysine (PDL)-coated surfaces and then evaluated for differentiation potential using in vivo function as a surrogate marker for the presence of differentiated precursor cells. Streptozotocin-induced diabetic SCID mice implanted with PDL-induced cell aggregates were able to maintain glucose concentrations below 200 mg/dL for over 70 days (n = 5). In addition, human C-peptide was detectable in implanted animals but not in control animals. These findings show that a population of human fetal pancreas-derived cells (1) can be cultured and expanded in vitro, (2) can maintain the ability to differentiate into beta-islet-like cells, and (3) can correct hyperglycemia in a mouse model of diabetes. Further improvements in isolation, culture, and differentiation of human pancreas-derived beta-cell precursors may one day help to provide a novel source of islets for use in transplantation therapy to treat type I diabetes.
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PMID:Long-term correction of hyperglycemia in diabetic mice after implantation of cultured human cells derived from fetal pancreas. 1521 Nov 20

Tubular complexes (TC) in the pancreas contain duct-like structures with low cuboidal or flattened cells surrounding a large lumen and are thought to be a response to pancreatic injury. TC have been studied in animal models of chemical or surgically induced pancreatic damage but their occurrence has not been reported in rodent models of spontaneous autoimmune type I diabetes. We hypothesized that TC would be increased during the active phase of islet destruction in autoimmune diabetes and could contain islet progenitor cells. We analyzed TC in pancreas of Wistar Furth (WF), control (BBc) and diabetes-prone BioBreeding (BBdp) rats using immunohistochemistry and morphometry. TC were observed in all rat strains during active pancreas remodeling ( approximately 13 days). They increased between 60 and 93 days only in BBdp rats coincident with the increase in diabetes cases. Most TC were infiltrated with CD3(+) T-cells. Duct-like cells in the TC had low expression of the exocrine marker amylase, increased expression of epithelial cell markers, keratin and vimentin, and remarkably high cell proliferation and cell death. TC islets contained cells stained positive for insulin, glucagon, somatostatin, pancreatic polypeptide, as well as PDX-1, chromogranin, and hepatocyte-derived growth factor receptor, c-met. Transitional cells that were keratin(+)/insulin(+) and keratin(+)/amylase(+) cells were present in TC. The stem cell marker, nestin was upregulated in the TC region. Duct-like cells in TC of BBdp rats expressed markers of committed endocrine precursors: PDX-1, neurogenin 3 and protein gene product 9.5. This study demonstrates that TC are upregulated during beta-cell destruction and contain potential endocrine progenitors.
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PMID:Tubular complexes as a source for islet neogenesis in the pancreas of diabetes-prone BB rats. 1576 20

In many diseases, including progressive renal disorders, tissue injury and pathological intracellular signaling events are dependent on oxidative stress. Glutathione peroxidase-1 (Gpx1) is an antioxidant enzyme that is highly expressed in the kidney and removes peroxides and peroxynitrite that can cause renal damage. Therefore, we examined whether this abundant renal antioxidant enzyme limits renal damage during the development of type 1 diabetic nephropathy. Wild-type (Gpx1+/+) and deficient (Gpx1-/-) mice were made diabetic by intraperitoneal injection of streptozotocin (100 mg/kg) on 2 consecutive days. Diabetic Gpx1+/+ and -/- mice with equivalent blood glucose levels (23 +/- 4 mM) were selected and examined after 4 mo of diabetes. Compared with normal mice, diabetic Gpx1+/+ and -/- mice had a two- to threefold increase in urine albumin excretion at 2 and 4 mo of diabetes. At 4 mo, diabetic Gpx1+/+ and -/- mice had equivalent levels of oxidative renal injury (increased kidney reactive oxygen species, kidney lipid peroxidation, urine isoprostanes, kidney deposition of advanced glycoxidation, and nitrosylation end products) and a similar degree of glomerular damage (hypertrophy, hypercellularity, sclerosis), tubular injury (apoptosis and vimentin expression), and renal fibrosis (myofibroblasts, collagen, TGF-beta excretion). A lack of Gpx1 was not compensated for by increased levels of catalase or other Gpx isoforms in diabetic kidneys. Contrary to expectations, this study showed that the high level of Gpx1 expressed in the kidney is not protective against the development of renal oxidative stress and nephropathy in a model of type 1 diabetes.
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PMID:Kidney expression of glutathione peroxidase-1 is not protective against streptozotocin-induced diabetic nephropathy. 1582 46

