Urinary liver-type fatty acid binding protein is a biomarker reflecting renal damage and the ameliorative effect of drugs at an early stage of histone-induced acute kidney injury

AIM

Circulated histones play a crucial role in the pathogenesis of infectious diseases and severe trauma, and it is one of the potential molecular targets for therapeutics. Recently, we reported that histone is one of the causative agents for urinary L-FABP increase. However, the mechanism is still unclear, especially in severe cases. We further investigated the mechanism of urinary L-FABP increase using a more severe mouse model with histone-induced kidney injury. This study also aims to evaluate the therapeutic responsiveness of urinary L-FABP as a preliminary study.

METHODS

Human L-FABP chromosomal transgenic mice were administrated 30 mg/kg histone from a tail vein with a single dose. We also performed a comparative study in LPS administration model. For the evaluation of the therapeutic responsiveness of urinary L-FABP, we used heparin and rolipram.

RESULTS

The histological change with cast formation as a characteristic of the models was observed in proximal tubules. Urinary L-FABP levels were significantly elevated and these levels tended to be higher in those with more cast formation. Heparin and rolipram had the ameliorative effect of the cast formation induced by histone and urinary L-FABP levels significantly decreased.

CONCLUSION

Histone is one of the causative agents for the increase of urinary L-FABP at an early stage of AKI. In addition, it suggested that urinary L-FABP may be useful as a subclinical AKI marker reflecting kidney damage induced by histone. Furthermore, urinary L-FABP reflected the degree of the damage after the administration of therapeutic agents such as heparin and PDE4 inhibitor.

Granulomatous Myocarditis Caused by Candida Spp Infection in a Spontaneously Diabetic Torii Rat

Background

Myocarditis refers to myocardial inflammation with necrosis caused by non-infectious of infectious agents such as bacteria, fungi, or drugs. Candida is known to cause myocarditis in healthy and immunocompromised individuals. Diabetes mellitus causes chronic hyperglycemia due to impaired secretion or hypofunction of insulin, induces a compromised state, and increases the risk of contracting various infections.

Objective

We report a case of granulomatous myocarditis caused by Candida in a Spontaneously Diabetic Torii rat, a non-obese diabetic model.

Case report

A male SDT rat, 61 weeks of age, was housed in conventional environment. The rat was provided a commercial diet and tap water ad libitum. The heart was sampled and prepared the specimen of hematoxylin-and-eosin-, Sirius-red-, Giemsa-, Grocott-stain. Histologically, formation of large granulation tissue was observed in the left ventricular wall. A center of the foci showed necrosis. Moreover, inflammatory cells infiltration and fibrous component were increased surrounding the foci and between myocardial cells. A Grocott and Giemsa staining-positive cell masses occasionally appearing in the foci were considered to be Candida because of their characteristic form.

Conclusion

The development and progression of myocarditis were potentially related to a diabetes-induced compromised state.

Nonalcoholic steatohepatitis-associated hepatocarcinogenesis in mice fed a modified choline-deficient, methionine-lowered, L-amino acid-defined diet and the role of signal changes

Nonalcoholic steatohepatitis (NASH) can progress to cirrhosis and even hepatocellular carcinoma (HCC). The incidence of NASH-associated HCC is increasing, posing a serious public health threat. Unfortunately, the underlying pathological mechanisms, including the possible differences between neoplastic and non-neoplastic lesions, remain largely unknown. Previously, we reported a dietary mouse NASH model with a choline-deficient, methionine-lowered, L-amino-acid-defined, high-fat diet containing shortening without trans fatty acids (CDAA-HF-T[-]), which rapidly induces fibrosis and proliferative lesions in the liver. This study aimed to develop a mouse CDAA-HF-T(-) model capable of assessing NASH-associated hepatocarcinogenesis and identifying key signaling factors involved in its underlying mechanisms. Multiple large masses, histopathologically hepatocellular adenomas and carcinomas, and hemangiosarcomas were detected in the liver samples of mice fed CDAA-HF-T(-) for 52 or 63 weeks, along with highly advanced fibrosis and numerous foamy, phagocytic macrophages in the adjacent nontumoral area. Multiple metastatic nodules were found in the lungs of one of the animals, and lymphoid clusters were found in all CDAA-HF-T(-) group mice. In the Ingenuity Pathways Analysis of RNA expression data, the CDAA-HF-T(-) feeding revealed common signal changes in nontumoral and tumoral liver tissues, including increased IL-8 and RhoGTPases signaling and decreased lipid metabolism. Meanwhile, macrophage inflammatory protein 2 (MIP-2) expression levels were upregulated in nontumoral liver tissue from the end of Week 13 of CDAA-HF-T(-) feeding to the end of Week 63. On the other hand, MIP-2 was expressed on macrophages in non-tumor areas and hepatocytes in tumor areas. Therefore, the CDAA-HF-T(-) mouse model is useful for assessing NASH and NASH-associated hepatocarcinogenesis, and IL-8 signaling plays important roles in NASH-associated carcinogenesis and cirrhosis, but it may also play different roles in nontumoral liver tissue and tumorigenesis.

High-cholesterol diet in combination with hydroxypropyl-beta-cyclodextrin induces NASH-like disorders in the liver of rats

Non-alcoholic fatty liver disease (NAFLD) is a general term for fatty liver disease not caused by viruses or alcohol. Fibrotic hepatitis, cirrhosis, and hepatocellular carcinoma can develop. The recent increase in NAFLD incidence worldwide has stimulated drug development efforts. However, there is still no approved treatment. This may be due in part to the fact that non-alcoholic steatohepatitis (NASH) pathogenesis is very complex, and its mechanisms are not well understood. Studies with animals are very important for understanding the pathogenesis. Due to the close association between the establishment of human NASH pathology and metabolic syndrome, several animal models have been reported, especially in the context of overnutrition. In this study, we investigated the induction of NASH-like pathology by enhancing cholesterol absorption through treatment with hydroxypropyl-beta-cyclodextrin (CDX). Female Sprague-Dawley rats were fed a normal diet with normal water (control group); a high-fat (60 kcal%), cholesterol (1.25 %), and cholic acid (0.5 %) diet with normal water (HFCC group); or HFCC diet with 2 % CDX water (HFCC+CDX group) for 16 weeks. Compared to the control group, the HFCC and HFCC+CDX groups showed increased blood levels of total cholesterol, aspartate aminotransferase, and alanine aminotransferase. At autopsy, parameters related to hepatic lipid synthesis, oxidative stress, inflammation, and fibrosis were elevated, suggesting the development of NAFLD/NASH. Elevated levels of endoplasmic reticulum stress-related genes were evident in the HFCC+CDX group. In the novel rat model, excessive cholesterol intake and accelerated absorption contributed to NAFLD/NASH pathogenesis.

Choline-deficient Diet-induced NAFLD Animal Model Recaptures Core Human Pathophysiology With Similar Gene Co-expression Networks

BACKGROUND/AIM

Nonalcoholic fatty liver disease (NAFLD) is a wide spectrum of liver disorders ranging from simple steatosis to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. Recently, the prevalence of NAFLD has dramatically increased, and treatment is urgently needed. Animal models are often used to understand the molecular mechanisms of disease development and progression, but their relevance to human diseases has not been fully understood. This study aimed to establish the usefulness of the animal model for preclinical research, we evaluated its relevance to human disease by gene expression analysis.

MATERIALS AND METHODS

We performed weighted gene co-expression network analysis of liver tissues from a choline-deficient L-amino acid-defined (CDAA) diet-induced NAFLD animal model. In addition, module preservation analysis was conducted to evaluate similarity across species.

