1
|
Ding T, Wen B, Chen J, Chu W, Fan R, Chen X. Excess homocysteine inhibits pancreatic β-cell secretory function by repressing Zbtb20 expression. Mol Cell Endocrinol 2024; 586:112195. [PMID: 38432501 DOI: 10.1016/j.mce.2024.112195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
Homocysteine (Hcy) is a sulfur-containing amino acid. An elevated level of Hcy is a risk factor for diabetes development. However, the mechanism of its effect on pancreatic β-cell function is unclear. In this study, we constructed a hyperhomocysteinemia (HHcy) mouse model by feeding mice a high methionine diet (HMD). The mice suffered impaired glucose tolerance and reduced insulin secretion. Furthermore, at the cellular level, INS1 cells exhibited impaired insulin secretory function after the Hcy intervention. Transcriptomics revealed that Zbtb20 expression was downregulated and the downstream gene Fbp1 was upregulated in HHcy-induced mice compared with mice fed with normal diet. Insulin secretion could be restored by Zbtb20 overexpression or fructose 1,6-bisphosphatase (FBPase) activity inhibition in INS1 cells. In conclusion, our study suggested that Hcy inhibited the insulin secretory function of pancreatic β-cells by suppressing Zbtb20 expression, leading to the development of diabetes. Zbtb20 may be a key target in the development of diabetes associated with elevated Hcy levels.
Collapse
Affiliation(s)
- Tianqi Ding
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Bo Wen
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Jian Chen
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Wenbin Chu
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Rong Fan
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China; Central Laboratory, Tianjin Xiqing Hospital, Tianjin, 300380, China.
| | - Xuewei Chen
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China.
| |
Collapse
|
2
|
Pack M, Gulde TN, Völcker MV, Boewe AS, Wrublewsky S, Ampofo E, Montenarh M, Götz C. Protein Kinase CK2 Contributes to Glucose Homeostasis by Targeting Fructose-1,6-Bisphosphatase 1. Int J Mol Sci 2022; 24:ijms24010428. [PMID: 36613872 PMCID: PMC9820633 DOI: 10.3390/ijms24010428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/16/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Glucose homeostasis is of critical importance for the survival of organisms. It is under hormonal control and often coordinated by the action of kinases and phosphatases. We have previously shown that CK2 regulates insulin production and secretion in pancreatic β-cells. In order to shed more light on the CK2-regulated network of glucose homeostasis, in the present study, a qRT-PCR array was carried out with 84 diabetes-associated genes. After inhibition of CK2, fructose-1,6-bisphosphatase 1 (FBP1) showed a significant lower gene expression. Moreover, FBP1 activity was down-regulated. Being a central enzyme of gluconeogenesis, the secretion of glucose was decreased as well. Thus, FBP1 is a new factor in the CK2-regulated network implicated in carbohydrate metabolism control.
Collapse
Affiliation(s)
- Mandy Pack
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Tim Nikolai Gulde
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Michelle Victoria Völcker
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Anne S. Boewe
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66421 Homburg, Germany
| | - Selina Wrublewsky
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66421 Homburg, Germany
| | - Emmanuel Ampofo
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66421 Homburg, Germany
| | - Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
- Correspondence:
| |
Collapse
|
3
|
Westermeier F, Holyoak T, Asenjo JL, Gatica R, Nualart F, Burbulis I, Bertinat R. Gluconeogenic Enzymes in β-Cells: Pharmacological Targets for Improving Insulin Secretion. Trends Endocrinol Metab 2019; 30:520-531. [PMID: 31213347 DOI: 10.1016/j.tem.2019.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 02/06/2023]
Abstract
Pancreatic β-cells express the gluconeogenic enzymes glucose 6-phosphatase (G6Pase), fructose 1,6-bisphosphatase (FBP), and phosphoenolpyruvate (PEP) carboxykinase (PCK), which modulate glucose-stimulated insulin secretion (GSIS) through their ability to reverse otherwise irreversible glycolytic steps. Here, we review current knowledge about the expression and regulation of these enzymes in the context of manipulating them to improve insulin secretion in diabetics. Because the regulation of gluconeogenic enzymes in β-cells is so poorly understood, we propose novel research avenues to study these enzymes as modulators of insulin secretion and β-cell dysfunction, with especial attention to FBP, which constitutes an attractive target with an inhibitor under clinical evaluation at present.
