T2DM Rats Research Articles

Extract of pre-germinated brown rice protects against cardiovascular dysfunction by reducing levels of inflammation and free radicals in a rat model of type II diabetes

The aim of this study was to examine the effect of extract of pre-germinated brown rice (EP) on metabolic and cardiovascular dysfunction in a rat model of T2DM. Hypertensive rats were divided into: (1) normal diet (ND group), (2) induced T2DM (DM group), and T2DM rats that were treated with (3) EP30 mg/kg (EP30 group) or (4) EP300 mg/kg (EP300 group) per day for 4 weeks. T2DM symptoms included: weight loss, hyperglycaemia, hypoinsulinemia, hyperlipidaemia, higher HbA1c, glucose in urine, and lower GLP-1. EP treatment improved metabolic parameters, activated insulin signalling, and increased lipid metabolism, and also ameliorated T2DM-associated increases in levels of inflammation, free radicals, cardiac hypertrophy and fibrosis. EP reduced T2DM and related cardiovascular complications by increasing insulin signalling and lipid metabolism, and reducing levels of inflammation and free radicals. Thus, EP may be a potential candidate for the treatment of metabolic syndrome and related cardiovascular complications.

Exosomes derived from bone marrow mesenchymal stem cells harvested from type two diabetes rats promotes neurorestorative effects after stroke in type two diabetes rats

Background and purposeDiabetes elevates the risk of stroke, promotes inflammation, and exacerbates vascular and white matter damage post stroke, thereby hindering long term functional recovery. Here, we investigated the neurorestorative effects and the underlying therapeutic mechanisms of treatment of stroke in type 2 diabetic rats (T2DM) using exosomes harvested from bone marrow stromal cells obtained from T2DM rats (T2DM-MSC-Exo). MethodsT2DM was induced in adult male Wistar rats using a combination of high fat diet and Streptozotocin. Rats were subjected to transient 2 h middle cerebral artery occlusion (MCAo) and 3 days later randomized to one of the following treatment groups: 1) phosphate-buffered-saline (PBS, i.v), 2) T2DM-MSC-Exo, (3 × 1011, i.v), 3) T2DM-MSC-Exo with miR-9 over expression (miR9+/+-T2DM-MSC-Exo, 3 × 1011, i.v) or 4) MSC-Exo derived from normoglycemic rats (Nor-MSC-Exo) (3 × 1011, i.v). T2DM sham control group is included as reference. Rats were sacrificed 28 days after MCAo. ResultsT2DM-MSC-Exo treatment does not alter blood glucose, lipid levels, or lesion volume, but significantly improves neurological function and attenuates post-stroke weight loss compared to PBS treated as well as Nor-MSC-Exo treated T2DM-stroke rats. Compared to PBS treatment, T2DM-MSC-Exo treatment of T2DM-stroke rats significantly 1) increases tight junction protein ZO-1 and improves blood brain barrier (BBB) integrity; 2) promotes white matter remodeling indicated by increased axon and myelin density, and increases oligodendrocytes and oligodendrocyte progenitor cell numbers in the ischemic border zone as well as increases primary cortical neuronal axonal outgrowth; 3) decreases activated microglia, M1 macrophages, and inflammatory factors MMP-9 (matrix mettaloproteinase-9) and MCP-1 (monocyte chemoattractant protein-1) expression in the ischemic brain; and 4) decreases miR-9 expression in serum, and increases miR-9 target ABCA1 (ATP-binding cassette transporter 1) and IGFR1 (Insulin-like growth factor 1 receptor) expression in the brain. MiR9+/+-T2DM-MSC-Exo treatment significantly increases serum miR-9 expression compared to PBS treated and T2DM-MSC-Exo treated T2DM stroke rats. Treatment of T2DM stroke with miR9+/+-T2DM-MSC-Exo fails to improve functional outcome and attenuates T2DM-MSC-Exo treatment induced white matter remodeling and anti-inflammatory effects in T2DM stroke rats. ConclusionsT2DM-MSC-Exo treatment for stroke in T2DM rats promotes neurorestorative effects and improves functional outcome. Down regulation of miR-9 expression and increasing its target ABCA1 pathway may contribute partially to T2DM-MSC-Exo treatment induced white matter remodeling and anti-inflammatory responses.