RESULTS

Several modules were identified to be associated with disease severity, and their gene co-expression network was found to be preserved in the human NAFLD datasets. Of note, module brown (immune cell clusters involved in inflammatory responses) was positively associated with disease severity, and its gene co-expression network was highly preserved in the human datasets. Tyrobp, Laptm5 and Lgals3 were identified as hub genes in the brown module, and their increased expression was confirmed in the human datasets.

CONCLUSION

CDAA diet-induced NAFLD animal model recaptured key aspects of human pathophysiology (especially immune cell functions) and is thought to be a powerful tool for understanding the molecular mechanisms of NAFLD development and progression.

Unilateral nephrectomized SHR/NDmcr-cp rat shows a progressive decline of glomerular filtration with tubular interstitial lesions

In patients with diabetic kidney disease (DKD), the estimated glomerular filtration rate (eGFR) or creatinine clearance rate (Ccr) is always used as an index of decline in renal function. However, there are few animal models of DKD that could be used to evaluate renal function based on GFR or Ccr. For this reason, it is desirable to develop animal models to assess renal function, which could also be used for the evaluation of novel therapeutic agents for DKD. Therefore, we aimed to develop such animal model of DKD by using spontaneously hypertensive rat (SHR)/NDmcr-cp (cp/cp) rats with the characteristics of obese type 2 diabetes and metabolic syndrome. As a result, we have found that unilateral nephrectomy (UNx) caused a chronic Ccr decline, development of glomerular sclerosis, tubular lesions, and tubulointerstitial fibrosis, accompanied by renal anemia. Moreover, losartan-mixed diet suppressed the Ccr decline in UNx-performed SHR/NDmcr-cp rats (UNx-SHR/cp rats), with improvement in renal anemia and histopathological changes. These results suggest that UNx-SHR/cp rats could be used as a DKD model for evaluating the efficacy of therapeutic agents based on suppression of renal function decline.

Urinary liver-type fatty acid binding protein is increased in the early stages of the disease with a risk of acute kidney injury induced by histone

AIM

Urinary liver-type fatty acid binding protein (L-FABP) has potential utility as an early prognostic biomarker ahead of traditional severity scores in coronavirus disease 2019 and sepsis, however, the mechanism of elevated urinary L-FABP in the disease has not been clearly elucidated. We investigated the background mechanisms of urinary L-FABP excretion through non-clinical animal model focusing on histone, which is one of the aggravating factors in these infectious diseases.

METHODS

Male Sprague-Dawley rats were placed in central intravenous catheters, and these rats were given a continuous intravenous infusion of 0.25 or 0.5 mg/kg/min calf thymus histones for 240 min from caudal vena cava.

RESULTS

After the administration of histone, urinary L-FABP and gene expression of an oxidative stress marker in the kidney increased in a histone dose-dependent manner before increased serum creatinine. Upon further investigation, fibrin deposition in the glomerulus was observed and it tended to be remarkable in the high dose administrated groups. The levels of coagulation factor were significantly changed after the administration of histone, and these were significantly correlated with the levels of urinary L-FABP.

CONCLUSIONS

Firstly, it was suggested that histone is one of the causative agents for the urinary L-FABP increase at an early stage of the disease with a risk of acute kidney injury. Secondly, urinary L-FABP could be a marker reflecting the changes of coagulation system and microthrombus caused by histone in the early stage of acute kidney injury before becoming severely ill and maybe a guide to early treatment initiation.

Effects of Siraitia grosvenorii extract on nonalcoholic steatohepatitis-like lesions in Sprague Dawley rats fed a choline-deficient, methionine-lowered, l-amino acid-defined diet

Siraitia grosvenorii is the fruit of a cucurbitaceous vine endemic to China. Its extract has been used as a sweetener and exhibits various anti-inflammatory and anticarcinogenic effects mediated via its antioxidant properties. In the present study, we aimed to clarify the preventive or ameliorative effects of S. grosvenorii extract (SGE) on nonalcoholic steatohepatitis-like lesions induced in male Hsd: Sprague Dawley rats fed a choline-deficient, methionine-lowered, l-amino acid-defined diet for 13 weeks. This diet increased hepatotoxicity parameters and upregulated the expression of inflammation- and fibrosis-related genes in the liver, resulting in the progression of hepatic lesions, oxidative stress, hepatocellular apoptosis, and fibrosis. Furthermore, this diet upregulated the expression of phosphorylated nuclear factor-κB (NF-κB) and CD44. SGE administration inhibited these lesions, similar to CD44, a factor that controls hepatic inflammation and fibrosis. These results revealed that SGE impacts the disease stage via antioxidative effects and regulation of CD44 expression. SGE was found to be useful for preventing and treating steatohepatitis.

Effects of salt supplementation in uninephrectomized KK-Ay mice: Examining the potential of a diabetic kidney disease model

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD). Although current therapeutic strategies for DKD, including sodium-glucose cotransporter-2 inhibitors and mineralocorticoid receptor antagonists, have shown some degree of efficacy, they have failed to completely halt the progression of DKD to ESRD owing to the complexity of DKD pathogenesis. Elucidating the pathophysiological mechanism of DKD is essential for the development of novel therapeutic strategies. In this study, we investigated the pathophysiological characteristics of uninephrectomized (UNx) KK-Ay mice and examined the effects of salt supplementation on the acceleration of renal injury in these mice. UNx KK-Ay mice exhibited pathophysiological renal abnormalities with glomerular and tubulointerstitial fibrosis. Additionally, salt supplementation exacerbated renal injury, particularly tubular injury. These results suggest that UNx KK-Ay mice are useful models for advanced DKD and that salt exacerbates tubular damage in DKD.

Effects of dietary phosphorus concentration and phosphate salt form on renal tubule function in unilateral nephrectomized rats

Background: Excessive consumption of phosphorus (P) impairs renal tubule function; however, the effects of different dietary phosphate salts on chronic kidney disease (CKD) are unclear. Aim: To examine the effects of potassium dihydrogen phosphate (KH2PO4) and potassium tripolyphosphate (K5P3O10) and P concentration on renal function in a rat model of early CKD. Methods: Male sham-operated Sprague-Dawley rats were fed a diet containing KH2PO4 with a normal P level. Kidney injury was induced by unilateral nephrectomy (UNx), and the rats were divided into four groups fed dietary KH2PO4 or K5P3O10 with a normal (UNx-NKH, UNx-NKP) or high (UNx-HKH, UNx-HKP) P concentration, respectively, for 21 days. Results: UNx-NKH rats showed significantly lower creatinine clearance (CCr) and higher albumin (ALB) compared with those of sham rats, confirming UNx-induced kidney injury. The urinary levels of liver-type fatty acid-binding protein (L-FABP) and ALB were significantly higher in UNx-HKP rats than in UNx-HKH rats. However, other markers of renal tubule function, such as CCr, serum creatinine (CRE), calcium (Ca), and hormones, only differed among groups according to the P concentration and not the dietary phosphate salt form. Histological examination showed higher incidence and severity of tubulointerstitial lesions, tubule regeneration, tubule dilation, and calcification in the high-phosphorus than in the normal-phosphorus UNx groups. These changes were more severe in the UNx-HKP group compared with the UNx-HKH group. Conclusion: This study highlights the importance of controlling dietary P intake in terms of both concentration and source to prevent the progression of CKD.

