MYCT1 attenuates renal fibrosis and tubular injury in diabetic kidney disease

Tubulointerstitial abnormalities contribute to the progression of diabetic kidney disease (DKD). However, the underlying mechanism of the pathobiology of tubulointerstitial disease is largely unknown. Here, we showed that MYCT1 expression was downregulated in in vitro and in vivo DKD models. Adeno-associated virus (AAV)-Myct1 significantly attenuated renal dysfunction and tubulointerstitial fibrosis in diabetic db/db mice and downregulated Sp1 transcription and TGF-β1/SMAD3 pathway activation. In human proximal tubular epithelial cells, high glucose-induced high expression of SP1 and TGF-β1/SMAD3 pathway activation as well as overaccumulation of extracellular matrix (ECM) were abrogated by MYCT1 overexpression. Mechanistically, the binding of VDR to the MYCT1 promoter was predicted and confirmed using dual-luciferase reporter and ChIP analysis. VDR transcriptionally upregulates MYCT1. Our data reveal MYCT1 as a new and potential therapeutic target in treating DKD.

YY1-induced upregulation of LncRNA-ARAP1-AS2 and ARAP1 promotes diabetic kidney fibrosis via aberrant glycolysis associated with EGFR/PKM2/HIF-1α pathway

Objectives: Dimeric pyruvate kinase (PK) M2 (PKM2) plays an important role in promoting the accumulation of hypoxia-inducible factor (HIF)-1α, mediating aberrant glycolysis and inducing fibrosis in diabetic kidney disease (DKD). The aim of this work was to dissect a novel regulatory mechanism of Yin and Yang 1 (YY1) on lncRNA-ARAP1-AS2/ARAP1 to regulate EGFR/PKM2/HIF-1α pathway and glycolysis in DKD. Materials and methods: We used adeno-associated virus (AAV)-ARAP1 shRNA to knocked down ARAP1 in diabetic mice and overexpressed or knocked down YY1, ARAP1-AS2 and ARAP1 expression in human glomerular mesangial cells. Gene levels were assessed by Western blotting, RT-qPCR, immunofluorescence staining and immunohistochemistry. Molecular interactions were determined by RNA pull-down, co-immunoprecipitation, ubiquitination assay and dual-luciferase reporter analysis. Results: YY1, ARAP1-AS2, ARAP1, HIF-1α, glycolysis and fibrosis genes expressions were upregulated and ARAP1 knockdown could inhibit dimeric PKM2 expression and partly restore tetrameric PKM2 formation, while downregulate HIF-1α accumulation and aberrant glycolysis and fibrosis in in-vivo and in-vitro DKD models. ARAP1 knockdown attenuates renal injury and renal dysfunction in diabetic mice. ARAP1 maintains EGFR overactivation in-vivo and in-vitro DKD models. Mechanistically, YY1 transcriptionally upregulates ARAP1-AS2 and indirectly regulates ARAP1 and subsequently promotes EGFR activation, HIF-1α accumulation and aberrant glycolysis and fibrosis. Conclusion: Our results first highlight the role of the novel regulatory mechanism of YY1 on ARAP1-AS2 and ARAP1 in promoting aberrant glycolysis and fibrosis by EGFR/PKM2/HIF-1α pathway in DKD and provide potential therapeutic strategies for DKD treatments.

Genetically predicted body fat mass and distribution with diabetic kidney disease: A two-sample Mendelian randomization study

The aim of this study is to apply a Mendelian randomization (MR) design to investigate the potential causal associations between the body mass index (BMI), body fat mass such as trunk fat mass and waist circumference (WC), and diabetic kidney disease (DKD). A two-sample MR study was conducted to obtain exposure and outcome data from previously published studies. The instrumental variables for BMI, trunk fat mass, and WC were selected from genome-wide association study datasets based on summary-level statistics. The random-effects inverse-variance weighted (IVW) method was used for the main analyses, and the weighted median and MR-Egger approaches were complementary. In total, three MR methods suggested that genetically predicted BMI, trunk fat mass, and WC were positively associated with DKD. Using IVW, we found evidence of causal relationships between BMI [odds ratio (OR) = 1.99; 95% confidence interval (CI), 1.47–2.69; p = 7.89 × 10−6], trunk fat mass (OR = 1.80; 95% CI, 1.28–2.53; p = 6.84 × 10−4), WC (OR = 2.48; 95% CI, 1.40–4.42; p = 1.93 × 10−3), and DKD. MR-Egger and weighted median regression also showed directionally similar estimates. Both funnel plots and MR-Egger intercepts showed no directional pleiotropic effects involving the aforementioned variables and DKD. Our MR analysis supported the causal effect of BMI, trunk fat mass, and WC on DKD. Individuals can substantially reduce DKD risk by reducing body fat mass and modifying their body fat distribution.

