Hearing Impairment in a Mouse Model of Diabetes Is Associated with Mitochondrial Dysfunction,Synaptopathy, and Activation of the Intrinsic Apoptosis Pathway

Although previous studies continuously report an increased risk of hearing loss in diabetes patients, the impact of the disease on the inner ear remains unexplored. Herein, we examine the pathophysiology of diabetes-associated hearing impairment and cochlear synaptopathy in a mouse model of diabetes. Male B6.BKS(D)-Lepr^db/J (db/db, diabetes) and heterozygote (db/+, control) mice were assigned into each experimental group (control vs. diabetes) based on the genotype and tested for hearing sensitivity every week from 6 weeks of age. Each cochlea was collected for histological and biological assays at 14 weeks of age. The diabetic mice exerted impaired hearing and a reduction in cochlear blood flow and C-terminal-binding protein 2 (CtBP2, a presynaptic ribbon marker) expression. Ultrastructural images revealed severely damaged mitochondria from diabetic cochlea accompanied by a reduction in Cytochrome c oxidase subunit 4 (COX4) and CR6-interacting factor 1 (CRIF1). The diabetic mice presented significantly decreased levels of platelet endothelial cell adhesion molecule (PECAM-1), B-cell lymphoma 2 (BCL-2), and procaspase-9, but not procaspase-8. Importantly, significant changes were not found in necroptotic programmed cell death markers (receptor-interacting serine/threonine-protein kinase 1, RIPK1; RIPK3; and mixed lineage kinase domain-like pseudokinase, MLKL) between the groups. Taken together, diabetic hearing loss is accompanied by synaptopathy, microangiopathy, damage to the mitochondrial structure/function, and activation of the intrinsic apoptosis pathway. Our results imply that mitochondrial dysfunction is deeply involved in diabetic hearing loss, and further suggests the potential benefits of therapeutic strategies targeting mitochondria.     

Tofacitinib Ameliorates Retinal Vascular Leakage in a Murine Model of Diabetic Retinopathy with Type 2 Diabetes

We have previously reported that inhibition of the Janus kinase 1 (JAK1) signaling ameliorates IL-17A-mediated blood-retinal barrier (BRB) dysfunction. Higher levels of IL-17A have been observed in the blood and intraocular fluids in patients with diabetic retinopathy (DR), in particular those with diabetic macular oedema. This study aimed to understand whether JAK1 inhibition could prevent BRB dysfunction in db/db mice, a model of type 2 diabetes (T2D). An in vitro study showed that high glucose treatment disrupted the junctional distribution of claudin-5 in bEnd3 cells and ZO-1 in ARPE19 cells and that tofacitinib citrate treatment prevented high glucose-mediated tight junction disruption. Albumin leakage, accompanied by increased levels of the phosphorylated form of JAK1 (pJAK1), was observed in three-month-old db/db mice. Treatment of two-and-a-half-month-old db/db mice with tofacitinib citrate for two weeks significantly reduced retinal albumin leakage and reduced pJAK1 expression. pJAK1 expression was also detected in human DR retina. Our results suggest that JAK1 inhibition can ameliorate BRB dysfunction in T2D, and JAK1 inhibitors such as tofacitinib citrate may be re-purposed for the management of diabetic macular oedema.     

C57BL/KsJ-db/db-Apc Mice Exhibit an Increased Incidence of Intestinal Neoplasms

The numbers of obese people and diabetic patients are ever increasing. Obesity and diabetes are high-risk conditions for chronic diseases, including certain types of cancer, such as colorectal cancer (CRC). The aim of this study was to develop a novel animal model in order to clarify the pathobiology of CRC development in obese and diabetic patients. We developed an animal model of obesity and colorectal cancer by breeding the C57BL/KsJ-db/db (db/db) mouse, an animal model of obesity and type II diabetes, and the C57BL/6J-Apc(Min/+) (Min/+) mouse, a model of familial adenomatous polyposis. At 15 weeks of age, the N9 backcross generation of C57BL/KsJ-db/db-Apc(Min/+) (db/db-Min/+) mice developed an increased incidence and multiplicity of adenomas in the intestinal tract when compared to the db/m-Min/+ and m/m-Min/+ mice. Blood biochemical profile showed significant increases in insulin (8.3-fold to 11.7-fold), cholesterol (1.2-fold to 1.7-fold), and triglyceride (1.2-fold to 1.3-fold) in the db/db-Min/+ mice, when compared to those of the db/m-Min/+ and m/m-Min/+ mice. Increases (1.4-fold to 2.6-fold) in RNA levels of insulin-like growth factor (IGF)-1, IRF-1R, and IGF-2 were also observed in the db/db- Min/+ mice. These results suggested that the IGFs, as well as hyperlipidemia and hyperinsulinemia, promoted adenoma formation in the db/db-Min/+ mice. Our results thus suggested that the db/db-Min/+ mice should be invaluable for studies on the pathogenesis of CRC in obese and diabetes patients and the therapy and prevention of CRC in these patients.     