Agmatine modulates anxiety and depression-like behaviour in diabetic insulin-resistant rats

Epidemiological studies indicated that mood disorders like depression and anxiety are highly prevalent in type-II diabetes mellitus (T2DM). However, the neurobiological mechanisms underlying the relationship between T2DM and depression have yet to be identified. Thus, understanding the neural mechanisms that mediate the co-morbidity of depression and type-II diabetes mellitus may unlock new pharmacological treatments for this condition. The present study investigated the role of the agmatinergic system in T2DM induced depression using forced swim test (FST) and anxiety in the elevated plus-maze (EPM)in rats. T2DM was induced by the combination of high-fat diet (HFD) and streptozotocin (STZ) injection and confirmed by high blood glucose levels. After 12 weeks, HFD fed and STZ injected rats exhibited depression-like behaviors and anxiety. It was associated with increased expression of pro-inflammatory cytokines like IL-6 and TNF-α, and reduced BDNF immunocontent in the hippocampal tissues. The T2DM-induced depression, anxiety, and neuroinflammatory markers were significantly inhibited by agmatine (10–20 mg/kg, i.p.), by once-daily administration during 9th to 12th week of the protocol. Agmatine levels were significantly reduced in the hippocampus of T2DM rats as compared to the normal fed (NF) control animals. In conclusion, the present study suggests the importance of endogenous agmatine in T2DM induced anxiety and depressive-like behavior in rats. The data projects agmatine as a potential therapeutic target for T2DM-associated depression, anxiety, and comorbidities.

Early intervention with Di-Dang Decoction prevents macrovascular fibrosis in diabetic rats by regulating the TGF-β1/Smad signalling pathway.

Macroangiopathy is a complication of Type II Diabetes Mellitus (T2DM), which is mainly caused by fibrosis of blood vessels. Using T2DM rat models, we investigated whether the traditional Chinese medicine, Di-Dang Decoction (DDD), exhibited anti-fibrotic actions on great vessels. T2DM rats were randomly divided into non-intervention group, early-, middle-, late-stage DDD intervention groups and control groups, including pioglitazone group and aminoguanidine group. After administration of DDD to T2DM rats at different times, we detected the amount of extracellular matrix (ECM) deposition in the thoracic aorta. The results showed that early-stage intervention with DDD could effectively protect great vessels from ECM deposition. Considering that TGF-β1 is the master regulator of fibrosis, we further validated at the molecular level that, compared to middle- and late-stage intervention with DDD, early-stage intervention with DDD could significantly decrease the expression levels of factors related to the activated TGF-β1/Smad signalling pathway, as well as the expression levels of downstream effectors including CTGF, MMP and TIMP family proteins, which were directly involved in ECM remodelling. Therefore, early-stage intervention with DDD can reduce macrovascular fibrosis and prevent diabetic macroangiopathy.

1874-P: The Improvement of Type 2 Diabetes by DJB Is related to the Improvement of Intestinal Glucose Sensing and Glucose Transportation

Duodenojejunal bypass (DJB) is an experimental procedure to study the mechanism of metabolic surgery in type 2 diabetes (T2DM),independent of weight changes. The aim of this study was to evaluate the role of Gastrointestinal (GI) glucose sensing and glucose transportation in DJB regulated glucose metabolism using T2DM rat model. T2DM was induced in Wistar rats with 2 months of high-fat diet and one low-dose streptozocin (STZ) injection. T2DM rats were randomly divided into sham operation group (T2DM-Sham, n=8) and DJB group (T2DM-DJB, n=8). Eight Wistar rats were used as wild type control group(Control, n=8). The results showed that DJB surgery significantly improved blood glucose homeostasis in T2DM rats. The hematoxylin-eosin staining results revealed that DJB operation thickened the wall of small intestine comparing to Sham operation. DJB also increased the length of villus in small intestine. Western Blot and qRT-PCR results showed that DJB significantly increased the expression of sodium-glucose co-transporter-1 (SGLT1) while reducing the expression of glucose transporter-2 (GLUT2) in the alimentary limb of DJB rats. The results also showed the expression of intestinal sweet receptors (T1R2/T1R3), Glucagon-like peptide 1/2 (GLP1/2) and its receptor (GLP1/2R) increased significantly in the alimentary limb after DJB surgery. Here we describe a new observation that DJB surgery lowers blood glucose level via intestinal glucose transport and glucose sensing regulation in the alimentary limb. Disclosure B. Jiang: None. H. Wang: None. W. Wang: None. Q. Yan: None. M. Qu: None. Z. Gao: None. Funding National Natural Science Foundation of China (81871892); Natural Science Foundation of Shandong Province (ZR2019BH036); Technology Development Plan of Weifang (2018YX027)

