51 results about "Glucose stimulation" patented technology

The subject invention a method for converting liver stem/progenitor cells to a pancreatic functional cell by transfecting said liver cells with a pancreatic development gene and/or by culturing with pancreatic differentiation factors. The resulting cells produce and secrete insulin protein in response to glucose stimulation.

The present invention provides a method of stimulating growth of a pancreatic islet beta cell and/or enhancing glucose stimulated insulin secretion of a pancreatic islet beta cell, comprising delivering to the cell an exogenous nucleotide sequence encoding Nkx6.1 transcription factor.

Expression of beta-TRP is enriched in islet cells. Introduction of expression cassettes encoding beta-TRP into diabetic islet cells improved glucose-stimulated insulin production. Therefore, the invention provides methods of identifying beta-TRP modulators for treating diabetic individuals and introducing beta-TRP into islet cells

The present invention relates to providing novel therapeutics for treating diabetes other glycemic disorders. Such therapeutics involve the signaling pathways that contribute to regulation of glucose-stimulated insulin secretion. Of particular interest are modulators of a key component in the glucokinase pathway. Thus, the present provides methods of screening for modulators of glucokinase activity, expression, translocation, conformation, nitrosylation and interaction with other molecules as useful target for pharmacological manipulation in the treatment of diabetes and other glycemic disorders.

The invention discloses a preparation method of quick-response glucose-sensitive hydrogel which is quick in response to glucose stimulation in a physiological environment. The preparation method particularly includes adding acrylamidophenylboronic acid and acrylic acid amino ester, N-alkyl acrylamide and acrylamide or methacrylamide and N,N'-methylenebisacrylamide into an alkaline macromolecule aqueous solution, and stirring to dissolve completely so as to obtain a mixed solution; adding catalytic reaction accelerators tetramethylethylenediamine into the mixed solution with uniformly mixing; adding initiators accounting for 0.03-0.3% of monomer mass, into the obtained solution, and conducting room temperature reaction to obtain the hydrogel containing a macromolecular copolymer shown as structural formula (I). Alkaline macromolecules in the preparation method are a macromolecule component containing amino or partially containing lactam group and can enhance glucose sensitivity and responsiveness of the hydrogel in the physiological environment by being added, so that stability in use of the hydrogel is improved.

The invention provides for methods of differentiating pancreatic endocrine cells into pancreatic beta cells expressing PDX1, NKX6.1, MAFA, UCN3 and SLC2A. These pancreatic beta cells may be obtained by step-wise differentiation of pluripotent stem cells. The pancreatic beta cells exhibit glucose-dependent mitochondrial respiration and glucose-stimulated insulin secretion similar to islet cells.

The invention discloses an improved culture medium for neonatal pig islet cells and a use method of the same. An apoptosis inhibitor Z-VAD-FMK, a human basic fibroblast growth factor hFGF-beta, a vascular endothelial growth factor VEGF, an insulin-like growth factor R3-IGF-1, a human epidermal growth factor hEGF, a hepatocyte growth factor hHGF, pig serum, sodium selenite, insulin, transferrin, ethanol amine, 1-methyl 3-isobutyl xanthine, nicotine, cortisol, penicillin and streptomycin are added in HAM'S F10 culture medium. According to the culture medium, apoptosis can be reduced and recovery rate can be increased; the cultured cells have a sensitive glucose stimulation response and more mature functions compared with generally-cultured islet cells; the insulin secretion amount of the islet cells with the same quantity is increased; the viability of islet beta-cells is improved; the breakages of islet cell clusters are reduced, and the envelops of the cell clusters are complete, so that the cell clusters are more suitable for being transplanted.

The invention discloses an establishment method for a type 2 diabetes mellitus animal model. The establishment method comprises the following steps: (1) preparing a lipopolysaccharide solution with aconcentration of 100ug/ml by virtue of normal saline; (2) selecting male rats which are 4-6 weeks old, feeding by virtue of a common feed, and simultaneously injecting the lipopolysaccharide solution;(3) weighing the male rats after 28 days; (4) after the weighing, fasting for 8 hours, separating serum, and measuring blood glucose and insulin; (5) evaluating the resistance of the insulin and glucose stimulated insulin secretion capacity; (6) respectively intraperitoneally injecting an STZ solution into the male rats in the 30th day and the 32th day; and (7) determining that the establishmentof the type 2 diabetes mellitus animal model is finished when the random blood sugar is more than 16.8mmol/L. According to the establishment method, lipopolysaccharide in Escherichia coli 0111:B4 subspecies is selected and is matched with the feeding of the common feed and the STZ injection so as to successfully establish the type 2 diabetes mellitus animal mode; according to the establishment method, the operation is easy, the model establishment cost is low, the model establishment rate is high, and the model establishment period is short.