Epithelial-to-mesenchymal transition (EMT) of tubular cells contributes to the renal accumulation of matrix protein that is associated with diabetic nephropathy. Both TGF-beta1 and advanced glycation end products (AGE) are able to induce EMT in cell culture. This study examined the role of the prosclerotic growth factor connective tissue growth factor (CTGF) as a downstream mediator of these processes. EMT was assessed by the expression of alpha-smooth muscle actin, vimentin, E-cadherin, and matrix proteins and the induction of a myofibroblastic phenotype. CTGF, delivered in an adenovirus or as recombinant human CTGF (250 ng/ml), was shown to induce a partial EMT. This was not blocked by neutralizing anti-TGF-beta1 antibodies, suggesting that this action was TGF-beta1 independent. NRK-52E cells that were exposed to AGE-modified BSA (AGE-BSA; 40 microM) or TGF-beta1 (10 ng/ml) also underwent EMT. This was associated with the induction of CTGF gene and protein expression. Transfection with siRNA to CTGF was able to attenuate EMT-associated phenotypic changes after treatment with AGE or TGF-beta1. These in vitro effects correlate with the in vivo finding of increased CTGF expression in the diabetic kidney, which co-localizes on the tubular epithelium with sites of EMT. In addition, inhibition of AGE accumulation was able to reduce CTGF expression and attenuate renal fibrosis in experimental diabetes. These findings suggest that CTGF represents an important independent mediator of tubular EMT, downstream of the actions of AGE or TGF-beta1. This interaction is likely to play an important role in progressive diabetic nephropathy and strengthens the rationale to consider CTGF as a potential target for the treatment of diabetic nephropathy.
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PMID:Connective tissue growth factor plays an important role in advanced glycation end product-induced tubular epithelial-to-mesenchymal transition: implications for diabetic renal disease. 1691 37

We report a rare case of sertoliform endometrioid carcinoma of the endometrium in a 71-year-old African American woman who presented with postmenopausal bleeding. Her medical condition was remarkable for hypertension, diabetes, and obesity. She underwent total hysterectomy, right salpingo-oophorectomy and lymph node sampling. The endometrium was occupied by a 4.5-cm solid polypoid tumor, which grossly invaded into the myometrium. Microscopically, the tumor consisted of small hollow tubules, anastomosing cords and trabeculae, and tightly packed nests. Microglandular areas mimicking adult granulosa cell tumors were also present. But true Call-Exner bodies were absent. Component of typical endometrioid carcinoma was noted only focally. The uninvolved endometrium demonstrated atypical complex hyperplasia. The tumor cells were diffusely immunoreactive for epithelial membrane antigen, estrogen receptor, and progesterone receptor (PR), and focally for vimentin. The tumor cells were also diffusely positive for inhibin alpha and CD99. Immunostains for other sex cord markers (calretinin, WT-1, and Melan-A) were also positive in approximately 30% to 40% of the tumor cells. Immunostains for CD10, smooth muscle actin, desmin, or HHF35 were negative. Two ovarian sertoliform endometrioid carcinomas from our archived tissue were, however, immunoreactive for epithelial membrane antigen but negative for inhibin alpha. Despite the prominent sertoliform features, both histologically and immunohistochemically, the tumor was of a high-grade endometrial carcinoma and will likely behave as such. As of today, dual differentiation of epithelium and sex cord by immunohistochemical staining has not been demonstrated in sertoliform endometrioid carcinomas of either endometrial or ovarian origin. Our case is the first documentation of such example and suggests that endometrial carcinoma can undergo true sex cord differentiation.
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PMID:Sertoliform endometrioid carcinoma of the endometrium with dual immunophenotypes for epithelial membrane antigen and inhibin alpha: case report and literature review. 1758 14