Protective Effects of Ethanolic Extract from Rhizome of Polygoni avicularis against Renal Fibrosis and Inflammation in a Diabetic Nephropathy Model

Progressive diabetic nephropathy (DN) in diabetes leads to major morbidity and mortality. The major pathological alterations of DN include mesangial expansion, extracellular matrix alterations, tubulointerstitial fibrosis, and glomerular sclerosis. Polygoni avicularis is widely used in traditional oriental medicine and has long been used as a diuretic, astringent, insecticide and antihypertensive. However, to the best of the authors’ knowledge, the effects of the ethanolic extract from rhizome of Polygoni avicularis (ER-PA) on DN have not yet been assessed. The present study aimed to identify the effect of ER-PA on renal dysfunction, which has been implicated in DN in human renal mesangial cells and db/db mice and investigate its mechanism of action. The in vivo experiment was performed using Polygoni avicularis-ethanol soluble fraction (ER-PA) and was administrated to db/db mice at 10 and 50 mg/kg dose. For the in vitro experiments, the human renal mesangial cells were induced by high glucose (HG, 25 mM). The ER-PA group showed significant amelioration in oral glucose tolerance, and insulin resistance index. ER-PA significantly improved the albumin excretion and markedly reduced plasma creatinine, kidney injury molecule-1 and C-reactive protein. In addition, ER-PA significantly suppressed inflammatory cytokines. Histopathologically, ER-PA attenuated glomerular expansion and tubular fibrosis in db/db mice. Furthermore, ER-PA suppressed the expression of renal fibrosis biomarkers (TGF and Collagen IV). ER-PA also reduced the NLR family pyrin domain containing 3 inflammatory factor level. These results suggest that ER-PA has a protective effect against renal dysfunction through improved insulin resistance as well as the inhibition of nephritis and fibrosis in DN.     

TP63 Is Significantly Upregulated in Diabetic Kidney

The role of tumor protein 63 (TP63) in regulating insulin receptor substrate 1 (IRS-1) and other downstream signal proteins in diabetes has not been characterized. RNAs extracted from kidneys of diabetic mice (db/db) were sequenced to identify genes that are involved in kidney complications. RNA sequence analysis showed more than 4- to 6-fold increases in TP63 expression in the diabetic mice’s kidneys, compared to wild-type mice at age 10 and 12 months old. In addition, the kidneys from diabetic mice showed significant increases in TP63 mRNA and protein expression compared to WT mice. Mouse proximal tubular cells exposed to high glucose (HG) for 48 h showed significant decreases in IRS-1 expression and increases in TP63, compared to cells grown in normal glucose (NG). When TP63 was downregulated by siRNA, significant increases in IRS-1 and activation of AMP-activated protein kinase (AMPK (p-AMPK-Th¹⁷²)) occurred under NG and HG conditions. Moreover, activation of AMPK by pretreating the cells with AICAR resulted in significant downregulation of TP63 and increased IRS-1 expression. Ad-cDNA-mediated over-expression of tuberin resulted in significantly decreased TP63 levels and upregulation of IRS-1 expression. Furthermore, TP63 knockdown resulted in increased glucose uptake, whereas IRS-1 knockdown resulted in a decrease in the glucose uptake. Altogether, animal and cell culture data showed a potential role of TP63 as a new candidate gene involved in regulating IRS-1 that may be used as a new therapeutic target to prevent kidney complications in diabetes.     

Prunella vulgaris Suppresses HG-Induced Vascular Inflammation via Nrf2/HO-1/eNOS Activation

Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from Prunella vulgaris (APV) on high glucose (HG)-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC) are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS). HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1), eNOS, and nuclear factor E2-related factor 2 (Nrf2), which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that Prunella vulgaris may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.     