Cyclocarya paliurus (Batal.) Iljinskaja polysaccharides alleviate type 2 diabetes mellitus in rats by resisting inflammatory response and oxidative stress

Abstract This study aimed to investigate the effects of Cyclocarya paliurus (Batal.) Iljinskaja polysaccharides (CPP) on the glucose-lipid metabolism in T2DM rats. T2DM model was established in 40 Wistar rats which were then randomly divided into model, CPP-1, CPP-2 and CPP-3 groups. Ten normal rats were selected as the control group. The CPP-1, CPP-2 and CPP-3 group were intragastrically administrated with 100, 200 and 400 mg/kg CPP for 4 weeks, respectively. Results showed that, during the treatment, compared with model group, in CPP treatment groups the T2DM symptoms were lightened, and the body weight was improved. After treatment, compared with model group, in CPP-3 group the blood fasting plasma glucose, fasting insulin and glycosylated hemoglobin levels were reduced (P < 0.05), the blood total cholesterol, triglyceride and low-density lipoprotein cholesterol levels were decreased (P < 0.05), the serum C-reactive protein, tumor necrosis factor α and interleukin 6 levels were decreased (P < 0.05), the serum malondialdehyde level was reduced (P < 0.05), and the serum superoxide dismutase and glutathione peroxidase levels were increased (P < 0.05). In conclusion, CPP can alleviate the T2DM in rats, which may be related to its resisting inflammatory response and oxidative stress in body.

Sulfated fucan/fucosylated chondroitin sulfate-dominated polysaccharide fraction from low-edible-value sea cucumber ameliorates type 2 diabetes in rats: New prospects for sea cucumber polysaccharide based-hypoglycemic functional food

Sulfated fucan chondroitin sulfate-dominated polysaccharide fraction from low-edible-value sea cucumber may be a good alternative to high-edible-value sea cucumber-derived polysaccharide for application in hypoglycemic functional foods. To evaluate the potential effect of low-edible-value sea cucumber-derived polysaccharide fraction on type 2 diabetes (T2DM), two sulfated fucan/fucosylated chondroitin sulfate-dominated polysaccharide fractions screening from 10 global commercial low-edible-value sea cucumber species were investigated to identify their anti-diabetics efficacies using a high-fat diet and streptozotocin-induced T2DM rat model. Sulfated fucan-dominated polysaccharide fraction from Thelenota ananas and fucosylated chondroitin sulfate-dominated polysaccharide fraction from Cucumaria frondosa ameliorated hyperglycemia, restored hypertriglyceridemia and hypercholesterolemia, decreased inflammatory status and oxidative stress, protected against liver injury, as well as improved insulin resistance and promoted accumulation of hepatic glycogen by activating IRS/PI3K/AKT signaling and regulating GSK-3β gene expression in T2DM rats. The current findings provide an available strategy for the commercialization of sea cucumber polysaccharide based-hypoglycemic functional food.

The role of Visfatin / Cytoglobin and the Modulatory Effects of Raspberry ketone (RK) as Weight Management Supplement (WMS) in HFD/STZ T2DM rats.

The role of Visfatin / Cytoglobin and the Modulatory Effects of Raspberry ketone (RK) as Weight Management Supplement (WMS) in HFD/STZ T2DM rats.

A novel metformin derivative showed improvement of lipid metabolism in obese rats with type 2 diabetes.

In this study, we investigated the lipid metabolism regulatory activity of a novel metformin derivative (MD568) and its potential mechanism of action in obese rats with type 2 diabetes mellitus (T2 DM). Previous gene chip analysis of 3T3-L1 cells have shown that MD568 regulates the transcription of genes involved in the peroxisome proliferator-activated receptor (PPAR) signalling pathway, fatty acid metabolism, and glycerolipid metabolism. In this study, obese T2 DM rats were treated with MD568 (200mg/kg) for 8weeks. Results showed that MD568 significantly reduced the body weight gain, plasma glucose, insulin, total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels. MD568 treatment also improved the insulin resistance of obese T2 DM model rats. In particular, in white adipose tissue, MD568 inhibited the excessive volume increment of adipose cells by down-regulating the protein levels of CCAAT/enhancer-binding protein-α (C/EBP-α) and PPAR-γ, as well as the transcription of their target lipid metabolism-related genes. In the liver, MD568 inhibited hepatic fatty lesions and interfered with hepatic gluconeogenesis by regulating the expression of lipid metabolism-related genes and glycogen-related kinases. In conclusion, our results suggest that the newly synthesized MD568 affects the maintenance of lipid homeostasis in obese type 2 diabetic rats.