Collapse
Affiliation(s)
- Francisco Westermeier
- FH JOANNEUM Gesellschaft mbH University of Applied Sciences, Institute of Biomedical Science, Eggenberger Allee 13, 8020 Graz, Austria
| | - Todd Holyoak
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Joel L Asenjo
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Independencia 631, 5110566 Valdivia, Chile
| | - Rodrigo Gatica
- Escuela de Veterinaria, Facultad de Ciencias, Universidad Mayor, La Pirámide 5750, 8580745 Santiago, Chile
| | - Francisco Nualart
- Centro de Microscopía Avanzada, CMA BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160 C, 4030000 Concepción, Chile
| | - Ian Burbulis
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Jordan Hall Room 6022, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Escuela de Medicina, Universidad San Sebastián, Sede Patagonia, Lago Panguipulli 1390, 5501842 Puerto Montt, Chile
| | - Romina Bertinat
- Centro de Microscopía Avanzada, CMA BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160 C, 4030000 Concepción, Chile.
| |
Collapse
|
4
|
Westermeier F, Holyoak T, Gatica R, Martínez F, Negrón M, Yáñez AJ, Nahmias D, Nualart F, Burbulis I, Bertinat R. Cytosolic phosphoenolpyruvate carboxykinase is expressed in α-cells from human and murine pancreas. J Cell Physiol 2019; 235:166-175. [PMID: 31180589 DOI: 10.1002/jcp.28955] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 05/24/2019] [Indexed: 12/16/2022]
Abstract
The pancreatic islets of Langerhans, mainly formed by glucagon-producing α-cells and insulin-producing β-cells, are critical for glucose homeostasis. Insulin and glucagon oppositely modulate blood glucose levels in health, but a combined decline in insulin secretion together with increased glucagon secretion contribute to hyperglycemia in diabetes. Despite this bi-hormonal dysregulation, most studies have focused on insulin secretion and much less is known about glucagon secretion. Therefore, a deeper understanding of α-cell metabolism and glucagon secretion is of great interest. Here, we show that phosphoenolpyruvate carboxykinase (PCK1), an essential cataplerotic enzyme involved in metabolism and long considered to be absent from the pancreatic islet, is expressed in pancreatic α-cells of both murine and human. Furthermore, PCK1 transcription is induced by fasting and diabetes in rat pancreas, which indicates that the PCK1 activity is required for α-cell adaptation to different metabolic states. To our knowledge, this is the first evidence implicating PCK1 expression in α-cell metabolism.
Collapse
Affiliation(s)
- Francisco Westermeier
- FH JOANNEUM Gesellschaft mbH University of Applied Sciences, Institute of Biomedical Science, Department of Health Studies, Graz, Austria
| | - Todd Holyoak
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Rodrigo Gatica
- Escuela de Veterinaria, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Fernando Martínez
- Centro de Microscopía Avanzada, CMA-BIO BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Marianne Negrón
- Centro de Microscopía Avanzada, CMA-BIO BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Alejandro J Yáñez
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Daniel Nahmias
- Anatomía patológica, Hospital Puerto Montt, Puerto Montt, Chile
| | - Francisco Nualart
- Centro de Microscopía Avanzada, CMA-BIO BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Ian Burbulis
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, Virginia.,Escuela de Medicina, Universidad San Sebastián, Sede de la Patagonia, Puerto Montt, Chile
| | - Romina Bertinat
- Centro de Microscopía Avanzada, CMA-BIO BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| |
Collapse
|
5
|