Stem Cell Replacement Improves Expression of SMP30 in db/db Mice

We have previously reported that replacing bone marrow stem cells may improve hyperglycemia and oxidative stress in db/db mice, a type 2 diabetic mouse model. Senescence marker protein 30 (SMP30) is an antioxidant protein that decreases with aging. However, it has not been clear whether SMP30 decreases in the livers of obese mice, and whether stem cell replacement would improve SMP30 expression in the liver. Bone marrow stem cells of db/db mice were replaced with the bone marrow stem cells of C57BL/6 mice. Plasma cytokine and insulin levels were measured, and glycogen content, expression of SMP30, and fibrosis in the liver were assessed. Our results showed that stem cell replacement increased the expression of SMP30 in the liver, resulting from decreased plasma inflammation cytokines and hyperinsulinemia in db/db mice. This is the first report that stem cell replacement increased the expression of SMP30 in the liver, and may help prevent fibrosis in the liver of db/db mice.     

Opa1 Deficiency Promotes Development of Retinal Vascular Lesions in Diabetic Retinopathy

This study investigates whether reduced optic atrophy 1 (Opa1) level promotes apoptosis and retinal vascular lesions associated with diabetic retinopathy (DR). Four groups of mice: wild type (WT) control mice, streptozotocin (STZ)-induced diabetic mice, Opa1^+/− mice, and diabetic Opa1^+/− mice were used in this study. 16 weeks after diabetes onset, retinas were assessed for Opa1 and Bax levels by Western blot analysis, and retinal networks were examined for acellular capillaries (AC) and pericyte loss (PL). Apoptotic cells were detected in retinal capillaries using TUNEL assay, and caspase-3 activity was assessed using fluorometric analysis. Opa1 expression was significantly downregulated in retinas of diabetic and Opa1^+/− mice compared with those of WT mice. Inducing diabetes further decreased Opa1 expression in retinas of Opa1^+/− mice. Increased cytochrome c release concomitant with increased level of pro-apoptotic Bax and elevated caspase-3 activity were observed in retinas of diabetic and Opa1^+/− mice; the number of TUNEL-positive cells and AC/PL was also significantly increased. An additional decrease in the Opa1 level in retinas of diabetic Opa1^+/− mice exacerbated the development of apoptotic cells and AC/PL compared with those of diabetic mice. Diabetes-induced Opa1 downregulation contributes, at least in part, to the development of retinal vascular lesions characteristic of DR.     

Effects of Aging and Hypercholesterolemia on Oxidative Stress and DNA Damage in Bone Marrow Mononuclear Cells in Apolipoprotein E-deficient Mice

Recent evidence from apolipoprotein E-deficient (apoE^−/−) mice shows that aging and atherosclerosis are closely associated with increased oxidative stress and DNA damage in some cells and tissues. However, bone marrow cells, which are physiologically involved in tissue repair have not yet been investigated. In the present study, we evaluated the influence of aging and hypercholesterolemia on oxidative stress, DNA damage and apoptosis in bone marrow cells from young and aged apoE^−/− mice compared with age-matched wild-type C57BL/6 (C57) mice, using the comet assay and flow cytometry. The production of both superoxide and hydrogen peroxide in bone marrow cells was higher in young apoE^−/− mice than in age-matched C57 mice, and reactive oxygen species were increased in aged C57 and apoE^−/− mice. Similar results were observed when we analyzed the DNA damage and apoptosis. Our data showed that both aging and hypercholesterolemia induce the increased production of oxidative stress and consequently DNA damage and apoptosis in bone marrow cells. This study is the first to demonstrate a functionality decrease of the bone marrow, which is a fundamental extra-arterial source of the cells involved in vascular injury repair.     

Effect of selenium and vitamin E supplements on tissue lipids, peroxides, and fatty acid distribution in experimental diabetes