LncRNA ARAP1-AS2 promotes high glucose-induced human proximal tubular cell injury via persistent transactivation of the EGFR by interacting with ARAP1

The persistent transactivation of epidermal growth factor receptor (EGFR) causes subsequent activation of the TGF-β/Smad3 pathway, which is closely associated with fibrosis and cell proliferation in diabetic nephropathy (DN), but the exact mechanism of persistent EGFR transactivation in DN remains unclear. ARAP1, a susceptibility gene for type 2 diabetes, can regulate the endocytosis and ubiquitination of membrane receptors, but the effect of ARAP1 and its natural antisense long non-coding RNA (lncRNA), ARAP1-AS2, on the ubiquitination of EGFR in DN is not clear. In this study, we verified that the expression of ARAP1 and ARAP1-AS2 was significantly up-regulated in high glucose-induced human proximal tubular epithelial cells (HK-2 cells). Moreover, we found that overexpression or knockdown of ARAP1-AS2 could regulate fibrosis and HK-2 cell proliferation through EGFR/TGF-β/Smad3 signalling. RNA pulldown assays revealed that ARAP1-AS2 directly interacts with ARAP1. Coimmunoprecipitation, dual-immunofluorescence and ubiquitination assays showed that ARAP1 may maintain persistent EGFR activation by reducing EGFR ubiquitination through competing with Cbl for CIN85 binding. Taken together, our results suggest that the lncRNA ARAP1-AS2 may promote high glucose-induced proximal tubular cell injury via persistent EGFR/TGF-β/Smad3 pathway activation by interacting with ARAP1.

A small molecule inhibitor MCC950 ameliorates kidney injury in diabetic nephropathy by inhibiting NLRP3 inflammasome activation

BACKGROUND

Diabetic nephropathy (DN) is a lethal diabetic microvascular complication characterized by chronic low-grade inflammation. The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome is implicated in the progression of DN. MCC950 is a selective and potent inhibitor of NLRP3; however, its efficacy in DN requires further investigation.

METHODS

To investigate the efficacy of MCC950 in DN, eight-week-old type 2 diabetic db/db mice received injections of MCC950 intraperitoneally (10 mg/kg) twice per week for 12 weeks. Urinary albumin-to-creatinine ratio (ACR) and neutrophil gelatinase-associated lipocalin (NGAL), renal function, pathological changes, markers of podocyte and fibrosis and NLPR3/caspase-1/IL-1β expression in the renal cortices of db/db mice were evaluated. High-glucose (HG)-treated rat glomerular mesangial cells were treated with various concentrations of MCC950 for 48 hrs. Markers of fibrosis and NLPR3/caspase-1/IL-1β expression in the glomerular mesangial cells were measured.

RESULTS

The NLRP3 inflammasome was activated in db/db mice and HG-induced mesangial cells by upregulating NLRP3/caspase-1/IL-1β pathway. Inhibition of the NLRP3 inflammasome with MCC950 reduced the production of active caspase-1 and active IL-1β in db/db mice and HG-induced mesangial cells. MCC950 reduced serum creatinine, urinary ACR and NGAL, attenuated mesangial expansion with increased matrix and tubular dilatation, alleviated thickened glomerular basement membrane (GBM) and foot process fusion without affecting body weight and blood glucose levels in db/db mice. MCC950 increased the expression of podocin in db/db mice, and decreased the expression of TGF-β1, fibronectin, collagen I and α-smooth muscle actin (α-SMA) in renal cortices of db/db mice and HG-induced mesangial cells.