A new level of regulation in gluconeogenesis: metabolic state modulates the intracellular localization of aldolase B and its interaction with liver fructose-1,6-bisphosphatase. Biochem J 2015; 472:225-37. [PMID: 26417114 DOI: 10.1042/bj20150269] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 09/25/2015] [Indexed: 11/17/2022]
Abstract
Understanding how glucose metabolism is finely regulated at molecular and cellular levels in the liver is critical for knowing its relationship to related pathologies, such as diabetes. In order to gain insight into the regulation of glucose metabolism, we studied the liver-expressed isoforms aldolase B and fructose-1,6-bisphosphatase-1 (FBPase-1), key enzymes in gluconeogenesis, analysing their cellular localization in hepatocytes under different metabolic conditions and their protein-protein interaction in vitro and in vivo. We observed that glucose, insulin, glucagon and adrenaline differentially modulate the intracellular distribution of aldolase B and FBPase-1. Interestingly, the in vitro protein-protein interaction analysis between aldolase B and FBPase-1 showed a specific and regulable interaction between them, whereas aldolase A (muscle isozyme) and FBPase-1 showed no interaction. The affinity of the aldolase B and FBPase-1 complex was modulated by intermediate metabolites, but only in the presence of K(+). We observed a decreased association constant in the presence of adenosine monophosphate, fructose-2,6-bisphosphate, fructose-6-phosphate and inhibitory concentrations of fructose-1,6-bisphosphate. Conversely, the association constant of the complex increased in the presence of dihydroxyacetone phosphate (DHAP) and non-inhibitory concentrations of fructose-1,6-bisphosphate. Notably, in vivo FRET studies confirmed the interaction between aldolase B and FBPase-1. Also, the co-expression of aldolase B and FBPase-1 in cultured cells suggested that FBPase-1 guides the cellular localization of aldolase B. Our results provide further evidence that metabolic conditions modulate aldolase B and FBPase-1 activity at the cellular level through the regulation of their interaction, suggesting that their association confers a catalytic advantage for both enzymes.
Collapse
|
6
|
Bertinat R, Nualart F, Li X, Yáñez AJ, Gomis R. Preclinical and Clinical Studies for Sodium Tungstate: Application in Humans. ACTA ACUST UNITED AC 2015; 6. [PMID: 25995968 PMCID: PMC4435618 DOI: 10.4172/2155-9899.1000285] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Diabetes is a complex metabolic disorder triggered by the deficient secretion of insulin by the pancreatic β-cell or the resistance of peripheral tissues to the action of the hormone. Chronic hyperglycemia is the major consequence of this failure, and also the main cause of diabetic problems. Indeed, several clinical trials have agreed in that tight glycemic control is the best way to stop progression of the disease. Many anti-diabetic drugs for treatment of type 2 diabetes are commercially available, but no ideal normoglycemic agent has been developed yet. Moreover, weight gain is the most common side effect of many oral anti-diabetic agents and insulin, and increased weight has been shown to worsen glycemic control and increase the risk of diabetes progression. In this sense, the inorganic salt sodium tungstate (NaW) has been studied in different animal models of metabolic syndrome and diabetes, proving to have a potent effect on normalizing blood glucose levels and reducing body weight, without any hypoglycemic action. Although the liver has been studied as the main site of NaW action, positive effects have been also addressed in muscle, pancreas, brain, adipose tissue and intestine, explaining the effective anti-diabetic action of this salt. Here, we review NaW research to date in these different target organs. We believe that NaW deserves more attention, since all available anti-diabetic treatments remain suboptimal and new therapeutics are urgently needed.
