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1.
Med Arch ; 78(2): 177-179, 2024.
Article in English | MEDLINE | ID: mdl-38566880

ABSTRACT

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.


Subject(s)
Diabetes Mellitus, Type 2 , Myocarditis , Rats , Male , Animals , Disease Models, Animal , Myocarditis/etiology , Necrosis , Candida
2.
Nephrology (Carlton) ; 29(3): 117-125, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37950597

ABSTRACT

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.


Subject(s)
Acute Kidney Injury , Histones , Mice , Animals , Humans , Pharmaceutical Preparations , Rolipram , Kidney/pathology , Acute Kidney Injury/chemically induced , Acute Kidney Injury/diagnosis , Mice, Transgenic , Fatty Acid-Binding Proteins/genetics , Fatty Acid-Binding Proteins/urine , Biomarkers/urine , Heparin , Liver
3.
J Toxicol Sci ; 48(11): 597-606, 2023.
Article in English | MEDLINE | ID: mdl-37914287

ABSTRACT

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.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Nephropathies , Kidney Failure, Chronic , Sodium-Glucose Transporter 2 Inhibitors , Mice , Animals , Diabetic Nephropathies/etiology , Diabetic Nephropathies/pathology , Sodium-Glucose Transporter 2 Inhibitors/pharmacology , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , Kidney , Kidney Failure, Chronic/pathology , Dietary Supplements
4.
PLoS One ; 18(8): e0287657, 2023.
Article in English | MEDLINE | ID: mdl-37535625

ABSTRACT

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.


Subject(s)
Carcinoma, Hepatocellular , Choline Deficiency , Liver Neoplasms , Non-alcoholic Fatty Liver Disease , Mice , Animals , Non-alcoholic Fatty Liver Disease/metabolism , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology , Interleukin-8/metabolism , Choline Deficiency/metabolism , Liver/metabolism , Liver Cirrhosis/pathology , Amino Acids/metabolism , Diet, High-Fat , Disease Models, Animal , Fibrosis , Cell Transformation, Neoplastic/pathology , Methionine/metabolism , Choline/metabolism , Mice, Inbred C57BL
5.
In Vivo ; 37(4): 1517-1531, 2023.
Article in English | MEDLINE | ID: mdl-37369510

ABSTRACT

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.


Subject(s)
Liver Neoplasms , Non-alcoholic Fatty Liver Disease , Animals , Humans , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/complications , Choline/metabolism , Liver/pathology , Diet/adverse effects , Liver Neoplasms/pathology , Disease Models, Animal , Amino Acids/metabolism
6.
Nephrology (Carlton) ; 28(6): 345-355, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37076661

ABSTRACT

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.


Subject(s)
Acute Kidney Injury , COVID-19 , Male , Animals , Rats , Histones , Rats, Sprague-Dawley , Biomarkers , COVID-19/complications , Acute Kidney Injury/diagnosis , Acute Kidney Injury/etiology , Fatty Acid-Binding Proteins , Liver
7.
J Toxicol Pathol ; 36(1): 1-10, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36683724

ABSTRACT

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.

8.
Nutr Health ; : 2601060221122223, 2022 Aug 29.
Article in English | MEDLINE | ID: mdl-36039529

ABSTRACT

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.

9.
J Pharmacol Toxicol Methods ; 116: 107190, 2022.
Article in English | MEDLINE | ID: mdl-35688322

ABSTRACT

An increasing number of patients worldwide are being diagnosed with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NAFLD/NASH) because of the growing prevalence of obesity and metabolic disorders. The incidence of NAFLD is higher in postmenopausal women than in premenopausal women. The decline in the level of female hormones might have an effect on the deterioration of metabolism. In the present study, we investigated the potential of Spontaneously Diabetic Torii (SDT) fatty rats as a new animal model for NAFLD. We created a menopausal model by ovariectomy (OVX) in female rats. Sprague-Dawley (SD) rats, SDT rats, and SDT-fatty rats were divided into sham and OVX groups and maintained until 40 weeks of age. The results showed that OVX-induced weight gain was observed in SD and SDT rats. In addition, OVX-induced hepatic triglyceride accumulation was increased in all strains, and there was a significant increase in hepatic triglyceride levels in OVX-SDT fatty rats compared to those in Sham-SD rats. Furthermore, liver fibrosis was worsened in the OVX-SDT fatty rats. In addition, OVX-induced increase in blood ALT level was observed in SDT-fatty rats. Gene expression analysis showed OVX-induced upregulation of Srebp1 expression and downregulation of Pemt and Mttp in OVX rats. These results indicate that OVX-SDT fatty rats exhibit NASH with more severe hepatic fibrosis than untreated animals, suggesting that OVX-induced estrogen reduction may have enhanced lipid synthesis in the liver. It is also possible, although hypothetical, that OVX may decrease VLDL secretion, which may more strongly induce NASH.


