Animal Model Of Type Research Articles

Hypoglycemic, hypolipidemic and antioxidant potential of Myrcia pubipetala in an animal model of type 1 diabetes

Myrcia genus plants, like Myrcia pubipetala, traditionally used as hypoglycemic agents, hold promise for Type 1 Diabetes Mellitus (DM1) research but need more comprehensive chemical and pharmacological investigation. This is an experimental study involving controlled administration of treatments to a group of rats to assess their effects compared with a control group, investigating the effects of M. pubipetala on alloxan-induced Type 1 Diabetes Mellitus in rats. After the induction of diabetes, the rats received the hydroalcoholic extract (HAE) or aqueous fraction (AF) (25, 50, 100, or 150 mg kg-1) of M. pubipetala, or water. The results showed that diabetic rats presented cell damage in kidneys, oxidative stress, and high levels of glucose and triglycerides in their plasma and erythrocytes. The HAE (150 mg kg-1), per se, reduced lipid and protein oxidation, and the AF (150 mg kg-1) decreased lipoperoxidation. AF (150 mg kg-1), per se, decreased triglyceride levels. Conclusion: treatment with HAE and AF reduced oxidative damage, positively modulated antioxidant defenses, and exerted hypoglycemic and hypolipidemic effects, representing a potential adjuvant treatment for diabetes.

Disruption of branched-chain amino acid homeostasis promotes the progression of DKD via enhancing inflammation and fibrosis-associated epithelial-mesenchymal transition

Background and aimsThe disrupted homeostasis of branched-chain amino acids (BCAAs, including leucine, isoleucine, and valine) has been strongly correlated with diabetes with a potential causal role. However, the relationship between BCAAs and diabetic kidney disease (DKD) remains to be established. Here, we show that the elevated BCAAs from BCAAs homeostatic disruption promote DKD progression unexpectedly as an independent risk factor. Methods and resultsSimilar to other tissues, the suppressed BCAAs catabolic gene expression and elevated BCAAs abundance were detected in the kidneys of type 2 diabetic mice and individuals with DKD. Genetic and nutritional studies demonstrated that the elevated BCAAs from systemic disruption of BCAAs homeostasis promoted the progression of DKD. Of note, the elevated BCAAs promoted DKD progression without exacerbating diabetes in the animal models of type 2 DKD. Mechanistic studies demonstrated that the elevated BCAAs promoted fibrosis-associated epithelial-mesenchymal transition (EMT) by enhancing the activation of proinflammatory macrophages through mTOR signaling. Furthermore, pharmacological enhancement of systemic BCAAs catabolism using small molecule inhibitor attenuated type 2 DKD. Finally, the elevated BCAAs also promoted DKD progression in type 1 diabetic mice without exacerbating diabetes. ConclusionBCAA homeostatic disruption serves as an independent risk factor for DKD and restoring BCAA homeostasis pharmacologically or dietarily represents a promising therapeutic strategy to ameliorate the progression of DKD.

Deciphering the kidney hemodynamic effects of SGLT2 inhibition: translating insights from rats to humans in type 2 diabetes

The attenuation of glomerular hyperfiltration is posited to be a principal mechanism underlying the kidney protective effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors in diabetic kidney disease. Notably, the impact of SGLT2 inhibitors on kidney hemodynamic function has been posited to vary between type 1 and type 2 diabetes. The study by Wada etal. documents that in an animal model of type 2 diabetes, SGLT2 inhibitors mitigate glomerular hyperfiltration predominantly through afferent arteriolar constriction, a process mediated by the adenosine/A1 receptor pathway. This observation is consistent with mechanisms identified in type 1 diabetes, arguing for similar methods in type 1 and 2 diabetes.

Arylphthalide Delays Diabetic Retinopathy via Immunomodulating the Early Inflammatory Response in an Animal Model of Type 1 Diabetes Mellitus.