Collapse
Affiliation(s)
- Romina Bertinat
- Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile ; Centro de Microscopía Avanzada, CMA-Bío Bío, Universidad de Concepción, Concepción, Chile
| | - Francisco Nualart
- Centro de Microscopía Avanzada, CMA-Bío Bío, Universidad de Concepción, Concepción, Chile
| | - Xuhang Li
- Division of Gastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Alejandro J Yáñez
- Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile ; Centro de Microscopía Avanzada, CMA-Bío Bío, Universidad de Concepción, Concepción, Chile
| | - Ramón Gomis
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain ; Diabetes and Obesity Research Laboratory, IDIBAPS, Barcelona, Spain ; Department of Endocrinology and Nutrition, Hospital Clinic, Barcelona, Spain ; Faculty of Medicine, University of Barcelona, Barcelona, Spain
| |
Collapse
|
7
|
Zhang Y, Xie Z, Zhou L, Li L, Zhang H, Zhou G, Ma X, Herrera PL, Liu Z, Grusby MJ, Zhang WJ. The zinc finger protein ZBTB20 regulates transcription of fructose-1,6-bisphosphatase 1 and β cell function in mice. Gastroenterology 2012; 142:1571-1580.e6. [PMID: 22374165 DOI: 10.1053/j.gastro.2012.02.043] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 01/31/2012] [Accepted: 02/22/2012] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Fructose-1,6-bisphosphatase (FBP)-1 is a gluconeogenic enzyme that regulates glucose metabolism and insulin secretion in β cells, but little is known about how its transcription is controlled. The zinc finger protein ZBTB20 regulates glucose homeostasis, so we investigated its effects on expression of FBP-1. METHODS We analyzed gene expression using real-time reverse-transcription polymerase chain reaction, immunoblotting, and immunohistochemistry. We generated mice with β cell-specific disruption of Zbtb20 using Cre/LoxP technology. Expression of Zbtb20 in β cells was reduced using small interfering RNAs, and promoter occupancy and transcriptional regulation were analyzed by chromatin immunoprecipitation and reporter assays. RESULTS ZBTB20 was expressed at high levels by β cells and other endocrine cells in islets of normal mice; expression levels were reduced in islets from diabetic db/db mice. Mice with β cell-specific knockout of Zbtb20 had normal development of β cells but had hyperglycemia, hypoinsulinemia, glucose intolerance, and impaired glucose-stimulated insulin secretion. Islets isolated from these mice had impaired glucose metabolism, adenosine triphosphate production, and insulin secretion after glucose stimulation in vitro, although insulin secretion returned to normal levels in the presence of KCl. ZBTB20 knockdown with small interfering RNAs impaired glucose-stimulated insulin secretion in the β cell line MIN6. Expression of Fbp1 was up-regulated in β cells with ZBTB20 knockout or knockdown; impairments to glucose-stimulated insulin secretion were restored by inhibition of FBPase activity. ZBTB20 was recruited to the Fbp1 promoter and repressed its transcription in β cells. CONCLUSIONS The transcription factor ZBTB20 regulates β cell function and glucose homeostasis in mice. It might be a therapeutic target for type 2 diabetes mellitus.
Collapse
Affiliation(s)
- Ye Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Zhang Y, Xie Z, Zhou G, Zhang H, Lu J, Zhang WJ. Fructose-1,6-bisphosphatase regulates glucose-stimulated insulin secretion of mouse pancreatic beta-cells. Endocrinology 2010; 151:4688-95. [PMID: 20719858 DOI: 10.1210/en.2009-1185] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pancreatic β-cells can precisely sense glucose stimulation and accordingly adjust their insulin secretion. Fructose-1,6-bisphosphatase (FBPase) is a gluconeogenic enzyme, but its physiological significance in β-cells is not established. Here we determined its physiological role in regulating glucose sensing and insulin secretion of β-cells. Considerable FBPase mRNA was detected in normal mouse islets and β-cell lines, although their protein levels appeared to be quite low. Down-regulation of FBP1 in MIN6 cells by small interfering RNA could enhance the glucose-stimulated insulin secretion (GSIS), whereas FBP1-overexpressing MIN6 cells exhibited decreased GSIS. Inhibition of FBPase activity in islet β-cells by its specific inhibitor MB05032 led to significant increase of their glucose utilization and cellular ATP to ADP ratios and consequently enhanced GSIS in vitro. Pretreatment of mice with the MB05032 prodrug MB06322 could potentiate GSIS in vivo and improve their glucose tolerance. Therefore, FBPase plays an important role in regulating glucose sensing and insulin secretion of β-cells and serves a promising target for diabetes treatment.
