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1.
Curr Diabetes Rev ; 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38303524

RESUMO

BACKGROUND: The global incidence of type 2 diabetes (T2D) persists at epidemic proportions. Early diagnosis and/or preventive efforts are critical to attenuate the multi-systemic clinical manifestation and consequent healthcare burden. Despite enormous strides in the understanding of pathophysiology and on-going therapeutic development, effectiveness and access are persistent limitations. Among the greatest challenges, the extensive research efforts have not promulgated reliable predictive biomarkers for early detection and risk assessment. The emerging fields of multi-omics combined with machine learning (ML) and augmented intelligence (AI) have profoundly impacted the capacity for predictive, preventive, and personalized medicine. OBJECTIVE: This paper explores the current challenges associated with the identification of predictive biomarkers for T2D and discusses potential actionable solutions for biomarker identification and validation. METHODS: The articles included were collected from PubMed queries. The selected topics of inquiry represented a wide range of themes in diabetes biomarker prediction and prognosis. RESULTS: The current criteria and cutoffs for T2D diagnosis are not optimal nor consider a myriad of contributing factors in terms of early detection. There is an opportunity to leverage AI and ML to significantly enhance the understanding of the underlying mechanisms of the disease and identify prognostic biomarkers. The innovative technologies being developed by GATC are expected to play a crucial role in this pursuit via algorithm training and validation, enabling comprehensive and in-depth analysis of complex biological systems. CONCLUSION: GATC is an emerging leader guiding the establishment of a systems approach towards research and predictive, personalized medicine. The integration of these technologies with clinical data can contribute to a more comprehensive understanding of T2D, paving the way for precision medicine approaches and improved patient outcomes.

2.
Int J Mol Sci ; 22(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34445075

RESUMO

Pre-weaned porcine islets (PPIs) represent an unlimited source for islet transplantation but are functionally immature. We previously showed that necrostatin-1 (Nec-1) immediately after islet isolation enhanced the in vitro development of PPIs. Here, we examined the impact of Nec-1 on the in vivo function of PPIs after transplantation in diabetic mice. PPIs were isolated from pancreata of 8-15-day-old, pre-weaned pigs and cultured in media alone, or supplemented with Nec-1 (100 µM) on day 0 or on day 3 of culture (n = 5 for each group). On day 7, islet recovery, viability, oxygen consumption rate, insulin content, cellular composition, insulin secretion capacity, and transplant outcomes were evaluated. While islet viability and oxygen consumption rate remained high throughout 7-day tissue culture, Nec-1 supplementation on day 3 significantly improved islet recovery, insulin content, endocrine composition, GLUT2 expression, differentiation potential, proliferation capacity of endocrine cells, and insulin secretion. Adding Nec-1 on day 3 of tissue culture enhanced the islet recovery, proportion of delta cells, beta-cell differentiation and proliferation, and stimulation index. In vivo, this leads to shorter times to normoglycemia, better glycemic control, and higher circulating insulin. Our findings identify the novel time-dependent effects of Nec-1 supplementation on porcine islet quantity and quality prior to transplantation.


Assuntos
Diabetes Mellitus Experimental/terapia , Imidazóis/farmacologia , Indóis/farmacologia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/efeitos dos fármacos , Técnicas de Cultura de Tecidos/métodos , Animais , Diabetes Mellitus Experimental/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/fisiologia , Camundongos Nus , Suínos , Transplante Heterólogo/métodos , Transplantes/efeitos dos fármacos , Transplantes/fisiologia
3.
Cell Transplant ; 30: 963689721999617, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33757335

RESUMO

The origins of low-temperature tissue storage research date back to the late 1800s. Over half a century later, osmotic stress was revealed to be a main contributor to cell death during cryopreservation. Consequently, the addition of cryoprotective agents (CPAs) such as dimethyl sulfoxide (DMSO), glycerol (GLY), ethylene glycol (EG), or propylene glycol (PG), although toxic to cells at high concentrations, was identified as a necessary step to protect against rampant cell death during cryopreservation. In addition to osmotic stress, cooling and thawing rates were also shown to have significant influence on cell survival during low temperature storage. In general, successful low-temperature cell preservation consists of the addition of a CPA (commonly 10% DMSO), alone or in combination with additional permeating or non-permeating agents, cooling rates of approximately 1ºC/min, and storage in either liquid or vapor phase nitrogen. In addition to general considerations, cell-specific recommendations for hepatocytes, pancreatic islets, sperm, oocytes, and stem cells should be observed to maximize yields. For example, rapid cooling is associated with better cryopreservation outcomes for oocytes, pancreatic islets, and embryonic stem cells while slow cooling is recommended for cryopreservation of hepatocytes, hematopoietic stem cells, and mesenchymal stem cells. Yields can be further maximized by implementing additional pre-cryo steps such as: pre-incubation with glucose and anti-oxidants, alginate encapsulation, and selecting cells within an optimal age range and functional ability. Finally, viability and functional assays are critical steps in determining the quality of the cells post-thaw and improving the efficiency of the current cryopreservation methods.