Diabetic retinopathy (DR) is one of the most prevalent secondary complications associated with diabetes. Specifically, Type 1 Diabetes Mellitus (T1D) has an immune component that may determine the evolution of DR by compromising the immune response of the retina, which is mediated by microglia. In the early stages of DR, the permeabilization of the blood-retinal barrier allows immune cells from the peripheral system to interact with the retinal immune system. The use of new bioactive molecules, such as 3-(2,4-dihydroxyphenyl)phthalide (M9), with powerful anti-inflammatory activity, might represent an advance in the treatment of diseases like DR by targeting the immune systems responsible for its onset and progression. Our research aimed to investigate the molecular mechanisms involved in the interaction of specific cells of the innate immune system during the progression of DR and the reduction in inflammatory processes contributing to the pathology. In vitro studies were conducted exposing Bv.2 microglial and Raw264.7 macrophage cells to proinflammatory stimuli for 24 h, in the presence or absence of M9. Ex vivo and in vivo approaches were performed in BB rats, an animal model for T1D. Retinal explants from BB rats were cultured with M9. Retinas from BB rats treated for 15 days with M9 via intraperitoneal injection were analyzed to determine survival, cellular signaling, and inflammatory markers using qPCR, Western blot, or immunofluorescence approaches. Retinal structure images were acquired via Spectral-Domain-Optical Coherence Tomography (SD-OCT). Our results show that the treatment with M9 significantly reduces inflammatory processes in in vitro, ex vivo, and in vivo models of DR. M9 works by inhibiting the proinflammatory responses during DR progression mainly affecting immune cell responses. It also induces an anti-inflammatory response, primarily mediated by microglial cells, leading to the synthesis of Arginase-1 and Hemeoxygenase-1(HO-1). Ultimately, in vivo administration of M9 preserves the retinal integrity from the degeneration associated with DR progression. Our findings demonstrate a specific interaction between both retinal and systemic immune cells in the progression of DR, with a differential response to treatment, mainly driven by microglia in the anti-inflammatory action. In vivo treatment with M9 induces a switch in immune cell phenotypes and functions that contributes to delaying the DR progression, positioning microglial cells as a new and specific therapeutic target in DR.

The administration of Cerebrolysin elicits neuroprotective and neurorepair effects in an animal model of type 1 diabetes mellitus

Diabetes mellitus (DM) is a metabolic disorder impacting cerebral function. The administration of Streptozotocin (STZ) is a well-known animal model of insulinopenic type 1 DM in rats. STZ-induced DM results in a myriad of alteration in the periphery and central nervous system (CNS). Cerebrolysin (CBL) is a neuropeptide preparation that promotes synaptic and neuronal plasticity in various animal models. In all cases, CBL was administered when the model was established. This research aims to investigate the neuroprotective and neurorepair effect of CBL on the cytoarchitecture of neurons and spine density in pyramidal neurons of the prefrontal (PFC) and the CA1 region of the dorsal hippocampus, as well as spheroidal neurons of the dentate gyrus (DG), in STZ-induced DM. In the first experimental condition, STZ and CBL are administered at the same time to evaluate the potential preventive effect of CBL. In the second experimental condition, CBL was administered two months after establishing the DM model to measure the potential neurorepair effect of CBL. STZ-induced hyperglycemia remained unaltered by the administration of CBL in both experimental conditions. In the first experimental condition, CBL treatment preserved the neuronal morphology in PFC layer 3, PFC layer 5 and the DG of the hippocampus, while also maintaining spine density in the PFC-3, DG and CA1 hippocampus. Furthermore, CBL induced neurorepair in neurons within the PFC-3, PFC-5 and CA1 regions of the hippocampus, along with an increase in spine density in the PFC-3, DG and CA1 hippocampus. These findings suggest that CBL´s effects on neuroplasticity could be observed before or after the damage was evident.

Evaluation of glomerular hemodynamic changes by sodium-glucose-transporter 2 inhibition in type 2 diabetic rats using in vivo imaging