Subject(s)
Diabetes Mellitus, Experimental , Non-alcoholic Fatty Liver Disease , Animals , Female , Humans , Liver/pathology , Liver Cirrhosis/pathology , Non-alcoholic Fatty Liver Disease/pathology , Ovariectomy/adverse effects , Rats , Rats, Sprague-Dawley , Triglycerides
10.
J Toxicol Pathol ; 35(2): 149-157, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35516840

ABSTRACT

Nonalcoholic steatohepatitis is a lifestyle-related disease and an increasing threat worldwide. Hepatic fibrosis, which results from chronic hepatic diseases including nonalcoholic steatohepatitis, is closely correlated with mortality among hepatic lesions, such as steatosis and inflammation. Thus, it is important to identify factors that can serve as diagnostic and therapeutic targets for hepatic fibrosis. In this study, we examined the function of CD44 in the development of hepatic fibrosis in choline-deficient, methionine-lowered, L-amino-acid diet-fed rats, especially with respect to the proliferation of bile duct epithelium. Male Fischer 344 rats were fed a choline-deficient, methionine-lowered, L-amino-acid diet for 2, 4, 13, or 26 weeks. This diet decreased the body weight; increased the levels of serum parameters indicating liver injury, such as aspartate and alanine aminotransferase; upregulated inflammation- and fibrosis-related gene expression in the liver; and resulted in the development of hepatic lesions, including fatty changes in hepatocytes, inflammatory cell infiltration, and fibrosis. Hepatic hyaluronan was synthesized and deposited in the liver tissue. The expression of both CD44 mRNA and protein was significantly increased throughout the experimental period. CD44 protein was observed in some of the bile duct epithelium, around which hyaluronic acid was deposited, and these bile duct lesions were concordant with the area of hepatic fibrosis. Thus, CD44 expressed in the bile duct epithelium may be a target for controlling nonalcoholic steatohepatitis-related hepatic fibrosis.

11.
Shokuhin Eiseigaku Zasshi ; 63(1): 34-42, 2022.
Article in Japanese | MEDLINE | ID: mdl-35264520

ABSTRACT

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.


Subject(s)
Carcinogenicity Tests , Carcinogens , Pesticide Residues/toxicity , Rodentia , Animals , Biological Assay , Carcinogens/toxicity , Risk Assessment
13.
Clin Exp Pharmacol Physiol ; 49(4): 492-500, 2022 04.
Article in English | MEDLINE | ID: mdl-35066915

ABSTRACT

For the evaluation of novel therapeutic agents for diabetic kidney disease (DKD), it is desirable to examine their efficacy in animal models by using the glomerular filtration rate (GFR) as an index. For this purpose, animal models that demonstrate a short-term GFR decline because of disease progression are required. Therefore, we aimed to develop such an animal model of DKD by using obese type 2 diabetic spontaneously diabetic Torii (SDT) fatty rats treated with salt loading by drinking water containing sodium chloride with or without unilateral nephrectomy. As a result, we have found that 0.3% salt loading with unilateral nephrectomy or 0.8% salt loading alone caused a rapid GFR decline, hypertension and rapid development of tubulointerstitial fibrosis. Moreover, the addition of losartan to a mixed diet suppressed the GFR decline in SDT fatty rats treated with 0.3% salt loading with unilateral nephrectomy. These results suggest that the model of SDT fatty rats treated with 0.3% salt loading and unilateral nephrectomy could be used as a hypertensive DKD model for evaluating therapeutic agents based on suppression of GFR decline.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Nephropathies , Hypertension , Animals , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/surgery , Diabetic Nephropathies/etiology , Disease Models, Animal , Female , Glomerular Filtration Rate , Humans , Hypertension/complications , Hypertension/surgery , Male , Nephrectomy/adverse effects , Obesity/complications , Obesity/surgery , Rats , Sodium Chloride , Sodium Chloride, Dietary
14.
J Toxicol Sci ; 46(12): 589-599, 2021.
Article in English | MEDLINE | ID: mdl-34853244

ABSTRACT

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-Leprfa (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-1ß (IL-1ß), monocyte chemotactic protein-1 (MCP-1) and transforming growth factor-ß (TGF-ß) 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.


Subject(s)
Diabetes Mellitus, Type 2 , Animals , Disease Models, Animal , Female , Humans , Male , Obesity , Rats , Rats, Sprague-Dawley , Sodium Chloride
15.
J Toxicol Pathol ; 34(4): 353-358, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34621110

ABSTRACT

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.