[Important Points at Interpretation ofNongenotoxic-Carcinogenicity Induced by Pesticidesin Rodent Bioassays]

Assessment of carcinogenicity is important for human health at dietary risk assessment of pesticide residues. This article indicated important points on interpretation of carcinogenicity in toxicological evaluation of pesticide residues based on principles of risk analysis in foods by CODEX to be a guide for risk assessors. This guidance was referred from the guidance on carcinogenicity evaluation by international and/or national organizations, and the interpretations of Food Safety Commissions of Japan (FSCJ) published in their risk assessment reports. We focused on carcinogenicity obtained from routine carcinogenicity bioassays in rodents. The guidance includes the purpose and usefulness of the bioassay studies, consideration points to be carcinogenicity and influencing factors to carcinogenicity in the test to judge carcinogenic hazard at hazard identification. Considering on human relevance as carcinogenic hazard also was proposed using practical case examples. Next, a carcinogenic hazard is evaluated on dose-response relationship to judge points of departure on carcinogenicity. At the end of this article, we challenged our recommendation on future assessment of carcinogenicity to progress from hazard to risk.

Effects of excessive sodium chloride loading in the spontaneously diabetic torii (SDT) fatty rats, a preclinical model of type 2 diabetes mellitus

Type 2 diabetes mellitus represents an international health concern with its growing number of patients worldwide. At the same time, excessive salt consumption is also seen as a major cause of diseases such as hypertension and may expedite renal complications in diabetic patients. In this study, we investigated the effects of excessive sodium chloride supplementation on the kidney of the Spontaneously Diabetic Torii-Lepr^fa (SDT fatty) rat, an obese type 2 diabetes model. Male and female SDT fatty rats and normal Sprague-Dawley (SD) rats at 5 weeks of age were loaded with 0.3% sodium chloride (NaCl) in drinking water for 13 weeks. Blood serum and urinary parameters were observed throughout the experiment and kidney samples were examined in histopathological and genetical analyses. Significant changes on the body weight, blood pressure, urine volume, creatinine clearance, blood urea nitrogen (BUN), relative gene expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemotactic protein-1 (MCP-1) and transforming growth factor-β (TGF-β) were observed in the salt-loaded male SDT fatty rats. Urinary L-type fatty acid-binding protein (L-FABP) and albumin levels were higher observed in the salt-loaded male SDT fatty rats throughout the period, but urinary albumin levels in the female SDT fatty rats remain unchanged. In the kidney, slight Armani-Ebstein changes, tubular degeneration, hyaline cast, and inflammatory cell infiltration were observed in female SDT fatty rats while the levels of some changes were higher in the salt-loaded group. The kidney of the salt-loaded male SDT fatty rats demonstrated a higher degree of lesions compared to the female group and the male unloaded group. Histopathological changes in salt-loaded SDT fatty rats show that excessive salt consumption may act as a diabetic pathology exacerbation factor, but the pathology may be influenced by gender difference. Urinary L-FABP levels may act as a useful biomarker to detect slight tubular damages in the kidney. Excessive salt loading was shown to exacerbate the renal injury in SDT fatty rats.

A case of spontaneous Zymbal's gland carcinoma with lung metastasis in an aged Fischer 344 rat

Zymbal’s gland neoplasms are induced in rats through the administration of various carcinogens, but spontaneous neoplasia is rare. This report describes a spontaneous Zymbal’s gland carcinoma with lung metastasis found in an aged male Fischer 344 rat. Macroscopically, the dome-like tumor nodule, approximately 30 mm in diameter with ulceration, was located near the ear canal of the rat. No healthy tissue or structure of Zymbal’s gland was identified on the corresponding side, while the normal salivary glands and a lacrimal gland were observed. Histologically, a large part of the tumor mass was occupied by poorly differentiated neoplastic cells, the shapes of which were oval to polygonal or fusiform. Additionally, clusters of sebaceous-like foamy cells and squamous metaplasia with prominent keratinization were observed. Tumor cells were found to metastasize to the lung; these cells displayed histological similarities, including a sebaceous gland-like pattern, to those in the primary site. The tumor cells were immunohistochemically positive for cytokeratin AE1/AE3 or vimentin but negative for CD68, S100, α-smooth muscle actin, von Willebrand factor, and desmin. Our results indicate that the tumor was a poorly differentiated Zymbal’s gland carcinoma with lung metastasis.

Non-obese mice with nonalcoholic steatohepatitis fed on a choline-deficient, L-amino acid-defined, high-fat diet exhibit alterations in signaling pathways

Nonalcoholic steatohepatitis (NASH) is often associated with obesity, but some patients develop NASH without obesity. The physiological processes by which non-obese patients develop NASH and cirrhosis have not yet been determined. Here, we analyzed the effects of dietary methionine content on NASH induced in mice fed on a choline-deficient, methionine-lowered, L-amino acid-defined high-fat diet (CDAHFD). CDAHFD with insufficient methionine induced insulin sensitivity and enhanced NASH pathology, but without obesity. In contrast, CDAHFD with sufficient methionine induced steatosis, and unlike CDAHFD with insufficient methionine, also induced obesity and insulin resistance. Gene profile analysis revealed that the disease severity in CDAHFD may partially be due to upregulation of the Rho family GTPases pathway, and mitochondrial and nuclear receptor signal dysfunction. The signaling factors/pathways detected in this study may assist in future study of NASH regulation, especially its "non-obese" subtype.

Case analysis of kinetics investigations in toxicity studies of pesticides to identify the nonlinearity of internal exposure and the influences of nonlinearity on the toxicological interpretation of pesticide residue

The nonlinearity of internal exposure to 8 pesticides was investigated in toxicity studies using kinetics to identify nonlinearity visually and to investigate the influence of nonlinearity on toxicological evaluation. Data were obtained from risk assessment reports published by the Food Safety Commission (FSCJ). Nonlinearity was defined using 2 indicators: the lowest visual inflection point (LVIP) and the second lowest visual inflection point (SVIP) of kinetics by drawing a linear distribution chart. The area under the curve and 24-h urine concentrations were stable parameters used to identify the LVIP/SVIP. The sampling timing affected the blood concentrations, and the LVIP/SVIP was detected for 6 pesticides using the parent compounds or their metabolites as analytes. The subproportional nonlinearity was significant for these pesticides. The LVIP/SVIP values were consistent in the same species up to a 1-year period, but the values showed species-specific differences in several compounds. In all compounds found to be nonlinear, apical outcomes were observed at the SVIP or above. The presence of nonlinearity was recognized by the FSCJ. The recognition influenced their judgment of no-observed-adverse-effect levels (NOAELs) for carcinogenicity or health-based guidance values, indicating the importance of appropriate kinetics to identify the nonlinearity for toxicological evaluation of pesticide residue.

Glomerular hyperfiltration with hyperglycemia in the spontaneously diabetic Torii (SDT) fatty rat, an obese type 2 diabetic model

Glomerular hyperfiltration is observed in an early stage of kidney diseases including diabetic nephropathy. A better understanding of pathophysiological changes in glomerular hyperfiltration is essential for development of new therapies to prevent kidney disease progression. In this study, we investigated glomerular changes including glomerular filtration rate (GFR) and glomerular size in the Spontaneously Diabetic Torii (SDT) fatty rat, an obese type 2 diabetic model, and we also evaluated pharmacological effects of the sodium glucose cotransporter 2 inhibitor dapagliflozin on the renal lesions. Dapagliflozin was administered to SDT fatty rats from 5 to 17 weeks of age. Blood and urinary biochemical parameters were periodically measured. GFR was determined by transdermal GFR monitor at 16 weeks of age and histopathological analysis was performed at 17 weeks of age. SDT fatty rat developed severe hyperglycemia and exhibited pathophysiological abnormalities in the kidney, such as an increased GFR, glomerular hypertrophy and tissue lesions. Dapagliflozin achieved good glycemic control during the experimental period, inhibited the increase in GFR, and improved histopathological abnormalities in tubules. These results suggest that the SDT fatty rat is a useful model for analyzing the pathogenesis of diabetic nephropathy during its early stage and dapagliflozin improves not only hyperglycemia but also glomerular hyperfiltration and tubule lesions in SDT fatty rat.