Collapse
Affiliation(s)
- Ye Zhang
- Center for Obesity & Diabetes Research and Innovation, Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
| | | | | | | | | | | |
Collapse
|
9
|
Ezquer F, Ezquer M, Simon V, Pardo F, Yañez A, Carpio D, Conget P. Endovenous administration of bone-marrow-derived multipotent mesenchymal stromal cells prevents renal failure in diabetic mice. Biol Blood Marrow Transplant 2009; 15:1354-65. [PMID: 19822294 DOI: 10.1016/j.bbmt.2009.07.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Accepted: 07/24/2009] [Indexed: 01/12/2023]
Abstract
Twenty-five to 40% of diabetic patients develop diabetic nephropathy, a clinical syndrome that comprises renal failure and increased risk of cardiovascular disease. It represents the major cause of chronic kidney disease and is associated with premature morbimortality of diabetic patients. Multipotent mesenchymal stromal cells (MSC) contribute to the regeneration of several organs, including acutely injured kidney. We sought to evaluate if MSC protect kidney function and structure when endovenously administered to mice with severe diabetes. A month after nonimmunologic diabetes induction by streptozotocin injection, C57BL/6 mice presented hyperglycemia, glycosuria, hypoinsulinemia, massive beta-pancreatic islet destruction, low albuminuria, but not renal histopathologic changes (DM mice). At this stage, one group of animals received the vehicle (untreated) and other group received 2 doses of 0.5 x 10(6) MSC/each (MSC-treated). Untreated DM mice gradually increased urinary albumin excretion and 4 months after diabetes onset, they reached values 15 times higher than normal animals. In contrast, MSC-treated DM mice maintained basal levels of albuminuria. Untreated DM mice had marked glomerular and tubular histopathologic changes (sclerosis, mesangial expansion, tubular dilatation, proteins cylinders, podocytes lost). However, MSC-treated mice showed only slight tubular dilatation. Observed renoprotection was not associated with an improvement in endocrine pancreas function in this animal model, because MSC-treated DM mice remained hyperglycemic and hypoinsulinemic, and maintained few remnant beta-pancreatic islets throughout the study period. To study MSC biodistribution, cells were isolated from isogenic mice that constitutively express GFP (MSC(GFP)) and endovenously administered to DM mice. Although at very low levels, donor cells were found in kidney of DM mice 3 month after transplantation. Presented preclinical results support MSC administration as a cell therapy strategy to prevent chronic renal diseases secondary to diabetes.
Collapse
Affiliation(s)
- Fernando Ezquer
- Instituto de Ciencias, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | | | | | | | | | | | | |
Collapse
|
10
|
Ezquer FE, Ezquer ME, Parrau DB, Carpio D, Yañez AJ, Conget PA. Systemic administration of multipotent mesenchymal stromal cells reverts hyperglycemia and prevents nephropathy in type 1 diabetic mice. Biol Blood Marrow Transplant 2008; 14:631-40. [PMID: 18489988 DOI: 10.1016/j.bbmt.2008.01.006] [Citation(s) in RCA: 229] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Accepted: 01/20/2008] [Indexed: 12/18/2022]
Abstract
Multipotent mesenchymal stromal cells (MSCs), often labeled mesenchymal stem cells, contribute to tissue regeneration in injured bone and cartilage, as well as in the infarcted heart, brain, and kidney. We hypothesize that MSCs might also contribute to pancreas and kidney regeneration in diabetic individuals. Therefore, in streptozotocin (STZ)-induced type 1 diabetes C57BL/6 mice, we tested whether a single intravenous dose of MSCs led to recovery of pancreatic and renal function and structure. When hyperglycemia, glycosuria, massive beta-pancreatic islets destruction, and mild albuminuria were evident (but still without renal histopathologic changes), mice were randomly separated in 2 groups: 1 received 0.5 x 10(6) MSCs that have been ex vivo expanded (and characterized according to their mesenchymal differentiation potential), and the other group received the vehicle. Within a week, only MSC-treated diabetic mice exhibited significant reduction in their blood glucose levels, reaching nearly euglycemic values a month later. Reversion of hyperglycemia and glycosuria remained for 2 months at least. An increase in morphologically normal beta-pancreatic islets was observed only in MSC-treated diabetic mice. Furthermore, in those animals albuminuria was reduced and glomeruli were histologically normal. On the other side, untreated diabetic mice presented glomerular hyalinosis and mesangial expansion. Thus, MSC administration resulted in beta-pancreatic islets regeneration and prevented renal damage in diabetic animals. Our preclinical results suggest bone marrow-derived MSC transplantation as a cell therapy strategy to treat type 1 diabetes and prevent diabetic nephropathy, its main complication.