Assuntos
Sobrevivência Celular/fisiologia , Criopreservação/métodos , Crioprotetores/uso terapêutico , Humanos
4.
Cell Transplant ; 29: 963689720977835, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33267618

RESUMO

For the advancement of porcine xenotransplantation for clinical use in type 1 diabetes mellitus, the concerns of a sustainable and safe digestion enzyme blend must be overcome. Incorporating good manufacturing practices (GMP) can facilitate this through utilizing GMP-grade enzymes. In conjunction, still taking into account the cost-effectiveness, a wide concern. We evaluated how GMP-grade enzyme blends impact our piglet islets and their long-term effects. Preweaned porcine islets (PPIs) were isolated from 8- to 10-day-old pigs. Digestion enzyme blends, collagenase type V (Type V), collagenase AF-1 GMP-grade with collagenase NB 6 GMP-grade (AF-1 and NB 6), and collagenase AF-1 GMP-grade with collagenase neutral protease AF GMP-grade (AF-1 and NP AF) were compared. Islet quality control assessments, islet yield, viability, and function, were performed on days 3 and 7, and cell content was performed on day 7. GMP-grade AF-1 and NB 6 (17,209 ± 2,730 islet equivalent per gram of pancreatic tissue [IE/g] on day 3, 9,001 ± 1,034 IE/g on day 7) and AF-1 and NP AF (17,214 ± 3,901 IE/g on day 3, 8,833 ± 2,398 IE/g on day 7) showed a significant increase in islet yield compared to Type V (4,618 ± 1,240 IE/g on day 3, 1,923 ± 704 IE/g on day 7). Islet size, viability, and function showed comparable results in all enzyme blends. There was no significant difference in islet cellular content between enzyme blends. This study demonstrated a comparison of GMP-grade collagenase enzyme blends and a standard crude collagenase enzyme in preweaned-aged porcine, a novel topic in this age. GMP-grade enzyme blends of AF-1 and NB 6 and AF-1 and NP AF resulted in substantially higher yields and as effective PPIs compared to Type V. In the long run, considering costs, integrity, and sustainability, GMP-grade enzyme blends are more favorable for clinical application due to high reproducibility in comparison to undefined manufacturing processes of standard enzymes.


Assuntos
Colagenases/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Animais , Ilhotas Pancreáticas/fisiologia , Transplante das Ilhotas Pancreáticas , Pâncreas , Suínos , Sobrevivência de Tecidos/fisiologia
5.
Cell Transplant ; 29: 963689720952343, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33023311

RESUMO

Transplantation of pancreatic islets within a biomaterial device is currently under investigation in clinical trials for the treatment of patients with type 1 diabetes (T1D). Patients' preferences on such implants could guide the designs of next-generation implantable devices; however, such information is not currently available. We surveyed the preferences of 482 patients with T1D on the size, shape, visibility, and transplantation site of islet containing implants. More than 83% of participants were willing to receive autologous stem cells, and there was no significant association between implant fabricated by one's own stem cell with gender (χ2 (1, n = 468) = 0.28; P = 0.6) or with age (χ2 (4, n = 468) = 2.92; P = 0.6). Preferred location for islet transplantation within devices was under the skin (52.7%). 48.3% preferred microscopic disks, and 32.3% preferred a thin device (like a credit card). Moreover, 58.4% preferred the implant to be as small as possible, 25.4% did not care about visibility, and 16.2% preferred their implants not to be visible. Among female participants, 81% cared about the implant visibility, whereas this number was 64% for male respondents (χ2 test (1, n = 468) = 16.34; P < 0.0001). 22% of those younger than 50 years of age and 30% of those older than 50 did not care about the visibility of implant (χ2 test (4, n = 468) = 23.69; P < 0.0001). These results suggest that subcutaneous sites and micron-sized devices are preferred choices among patients with T1D who participated in our survey.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas/instrumentação , Adolescente , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
6.
Cryobiology ; 88: 23-28, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30991035