The mechanisms responsible for glomerular hemodynamic regulation with sodium-glucose co-transporter 2 (SGLT2) inhibitors in kidney disease due to type 2 diabetes remain unclear. Therefore, we investigated changes in glomerular hemodynamic function using an animal model of type 2 diabetes, treated with an SGLT2 inhibitor alone or in combination with a renin-angiotensin-aldosterone system inhibitor using male Zucker lean (ZL) and Zucker diabetic fatty (ZDF) rats. Afferent and efferent arteriolar diameter and single-nephron glomerular filtration rate (SNGFR) were evaluated in ZDF rats measured at 0, 30, 60, 90, or 120 minutes after the administration of a SGLT2 inhibitor (luseogliflozin). Additionally, we assessed these changes under the administration of the adenosine A1 receptor (A1aR) antagonist (8-cyclopentyl-1,3-dipropylxanthine), along with coadministration of luseogliflozin and an angiotensin II receptor blocker (ARB), telmisartan. ZDF rats had significantly increased SNGFR, and afferent and efferent arteriolar diameters compared to ZL rats, indicating glomerular hyperfiltration. Administration of luseogliflozin significantly reduced afferent vasodilatation and glomerular hyperfiltration, with no impact on efferent arteriolar diameter. Urinary adenosine levels were increased significantly in the SGLT2 inhibitor group compared to the vehicle group. A1aR antagonism blocked the effect of luseogliflozin on kidney function. Co-administration of the SGLT2 inhibitor and ARB decreased the abnormal expansion of glomerular afferent arterioles, whereas the efferent arteriolar diameter was not affected. Thus, regulation of afferent arteriolar vascular tone via the A1aR pathway is associated with glomerular hyperfiltration in type 2 diabetic kidney disease.

#1071 The effect and mechanism of SGLT2 inhibitor on improving inflammatory injury of glomerular endothelial cells in diabetes

Abstract Background and Aims ATP-binding cassette transporter A1 (ABCA1), which reduces intracellular cholesterol accumulation, is highly expressed in the kidney. Studies have shown that sodium-glucose co-transporter 2 inhibitors (SGLT2) inhibitors promote ABCA1 expression in multiple tissues and organs. However, the effect of SGLT2 inhibitors on ABCA1 expression in diabetic kidney disease (DKD) is unclear. In this study, the effect of empagliflozin, an SGLT2 inhibitor, on ABCA1 in glomerular endothelial cells(GECs) of DKD and the possible mechanisms linking ABCA1 to GECs inflammatory injury were investigated. Method Kidney tissues were obtained from renal biopsies of patients with early and advanced DKD. db/db mice were used as animal models of type 2 diabetes and the effects of SGLT2 inhibitors on ABCA1 were analyzed by treatment with empagliflozin. The effects of ABCA1 overexpression on glomerular lipid deposition and kidney injury were examined in a type 2 diabetic mouse model with ABCA1 overexpression (db/db + ABCA1 mice), and human renal glomerular endothelial cells (HRGECs) cultured in high glucose and high cholesterol conditions, which simulated type 2 diabetes in vitro. Results The expression of ABCA1 in the glomeruli of DKD patients and db/db mice was significantly decreased. Enhancing ABCA1 expression in the kidney tissue of diabetic mice by adenovirus transduction improved renal cholesterol deposition, inhibited the overactivation of C3a/C5a, and improved renal inflammatory injury. In addition, in cultured HRGECs under high glucose and high cholesterol conditions, ABCA1 deficiency increased the deposit of cellular cholesterol, contributed to overactivation of C3a/C5a, and induced inflammatory injury. Overexpression of ABCA1 enhancing cholesterol efflux or inhibition of C3a/C5a activation in vitro significantly protected against glomerular endothelial injury stimulated by high glucose and high cholesterol. Moreover, SGLT2 inhibitor empagliflozin up-regulated the expression of ABCA1 and down-regulated the levels of cholesterol, C3a/C5a and inflammatory cytokines in diabetic mice and HRGECs. Conclusion SGLT2 inhibitor (empagliflozin) might play a renal protective role by up-regulating ABCA1-mediated cholesterol outflow, inhibiting the activation of C3a/C5a, and then ameliorating the inflammatory injury of GECs.

Animal models for type 1 and type 2 diabetes: advantages and limitations.

Diabetes mellitus, commonly referred to as diabetes, is a group of metabolic disorders characterized by chronic elevation in blood glucose levels, resulting from inadequate insulin production, defective cellular response to extracellular insulin, and/or impaired glucose metabolism. The two main types that account for most diabetics are type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), each with their own pathophysiological features. T1D is an autoimmune condition where the body's immune system attacks and destroys the insulin-producing beta cells in the pancreas. This leads to lack of insulin, a vital hormone for regulating blood sugar levels and cellular glucose uptake. As a result, those with T1D depend on lifelong insulin therapy to control their blood glucose level. In contrast, T2DM is characterized by insulin resistance, where the body's cells do not respond effectively to insulin, coupled with a relative insulin deficiency. This form of diabetes is often associated with obesity, sedentary lifestyle, and/or genetic factors, and it is managed with lifestyle changes and oral medications. Animal models play a crucial role in diabetes research. However, given the distinct differences between T1DM and T2DM, it is imperative for researchers to employ specific animal models tailored to each condition for a better understanding of the impaired mechanisms underlying each condition, and for assessing the efficacy of new therapeutics. In this review, we discuss the distinct animal models used in type 1 and type 2 diabetes mellitus research and discuss their strengths and limitations.