Re‐expression of REST in ventricular vagal neurons aggravates myocardial infarctionevoked ventricular arrhythmia in type 2 diabetes mellitus

Diabetes mellitus, especially type 2 diabetes mellitus (T2DM, 90 to 95% of diabetic population), is a major public health problem worldwide and has become a leading cause of mortality. Myocardial infarction (MI) is the most common cause of mortality in T2DM. Comparing with non‐diabetic patients, patients with T2DM are twice to die from MI. Withdrawal of cardiac vagal activity is considered to be an important trigger for MI‐induced ventricular arrhythmias in T2DM. Our previous study has demonstrated that N‐type Ca2+ currents and cell excitability of atrioventricular ganglion (AVG) neurons were reduced in T2DM rats. We have recently demonstrated that reduced expression of Cav2.2‐α in AVG neurons contributes to cardiac vagal dysfunction and ventricular arrhythmogenesis. The repressor element 1‐silencing transcription factor (REST) is a key factor to block Cav2.2‐α expression. Normally REST is not expressed in neuronal cells. Here, we test the hypothesis that re‐expression of REST inhibits N‐type Ca2+ channel function in AVG neurons and further reduces cardiac vagal activity and promotes MI‐evoked fatal ventricular arrhythmias in T2DM rats. Using reverse‐phase protein array, we found that there was no expression of REST in the AVG from sham rats, while REST expression was significantly increased in the AVG from T2DM rats. In vivo infection of lentiviral REST shRNA (2 μl, 1×107 TU/ml) to the AVG markedly reduced REST expression in the AVG from T2DM rats. REST shRNA also increased Cav2.2‐α expression in AVG neurons from T2DM rats. The results from whole‐cell patch clamp recording showed that REST shRNA markedly restored T2DM‐reduced N‐type Ca2+ currents and cell excitability in AVG neurons. Additionally, infection of REST shRNA to AVG neurons markedly restored cardiac vagal activity, as evidenced by blunted response of LVSP to left efferent vagal stimulation. Moreover, REST shRNA also decreased the inducibility of ventricular arrhythmia in anesthetized T2DM rats (0.67±0.6 in T2DM+REST group vs. 3.6±1.03 in T2DM group). The ECG data obtained from 24‐hour radiotelemetry recording in conscious rat demonstrated that REST shRNA significantly reduced the duration of MI‐evoked ventricular arrhythmia (39.39±13.03 sec/hour in T2DM+REST group vs. 64.26±13.17 sec/hour in T2DM group). Based on above data, we conclude that re‐expression of REST decreases Cav2.2‐α expression and N‐type Ca2+ currents in AVG neurons, and subsequently reduces cardiac vagal function and increases susceptibility to ventricular arrhythmias in the T2DM.Support or Funding InformationDHHS/NIH/NHLBI, 34‐5370‐2003‐001

Bioenergetic functions in subpopulations of heart mitochondria are preserved in a non-obese type 2 diabetes rat model (Goto-Kakizaki)

A distinct bioenergetic impairment of heart mitochondrial subpopulations in diabetic cardiomyopathy is associated with obesity; however, many type 2 diabetic (T2DM) patients with high-risk for cardiovascular disease are not obese. In the absence of obesity, it is unclear whether bioenergetic function in the subpopulations of mitochondria is affected in heart with T2DM. To address this issue, a rat model of non-obese T2DM was used to study heart mitochondrial energy metabolism, measuring bioenergetics and enzyme activities of the electron transport chain (ETC). Oxidative phosphorylation in the presence of substrates for ETC and ETC activities in both populations of heart mitochondria in T2DM rats were unchanged. Despite the preservation of mitochondrial function, aconitase activity in T2DM heart was reduced, suggesting oxidative stress in mitochondria. Our study indicate that metabolic function of heart mitochondria is unchanged in the face of oxidative stress and point to a critical role of obesity in T2DM cardiomyopathy.