RESUMO

Islet transplantation has been shown to restore normoglycemia in animal models and for type 1 diabetic patients in clinical trials. One method of storing islets intended for transplantation is via cryobanking at very low temperatures (-196 °C). Cryobanking islets without the use of cryoprotecting agents (CPAs) contributes to cellular shear stress and cell death. Although current CPA protocols vary, high concentrations of these agents are toxic to islets cells. This study tested the effects of the permeating CPA dimethyl sulfoxide (Me2SO) with the addition of ethylene glycol (EG), both at reduced concentrations, on rat and human islet cell yield, viability, and glucose stimulated insulin release (GSIR). To test this, islets were treated using three combinations of CPAs (2M ME2SO, 1M ME2SO + 1M EG, and 1M ME2SO + 0.5M EG). Next, fresh islets, 2M ME2SO islets, and 1M ME2SO + 0.5M EG isolated rat islets were transplanted into streptozotocin-induced (STZ) diabetic mice. Our data showed that cryopreservation with a reduced concentration of ME2SO (1M ME2SO + multimolar EG) achieved a higher percent yield and viability when compared to the current standard 2M ME2SO treatment for both rat and human islets. Furthermore, STZ-induced diabetic mice achieved normoglycemia after transplantation with 1000 islet equivalents (IE), an average 12 days sooner, with islets cryopreserved with reduced-concentration (ME2SO + 0.5M EG), compared to islets preserved with 2M ME2SO. In conclusion, reduced concentration of penetrating CPAs during islet cryopreservation increases islet yield and viability in vitro and reduces delay before normoglycemia in diabetic mice.


Assuntos
Criopreservação/métodos , Crioprotetores/farmacologia , Diabetes Mellitus Experimental/terapia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/citologia , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Dimetil Sulfóxido/farmacologia , Etilenoglicol/farmacologia , Humanos , Masculino , Camundongos , Camundongos Nus , Ratos , Ratos Sprague-Dawley
7.
Cell Med ; 11: 2155179019876641, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-34557325

RESUMO

Islet transplantation has been shown to restore normoglycemia clinically. One of the current limitations to the widespread clinical use of islet transplantation is culturing and preserving more than 1 million islet equivalents in preparation for transplant. One possible solution is to bank frozen islets and use them when needed. Although promising, the standard islet freezing protocol introduces stress and cell death, resulting in high variability of islet quality post thawing. This study aimed to develop an improved cryopreservation protocol using alginate-encapsulated islets to improve islet survival and function for future transplants. Our data showed that encapsulation improved islet survival and function after thawing the frozen islets. Frozen encapsulated islets have an islet yield recovery of 84% when compared to non-encapsulated islets at 72% after thawing. Post-thaw viability was 78% for non-encapsulated islets compared to 88% for encapsulated islets. The stimulation index values after a static glucose test following thawing were 1.9 ± 0.5, 2.9 ± 0.1, and 3.3 ± 0.3 for the non-encapsulated, 1.75% alginate, and 2.5% alginate groups, respectively. In a transplant study, the mice that received 1.75% alginate-encapsulated cryopreserved islets achieved normoglycemia on average 5 days after transplant. In comparison, control mice that received fresh islets took 4 days, while those receiving unencapsulated cryopreserved islets took 18 days. In conclusion, encapsulating islets in 1.75% alginate prior to freezing was shown to improve islet survival, function post thawing, and graft response significantly when compared to islets frozen without encapsulation.

8.
J Diet Suppl ; 16(4): 454-462, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29958040

RESUMO

Cycloferin is an extract of the chemicals from the Cyclopia species, which grows only in small areas in the southwest and southeast of South Africa and has been consumed traditionally as a nourishing tea to treat numerous health issues and illnesses. Previous studies report that some of the active compounds in Cycloferin, such as pinitol (a modified sugar) and mangiferin (a glucoside), may reduce blood sugar levels and therefore may be used as a treatment for diabetes. Mangiferin, in particular, has been shown to stimulate carbohydrate oxidation and alleviate some effects of insulin resistance and hyperglycemia. Other active components of Cycloferin include flavones, isoflavones, coumestans, luteolin, 4-hydroxycinnamic acid, polyphenols, and xanthones. These active compounds are antioxidants, which can enhance glucose breakdown, lower blood lipids, and reduce the number of highly reactive compounds known as free radicals, which can alter cellular structure and function when present in large amounts. In this study, we explored the ameliorative effects of Cycloferin by treating streptozotocin- (STZ) injected rats with Cycloferin and evaluating its long-term and short-term effect on blood glucose levels and kidney and liver conditions of the diabetic-rendered rats. Our results demonstrated the ability of Cycloferin to both lower the blood glucose levels and reduce evidence of damage in kidney and liver in diabetic rats with and without exogenous insulin treatment for partial control of diabetic state.