Melanoxetin: A Hydroxylated Flavonoid Attenuates Oxidative Stress and Modulates Insulin Resistance and Glycation Pathways in an Animal Model of Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (DM) continues to escalate, necessitating innovative therapeutic approaches that target distinct pathways and address DM complications. Flavonoids have been shown to possess several pharmacological activities that are important for DM. This study aimed to evaluate the in vivo effects of the flavonoid melanoxetin using Goto-Kakizaki rats. Over a period of 14 days, melanoxetin was administered subcutaneously to investigate its antioxidant, anti-inflammatory, and antidiabetic properties. The results show that melanoxetin reduced insulin resistance in adipose tissue by targeting protein tyrosine phosphatase 1B. Additionally, melanoxetin counteracted oxidative stress by reducing nitrotyrosine levels and modulating superoxide dismutase 1 and hemeoxygenase in adipose tissue and decreasing methylglyoxal-derived hydroimidazolone (MG-H1), a key advanced glycation end product (AGE) implicated in DM-related complications. Moreover, the glyoxalase 1 expression decreased in both the liver and the heart, correlating with reduced AGE levels, particularly MG-H1 in the heart. Melanoxetin also demonstrated anti-inflammatory effects by reducing serum prostaglandin E2 levels, and increasing the antioxidant status of the aorta wall through enhanced acetylcholine-dependent relaxation in the presence of ascorbic acid. These findings provide valuable insights into melanoxetin's therapeutic potential in targeting multiple pathways involved in type 2 DM, particularly in mitigating oxidative stress and glycation.

Deficiency of Trex1 leads to spontaneous development of type 1 diabetes

BackgroundType 1 diabetes is believed to be an autoimmune condition, characterized by destruction of insulin-producing cells, due to the detrimental inflammation in pancreas. Growing evidences have indicated the important role of type I interferon in the development of type 1 diabetes.MethodsTrex1-deficient rats were generated by using CRISPR-Cas9. The fasting blood glucose level of rat was measured by a Roche Accuchek blood glucose monitor. The levels of insulin, islet autoantibodies, and interferon-β were measured using enzyme-linked immunosorbent assay. The inflammatory genes were detected by quantitative PCR and RNA-seq. Hematein-eosin staining was used to detect the pathological changes in pancreas, eye and kidney. The pathological features of kidney were also detected by Masson trichrome and periodic acid-Schiff staining. The distribution of islet cells, immune cells or ssDNA in pancreas was analyzed by immunofluorescent staining.ResultsIn this study, we established a Trex1-deletion Sprague Dawley rat model, and unexpectedly, we found that the Trex1−/− rats spontaneously develop type 1 diabetes. Similar to human diabetes, the hyperglycemia in rats is accompanied by diabetic complications such as diabetic nephropathy and cataract. Mechanistical investigation revealed the accumulation of ssDNA and the excessive production of proinflammatory cytokines, including IFN-β, in Trex1 null pancreas. These are likely contributing to the inflammation in pancreas and eventually leading to the decline of pancreatic β cells.ConclusionsOur study links the DNA-induced chronic inflammation to the pathogenesis of type 1 diabetes, and also provides an animal model for type 1 diabetes studies.

Changes in hippocampal volume, synaptic plasticity and amylin sensitivity in an animal model of type 2 diabetes are associated with increased vulnerability to amyloid-beta in advancing age.