The invention features compositions comprising in vitro generated beta cells capable of glucose-stimulated insulin secretion, methods of inducing beta cell maturation from embryonic or induced pluripotent stem cell-derived beta-like cells, and methods of using in vitro generated beta cells for the treatment of type 1 diabetes, type 2 diabetes, or a related disorder.

The invention discloses a mouse islet separation and purification method. A self-made puncture needle is adopted to reversely puncture a common bile duct and inject collagenase V to digest a pancreatic gland, and inslets are separated and purified by using the combination of density gradient medium centrifugation and manual sorting. Inset density is identified by dithizone staining, and inset activity is identified by AO/PI staining. Inset functionality is detected by a glucose stimulated insulin release experiment. By using the method to extract islets on a large scale, time can be greatly saved, the puncture success rate can be increased, and Ficoll400 formulation time and price can be reduced. In addition, all the yield, purity, activity and function of islets obtained by purification are relatively good, and the method is simple, fast, cheap and efficient.

The invention discloses a glucose stimulated insulin secretion determination model. 24 hours are determined as culture and drug administration time of pancreatic beta cells; insulin concentration is determined by utilizing an ELISA method; an OD value is determined by virtue of a CCK8 method, thus quantity of the cells is indirectly reflected; HBSS solution is selected and used as later extracellular buffer solution; and an insulin secretion positive drug glibenclamide is selected for promoting insulin secretion of the pancreatic beta cells. The model built in the invention can reflect difference between different stimuli, namely high glucose and basic glucose, and can reflect insulin secretion stimulating effects of the positive drug glibenclamide under the high glucose and basic glucoseconditions.

The invention relates to the technical field of medicines, in particular to application of an SIRT2 (Sirtuin 2) inhibitor in preparation of drugs treating type 2 diabetes and drugs inhibiting insulin secretion. The acute effect test of AGK2 on rat islet glucose stimulated insulin secretion (GSIS), the test of the influence of different concentrations of AGK2 on insulin secretion, the test of the influence of AGK2 on insulin secretion under different glucose concentrations, and the test experiment of the acute effect of AGK2 on high concentration glucose induced insulin hypersecretion together prove that the SIRT2 inhibitor AGK2 can obviously inhibit glucose stimulated insulin secretion, and the AGK2 with a concentration of 0.5 micromol/l already can inhibit insulin secretion, thus providing exact experimental data for preparation of drugs treating type 2 diabetes, and also providing more scientific bases for clinically more rational use of AGK2.

The invention relates to the technical field of medicines, especially relates to an application of deacetylase inhibitors in preparation of medicaments for promoting insulin secretion, and wherein the deacetylase inhibitor is nicotinamide (NAM) or trichostatin A (TSA). The rat islet cells are co-incubated with the deacetylase inhibitor NAM for 1 h, and insulin secretion stimulated by glucose is improved by about 50%; by using the deacetylase inhibitor TSA to treat islet cells for 12 h while the glucose concentration is 3.3 mmol/L, insulin secretion can be improved, and insulin secretion is improved obviously after 16 h; and insulin secretion is mildly up-regulated after islet cells are treated by NAM for 16 h. Therefore, the inhibitors NAM and TSA are applicable to preparation of the medicaments for promoting insulin secretion, and the medicaments will have good treatment effect in diabetes treatment. Also, more scientific bases are provided for more reasonable clinic use of the deacetylase inhibitors NAM and TSA.

Insulin producing β cells are found in three dimensional (3D) structures, the Islet of Langerhans. The 3D structure is required for normal β cell function and survival. β cell pseudoislets (PIs) are useful for study of β cell physiology. Co-culturing of primary human islets and β cell lines together with islet-derived epithelial cells can improve β cell function and survival and maintain the cells' 3D structure, resulting a rapid and spontaneous formation of free-floating PIs. β cells in PIs were similar in size to native islets and showed increased percentage of pro-insulin-positive cells, increased insulin gene expression in response to glucose stimulation, improved glucose-stimulated insulin secretion, and reduced β cell death. Key ECM proteins, absent in monolayer β cells, are deposited by iECs in and round the PIs. iEC induced PIs are a useful tool for examining β-cell/iEC interactions and studying β-cell function in a native 3D configuration.