The receptor for advanced glycation end products (RAGE) plays a crucial role in several disease processes, such as diabetes, inflammation, and neurodegeneration. In this article we report multiple roles of RAGE in neuronal differentiation and neurite outgrowth. In retinoic-induced P19 embryonic carcinoma stem cells, silencing the expression of RAGE by RNA interference (RNAi) blocked differentiation of the P19 cells into neuronal cells and enhanced the formation of vimentin-positive fibroblast-like cells. RAGE knockdown inhibited retinoic acid-induced activation and blocked nuclear translocation of NF-kappaB, suggesting RAGE regulates activation of NF-kappaB. RAGE was also shown to be involved in survival of P19 cells during retinoic acid differentiation. Additionally, knockdown of RAGE strongly inhibited neurite outgrowth in retinoic acid-differentiated P19 cells, indicating that RAGE is required for neurite outgrowth of differentiated P19 cells. Retinoic acid-treated P19 cells activated GTPases, Rac1, and Cdc42. This activation of the GTPases was inhibited in RAGE-knockdown cells. In primary cerebellar granule neurons, the knockdown of RAGE also inhibited neurite outgrowth. In these cells, overexpression of dominant-negative forms of Rac1 and Cdc42 inhibited neurite outgrowth, whereas overexpression of constitutively active forms of Rac1 and Cdc42 in RAGE-deficient neurons restored neurite outgrowth, indicating that RAGE mediated neurite outgrowth through the Rac1/Cdc42 pathway. This is the first report on the role of RAGE in cell lines and primary neurons, as determined by RNAi knockdown.
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PMID:Receptor for advanced glycation end products (RAGE) mediates neuronal differentiation and neurite outgrowth. 1805 43

The molecular pathogenesis of diabetic nephropathy (DN), the leading cause of end-stage renal disease worldwide, is complex and not fully understood. Transforming growth factor-beta (TGF-beta1) plays a critical role in many fibrotic disorders, including DN. In this study, we report protein kinase B (PKB/Akt) activation as a downstream event contributing to the pathophysiology of DN. We investigated the potential of PKB/Akt to mediate the profibrotic bioactions of TGF-beta1 in kidney. Treatment of normal rat kidney epithelial cells (NRK52E) with TGF-beta1 resulted in activation of phosphatidylinositol 3-kinase (PI3K) and PKB/Akt as evidenced by increased Ser473 phosphorylation and GSK-3beta phosphorylation. TGF-beta1 also stimulated increased Smad3 phosphorylation in these cells, a response that was insensitive to inhibition of PI3K or PKB/Akt. NRK52E cells displayed a loss of zona occludins 1 and E-cadherin and a gain in vimentin and alpha-smooth muscle actin expression, consistent with the fibrotic actions of TGF-beta1. These effects were blocked with inhibitors of PI3K and PKB/Akt. Furthermore, overexpression of PTEN, the lipid phosphatase regulator of PKB/Akt activation, inhibited TGF-beta1-induced PKB/Akt activation. Interestingly, in the Goto-Kakizaki rat model of type 2 diabetes, we also detected increased phosphorylation of PKB/Akt and its downstream target, GSK-3beta, in the tubules, relative to that in control Wistar rats. Elevated Smad3 phosphorylation was also detected in kidney extracts from Goto-Kakizaki rats with chronic diabetes. Together, these data suggest that TGF-beta1-mediated PKB/Akt activation may be important in renal fibrosis during diabetic nephropathy.
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PMID:Protein kinase B/Akt activity is involved in renal TGF-beta1-driven epithelial-mesenchymal transition in vitro and in vivo. 1849 98

The crucial pathology underlying progressive chronic kidney disease in diabetes is tubulointerstitial fibrosis. Central to this process is epithelial-mesenchymal transformation (EMT) of proximal tubular epithelial cells driven by maladaptive transforming growth factor-beta1 (TGF-beta1) signaling. Novel signaling roles for C-peptide have recently been discovered with evidence emerging that C-peptide may mitigate microvascular complications of diabetes. We studied the potential for C-peptide to interrupt injurious TGF-beta1 signaling pathways and thus block development of EMT in HK2 human kidney proximal tubular cells. Cells were incubated with TGF-beta1 either alone or with C-peptide in low or high glucose. Changes in cell morphology, TGF-beta1 receptor expression, vimentin, E-cadherin, and phosphorylated Smads were assessed. Luciferase reporters were used to assess Smad activity. The cytoskeleton was visualized by TRITC-phalloidin staining. The typical TGF-beta1-stimulated, EMT-associated morphological alterations of proximal tubular cells, including increased vimentin expression, decreased E-cadherin expression, and cytoskeletal rearrangements, were prevented by C-peptide treatment. C-peptide also blocked TGF-beta1-induced upregulation of expression of both type I and type II TGF-beta1 receptors and attenuated TGF-beta1-mediated Smad phosphorylation and Smad transcriptional activity. These effects of C-peptide were inhibited by pertussis toxin. The results demonstrate that C-peptide almost completely reversed the morphological changes in PT cells induced by TGF-beta1 and suggest a role or C-peptide as a renoprotective agent in diabetic nephropathy.
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PMID:C-peptide reverses TGF-beta1-induced changes in renal proximal tubular cells: implications for treatment of diabetic nephropathy. 1909 88


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