Type-2 diabetes (T2D) is a metabolic disorder that is considered a risk factor for Alzheimer's disease (AD). Cognitive impairment can arise due to hypoglycemia associated with T2D, and hyperamylinemia associated with insulin resistance can enhance AD pathology. We explored whether changes occur in the hippocampus in aging (6-12 months old) female V-Lep○b-/- transgenic (tg) mice, comprising an animal model of T2D. We also investigated whether an increase in vulnerability to Aβ (1-42), a known pathological hallmark of AD, is evident. Using magnetic resonance imaging we detected significant decreases in hippocampal brain volume in female tg-mice compared to wild-type (wt) littermates. Long-term potentiation (LTP) was impaired in tg compared to wt mice. Treatment of the hippocampus with Aβ (1-42) elicited a stronger debilitation of LTP in tg compared to wt mice. Treatment with an amylin antagonist (AC187) significantly enhanced LTP in wt and tg mice, and rescued LTP in Aβ (1-42)-treated tg mice. Taken together our data indicate that a T2D-like state results in an increased vulnerability of the hippocampus to the debilitating effects of Aβ (1-42) and that effects are mediated in part by changes in amylin receptor signaling.

The opioid growth regulatory system and naltrexone in diabetes: One side makes you taller and the other side makes you smaller

This article provides an overview of research into the inhibitory role of the Opioid Growth Regulatory System (OGRS), which is characterized by its mediator, Opioid Growth Factor (OGF), [Met 5 ]-enkephalin, and its specific receptor (OGFr), in the pathobiology of diabetic complications involving the ocular surface. Additionally, involvement of the OGRS in systemic diabetic complications is illustrated by its role in poor diabetic cutaneous wound healing. The title of this paper is derived from Lewis Carroll’s Alice’s Adventures in Wonderland in which Alice is invited by the caterpillar to eat either side of a mushroom with powerful growth inducing characteristics. In the context of this review, this metaphor highlights the antagonistic relationship between the OGRS and naltrexone (NTX), which blocks the binding of OGF to OGFr thereby preventing or reversing the deleterious effects of the OGRS in the pathobiology of diabetic complications such as dry eye, keratopathy (delayed corneal epithelial wound healing and decreased corneal sensitivity) and delayed cutaneous wound healing in animal models of type 1 and type 2 diabetes. In addition, we will show that topical NTX treatment has been demonstrated to be safe in early phase studies performed in humans. We believe these data support further clinical trials of NTX in the treatment of diabetic ocular surface disease and delayed cutaneous wound healing. Finally, our findings may have implications for the evaluation of the OGRS in the pathobiology of other systemic diabetic complications.

Strategy for the Identification of Host-Defense Peptides in Frog Skin Secretions with Therapeutic Potential as Antidiabetic Agents.

Several amphibian peptides that were first identified on the basis of their antimicrobial or cytotoxic properties have subsequently shown potential for development into agents for the treatment of patients with Type 2 diabetes. A strategy is presented for the isolation and characterization of such peptides that are present in norepinephrine-stimulated skin secretions from a range of frog species. The methodology involves (1) fractionation of the secretions by reversed-phase HPLC, (2) identification of fractions containing components that stimulate the rate of release of insulin from BRIN-BD11 clonal β-cells without simultaneously stimulating the release of lactate dehydrogenase, (3) identification of active peptides in the fractions in the mass range 1-6kDa by MALDI-ToF mass spectrometry, (4) purification of the peptides to near homogeneity by further reversed-phase HPLC on various column matrices, and (5) structural characterization by automated Edman degradation. The effect of synthetic replicates of the active peptides on glucose homeostasis in vivo may be evaluated in appropriate animal models of Type 2 diabetes such as db/db mice and mice fed a high fat diet to produce obesity, glucose intolerance, and insulin resistance.

Effects of total flavones of Abelmoschus manihot (L.) on the treatment of diabetic nephropathy via the activation of solute carriers in renal tubular epithelial cells