A trans fatty acid substitute enhanced development of liver proliferative lesions induced in mice by feeding a choline-deficient, methionine-lowered, L-amino acid-defined, high-fat diet

Background

Nonalcoholic steatohepatitis (NASH) is a form of liver disease characterized by steatosis, necroinflammation, and fibrosis, resulting in cirrhosis and cancer. Efforts have focused on reducing the intake of trans fatty acids (TFAs) because of potential hazards to human health and the increased risk for NASH. However, the health benefits of reducing dietary TFAs have not been fully elucidated. Here, the effects of TFAs vs. a substitute on NASH induced in mice by feeding a choline-deficient, methionine-lowered, L-amino acid-defined, high-fat diet (CDAA-HF) were investigated.

Methods

Mice were fed CDAA-HF containing shortening with TFAs (CDAA-HF-T(+)), CDAA-HF containing shortening without TFAs (CDAA-HF-T(−)), or a control chow for 13 or 26 weeks.

Results

At week 13, NASH was induced in mice by feeding CDAA-HF-T(+) containing TFAs or CDAA-HF-T(−) containing no TFAs, but rather mostly saturated fatty acids (FAs), as evidenced by elevated serum transaminase activity and liver changes, including steatosis, inflammation, and fibrosis. CDAA-HF-T(−) induced a greater extent of hepatocellular apoptosis at week 13. At week 26, proliferative (preneoplastic and non-neoplastic) nodular lesions were more pronounced in mice fed CDAA-HF-T(−) than CDAA-HF-T(+).

Conclusions

Replacement of dietary TFAs with a substitute promoted the development of proliferation lesions in the liver of a mouse NASH model, at least under the present conditions. Attention should be paid regarding use of TFA substitutes in foods for human consumption, and a balance of FAs is likely more important than the particular types of FAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-020-01423-3.

Usefulness of lead delivery catheter system for true right ventricular septal pacing

Background

Right ventricular (RV) septal pacing is often selected to preserve a more physiologic ventricular activation. But the pacing leads are not always located in true septal wall, rather in hinge or free wall in some cases with the conventional stylet-guided lead implantation. In recent years, new guiding catheter systems has attracted attention as a solution to that problem.

Objective

The aim of this study is to investigate that true ventricular sepal pacing can be achieved by use of the new guiding catheter system for pacing lead.

Methods

We enrolled 198 patients who underwent RV septal lead implantation and computed tomography (CT) after pacemaker implantation. 16 cases were used delivery catheter (Delivery), and 182 cases were used stylet for targeting ventricular septum (Conventional). We analyzed the lead locations with CT, and evaluated capture thresholds, R-wave amplitudes, lead impedances and 12-lead electrocardiogram findings one month after implantation.

Results

All cases of delivery catheter group had true septal lead positions (Delivery; 100% vs Conventional; 44%, p<0.01). Capture thresholds and lead impedances had not significant differences between between two groups (0.65±0.15V vs 0.60±0.15V, p=0.21, 570±95Ω vs 595±107Ω, p=0.39, respectively). R-wave amplitudes were significantly higher in delivery catheter group (13.0±4.8mV vs 10±4.6mV, p<0.01). Paced QRS durations were shorter in delivery catheter group (128±16ms vs 150±21ms, p<0.01).

Conclusions

The delivery catheter system designated for pacing lead can contribute to select the true ventricular septal sites and to attain the more physiologic ventricular activation.

Funding Acknowledgement

Type of funding source: None

The sphingosine-1-phosphate receptor modulator, FTY720, prevents the incidence of diabetes in Spontaneously Diabetic Torii rats

The sphingosine-1-phosphate (S1P) receptor modulator regulates lymphocyte trafficking, resulting in its depletion from circulation, which ultimately causes immunosuppression. In this study, we investigated the preventive effect of fingolimod (FTY720) in the non-obese type 2 diabetic model, Spontaneously Diabetic Torii (SDT) rats. The S1P receptor modulator, FTY720 (0.3 mg/kg p.o.), was administered for 12 weeks to SDT rats from 5 to 17 weeks of age. Based on our findings, FTY720 could suppress the incidence of diabetes in SDT rats. Further, glucose intolerance was improved in FTY720-treated SDT rats at 14 weeks of age. Based on the haematological and histological analyses performed at 17 to 18 weeks of age, a decrease in lymphocytes and monocytes in the peripheral blood and a decrease in lymphocyte and atrophy in spleen occurred in the FTY720-treated SDT rats. Furthermore, the pancreatic changes, such as inflammation, atrophy, and fibrosis in islets observed in SDT rats were improved by FTY720 treatment. These findings suggest that the immunomodulatory effects of FTY720 reduced the pancreatic lesion in SDT rats, thereby demonstrating its preventive effect against diabetes. The development of diabetes in SDT rats is related to disorders of the immune system. However, the S1P receptor modulator may be useful for treating type 2 diabetes.

Impact of altered dietary calcium-phosphorus ratio caused by high-phosphorus diets in a rat chronic kidney disease (CKD) model created by partial ligation of the renal arteries

This study aimed to establish a rat chronic kidney disease (CKD) model by studying the effects of a high-phosphorus diet in rats that had undergone partial ligation of the renal arteries (RL). Separate groups of 10-week-old male Slc:Sprague-Dawley rats underwent RL and were fed diets with varying phosphorous levels for a period of 48 days. A marked suppression of body weight gain necessitating humane euthanization occurred on day 28 in rats that had undergone RL and were given high-phosphorus feed. By contrast, the group of intact animals on a high-phosphorus feed exhibited a slightly decreased body weight gain from day 21 and survived until scheduled euthanization. In rats with RL, hematological, blood biochemical, and histopathological analyses demonstrated the presence of CKD-like conditions, particularly in the group that were fed a high-phosphorus diet. Hyperphosphatemia and hypocalcemia were induced by a high-phosphorus diet in both the RL and intact groups, both of which had high levels of FGF23 and parathyroid hormone in the blood. Rats with RL on a high-phosphorus diet showed decreased hematopoiesis by the hematopoietic cell area being narrower in the medullary cavity, proliferation of mesenchymal cells and osteoblasts/osteoclasts, and expansion of the osteoid area, a furthermore generalized vascular lesions, such as calcification, were observed. These findings demonstrate that the partial ligation of the renal arteries combined with a calcium–phosphorus imbalance induced by a high-phosphorus diet serves as an animal model for CKD-like conditions accompanied by bone lesions, helping to elucidate this clinical condition and its underlying molecular mechanisms.

P7 The impact of coronary calcification on diagnostic performance of workstation CT derived fractional flow reserve - a multicentre experience

Background

On-site workstation based computed tomography derived fractional flow reserve (CT-FFR) is an emerging method to assess the vessel specific ischaemia in coronary artery disease (CAD). The impact of coronary calcification on its diagnostic performance is unknown.