The protective role of selenium (Se), given as a Se-rich yeast, selenomethionine or selenomethionine+vitamin E supplement, toward changes in lipid, peroxide, and fatty acid distribution in tissues of streptozotocin-induced diabetic rats, was investigated, after 24 wk of disease. Diabetes increased liver thiobarbituric acid-reactive substances and conjugated dienes; Se supplement completely corrected these changes. In kidney, as in heart, the peroxide levels were not significantly changed by diabetes. In diabetic rat liver, a significant drop in triglycerides and phospholipids (P<0.05) was observed; this was modulated by Se+vitamin F supplementation. Se+vitamin E supplementation also inhibited the decrease in 18∶2n-6 and the increase in 22∶6n-3 observed in liver of diabetic rats, changes which reflect altered glycemic control. In kidney, heart, and aorta, diabetes produced some changes in lipid content and fatty acid distribution, especially an increase in heart triglycerides which was also corrected by the Se supplement. Se supplementation to diabetic rats also increased 18∶0 etherlinked alcohol, 20∶4 n-6, and 22∶5 n-3 in cardiac lipids. In aorta, Se + vitamin E significanlty increased 20∶5 n-3. These polyunsaturated fatty acids are precursors, in situ, of prostaglandin l₂ (PGl₂) and PGl₃ which may protect against cardiovascular dysfunction. In kidney, converrely, Se decreased 20∶4 n-6, the precursor of thromboxane A₁ implicated in diabetic glomerular injury. thus Se, and more efficiently Se + vitamin E supplementation, in experimental diabetes could play a role in controlling oxidative status and altered lipid metabolism in liver, thereby maintaining favorable fatty acid distribution in the major tissues affected by diabetic complications.     

MMP-9 Deletion Attenuates Arteriovenous Fistula Neointima through Reduced Perioperative Vascular Inflammation

Matrix metalloproteinase 9 (MMP-9) expression is upregulated in vascular inflammation and participates in vascular remodeling, including aneurysm dilatation and arterial neointima development. Neointima at the arteriovenous (AV) fistula anastomosis site primarily causes AV fistula stenosis and failure; however, the effects of MMP-9 on perioperative AV fistula remodeling remain unknown. Therefore, we created AV fistulas (end-to-side anastomosis) in wild-type (WT) and MMP-9 knockout mice with chronic kidney disease to further clarify this. Neointima progressively developed in the AV fistula venous segment of WT mice during the four-week postoperative course, and MMP-9 knockout increased the lumen area and attenuated neointima size by reducing smooth muscle cell and collagen components. Early perioperative AV fistula mRNA sequencing data revealed that inflammation-related gene sets were negatively enriched in AV fistula of MMP-9 knockout mice compared to that in WT mice. qPCR results also showed that inflammatory genes, including tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), were downregulated. In addition, Western blot results showed that MMP-9 knockout reduced CD44 and RAC-alpha serine/threonine-protein kinase (Akt) and extracellular signal-regulated kinases (ERK) phosphorylation. In vitro, MMP-9 addition enhanced IL-6 and MCP-1 expression in vascular smooth muscle cells, as well as cell migration, which was reversed by an MMP-9 inhibitor. In conclusion, MMP-9 knockout attenuated AV fistula stenosis by reducing perioperative vascular inflammation.     

Deficient Leptin Cellular Signaling Plays a Key Role in Brain Ultrastructural Remodeling in Obesity and Type 2 Diabetes Mellitus

The triad of obesity, metabolic syndrome (MetS), Type 2 diabetes mellitus (T2DM) and advancing age are currently global societal problems that are expected to grow over the coming decades. This triad is associated with multiple end-organ complications of diabetic vasculopathy (maco-microvessel disease), neuropathy, retinopathy, nephropathy, cardiomyopathy, cognopathy encephalopathy and/or late-onset Alzheimer’s disease. Further, obesity, MetS, T2DM and their complications are associated with economical and individual family burdens. This review with original data focuses on the white adipose tissue-derived adipokine/hormone leptin and how its deficient signaling is associated with brain remodeling in hyperphagic, obese, or hyperglycemic female mice. Specifically, the ultrastructural remodeling of the capillary neurovascular unit, brain endothelial cells (BECs) and their endothelial glycocalyx (ecGCx), the blood-brain barrier (BBB), the ventricular ependymal cells, choroid plexus, blood-cerebrospinal fluid barrier (BCSFB), and tanycytes are examined in female mice with impaired leptin signaling from either dysfunction of the leptin receptor (DIO and db/db models) or the novel leptin deficiency (BTBR ob/ob model).     

Protective Effects of MDG-1, a Polysaccharide from Ophiopogon japonicus on Diabetic Nephropathy in Diabetic KKAy Mice