Effects of propofol on LC3II and mTOR/p-mTOR expression during ischemia-reperfusion myocardium injury in rats with type 2 diabetes mellitus.

To investigate the effects of propofol on myocardial ischemia reperfusion in rats with type 2 diabetes, male adult rats were divided into five groups: Sham-operation (CC), ischemia-reperfusion (CI), low-dose propofol (LP), moderate-dose propofol (MP) and high-dose propofol (HP). The LP, MP and HP groups were administered with 6, 12 and 24 mg/kg/h propofol, respectively, prior to occlusion. Heart rate (HR), left ventricular systolic pressure (LVSP) and the rate (dp/dt max) of left ventricular pressure rise in early systole (±dp/dt max) were recorded. The role of autophagy was also studied by measuring the levels of superoxide dismutase (SOD), malondialdehyde (MDA), autophagy marker protein LC3II, mammalian target of rapamycin (mTOR)/phosphorylate (p)-mTOR and cardiac troponin T (cTnT). The myocardial morphological features were assessed using light and electron microscopy. The present results demonstrated that the HR, LVSP, +dp/dt and -dp/dt levels in the propofol groups (LP, MP and HP) were significantly increased (P<0.05) when compared with the CI group. The myocardial cells in the MP group showed mild edematous changes and partially dissolved mitochondrial cristae and membrane rupture. SOD, cTnT and MDA levels were significantly decreased (P<0.05), mTOR expression decreased significantly (P<0.05) and p-mTOR expression increased significantly in the MP group (P<0.05). The present study demonstrated the protective effects of propofol in T2DM rats exhibiting MIRI, with an optimal protective effect at an infusion rate of 12 mg/kg/h. Additionally, the results revealed that propofol led to significant reductions in LC3II and mTOR serum levels and the inhibition of autophagy in myocardial cells.

Salidroside ameliorates diabetic nephropathy in rats by activating renal AMPK/SIRT1 signaling pathway.

This study investigated if the nephroprotective effect of Salidroside T1DM rats involves activation of AMPK/SIRT1. Rats were divided into control or T1DM and treated with vehicle or Salidroside (100mg/kg) for 56days. Mesangial cells were cultured in LG or HG media with or without Salidroside (100µM/L) for 24hr. Also, HG+Salidroside-treated cells were pre-incubated with EX-527 or compound C (CC) for 1hr. With reducing glucose levels, Salidroside improved kidney structure/function in the T1DM rat. It also increased GSH and Bcl-2 levels in control and T1DM rats and inhibited ROS, increased activation of AMPK and nuclear SIRT1, and lowered acetylation of P53 and FOXO-1 in control and T1DM rats and in LG and HG-treated cells. These effects were abolished by EX-527 and CC. Also, CC decreased the nuclear levels of SIRT1. In conclusion, Salidroside attenuates DN in T1DM rats by activation of AMPK and subsequently, SIRT1. PRACTICAL APPLICATIONS: This animal and pre-clinical study shows that Salidroside is able to ameliorate DN in T1DM-induced rats and showed that it mainly acts by a hypoglycemic effect and activation of renal AMPK/SIRT1 axis. Given the wide tissue stimulatory effect of AMPK on peripheral glucose utilization, lipogenesis, and other cell signaling pathways, these data are encouraging to investigate the anti-diabetic effect of glycoside in more clinical trials.

Long Non‑Coding RNAs Regulate Inflammation in Diabetic Peripheral Neuropathy by Acting as ceRNAs Targeting miR-146a-5p.