Purpose

To evaluate the impact of coronary calcification on the diagnostic performance of reduced-order CT-FFR at detecting vessel specific ischaemia.

Methods

This is a retrospective pooled analysis of 141 patients with suspected CAD enrolled from 3 global centres who underwent CT-coronary angiography (CTA), onsite CT-FFR and invasive FFR.  Coronary calcification was assessed by Agatston score (AS). The diagnostic performance of CT-FFR (≤0.8) and CTA (≥50%) in evaluation of vessel specific ischaemia (FFR ≤ 0.8) was assessed across AS quartiles (Q1-4). A comparison of diagnostic performance of the low to mid AS (Q1 to Q3) versus high AS (Q4) was performed.

Results

Mean age and median AS was 65.8 ± 9.9 and 327.3 (interquartile range = 78.5 – 798.1). Diagnostic accuracy, sensitivity and specificity of CT-FFR for low-mid AS (0-798) and high AS (799-4019) were 77.4% vs 82.9%; 78.9% vs 94.7%; 68.8% vs 76.5% respectively with no statistical difference between the two groups.  The AUC for ischaemia of CT-FFR in low to mid AS was comparable with AUC in the high AS (0.76 [95% CI: 0.66-0.86] vs 0.84 [0.69-0.99]; P = 0.397).  The AUC for ischemia for CT-FFR in both low to mid AS and high AS was significantly higher than for CTA (0.76 [0.66-0.86] vs 0.57 [0.50-0.64]; P = 0.003 and 0.84 [0.69-0.99] vs 0.48 [0.38-0.57]; P < 0.001 respectively).

Conclusion

On-site workstation CT-FFR demonstrated consistently high diagnostic performance in patients with high AS. Its diagnostic performance was superior when compared with significant stenosis assessment on CTA across all spectrum of Agatston scores.

A histopathological analysis of spontaneous neoplastic and non-neoplastic lesions in aged male RccHan:WIST rats

Histopathological information about spontaneous lesions in aged Hannover Wistar rats is limited. In this study, we describe spontaneous lesions found in 39 male RccHan:WIST rats used as a control in a carcinogenicity study. Neoplastic lesions were frequently seen in the endocrine system, such as pituitary adenomas in the pars distalis. This strain exhibited a high incidence of thymoma (10.3%), compared to other strains. We encountered an oligodendroglioma, a pituitary adenoma of the pars intermedia, and a prostate adenocarcinoma, which are comparatively rare in rats. While the variety and incidence of non-neoplastic lesions were similar to those in other strains, several interesting lesions occurred with relatively high incidence, including "harderianization" of the extraorbital lacrimal gland, common bile duct ectasia, and hyperplasia of pulmonary endocrine cells in the lung. Furthermore, comparative analyses demonstrated that the severity of chronic progressive nephropathy and murine progressive cardiomyopathy in RccHan:WIST rats was less than that in F344 rats.

Carrier and spin dynamics of high-density exciton magnetic polarons in Cd0.8Mn0.2Te

We investigated the carrier and spin dynamics of high-density exciton magnetic polarons (HD-EMPs) in Cd_0.8Mn_0.2Te based on the measurement of their time-resolved photoluminescence (PL) spectra and polarization states, and the utilization of photo-induced Faraday rotation techniques. The PL from the HD-EMPs were collected in a forward scattering configuration, and was observed as a pulsed emission of a few picoseconds duration, exhibiting a blue-shift with time evolution. The blue shift originated from the refractive-index dispersion of the sample. By excluding the influence of the refractive-index dispersion on the time profile, it was revealed that the ultra-short pulsed emission with a time width smaller than 1 ps was initially radiated with a time delay of ~2.4 ps after photoexcitation. From the results of time evolution of the polarization states, it is concluded that the exciton-Mn spin interactions occurs immediately after the excitation, which causes the Mn ion spins to align to follow the spin states of photoexcited excitons. The alignment of the Mn ion spins through the formation of the HD-EMPs was significantly faster than that of the localized EMP. On the other hand, the time evolution of the photo-induced Faraday rotation showed two decay components attributed to spin relaxations of the excitons and Mn ions within the HD-EMP. The observation of the Faraday rotation signal due to the Mn ion spins further confirms that these spins were aligned by the photo-excited spin-aligned excitons. Our findings suggest a novel mechanism for the effective optical control of spins in a semimagnetic semiconductor, which is associated with a multi-exciton system and its localized state.

P6178The optimal point of CT-FFR measurement in comparison with invasive FFR

Background

Currently, invasive fractional flow reserve (FFR), has become a gold standard to select patients requiring revascularization. Coronary computed tomography angiography (CTA) -derived FFR (FFRCT/CT-FFR) can be used for the management of coronary artery disease, which would be a gatekeeper of invasive coronary angiography. In most of the previous report to evaluate the diagnostic performance of FFRCT/CT-FFR, FFRCT/CT-FFR value was measured at the same point as the invasive FFR. Clinically, FFRCT/CT-FFR should be measured without the information of invasive FFR. However, optimal measurement point for CT-FFR has not been established yet.

Purpose

To assess the optimal measurement point of CT-FFR in comparison with invasive FFR as a gold standard.

Methods

CTA images scanned at 70–99% of R-R interval with 320 slice CT were screened. In the de-novo lesions with invasive FFR data were included in this study. Since calcified lesions could affect CT-FFR value, severe calcified lesions on CTA were excluded from the analysis. The CT-FFR analysis was performed by 2 cardiologists blinded to the results of the invasive FFR using a standard desktop computer and dedicated software. CT-FFR values could be provided at any point from ostium of coronary artery to the distal with vessel diameter of 1.8mm. To determine the optimal point for measurement of CT-FFR, CT-FFR values were obtained at 3 points in each coronary artery; 1) at the same point as invasive FFR; 2) lowest CT-FFR at distal point of coronary artery; 3) at 2.0 cm distal to the lesion. The diagnostic performance at each point was compared with invasive FFR.

Results

Fifty vessels of 44 patients (average age 68 years, male were 32) were included. Average Agatston score was 279.4. There was significant correlation between CT-FFR at each point and invasive FFR. CT-FFR at the same point as invasive FFR showed the good correlation with invasive FFR (R=0.641, 95% CI= 0.041–0.127, p<0.0001). Compared to the lowest CT-FFR at distal (R=0.608, 95% CI= 0.069–0.160, p<0.0001), CT-FFR at 2.0 cm distal to the lesion (R=0.604, 95% CI= 0.007–0.061, p<0.0001) revealed better correlation with invasive FFR. Sensitivity, specificity, positive and negative predictive value at each point were 92.8 / 93.3 / 81.8; 75.0 / 57.1 / 94.2; 61.9 / 48.2 / 60.0; and 96.0 / 95.2 / 84.6, respectively. Diagnostic accuracy showed that CT-FFR at 2cm distal to the lesion (0.84) was similar to CT-FFR at the same point as invasive FFR (0.80), and it was better than far distal (0.68) to detect invasive FFR derived ischemia.

Conclusions

CT-FFR was feasible to detect invasive FFR derived ischemia at the same point.

CT-FFR at 2.0 cm distal to the lesion showed higher diagnostic performance compared with CT-FFR measured at the far distal. CT-FFR measurement at 2.0 cm distal to the lesion would be a optimal position clinically.