Ophiopogon japonicus is a traditional Chinese medicine that might be effective for treating type 2 diabetes. Recent research confirmed that MDG-1, a polysaccharide from O. japonicas, activates the PI3K/Akt signaling pathway and improves insulin sensitivity in a diabetic KKA^y mouse model, but little is known about its effects on diabetic nephropathy. In this study, KKA^y mice were orally administered distilled water (control group), MDG-1, or rosiglitazone for 12 weeks. Blood glucose levels were tested every two weeks for the fed mice. At 6 and 12 weeks, blood samples were collected for biochemical examination. At the end of the experiment, all kidney tissues were collected for histological examination and western blot analysis. Results show that MDG-1 (300 mg/kg) significantly decreased the levels of blood glucose, triglycerides, blood urine nitrogen and albumin, and significantly inhibited the expression of transforming growth factor-beta 1 and connective tissue growth factor. Moreover, MDG-1 could alleviate glomerular mesangial expansion and tubulointerstitial fibrosis in the diabetic mice, as confirmed by histopathological examination. These data indicated that MDG-1 ameliorates renal disease in diabetic mice by reducing hyperglycemia, hyperinsulinemia, and hyperlipidemia, and by inhibiting intracellular signaling pathways.     

早期糖尿病肾病转化生长因子-β_1与尿白蛋白的相关性

目的探讨早期糖尿病肾病(DN)转化生长因子-β1(TGF-β1)与尿白蛋白的相关性。方法RT-PCR方法测定高糖刺激的系膜细胞内及2型糖尿病小鼠肾小球内TGF-β1mRNA的转录水平;ELISA方法检测DN患者尿TGF-β1和尿白蛋白排泄率(UAER)的变化。结果高糖刺激的系膜细胞内与肥胖db/db小鼠肾小球内TGF-β1mRNA转录水平与对照组比较均明显增高。糖尿病各组患者尿TGF-β1含量均显著高于正常对照组,且UAER增加呈递增趋势,两者呈正相关。结论TGF-β1与早期DN的发生与发展密切相关,是反映早期糖尿病肾损害的重要因子。     

Effect of FTY720 on Some Physiological Indexes of Non-Obese Diabetic (NOD) Mice

The studies were performed to investigate the physiological characteristics of non-obese diabetic (NOD) mice treated with FTY720. At the age of 12 weeks, each mouse was fed with FTY720 or physiological saline once a day for 10 weeks running, and their blood glucose, weight, anti-GAD antibody and organ indexes were determined. No mouse in group FTY720 (NOD mice treated with FTY720) showed diabetic symptoms. The average content of serum anti-GAD antibody in group FTY720 decreased 48.75% (P < 0.01). It was concluded that the spleen, kidney and liver of NOD mice treated with FTY720 shriveled significantly in the progression of diabetes (P < 0.01 or P < 0.05). The body weight of group FTY720 mice was slightly lower than that of the model control (MC) group and these two groups both had less body weight than the normal control (NC) group (P < 0.01). The result of tests of anti-GAD antibody suggested that FTY720 treatment could suppress the anti-GAD response.     

Oxidative Stress in Diabetes: Implications for Vascular and Other Complications

In recent decades, oxidative stress has become a focus of interest in most biomedical disciplines and many types of clinical research. Increasing evidence shows that oxidative stress is associated with the pathogenesis of diabetes, obesity, cancer, ageing, inflammation, neurodegenerative disorders, hypertension, apoptosis, cardiovascular diseases, and heart failure. Based on these studies, an emerging concept is that oxidative stress is the “final common pathway” through which the risk factors for several diseases exert their deleterious effects. Oxidative stress causes a complex dysregulation of cell metabolism and cell–cell homeostasis; in particular, oxidative stress plays a key role in the pathogenesis of insulin resistance and β-cell dysfunction. These are the two most relevant mechanisms in the pathophysiology of type 2 diabetes and its vascular complications, the leading cause of death in diabetic patients.     

Streptozotocin-Induced Diabetes Partially Attenuates the Effects of a High-Fat Diet on Liver and Brain Fatty Acid Composition in Mice

The current study addresses the effects of a high-fat diet on liver and brain fatty acid compositions and the interaction of that diet with diabetes in a type 1 mouse model. Adult, male, normal and streptozotocin-induced diabetic C57BL/6 mice were fed standard (14 % kcal from fat) or high-fat (54 % kcal from fat, hydrogenated vegetable shortening and corn oil) diets for 8 weeks. Liver and whole brain total phospholipid fatty acid compositions were then determined by TLC/GC. In the liver of non-diabetic mice, the high-fat diet increased the percentages of 18:1n-9, 20:4n-6, and 22:5n-6 and decreased 18:2n-6 and 22:6n-3. Diabetes increased 16:0 in liver, and decreased 18:1n-7 and 20:4n-6. The effects of the high-fat diet on liver phospholipids in diabetic mice were similar to those in non-diabetic mice, or were of smaller magnitude. In the brain, the high-fat diet increased 18:0 and 20:4n-6 of non-diabetic, but not diabetic mice. Brain 22:5n-6 acid was increased by the high-fat diet in both non-diabetic and diabetic mice, but this increase was smaller in diabetic mice. Diabetes alone did not alter the percentage of any individual fatty acid in brain. This indicates that the effects of a high-fat diet on liver and brain phospholipid fatty acid compositions are partially attenuated by concomitant hyperglycemia with hypoinsulinemia.     