As a traditional Chinese medicine, Huangkui capsule (HKC) has been used to treat patients with kidney diseases, including diabetic nephropathy (DN). We have recently demonstrated that HKC could re-regulate the activities of solute carriers (SLC)s in proximal and distal convoluted tubules of kidneys in regression of the development of DN. The main active chemical constituents of HKC are the flavones of Abelmoschus manihot (L.). The current study aims to further evaluate the efficacy of total flavones of A. manihot (TFA) in the regression of DN by analyzing SLC activities in proximal and distal convoluted tubules of kidneys. TFA (0.076 g/kg/d) or vehicle was administered in db/db mice, the animal model of type 2 diabetes and DN, daily via oral gavage for four weeks. Blood glucose levels and urinary albumin-to-creatinine ratio (UACR) were measured and used for the determination of T2D and DN. Ten SLCs, including slc2a2, slc4A1, slc5a2, slc5A3, slc5a8, slc6a20, slc27a2, slc12a3, slc34a1 and slc38a2 were highly expressed in proximal and distinct convoluted tubules of kidneys. Their expression at mRNA and protein levels before and after TFA treatment were analyzed with real-time RT-PCR and immunohistochemistry. Data showed that UACR in the db/db mice after TFA treatment was significantly decreased. Compared with the group of non-diabetic control, slc2a2, slc4A1, slc5a2, slc5A3, slc5a8, slc6a20, slc27a2, slc12a3, slc34a1 and slc38a2 in the group of DN were down-regulated but up-regulated after TFA treatment. Further analyses of whole kidney sections indicated that the numbers and structures of the nephron in db/db mice was increased and improved after TFA treatment. Thereby, the current study provides further evidence that the flavones in A. manihot have pharmacological effects on the treatment of DN by improving the biological function of SLCs in kidneys.

Insulin Resistance Develops Due to an Imbalance in the Synthesis of Cyclic AMP and the Natural Cyclic AMP Antagonist Prostaglandylinositol Cyclic Phosphate (Cyclic PIP)

The reasons initiating insulin resistance are not identified. Various metabolic derailments have been characterized. These are the outcome and not the initiation of insulin resistance. In animal models of type 2 diabetes and hypertension, a decreased hormonal stimulation of the synthesis of the cyclic AMP antagonist prostaglandylinositol cyclic phosphate (cyclic PIP) was determined. The resultant imbalance of the action of cyclic AMP and cyclic PIP shifts metabolic regulation to the dominance of catabolism and a decrease in imperative anabolism. This dominance develops gradually since the more cyclic AMP dominates, the more the synthesis of cyclic PIP will be inhibited. Vanishing actions of cyclic PIP are its 10-fold activation of glucose uptake in adipocytes, its inhibition of insulin release from pancreatic β-cells, its inhibition of PKA and its 7-fold activation of protein ser/thr phosphatase. Reduced synthesis of cyclic PIP results from (a) decreased substrate availability, (b) long-time elevated cyclic AMP levels resulting from stress overloads and (c) aging and the gradual decrease in the synthesis of hormones which likely maintain mechanisms that stimulate cyclic PIP synthesis. The need is to discover which hormones, such as growth hormone, insulin-like growth factor-1, dehydroepiandrosterone, and testosterone, are involved in maintaining the stimulation of cyclic PIP synthesis.

SAT035 Oligonucleotide IMT504 Markedly Improves Metabolic Sindrome And Type 2 Diabetes In High-Fat Diet Fed Mice