P6187Multicentre diagnostic performance of on-site workstation CT derived fractional flow reserve

Background

On-site workstation based computed tomography derived fractional flow reserve (CT-FFR) is an emerging method to assess vessel specific ischaemia in coronary artery disease (CAD). Global data on its diagnostic performance when compared with CT coronary angiography (CTA) is limited.

Purpose

To evaluate the on-site multicentre diagnostic performance of reduced-order CT-FFR at detecting vessel specific ischaemia.

Method

This is a retrospective pooled analysis of 141 patients (204 vessels) with suspected CAD enrolled from 3 global centres who underwent CTA, onsite CT-FFR and invasive FFR. On-site CT-FFR was performed using a reduced order model on a standard desktop computer with dedicated software. The per vessel diagnostic performance of CT-FFR (≤0.8) for vessel specific ischemia (FFR≤0.8) was compared with CTA (≥50% stenosis).

Results

Mean age was 65.8±9.9, 70.7% were male. FFR significant stenosis was present in 34.3% (70/204) of vessels. Pearson correlation of CT-FFR for invasive FFR was 0.52, P<0.001. Bland Altman analysis demonstrated a mean difference of 0.06±0.15 (95% limits of agreement −0.22 to 0.35). Per vessel diagnostic accuracy, sensitivity and specificity of CT-FFR and CTA were 79.9% vs 53.5%; 78.6% vs 85.7%; 80.6% vs 35.9% respectively. Diagnostic performance as assessed by area under the receiver operator curve (AUC) for CT FFR was superior to CTA (0.82 [95% CI 0.76–0.88] vs 0.61 [0.55–0.67]; P<0.001).

Conclusion

On-site workstation CT-FFR demonstrated high per vessel diagnostic performance and was superior when compared with CTA in assessment of vessel specific ischaemia as assessed by invasive FFR in a multicentre setting.

P6171Role of myocardial mass for identifying FFR-verified ischemia and determining therapeutic strategy

Background

Conventional noninvasive approach using coronary CT angiography (CTA) focusing on only coronary artery lesions remains mismatch in identifying functional ischemia and determining indication for coronary revascularization.

Purpose

We aimed to assess the usefulness of CT-verified myocardial mass for identifying FFR-verified myocardial ischemia and determining the indication of coronary revascularization after FFR examination.

Methods

We examined 244 vessels with intermediate stenoses (50 to 90% stenosis visually on CTA) in 216 patients (mean age 69.2±9.2, 166 men) who underwent both coronary CTA and invasive FFR. In addition to coronary stenosis severity and plaque characteristics on visual, minimal lumen diameter (MLD), minimal lumen area (MLA), plaque volume, the entire myocardial volume of the target vessel (MTV) and that exposed to ischemia (FFR ≤0.80) (myocardial volume of ischemia: MVI) were evaluated. Additionally, therapeutic strategy after FFR was recorded.

Results

Of 244 vessels, myocardial ischemia (FFR ≤0.80) was shown in 99 (40.6%). MTV was larger in the patients with FFR-verified ischemia than those without (53.3±19.2 vs. 41.5±21.6, P<0.001); MLA, plaque burden (PB) and percentage of aggregated plaque volume (%APV) were also associated with ischemia. The area under the curves (AUCs) of MLA, PB, %APV, and MTV were 0.69, 0.67, 0.64, and 0.71, respectively. Addition of MTV to a model with coronary stenosis on visual, MLA, PB, and %APV improved C-index (from 0.72 to 0.79, P<0.01), net reclassification improvement (NRI) (0.71, P<0.01), and integrated discrimination improvement (IDI) (0.10, P<0.01). Of 99 vessels with FFR ≤0.80, MVI was larger in the vessels with early revascularization after FFR than those without (38.8 vs. 29.1, P=0.01).

Conclusions

The measurement of myocardial mass improves the diagnostic performance of coronary CTA for the identification of coronary arteries with FFR-verified ischemia. Furthermore, it is associated with therapeutic strategy for the diseased vessels after FFR examination.

P2240CTA derived plaque characteristics and cardiac events in deferred lesions by invasive FFR

Background

Fractional flow reserve (FFR) based strategy for coronary artery disease (CAD) is widely accepted. However, cardiac events could occur at deferred lesions after FFR. We previous reported that CT derived high risk plaque (HRP) and residual stenosis were the independent predictors of cardiac events.

Purpose

The purpose of this study was to investigate if plaque characteristics on CTA could predict cardiac events in deferred lesions after FFR.

Methods

We included 211 vessels of 193 patients who were deferred revascularization after CTA and invasive FFR. The presence of HRP and the stenosis grading on CTA were analyzed.

Results

Median follow-up period after CTA was 623 days (IQR 302–945). HRP and obstructive stenosis were detected in 58 (27.5%) and 87 (41.2%) lesions, respectively. Cardiac events were occurred in 10 lesions at 440±167 days in average (range: 150–770 days). Multivaliate cox hazard regression analysis revealed that HRP (HR8.01, p=0.0032) and obstructive stenosis with ≥70% (HR 34.93, p<0.0001) were the independent predictors of cardiac events after adjusted for age, sex, and FFR≤0.8. Of 21 lesions with both HRP and obstructive stenosis, 29% lesions resulted in cardiac events in 2 years.

Conclusions

Even in the deferred lesions by invasive FFR, lesions with HRP and obstructive stenosis showed high rate of cardiac events. These lesions should be treated with intensive medical therapy to prevent cardiac events.

P52714D-flow cardiac magnetic resonance analysis of left ventricular blood flow dynamics in mid-ventricular obstructive hypertrophic cardiomyopathy

Background

Mid-ventricular obstructive hypertrophic cardiomyopathy (MVO-HCM) has different blood flow dynamics from other phenotypes, but there are few detailed data on blood flow dynamics in the left ventricle.

Methods

4D-Flow MRI were performed at 1.5 T or 3 T with 9 MVO-HCM patients and 22 control patients (LVEF>50%, no wall motion abnormality). Myocardial infarction, severe valvular disease, HCM cases other than MVO were excluded. We calculated the cardiac function parameters and observed blood flow dynamics in the left ventricle using 4D-Flow MRI.

Results

LV mass was significantly higher in MVO-HCM group than in Control group (Control group; 73.3g vs MVO-HCM group; 109.5g, P=0.019). LVEF was higher in MVO-HCM group (Control group; 61.6% vs MVO-HCM group; 70.6%, P=0.026), but Stroke volume did not differ between the two groups (Control group; 68.8ml vs MVO-HCM group; 64.4ml, P=0.43).One or two vortices were observed in the left ventricle after opening the mitral valve. Two vortices were observed in 16 cases (72.7%) in the control group and 9 cases (100%) in the MVO-HCM group. Two vortices were formed on the anterior side and the posterior side. Blood flow pattern in which the vortex on the posterior side was formed to be the same size or larger than the vortex on the anterior side was observed only in the MVO-HCM group (Control group; 0% vs MVO-HCM group; 66.7%, P<0.001).

Streamline of MVO-HCM & Control

Conclusion

Characteristic blood flow patterns in the left ventricle of the MVO-HCM were revealed by using 4D-MRI. We thought that blood flow collides with the left ventricle wall due to the marked hypertrophy in the mid-ventricle, and normal vortex ring can not be formed in the MVO-HCM cases.