Collapse
Affiliation(s)
- Fernando E Ezquer
- Instituto de Ciencias, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | | | | | | | | | | |
Collapse
|
11
|
Yap YL, Zhang XW, Smith D, Soong R, Hill J. Molecular gene expression signature patterns for gastric cancer diagnosis. Comput Biol Chem 2007; 31:275-87. [PMID: 17631416 DOI: 10.1016/j.compbiolchem.2007.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 06/05/2007] [Accepted: 06/05/2007] [Indexed: 12/24/2022]
Abstract
It is an accepted clinical practice to diagnose gastric cancer by using histological techniques on tissue obtained through endoscopic biopsy. However, the use of these techniques often results in difficulty distinguishing between benign and malignant growth due to the ambiguous nature of some of the morphological features observed. In order to improve this situation, public domain gene expression data has been analysed and a set of molecular gene expression signatures has been discovered that distinguishes between normal and malignant growth. In addition, a separate distinct gene expression signature has been identified that appears to aid in the prognosis and indicate survival rates of patients. It is proposed that the use of the molecular gene expression signatures described in this manuscript when used in conjunction with the traditional histological techniques already in clinical practice will enhance and improve the diagnosis of gastric cancer.
Collapse
Affiliation(s)
- Yee Leng Yap
- Bioinformatics Institute (BII), 30 Biopolis Street, #07-01, Matrix, Singapore 138671, Singapore.
| | | | | | | | | |
Collapse
|
12
|
Yáñez AJ, Bustamante X, Bertinat R, Werner E, Rauch MC, Concha II, Reyes JG, Slebe JC. Expression of key substrate cycle enzymes in rat spermatogenic cells: Fructose 1,6 bisphosphatase and 6 phosphofructose 1-kinase. J Cell Physiol 2007; 212:807-16. [PMID: 17492776 DOI: 10.1002/jcp.21077] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A substrate cycle composed of phosphofructo 1-kinase I (PFK) and fructose 1,6 bisphosphatase I (FBPase) has been proposed in rat spermatids. This substrate cycle can explain the ability of glucose to induce a decrease in intracellular ATP, a phenomenon that was related to regulation of [Ca(2+)]i in these cells. In spite of the importance of this metabolic cycle, the expression and activities of the enzymes that compose such cycle have not been systematically studied in spermatogenic cells. Here, we show that PFK and FBPase activities were present in pachytene spermatocytes and round spermatids extracts. Expression of PFK at the mRNA and protein levels showed a relatively similar expression in spermatogenic cells, but a stronger expression in Sertoli cells. Instead, expression of FBPase at the mRNA and protein levels was stronger in round and elongating spermatids as compared to other spermatogenic cells. A similar pattern was observed when evidencing FBPase activity by a NADPH-nitroblue tetrazolium-linked cytochemical assay in isolated pachytene spermatocytes and round spermatids. Rat spermatids also showed the ability to convert lactate to fructose- and glucose-6-P, indicating that both glycolytic and gluconeogenic fluxes are present in these cells. Our results indicate that a coordinated expression of key substrate cycle enzymes, at the level of PFK/FBPase, appear in the last stages of spermatogenic cell differentiation, suggesting that the co-regulation of these enzymes are required for the ability of these cells to respond to glucose and induce metabolic and Ca(2+) signals that can be important for sperm development and function.
Collapse
Affiliation(s)
- Alejandro J Yáñez
- Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | | | | | | | | | | | | | | |
Collapse
|