Abstract Disclosure: L. Domé: None. J.M. Riaño Gomez: None. M.M. Bonaventura: None. M.O. Fernandez: None. A.D. Montaner: None. V.A. Lux-Lantos: None. M.S. Bianchi: None. We have shown that the immunomodulatory oligonucleotide IMT504 (IMT) improves glucose homeostasis in several animal models of type 1 diabetes by regulating immunomodulatory factors and by improving beta-cell function. Here we evaluated the effects of IMT in a murine model of metabolic syndrome and type 2 diabetes induced by high-fat diet (HFD).Five weeks-old C57BL/6LP male mice were fed either standard diet (SD) or HFD (ResearchDiet, D12492) for 12 weeks. HFD mice showed higher non-fasting glycemia (NF-Gly: p<0.01), and body weight (BW: p<0.01). Thereafter, mice received one daily dose of IMT504 for 12 consecutive days [IMT(mg/kg/day), subcutaneous: 20, 6 or 2, only HFD mice) or saline (SD and HFD). Intraperitoneal glucose tolerance test (ipGTT, day 10), insulin secretion test (IST, day 10) and insulin tolerance test (ITT, day 11) were performed. On day 12, food intake (days 1-12), BW, and non-fasting Gly, were recorded; after 3 hours fasting, Gly were recorded, mice were sacrificed, and blood samples collected. Serum insulin levels were analyzed by ELISA.Food (F) and calories (C) consumed decreased with IMT treatment [F(g): ANOVA, p<0.001; HFD different from IMT6 and IMT20: p<0.05], [C (Kcal): ANOVA, p<0.001; HFD different from SD, IMT6, and IMT20: p<0.05]; BW also decreased [repeated measures ANOVA: interaction, p<0.05; SD: different from all on both days, p<0.01; IMT6: Day1 vs Day12, p<0.01; IMT20: Day1 vs Day12, p<0.002]. NF-Gly did not vary with time in SD and HFD mice (day 12 vs day 1), while it significantly diminished with IMT [NF-Gly (mg/dl): repeated measures ANOVA: interaction, p<0.05; IMT6: Day1 vs Day12, p<0.02; IMT20: Day1 vs Day12, p<0.02]. IMT also induced a significant recovery of glucose clearance [GTT-AUC: ANOVA, p<0.01; HFD different from SD, IMT6, and IMT20: p<0.01], as well as of insulin secretion in response to the glucose overload [IST-AUC: ANOVA: p<0.05; HFD different from SD, IMT6, and IMT20: p<0.05] and peripheral response to insulin [ITT- AUC: ANOVA, p<0.01; HFD different from SD, HFD, IMT6, and IMT20: p<0.01]. In addition, IMT decreased the higher Gly and insulinemia (Ins) present in fasting HFD mice [Gly: ANOVA: p<0.001; HFD different from SD, IMT6, and IMT20: p<0.005], [Ins (ng/mL): ANOVA p<0.05; SD vs HFD: p<0.06; HFD different from IMT6, and IMT20: p<0.05]. These effects were consistent with amelioration of peripheral insulin resistance [HOMA-IR index: ANOVA, p<0.006; HFD different from SD, IMT6, and IMT20: p<0.05], and insulin sensitivity [QUICKI: ANOVA, p<0.02; HFD different from SD and IMT20: p<0.05]. IMT treatment promotes a significant, dose-dependent, improvement in the diabetic condition and food intake in HFD mice. Further research is needed to understand its mechanism of action. Funding: CONICET, ANPCYT, Sidus Arg, F. R Barón, F. Williams. Presentation: Saturday, June 17, 2023

FRI604 Stem-cell Derived Islets For Treating Diabetes

Abstract Disclosure: W.L. Rust: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. P.M. Dalal: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. A.P. Koval: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. J.J. Ratiu: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. S.M. Southard: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. P.S. Strumph: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. C.A. Welsch: Employee; Self; Seraxis Inc. Stock Owner; Self; Seraxis Inc. Background and Aims: We report the development of a novel human multipotent immortal stem cell line, SR1423 that efficiently differentiates to clusters of functional endocrine pancreatic cells. These Synthetic Replacement Endocrine (SRE) clusters contain cell types that recapitulate native islet function in vitro and potently control blood glucose in animal models of type 1 diabetes. Detailed characterization reveals significant distinctions between SRE, native islets and SC-beta cells. SRE clusters are manufactured following GMP requirements in closed vessels with large-scale formats and are being developed for near-term clinical studies. Materials and Methods: SRE was generated by transient expression of the Yamanaka factors in human islet cells harvested from a consented donor pancreas. Rather than screen for pluripotency, this cell line was selected for its ability to differentiate to the definitive endoderm in a first screen, and Pdx1+ pancreatic progenitors in a second screen. SRE does not meet criteria for pluripotency as it fails to express the master control gene for mesoderm specification, brachyury, in response to mesoderm-inducing agents. Comparison against a pluripotent stem cell database demonstrates poor overall differentiation capability for the mesoderm lineage. In contrast, SRE responds to basic differentiation protocols that drive endocrine pancreatic fate choice and generates highly pure populations of cells with endocrine cell characteristics. We therefore characterize SR1423 as a multipotent, and not pluripotent stem cell. In a prospectively designed islet replacement study male NSG mice with streptozotocin-induced diabetes were implanted with SRE clusters to the kidney capsule or gonadal fat pad (as a surrogate for the omentum) and disease progression was monitored. Results: SRE resemble human islets in morphology and distribution of hormone expressing cells. In this mouse model of STZ-induced type 1 diabetes (blood glucose > 180 mg/dL), SRE transplantation resulted in euglycemia 3-4 weeks post-implant; 72 mg/dL +/− 12 SEM when implanted to the kidney capsule (n=13), and 79 mg/dL +/− 15 SEM when implanted to the gonadal fat pad (n=10). Control mice (without SRE implant) in this model of type 1 diabetes (n=2) remained hyperglycemic; 570 mg/dL +/− 20 SEM. Conclusion: These data are consistent with demonstration of proof of principle in this model with resolution of hyperglycemia after transplant of SRE. This is the first description of a novel cell type (non-native, non-SC-beta) with potential clinical therapeutic benefit. SRE clusters are currently in preparation for clinical studies. Presentation: Friday, June 16, 2023