A Method for Identifying Mouse Pancreatic Ducts

Proper identification of pancreatic ducts is a major challenge for researchers performing partial duct ligation (PDL), because pancreatic ducts, which are covered with acinar cells, are translucent and thin. Although damage to pancreatic ducts may activate quiescent ductal stem cells, which may allow further investigation into ductal stem cells for therapeutic use, there is a lack of effective techniques to visualize pancreatic ducts. In this study, we report a new method for identifying pancreatic ducts. First, we aimed to visualize pancreatic ducts using black, waterproof fountain pen ink. We injected the ink into pancreatic ducts through the bile duct. The flow of ink was observed in pancreatic ducts, revealing their precise architecture. Next, to visualize pancreatic ducts in live animals, we injected fluorescein-labeled bile acid, cholyl-lysyl-fluorescein into the mouse tail vein. The fluorescent probe clearly marked not only the bile duct but also pancreatic ducts when observed with a fluorescent microscope. To confirm whether the pancreatic duct labeling was successful, we performed PDL on Neurogenin3 (Ngn3)-GFP transgenic mice. As a result, acinar tissue is lost. PDL tail pancreas becomes translucent almost completely devoid of acinar cells. Furthermore, strong activation of Ngn3 expression was observed in the ligated part of the adult mouse pancreas at 7 days after PDL.

Assessment of Pharmacological Responses to an Anti-diabetic Drug in a New Obese Type 2 Diabetic Rat Model

Introduction

The number of diabetic patients has recently been increasing worldwide, and numerous anti-diabetic drugs have been developed to induce good glycemic control. In particular, metformin, which exhibits glucose-lowering effects by suppressing gluconeogenesis in the liver, is widely used as a first line oral anti-diabetic drug for type 2 diabetes mellitus.

Material and Methods

In this study, the pharmacological effects of metformin were investigated using female and male Spontaneously Diabetic Torii (SDT) fatty rats, a new obese type 2 diabetic model.

Results

Two experiments were performed: an assessment of repeated treatment with metformin in female SDT fatty rats 5 to 13 weeks of age (experiment 1), and an assessment of repeated treatment with metformin in male SDT fatty rats 6 to 10 weeks of age (experiment 2). In female SDT fatty rats, metformin treatment led to good glycemic control, increases in sensory nerve conduction velocity, and improvements in pancreatic abnormalities such as irregular boundaries and vacuole form of islets. In male SDT fatty rats, metformin decreased blood glucose levels 4 weeks after treatment.

Conclusion

Metformin treatment led to maintained good glycemic control and improved neuropathy and pancreatic lesions in female SDT fatty rats. The SDT fatty rat is useful for the development of novel anti-diabetic agents that show potential to improve glucose metabolic disorders in the liver.

Hepatic lesions induced by feeding Western diets to Zucker fatty rats, an insulin-resistant model

Metabolic diseases including nonalcoholic steatohepatitis develop due to various environmental factors. In particular, the westernization of food is closely related to the development of these diseases. In this study, we investigated pathophysiological changes in the livers of Zucker fatty (ZF) rats induced by feeding Western diets. Male ZF rats were fed a sucrose/fat/cholesterol-enriched diet (Western diet, WD) or standard diet (SD) for 18 weeks, from 7 to 25 weeks of age. Body weight, food intake, and biochemical parameters were periodically measured, histopathological analyses were performed at 25 weeks, and mRNA expression in the liver was determined. ZF rats fed the WD (ZF-WD rats) developed obesity, hyperinsulinemia, hyperglycemia, and hyperlipidemia, and their alanine aminotransferase and aspartate aminotransferase levels increased compared with those of ZF rats fed the SD (ZF-SD rats). Hepatic lesions including fibrosis and necrosis were observed in the ZF-WD rats at 25 weeks; however, fibrosis and necrosis were not observed in the ZF-SD rats. Oxidative stress markers also increased in the livers of ZF-WD rats. Hepatic mRNA expression related to inflammation and fibrosis increased in the ZF-WD rats; however, mRNA expression related to lipid synthesis decreased. Microsomal triglyceride transfer protein mRNA levels in the ZF-WD rats also decreased. In Zucker lean rats fed the WD, similar changes were observed in the liver; however, the hepatic changes were not serious compared with ZF-WD rats. In conclusion, hepatic lesions, such as inflammation, fibrosis, and necrosis, were observed in the ZF-WD rats. The sucrose/fat/cholesterol-enriched diet induced significant lipotoxicity in the livers of animals in this insulin-resistant model.

Pathophysiological characteristics of non-alcoholic steatohepatitis-like changes in cholesterol-loaded type 2 diabetic rats

Spontaneously Diabetic Torii (SDT) fatty rats, a new obese diabetic model, reportedly presented with features of non-alcoholic steatohepatitis (NASH) after 32 weeks of age. We tried to accelerate the onset of NASH in SDT fatty rats using dietary cholesterol loading and noticed changes in the blood choline level which is expected to be a NASH biomarker. Body weight and biochemical parameters were measured from 8 to 24 weeks of age. At 16, 20, 24 weeks, pathophysiological analysis of the livers were performed. Hepatic lipids, lipid peroxides, and the expression of mRNA related to triglyceride (TG) synthesis, inflammation, and fibrosis were evaluated at 24 weeks. Hepatic fibrosis was observed in SDT fatty rats fed cholesterol-enriched diets (SDT fatty-Cho) from 16 weeks. Furthermore, hepatic lipids and lipid peroxide were significantly higher in SDT fatty-Cho than SDT fatty rats fed normal diets at 24 weeks. Hepatic mRNA expression related to TG secretion decreased in SDT fatty-Cho, and the mRNA expression related to inflammation and fibrosis increased in SDT fatty-Cho at 24 weeks. Furthermore, SDT fatty-Cho presented with increased plasma choline, similar to human NASH. There were no significant changes in the effects of feeding a cholesterol-enriched diet in Sprague-Dawley rats. SDT fatty-Cho has the potential to become a valuable animal model for NASH associated with type 2 diabetes and obesity.

Investigation of pharmacological responses to anti-diabetic drugs in female Spontaneously Diabetic Torii (SDT) fatty rats, a new nonalcoholic steatohepatitis (NASH) model

Nonalcoholic steatohepatitis (NASH) is a progressive liver disease, and some patients develop hepatic cirrhosis/carcinoma. Animal models play key roles in the development of new therapies for NASH. In this study, the pharmacological effects of metformin and pioglitazone were investigated in female Spontaneously Diabetic Torii (SDT) fatty rats to verify the utility of this model. The anti-diabetic drugs were administered to SDT fatty rats fed a cholesterol-enriched diet from 4 to 25 weeks, and changes in food intake, body weight, and blood chemistry parameters were evaluated every 4 weeks. The hepatic lipid content, mRNA expression in relation to lipid synthesis, inflammation, and fibrosis, and histopathological analyses were performed at 25 weeks. Pioglitazone improved hyperglycemia, hyperlipidemia, and abnormalities in hepatic parameters. The insulin levels were lower than those in the control rats before 16 weeks. Plasma glucose levels in the metformin-treated rats were lower than those in the control rats, and plasma alanine aminotransferase levels temporarily decreased. The lipid content and some mRNA expression in relation to fibrosis in the liver decreased with pioglitazone treatment, and the mRNA expression of microsomal triglyceride transfer protein increased. Hepatic fibrosis observed in the SDT fatty rats improved with pioglitazone treatment; however, the effect with metformin treatment was partial. These results in both drugs are in line with results in the human study, suggesting that the SDT fatty rat is useful for developing new anti-NASH drugs that show potential to regulate glucose/lipid metabolism.