16.
FEBS Open Bio ; 11(11): 2950-2965, 2021 11.
Article in English | MEDLINE | ID: mdl-34390210

ABSTRACT

Nonalcoholic steatohepatitis (NASH) is often associated with obesity, but some patients develop NASH without obesity. The physiological processes by which nonobese 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 'nonobese' subtype.


Subject(s)
Non-alcoholic Fatty Liver Disease/metabolism , Signal Transduction/physiology , Amino Acids , Animals , Choline/metabolism , Choline Deficiency/physiopathology , Diet, High-Fat/adverse effects , Disease Models, Animal , Lipid Metabolism , Liver/metabolism , Liver Cirrhosis/metabolism , Male , Methionine/metabolism , Mice , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/physiopathology , Obesity/metabolism , Signal Transduction/drug effects
17.
Regul Toxicol Pharmacol ; 124: 104958, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33991633

ABSTRACT

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.


Subject(s)
Pesticide Residues/toxicity , Toxicity Tests/standards , Animals , Carcinogenesis/chemically induced , Data Interpretation, Statistical , Dogs , Hazard Analysis and Critical Control Points/methods , Japan , Mice , No-Observed-Adverse-Effect Level , Pesticide Residues/analysis , Pesticide Residues/pharmacokinetics , Pesticide Residues/standards , Rabbits , Rats , Species Specificity , Toxicity Tests/statistics & numerical data , Toxicokinetics
18.
Clin Exp Pharmacol Physiol ; 48(6): 869-876, 2021 06.
Article in English | MEDLINE | ID: mdl-32920892

ABSTRACT

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.


Subject(s)
Diabetes Mellitus, Type 2 , Fingolimod Hydrochloride , Animals , Blood Glucose , Disease Models, Animal , Incidence , Sphingosine-1-Phosphate Receptors
19.
Lipids Health Dis ; 19(1): 251, 2020 Dec 14.
Article in English | MEDLINE | ID: mdl-33317575

ABSTRACT

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.


Subject(s)
Amino Acids/metabolism , Animal Feed , Choline/metabolism , Liver/metabolism , Methionine/metabolism , Trans Fatty Acids/metabolism , Animals , Apoptosis , Body Weight , Choline Deficiency , Diet, High-Fat , Disease Models, Animal , Fatty Liver , Gene Expression Profiling , Humans , Inflammation , Insulin-Like Growth Factor I/metabolism , Male , Mice , Mice, Inbred C57BL , NF-kappa B/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Organ Size , Phosphorylation , RNA/metabolism , Soybean Oil , Sulfotransferases/metabolism
20.
Toxins (Basel) ; 12(10)2020 09 24.
Article in English | MEDLINE | ID: mdl-32987679

ABSTRACT

The different effects of deoxynivalenol (DON) on intestinal barrier and stem cells by its route of exposure remain less known. We explored the toxic effects of DON on intestinal barrier functions and stem cells after DON microinjection (luminal exposure) or addition to a culture medium (basolateral exposure) using three-dimensional mouse intestinal organoids (enteroids). The influx test using fluorescein-labeled dextran showed that basolateral DON exposure (1 micromolar (µM) disrupted intestinal barrier functions in enteroids compared with luminal DON exposure at the same concentration. Moreover, an immunofluorescence experiment of intestinal epithelial proteins, such as E-cadherin, claudin, zonula occludens-1 (ZO-1), and occludin, exhibited that only basolateral DON exposure broke down intestinal epithelial integrity. A time-lapse analysis using enteroids from leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5)-enhanced green fluorescence protein (EGFP) transgenic mice and 5-ethynyl-2-deoxyuridine (EdU) assay indicated that only the basolateral DON exposure, but not luminal DON exposure, suppressed Lgr5+ stem cell count and proliferative cell ratio, respectively. These results revealed that basolateral DON exposure has larger impacts on intestinal barrier function and stem cells than luminal DON exposure. This is the first report that DON had different impacts on intestinal stem cells depending on the administration route. In addition, RNA sequencing analysis showed different expression of genes among enteroids after basolateral and luminal DON exposure.


Subject(s)
Epithelial Cells/drug effects , Intestinal Mucosa/drug effects , Jejunum/drug effects , Stem Cells/drug effects , Trichothecenes/toxicity , Animals , Cell Proliferation/drug effects , Cells, Cultured , Epithelial Cells/metabolism , Epithelial Cells/pathology , Female , Gene Expression Regulation , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Jejunum/metabolism , Jejunum/pathology , Male , Mice, Inbred C57BL , Mice, Transgenic , Organoids , Permeability , Stem Cells/metabolism , Stem Cells/pathology , Time Factors
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