Spexin-based galanin receptor 2 agonist improves renal injury in mice with type 2 diabetes

ABSTRACT The spexin-based GALR2 agonist (NS200) is a novel drug, which has shown antidepressant and anxiolytic action in a recent experimental study. In this study, we investigated the effects of NS200 on renal injury in an animal model of type 2 diabetes. Eight-week-old diabetic db/db mice were administered NS200 for 12 weeks. NS200 was intraperitoneally administered at a dose of 1.0 mg/kg/day. Metabolic parameters and structural and molecular changes in the kidneys were compared among the three groups: non-diabetic db/m control, db/db mice, and NS200-treated db/db mice. In db/db mice, NS200 administration did not impact the body weight, food and water intake, urinary volume, fasting blood glucose level, or HbA1c levels. Insulin and glucose tolerance were also unaffected by NS200 treatment. However, NS200 improved urinary albumin excretion and glomerulosclerosis in diabetic kidneys. Activation of TGFβ1 and insulin signaling pathways, such as PI3 K /AKT/ERK, were inhibited by NS200. In conclusion, a spexin-based GALR2 agonist attenuated diabetic nephropathy by alleviating renal fibrosis in mice with type 2 diabetes. Spexin-based GALR2 agonists have considerable potential as novel treatment agents in diabetic nephropathy.

Lactobacillus johnsonii N6.2 phospholipids induce immature-like dendritic cells with a migratory-regulatory-like transcriptional signature

ABSTRACT Shifts in the gut microbiota composition, called dysbiosis, have been directly associated with acute and chronic diseases. However, the underlying biological systems connecting gut dysbiosis to systemic inflammatory pathologies are not well understood. Phospholipids (PLs) act as precursors of both, bioactive inflammatory and resolving mediators. Their dysregulation is associated with chronic diseases including cancer. Gut microbial-derived lipids are structurally unique and capable of modulating host’s immunity. Lactobacillus johnsonii N6.2 is a Gram-positive gut symbiont with probiotic characteristics. L. johnsonii N6.2 reduces the incidence of autoimmunity in animal models of Type 1 Diabetes and improves general wellness in healthy volunteers by promoting, in part, local and systemic anti-inflammatory responses. By utilizing bioassay-guided fractionation methods with bone marrow-derived dendritic cells (BMDCs), we report here that L. johnsonii N6.2 purified lipids induce a transcriptional signature that resembles that of migratory (mig) DCs. RNAseq-based analysis showed that BMDCs stimulated with L. johnsonii N6.2 total lipids upregulate maturation-mig related genes Cd86, Cd40, Ccr7, Icam1 along with immunoregulatory genes including Itgb8, Nfkbiz, Jag1, Adora2a, IL2ra, Arg1, and Cd274. Quantitative reverse transcription (qRT)-PCR analysis indicated that PLs are the bioactive lipids triggering the BMDCs response. Antibody-blocking of surface Toll-like receptor (TLR)2 resulted in boosted PL-mediated upregulation of pro-inflammatory Il6. Chemical inhibition of the IKKα kinase from the non-canonical NF-κB pathway specifically restricted upregulation of Il6 and Tnf. Phenotypically, PL-stimulated BMDCs displayed an immature like-phenotype with significantly increased surface ICAM-1. This study provides insight into the immunoregulatory capacity of Gram-positive, gut microbial-derived phospholipids on innate immune responses.

ANIMAL MODELS OF DIABETIC NEPHROPATHY

Diabetic nephropathy (DN) is the most common complication of diabetes mellitus (DM). It is characterized by high blood glucose levels or hyperglycemia and is accompanied by changes in lipid, carbohydrate, and protein metabolism which can lead to an increased risk of complications due to vascular disease. DN is probably the most insidious among these complications, causing substantial morbidity and mortality. In this article, we will review the literature on animal models of diabetes. We will discuss several species as animal models for Type 1 and 2 diabetes, including zebrafish, rabbits, mice, rats, and rat models. This article also provides various methods used in research with model animals and presents the required result for studying diabetic DN.