Extracts of black and brown rice powders improve hepatic lipid accumulation via the activation of PPARα in obese and diabetic model mice

Rice powder extract (RPE) from black and brown rice (Oryza sativa L. indica) improves hepatic lipid accumulation in obese and diabetic model mice via peroxisomal fatty acid oxidation. RPE showed PPARα agonistic activity which did not differ between black and brown RPE despite a higher anthocyanin content in black RPE.

Pathophysiological analysis of the progression of hepatic lesions in STAM mice

Nonalcoholic steatohepatitis (NASH) is a current health issue since the disease often leads to hepatocellular carcinoma; however, the pathogenesis of the disease has still not been fully elucidated. In this study, we investigated the pathophysiological changes observed in hepatic lesions in STAM mice, a novel NASH model. STAM mice, high fat-diet (HFD) fed mice, and streptozotocin (STZ) treated mice were prepared, and changes over time, such as biological parameters, mRNA expression, and histopathological findings, were evaluated once animal reached 5, 7, and 10 weeks of age. STZ mice presented with hyperglycemia and an increase in oxidative stress in immunohistochemical analyses of Hexanoyl-lysine: HEL from 5 weeks, with fibrosis in the liver also being observed from 5 weeks. HFD mice presented with hyperinsulinemia from 7 weeks and the slight hepatosteatosis was observed at 5 weeks, with changes significantly increasing until 10 weeks. STAM mice at 10 weeks showed significant hepatic changes, including hepatosteatosis, hypertrophic hepatocytes, and fibrosis, indicating pathological changes associated with NASH. These results suggested that the increase in oxidative stress with hyperglycemia triggered hepatic lesions in STAM mice, and insulin resistance promoted lesion formation with hepatic lipid accumulation. STAM mice may be a useful model for elucidating the pathogenesis of NASH with diabetes.

Hepatocellular adenoma with severe fatty change in a male Spontaneously Diabetic Torii rat

The Spontaneously Diabetic Torii (SDT) rat is a rat model of nonobese type 2 diabetes mellitus, and hepatocellular adenomas have not been reported in this model. We report a hepatocellular adenoma with severe fatty change in a male 42-week-old SDT rat fed a high-fat diet. At necropsy, the animal had a whitish nodular mass of approximately 2 cm in diameter in the right medial lobe. Histologically, the mass was well demarcated from the surrounding tissues, slightly compressing the adjacent hepatic parenchyma and widely compartmented by fibrous connective tissues. The mass consisted of vacuolated tumor cells resembling hepatocytes with a solid and occasionally trabecular growth pattern. Abundant neutral lipids, which were positive for fat with Oil Red O stain and which ultrastructurally had moderately dense material, were contained within the vacuoles of the tumor cells. Immunohistochemically, the tumor cells showed an increase in immunoreactivity or number for Cytokeratin 8/18 and proliferating cell nuclear antigen but were negative for mesenchymal markers. From these findings, the mass could be distinguished from hepatocellular hyperplasia and was diagnosed as hepatocellular adenoma. In rats, hepatocellular adenoma accompanied by severe fatty change is rare, and this is the first report of a hepatocellular tumor with severe fatty change in a SDT rat.

Different Effects of Eicosapentaenoic and Docosahexaenoic Acids on Atherogenic High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of metabolic syndrome, can progress to steatohepatitis (NASH) and advanced liver damage, such as that from liver cirrhosis and cancer. Recent studies have shown the benefits of consuming n-3 polyunsaturated fatty acids (PUFAs) for the treatment of NAFLD. In the present study, we investigated and compared the effects of the major n-3 PUFAs—eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6)—in preventing atherogenic high-fat (AHF) diet-induced NAFLD. Mice were fed the AHF diet supplemented with or without EPA or DHA for four weeks. Both EPA and DHA reduced the pathological features of AHF diet-induced NASH pathologies such as hepatic lobular inflammation and elevated serum transaminase activity. Intriguingly, EPA had a greater hepatic triacylglycerol (TG)-reducing effect than DHA. In contrast, DHA had a greater suppressive effect than EPA on AHF diet-induced hepatic inflammation and ROS generation, but no difference in fibrosis. Both EPA and DHA could be effective for treatment of NAFLD and NASH. Meanwhile, the two major n-3 polyunsaturated fatty acids might differ in a relative contribution to pathological intermediate steps towards liver fibrosis.

JTT-130, a novel intestine-specific inhibitor of microsomal triglyceride transfer protein, ameliorates lipid metabolism and attenuates atherosclerosis in hyperlipidemic animal models

JTT-130 was developed as an intestine-specific MTP inhibitor designed to rapidly catabolize after absorption to avoid causing hepatotoxicity due to hepatic MTP inhibition. In previous reports, we have demonstrated that JTT-130 suppresses dietary lipid absorption in the small intestine without inducing hepatic steatosis. Thus, in this report, JTT-130 was administered to hyperlipidemic animals fed a Western diet to investigate the effect of intestinal MTP inhibition on lipid metabolism and progression of atherosclerosis. JTT-130 potently lowered plasma non-high density lipoprotein-cholesterol, and elevated plasma high density lipoprotein-cholesterol (HDL-C), indicating improvement in atherogenic index in hamsters. HDL fractions obtained after two weeks treatment with JTT-130 significantly increased the efflux of cholesterol from macrophages, as an index parameter of HDL function. Furthermore, long-term treatment with JTT-130 also improved the plasma lipid profile without inducing hepatic steatosis in rabbits, resulting in the suppression of atherosclerosis formation in aortas. From these results, JTT-130 ameliorates lipid metabolism accompanied with the enhancement of the anti-atherosclerotic function of HDL, and attenuates the progression of atherosclerosis in hyperlipidemic animals. These findings indicate that intestinal MTP inhibition may be atherogenic in vivo and that JTT-130 may be a useful compound for the treatment of dyslipidemia and a potential anti-atherogenic drug.

Female spontaneously diabetic Torii fatty rats develop nonalcoholic steatohepatitis-like hepatic lesions

AIM: To investigate the histological features of the liver in spontaneously diabetic Torii (SDT) fatty rats compared with age-matched Sprague-Dawley (SD) rats.

METHODS: Female SDT Lepr^fa (SDT fatty) rats and age-matched SD rats were fed ad libitum. Body weight and biochemical parameters, such as serum glucose, triglyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels as well as fatty acid and TG accumulation in the liver were evaluated at 8 wk of age in the non-fasting state and at 8-wk intervals from 8 to 40 wk of age. Histopathological examinations of the liver were performed using hematoxylin and eosin and Sirius Red staining as well as double staining for ED-1 and toluidine blue. The expression of genes involved in TG synthesis, inflammation, and fibrosis was examined in the liver.

RESULTS: SDT fatty rats showed significantly increased body weight compared with SD rats. Serum glucose, TG, and TC levels were significantly higher in SDT fatty rats compared with SD rats. The serum AST and ALT levels in SDT fatty rats were significantly elevated at 8 wk of age compared with the levels in SD rats. Hepatic TG content was marked in SDT fatty rats from 8 to 32 wk of age. Histopathologically, severe hepatosteatosis accompanied by inflammation was observed at 8 wk of age, and fibrosis started to occur at 32 wk of age. Furthermore, Sirius Red and ED-1 staining were increased in the liver at 32 wk of age. Hepatic gene expression related to TG synthesis, inflammation and fibrosis tended to increase in SDT fatty rats compared with SD rats, and the gene expression related to TG secretion was decreased in SDT fatty rats compared with SD rats.

CONCLUSION: Female SDT fatty rats have the potential to become an important animal model of nonalcoholic steatohepatitis with type 2 diabetes and obesity.