Tangeretin Ameliorates Glucose-Induced Podocyte Injury through Blocking Epithelial to Mesenchymal Transition Caused by Oxidative Stress and Hypoxia

Podocyte injury inevitably results in leakage of proteins from the glomerular filter and is vital in the pathogenesis of diabetic nephropathy (DN). The underlying mechanisms of podocyte injury facilitate finding of new therapeutic targets for DN treatment and prevention. Tangeretin is an O-polymethoxylated flavone present in citrus peels with anti-inflammatory and antioxidant properties. This study investigated the renoprotective effects of tangeretin on epithelial-to-mesenchymal transition-mediated podocyte injury and fibrosis through oxidative stress and hypoxia caused by hyperglycemia. Mouse podocytes were incubated in media containing 33 mM glucose in the absence and presence of 1–20 μM tangeretin for up to 6 days. The in vivo animal model employed db/db mice orally administrated with 10 mg/kg tangeretin for 8 weeks. Non-toxic tangeretin inhibited glucose-induced expression of the mesenchymal markers of N-cadherin and α-smooth muscle actin in podocytes. However, the reduced induction of the epithelial markers of E-cadherin and P-cadherin was restored by tangeretin in diabetic podocytes. Further, tangeretin enhanced the expression of the podocyte slit diaphragm proteins of nephrin and podocin down-regulated by glucose stimulation. The transmission electron microscopic images revealed that foot process effacement and loss of podocytes occurred in diabetic mouse glomeruli. However, oral administration of 10 mg/kg tangeretin reduced urine albumin excretion and improved foot process effacement of diabetic podocytes through inhibiting loss of slit junction and adherenes junction proteins. Glucose enhanced ROS production and HIF-1α induction in podocytes, leading to induction of oxidative stress and hypoxia. Similarly, in diabetic glomeruli reactive oxygen species (ROS) production and HIF-1α induction were observed. Furthermore, hypoxia-evoking cobalt chloride induced epithelial-to-mesenchymal transition (EMT) process and loss of slit diaphragm proteins and junction proteins in podocytes, which was inhibited by treating submicromolar tangeretin. Collectively, these results demonstrate that tangeretin inhibited podocyte injury and fibrosis through blocking podocyte EMT caused by glucose-induced oxidative stress and hypoxia.     

Dietary Black Raspberry Seed Oil Ameliorates Inflammatory Activities in db/db Mice

The objective of this study was to evaluate the status of the markers related to inflammation in db/db mice fed black raspberry seed (BRS) oil, which is rich in α‐linolenic acid. Mice were divided into four groups: (1) C57BL/6 mice fed 16 % calories from soybean oil (normal CON); (2) C57BL/KsJ‐db/db mice fed 16 % calories from soybean oil (CON); (3) C57BL/KsJ‐db/db mice fed 8 % calories from soybean and 8 % calories from BRS oil (BRS 50 %); and (4) C57BL/KsJ‐db/db mice fed 16 % calories from BRS oil (BRS 100 %). After 10 weeks, n‐6/n‐3 fatty acid ratios were significantly (P < 0.05) lower in the livers and epididymal adipose tissues of the BRS 50 % and BRS 100 % mice than in the CON. Serum TNFα and IL‐6 were significantly (P < 0.05) lower in the BRS 50 % and BRS 100 % than in the CON. Serum IL‐10 was significantly (P < 0.05) higher in the BRS 100 % than the CON. In the liver and epididymal adipose tissue, mRNA levels of pro‐inflammatory markers in the BRS 50 % and BRS 100 % were lower than in the CON. Anti‐inflammatory markers were higher in the epididymal adipose tissues of the BRS 50 % and BRS 100 % than in the CON. In the epididymal adipose tissue, macrophage infiltration markers (F4/80 and CD68) and leptin mRNA were significantly (P < 0.05) lower in the BRS 50 % and BRS 100 % than in the CON. Results of this study suggest that BRS oil may have anti‐inflammatory effects in obese diabetic mice by ameliorating inflammatory responses.