BackgroundLong non-coding RNAs (lncRNAs), as competing endogenous RNAs (ceRNAs), can regulate various pathophysiological processes by binding competitively to microRNAs at the post-transcription level. Our previous work demonstrated that miR-146a-5p was lowly expressed in diabetic peripheral neuropathy (DPN) rats. However, the ceRNA network in DPN mediated by lncRNAs and miR-146a-5p remains to be explored.MethodsTwo groups of rats (n=4 per group), a type 2 diabetes (T2DM) group and a DPN group, were used in this study. Sciatic nerve conduction velocity (NCV) of each rat was determined at the 6th and the 12th week. LncRNA microarray analysis was performed in the sciatic nerve of DPN and T2DM rats. Based on the TargetScan algorithm and the miRanda database, we determined the differentially expressed (DE) lncRNAs bound to miR-146a-5p. Furthermore, we verified the DE lncRNAs potentially bound to miR-146a-5p by qRT-PCR. The genes targeted by miR-146a-5p were identified by bioinformatics prediction and experimental techniques.ResultsWe found 413 DE lncRNAs between DPN and T2DM rats (|log2FC| ≥ 2 and adjust P ≤ 0.05). Eight DE lncRNAs were predicted to bind to miR-146a-5p by both algorithms, of which four were verified by qRT-PCR. TRAF6, IRAK1, and SMAD4 were identified as miR-146a-5p targeted genes and were predominantly enriched in the inflammatory signaling pathway.ConclusionLncRNAs may contribute to the pathogenesis of DPN by regulating inflammation through functioning as ceRNAs of miR-146a-5p.

Acid Hydrolyzed Silk Peptide Consumption Improves Anti-Diabetic Symptoms by Potentiating Insulin Secretion and Preventing Gut Microbiome Dysbiosis in Non-Obese Type 2 Diabetic Animals.

Silk fibroin hydrolysates have been reported to reduce hyperglycemia, but the mechanism has not been determined in Asian type 2 diabetes (T2DM). We hypothesized that the consumption of acid hydrolyzed silk peptides (SPs) alleviates hyperglycemia by improving insulin sensitivity and subsequently normalizing glucose-stimulated insulin secretion in T2DM. We investigated this hypothesis in a partial pancreatectomized (Px) rat model. Px rats was assigned randomly to the following six groups and fed assigned diet for 8 weeks: the Px-control (0.5 g/kg/day dextrin), the SP-L (0.05 g/kg/day), the SP-M (0.1 g/kg/day), the SP-H (0.5 g/kg/day), the positive-control (40 mg/kg/day metformin), or the normal-control (sham-operated rats; 0.5 g/kg/day dextrin). SPs contained high levels of glycine, alanine, and serine. We found SPs dose-dependently increased food efficiency and body weight gain in Px rats. Animals in the Px-control group rats exhibited lower glucose metabolism, as evidenced by impaired glucose-stimulated insulin secretion coupled with impaired insulin sensitivity, and reduced bone mineral density (BMD) and lean body mass (LBM), compared to the normal-control. SPs and metformin similarly partially protected against Px-induced BMD loss in the lumbar spine and femur. Px-induced decreases in LBM were dose-dependently prevented by SPs, and muscle forces in the SP-M and SP-H groups were maintained at the normal-control level. Glucose tolerance was dose-dependently improved by SPs as determined by oral glucose tolerance and oral maltose tolerance tests, and glucose tolerances were similar in the SP-H and positive-control groups. Insulin tolerance, an index of insulin sensitivity, was dose-dependently enhanced by SPs, and the SP-H group exhibited better insulin tolerance than the positive-control group as determined by intraperitoneal insulin sensitivity testing. Insulin secretory capacity assessed using a hyperglycemic clamp improved in the following order: Px-control <SA-L <SA-M <positive-control <SA-H <normal-control. SP-M prevented gut microbiota dysbiosis. In conclusion, SPs administered at 0.1–0.5 g/kg/day improved glucose regulation by potentiating both insulin secretion and insulin sensitivity in non-obese T2DM rats.

Major Improvement in Wound Healing Through Pharmacologic Mobilization of Stem Cells in Severely Diabetic Rats.

Current therapeutic strategies for diabetic foot ulcer (DFU) have focused on developing topical healing agents, but few agents have controlled prospective data to support their effectiveness in promoting wound healing. We tested a stem cell mobilizing therapy for DFU using a combination of AMD3100 and low-dose FK506 (tacrolimus) (AF) in streptozocin-induced type 1 diabetic (T1DM) rats and type 2 diabetic Goto-Kakizaki (GK) rats that had developed peripheral artery disease and neuropathy. Here, we show that the time for healing back wounds in T1DM rats was reduced from 27 to 19 days, and the foot wound healing time was reduced from 25 to 20 days by treatment with AF (subcutaneously, every other day). Similarly, in GK rats treated with AF, the healing time on back wounds was reduced from 26 to 21 days. Further, this shortened healing time was accompanied by reduced scar and by regeneration of hair follicles. We found that AF therapy mobilized and recruited bone marrow-derived CD133+ and CD34+ endothelial progenitor cells and Ym1/2+ M2 macrophages into the wound sites, associated with enhanced capillary and hair follicle neogenesis. Moreover, AF therapy improved microcirculation in diabetic and neuropathic feet in GK rats. This study provides a novel systemic therapy for healing DFU.