Assuntos
Cyclopia (Planta)/química , Diabetes Mellitus Experimental/tratamento farmacológico , Insulina/uso terapêutico , Extratos Vegetais/administração & dosagem , Animais , Glicemia/análise , Diabetes Mellitus Experimental/complicações , Suplementos Nutricionais , Inositol/administração & dosagem , Inositol/análogos & derivados , Inositol/análise , Inositol/farmacologia , Nefropatias/patologia , Nefropatias/prevenção & controle , Hepatopatias/patologia , Hepatopatias/prevenção & controle , Masculino , Fitoterapia , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Xantonas/administração & dosagem , Xantonas/análise , Xantonas/farmacologia
9.
J Tissue Eng ; 8: 2041731417691645, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28228933

RESUMO

Success of cell therapy in avascular sites will depend on providing sufficient blood supply to transplanted tissues. A popular strategy of providing blood supply is to embed cells within a functionalized hydrogel implanted within the host to stimulate neovascularization. However, hydrogel systems are not always amenable for removal post-transplantation; thus, it may be advantageous to implant a device that contains cells while also providing access to the circulation so retrieval is possible. Here we investigate one instance of providing access to a vessel network, a thin sheet with through-cut slits, and determine if it can be vascularized from autologous materials. We compared the effect of slit width on vascularization of a thin sheet following subcutaneous implantation into an animal model. Polydimethylsiloxane sheets with varying slit widths (approximately 150, 300, 500, or 1500 µm) were fabricated from three-dimensional printed molds. Subcutaneous implantation of sheets in immunodeficient mice revealed that smaller slit widths have evidence of angiogenesis and new tissue growth, while larger slit widths contain native mature tissue squeezing into the space. Our results show that engineered slit sheets may provide a simple approach to cell transplantation by providing a prevascularized and innervated environment.

10.
Transplantation ; 99(4): 710-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25793438

RESUMO

BACKGROUND: Porcine islet xenotransplantation has been demonstrated in many animal studies to cure experimentally induced diabetes. However, several issues currently impede the translation of porcine islet xenotransplantation to sustained insulin independence clinically. Although adult pigs have mature islets that secrete insulin in response to a glucose challenge, and are physiologically similar to humans, there are logistical considerations with adult porcine tissue that are not present with juvenile porcine tissue. To circumvent these issues, we have identified 18- to 21-day-old preweaned juvenile pigs as islet donors as we have previously demonstrated superior islet yields and function from juvenile pigs using our islet isolation protocols. METHODS: We evaluated the efficacy of islets isolated from 18- to 24-day-old Yorkshire swine in vitro using a standard glucose-stimulated insulin response assay, and in vivo after xenotransplantation under the kidney capsule of streptozotocin-induced 8- to 10-week-old male athymic nude mice. The mice were monitored for a period of 60 days after transplantation, after which the grafts were explanted and analyzed. RESULTS: Diabetic athymic nude mice transplanted with 1500 to 3000 islet equivalents (IEq) of islets achieved sustained normoglycemia for up to 60 days after islet transplantation. When the grafts were explanted with the kidney, a rapid return to hyperglycemia was observed. CONCLUSIONS: Efficacy and dose-titration studies evaluating these islets in immunocompetent and nonobese diabetic mouse models are underway. The results of these studies will permit application for nonhuman primate and pivotal clinical trials in human diabetic patients in the near future.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Experimental/cirurgia , Transplante das Ilhotas Pancreáticas/métodos , Rim/cirurgia , Pâncreas/metabolismo , Fatores Etários , Animais , Biomarcadores/sangue , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/diagnóstico , Diabetes Mellitus Experimental/fisiopatologia , Sobrevivência de Enxerto , Rim/metabolismo , Masculino , Camundongos Nus , Pâncreas/patologia , Pâncreas/fisiopatologia , Recuperação de Função Fisiológica , Suínos , Fatores de Tempo , Técnicas de Cultura de Tecidos , Transplante Heterólogo
11.
Immune Netw ; 13(6): 235-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24385941

RESUMO

Encapsulation of tissue has been an area of intense research with a myriad number of therapeutic applications as diverse as cancer, tissue regeneration, and diabetes. In the case of diabetes, transplantation of pancreatic islets of Langerhans containing insulin-producing beta cells has shown promise toward a cure. However, anti-rejection therapy that is needed to sustain the transplanted tissue has numerous adverse effects, and the islets might still be damaged by immune processes. Furthermore, the profound scarcity of healthy human donor organs restricts the availability of islets for transplant. Islet encapsulation allows the protection of this tissue without the use of toxic medications, while also expanding the donor pool to include animal sources. Before the widespread application of this therapy, there are still issues that need to be resolved. There are many materials that can be used, differing shapes and sizes of capsules, and varied sources of islets to name a few variables that need to be considered. In this review, the current options for capsule generation, past animal and human studies, and future directions in this area of research are discussed.

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