The invention discloses a cryopreservation method, a resuscitation method and a reconstruction method of islet cells. According to the invention, the pancreas islet is dissociated into the pancreas islet single cells, and the pancreas islet single cells are cryopreserved, so that the problem that the pancreas islet is not easy to cryopreserve is solved, and the cryopreserved pancreas islet single cells are recovered and then co-cultured with human mesenchymal stem cells to obtain reconstructed cell cluster. According to the islet cell reconstruction method disclosed by the invention, the cryopreserved islet single cells can be rapidly reconstructed into a cell cluster after being recovered, the clustering rate is high (the highest clustering rate can reach 100%), and the repeatability is good. The islet cell cluster obtained through reconstruction is spherical and solid, the diameter is 100-750 microns, and the islet cell cluster is equivalently composed of 5-30 layers of cells. The islet cell cluster obtained through reconstruction can respond to glucose stimulation when being cultured in vitro. In blood glucose level detection of transplanted nude mice, the reconstructed cell cluster has a blood glucose regulation function equivalent to that of the pancreas islet.

This invention provides novel peptides that function in vivo as agonists of the VPAC2 receptor. These insulin secretagogue polypeptides are shown to lower blood glucose in vivo upon glucose challenge. The polypeptides of this invention are also stable in formulation and have long half-lives. The peptides of the present invention provide a therapy for patients with decreased endogenous insulin secretion, for example, type 2 diabetics. The invention is also directed to a method of treating a metabolic disease in a mammal comprising administering a therapeutically effective amount of the peptides to said mammal.

The present application discloses cell clusters resembling the function and characteristics of endogenous pancreatic islets, and methods for making and using such cell clusters. The present disclosureprovides an in vitro cell cluster comprising at least one non-native pancreatic beta cell that exhibits an in vitro glucose-stimulated insulin secretion response when exposed to a glucose challenge,wherein the cell cluster is an unsorted cell cluster, and wherein the cell cluster comprises: at least 35% of cells that express NKX6.1 and C-peptide; at least 70% of cells that express chromogranin A; at most about 2% of cells that express SOX2; or at most about 10% of cells that express SOX9. In some cases, when transplanted into a subject, the in vitro cell cluster exhibits an in vivo glucose-stimulated insulin secretion response to a glucose challenge in the subject.

The invention discloses a method for culturing a mini-porcine islet cell in vitro. The method comprises the following steps that a cell growth liquid is prepared; a cell culture liquid is prepared; amini-porcine islet cell cryopreservation tube is taken out, melted and placed into a centrifuge tube containing the cell growth liquid to be centrifuged, a liquid supernatant is removed, the cell growth liquid is adopted to suspend the cell at the bottom of the centrifuge tube, then the cell is extracted into a first culture dish containing the cell growth liquid, and the first culture dish is putinto an incubator for cultivation; after cultivation, the culture dish and a culture medium are replaced, a second culture dish containing the cell culture liquid is adopted for cultivation, and thenthe culture dish and the culture medium are replaced every 1-3 days, and the cell culture liquid is used as the culture medium all the time. The method for culturing the mini-porcine islet cell in vitro can reduce the cell wilting rate, increase the islet beta cell viability, and the cultured cell has a sensitive glucose stimulating response function, so that the method can meet the requirementsfor studying human islet diseases and has important market value and social value.

The invention provides a method for improving insulin secretion of pancreatic islet cells through gene modification. The pancreatic related cells are modified by adopting an ERRgamma gene. According to the invention, specific ERRgamma protein is brought into pancreatic islet cells to activate glycometabolism-related pathways, so that the content of ERRgamma protein secreted by pancreatic islet cells and the amount of insulin are increased. The pancreatic islet cells are obtained by culturing 7-9 pancreatic related cells infected by the virus containing the ERR gamma gene, and the content of secreted ERR gamma protein is 3.2-3.5 ng/ml; the content of insulin secreted under the stimulation of 22mmol of glucose is 71.2-75 ng/ml, and the content of insulin secreted under the stimulation of 2mmol of glucose is 11.6-12 ng/ml.

The present invention relates to an in vitro method for preparing and producing canine pancreatic islets from immature pancreatic tissue. Such islets express, produce and secrete insulin upon glucose stimulation. The invention further encompasses canine pancreatic islets obtainable according to the present method, islet population of said islets and compositions comprising said islets. It also relates to transduced canine pancreatic islets, or tumours or cells derived thereof. The present invention also concerns the use of said canine pancreatic islets or cells derived thereof for treating a canine pancreatic disorder, such as canine diabetes, or for diagnosing canine diabetes.