P121 Pressure overload-induced functional and metabolic impairments in type 2 diabetic hearts are ameliorated by inhibition of xanthine oxidase

Abstract Funding Acknowledgements SANWA KAGAKU KENKYUSHO Co., Ltd. Background We have recently demonstrated that AMP deaminase (AMPD) is upregulated in OLETF, obese type 2 diabetic (T2DM) rats, and that the upregulated AMPD contributes to depletion of myocardial ATP at the time of pressure overload, leading to diastolic dysfunction. On the other hand, AMPD promotes the formation of IMP from AMP, and IMP is in turn further converted to hypoxanthine and xanthine, substrates of xanthine oxidase (XO), which produces uric acid with ROS as a byproduct. Based on these findings, we tested the hypothesis that inhibition of XO ameliorates the pressure overload-induced diastolic dysfunction in T2DM rats. Methods and results Metabolomic analyses of the left ventricular myocardium revealed that levels of myocardial hypoxanthine and xanthine were significantly higher by 30% and 28%, respectively, in OLETF than in LETO, non-diabetic control rats, under the condition of pressure overloading (200-230 mmHg) induced by phenylephrine infusion. Myocardial XO activity in OLETF was 57.9% higher than that in LETO, and the activity was significantly attenuated by oral administration of topiroxostat, an XO inhibitor, at 0.1-0.5 mg/kg/day for 14 days in a dose-dependent manner. Pressure volume loop analyses showed that the pressure overloading induced by phenylephrine infusion resulted in significantly higher LVEDP in OLETF than in LETO (18.3 ± 1.5 vs. 12.2 ± 1.3 mmHg, p &amp;lt; 0.05, n = 7), though LVEDPs at baseline were comparable in OLETF and LETO (5.6 ± 0.4 vs. 4.7 ± 0.7 mmHg). Treatment with topiroxostat significantly suppressed the pressure overload-induced elevation of LVEDP in OLETF (18.3 ± 1.5 vs. 11.3 ± 1.1 mmHg, p &amp;lt; 0.05) but not in LETO. Tau, the time constant of LV pressure decay, was significantly prolonged to 14.7 ± 0.7 ms (p &amp;lt; 0.05) by pressure overloading in OLETF but not in LETO, though baseline Tau values were similar in LETO and OLETF (6.1 ± 0.2 vs. 8.0 ± 0.4 ms). The prolongation of Tau by pressure overloading in OLETF was significantly attenuated by treatment with topiroxostat. Ea/Ees, an index for ventricular-arterial coupling, was higher in OLETF than in LETO (2.3 ± 0.3 vs. 1.6 ± 0.3, p &amp;lt; 0.05) under the condition of pressure overloading, and it was also improved by topiroxostat in OLETF (1.2 ± 0.2, p &amp;lt; 0.05). Myocardial ATP content was lower in OLETF than in LETO under the condition of pressure overloading (2966 ± 400 vs. 1818 ± 171 nmol/g wet tissue, p &amp;lt; 0.05), but treatment with topiroxostat significantly restored the ATP level (2629 ± 307 nmo/g wet tissue). Conclusion: In T2DM hearts, not only XO activity but also XO substrates are upregulated and upregulated AMPD may be involved in the upregulation. Inhibition of XO ameliorates pressure overload-induced diastolic dysfunction and improves ventricular-arterial coupling most likely through augmented ATP preservation.

Cholesterol moieties as building blocks for assembling nanoparticles to achieve effective oral delivery of insulin.

Although nanoparticles (NPs) have emerged as a promising strategy to improve oral absorption of insulin, most of them still have minimal oral bioavailability due to the harsh gastrointestinal (GI) environment and epithelial barriers. A novel platform of oral insulin delivery is herein proposed based on amphiphilic cholesterol-phosphate conjugate (CHP). The CHP was synthesized with a cholesterol moiety as a hydrophobic block and a phosphate group as a hydrophilic block. The structural characteristics of CHP made cholesteryl moieties to point outward to form a shell coated on the surface of NPs, and phosphate groups toward inside as the core via the water-in-oil (W/O) emulsion method. The additional Ca2+ could chelate to phosphate groups in the core to bind adjacent phosphate groups and further increased the stability of NPs (CP-Ca NPs). Phospholipid and glycocholate were modified on the surface of CP-Ca NPs to form hydrophilic corona coated CP-Ca NPs (Hc@CP-Ca NPs) and didn't change the structure of CP-Ca NPs. The NPs exhibited high encapsulation efficiency (>95%) and had high stability in the GI tract by reducing insulin release and protecting insulin from enzymatic degradation. Compared to free insulin, Hc@CP-Ca NPs demonstrated 31-fold higher cellular uptake in Caco-2 cells for 1 h incubation. Furthermore, the transepithelial transport efficiency of Hc@CP-Ca NPs was 12-fold higher than that of free insulin. Moreover, CP-Ca NPs and Hc@CP-Ca NPs generated a rapid-onset and long-lasting hypoglycemic effect following gavage in type 1 diabetic mellitus (T1DM) rats. The pharmacological activity and the relative bioavailability were increased to 13.5% and 12.2%, respectively. Thus, these results indicated that CHP assembled NPs may provide a promising potential for oral insulin delivery by protection and absorption promotion.

Chlorophyll treatment combined with photostimulation increases glycolysis and decreases oxidative stress in the liver of type 1 diabetic rats.

Photodynamic therapy (PDT) promotes cell death, and it has been successfully employed as a treatment resource for neuropathic complications of diabetes mellitus (T1DM) and hepatocellular carcinoma. The liver is the major organ involved in the regulation of energy homeostasis, and in pathological conditions such as T1DM, changes in liver metabolic pathways result in hyperglycemia, which is associated with multiple organic dysfunctions. In this context, it has been suggested that chlorophyll-a and its derivatives have anti-diabetic actions, such as reducing hyperglycemia, hyperinsulinemia, and hypertriglyceridemia, but these effects have not yet been proven. Thus, the biological action of PDT with chlorophyll-a on hepatic parameters related to energy metabolism and oxidative stress in T1DM Wistar rats was investigated. Evaluation of the acute effects of this pigment was performed by incubation of isolated hepatocytes with chlorophyll-a and the chronic effects were evaluated by oral treatment with chlorophyll-based extract, with post-analysis of the intact liver by in situ perfusion. In both experimental protocols, chlorophyll-a decreased hepatic glucose release and glycogenolysis rate and stimulated the glycolytic pathway in DM/PDT. In addition, there was a reduction in hepatic oxidative stress, noticeable by decreased lipoperoxidation, reactive oxygen species, and carbonylated proteins in livers of chlorophyll-treated T1DM rats. These are indicators of the potential capacity of chlorophyll-a in improving the status of the diabetic liver.

Novel Modified GLP-1 Derivatives with Prolonged Glucose-Lowering Ability In Vivo

The rapid degradation of native glucagon-like peptide 1 (GLP-1) by dipeptidyl peptidase-IV (DPP-IV) has advanced new approaches to the generation of degradation-resistant GLP-1 analogs. Chemical coupling of GLP-1 analog to HSA is innovatively achieved by solid-phase peptide synthesis in this study and shows prolonged glucose-lowering ability in vivo. GLP-1(7–37)(Ala8Aib)-Cys-HSA was constructed by solid-phase peptide synthesis through two levels of modification: mutation of Ala8 to aminoisobutyric acid (Aib) to decrease DPP-IV degradation, and conjugation to large serum protein HSA by chemical modification to decrease renal filtration. Glucose tolerance test and insulin secretion assay were performed to examine the biological activity of GLP-1(7–37)(Ala8Aib)-Cys-HSA in vivo in the present research. Long-lasting glucose-lowering and insulin-releasing effects were evaluated up to 4 weeks in T2DM rats. GLP-1(7–37)(Ala8Aib)-Cys-HSA lowered blood glucose in normal mice and T2DM rats. Twice administration of GLP-1(7–37)(Ala8Aib)-Cys-HSA to T2DM rats daily significantly reduced glycemic excursion following IP glucose challenge (P < 0.01 to 0.05) and greatly increased insulin secretion during the 4-week study period. These findings demonstrate that the albumin-conjugated GLP-1 analog mimics the function of native GLP-1 with prolonged activity.