CONCLUSION

MCC950 ameliorated renal function, thickened GBM, podocyte injury and renal fibrosis in db/db mice, and decreased the production of fibrosis markers in HG-induced mesangial cells. MCC950 effectively ameliorated diabetic kidney injury by inhibiting NLRP3/caspase-1/IL-1β pathway, which may be a potential therapeutic strategy to prevent the progression of DN.

Ursolic Acid Treatment Alleviates Diabetic Kidney Injury By Regulating The ARAP1/AT1R Signaling Pathway

PURPOSE

This study aimed to investigate whether ursolic acid (UA) mitigates renal inflammation, oxidative stress and fibrosis by regulating the angiotensin II type 1 receptor-associated protein (ARAP1)/angiotensin II type 1 receptor (AT1R) signaling pathway and subsequently alleviating renal damage.

METHODS

db/db mice were divided randomly into a diabetic nephropathy (DN) group and a UA treatment group. Light microscopy and electron microscopy were used to observe pathological changes in renal tissues. Immunohistochemistry (IHC) was employed to examine changes in the expression of ARAP1, AT1R, 8-hydroxydeoxyguanosine (8-OHdG), NADPH oxidase 2 (NOX2), the extracellular matrix protein fibronectin (FN), IL-1β and IL-18 in renal tissues. Western blotting and RT-qPCR were used to detect the respective changes in the protein and mRNA levels of ARAP1, AT1R, NOX4, NOX2, transforming growth factor-β1 (TGF-β1), FN, collagen IV, IL-1β and IL-18 in renal tissues and mesangial cells. In addition, immunofluorescence staining was employed to examine changes in FN and NOX2 expression in mesangial cells.

RESULTS

UA treatment effectively reduced the body weights and blood glucose levels of db/db mice (p<0.05) as well as the urinary albumin/creatinine ratio (p<0.05). In addition, the renal tissue lesions and glomerulosclerosis index of the db/db mice were significantly improved after treatment (p<0.01). Histochemical analysis results showed significantly lower expression levels of ARAP1, AT1R, FN, NOX2, 8-OHdG, IL-1β and IL-18 in renal tissues in the UA treatment group than in the DN group. Western blotting and RT-qPCR data also revealed UA-induced decreases in the renal levels of the ARAP1, AT1, NOX4, NOX2, TGF-β1, FN, collagen IV, IL-1β and IL-18 proteins in vivo and/or in vitro (p<0.01). ARAP1 knockdown effectively reduced the expression of NOX2 and FN in vitro.

CONCLUSION

UA alleviated renal damage in type 2 diabetic db/db mice by downregulating proteins in the ARAP1/AT1R signaling pathway to inhibit extracellular matrix accumulation, renal inflammation, fibrosis and oxidative stress.

Measurement of the electron and ion temperatures by the x-ray imaging crystal spectrometer on joint Texas experimental tokamak

An x-ray imaging crystal spectrometer has been developed on joint Texas experimental tokamak for the measurement of electron and ion temperatures from the K_α spectra of helium-like argon and its satellite lines. A two-dimensional multi-wire proportional counter has been applied to detect the spectra. The electron and ion temperatures have been obtained from the Voigt fitting with the spectra of helium-like argon ions. The profiles of electron and ion temperatures show the dependence on electron density in ohmic plasmas.

Measurement of the internal magnetic fluctuation by the transport of runaways on J-TEXT

The measurement of internal magnetic fluctuation is important for the study of transport in tokamak plasmas. The runaway electron transport induced by the sawtooth crash can be used to obtain the internal magnetic fluctuation. Inversed sawtooth-like activities on hard x-ray (HXR) fluxes following sawtooth activities were observed after the application of electrode biasing on J-TEXT tokamak. The runaway diffusion coefficient D_r is deduced to be about 30 m²/s according to the time delay of HXR flux peaks to the sawtooth crashes. The averaged value of normalized magnetic fluctuation in the discharges with electrode biasing was increased to the order of 1 × 10^-4.

Designing of the massive gas injection valve for the joint Texas experimental tokamak

In order to mitigate the negative effects of the plasma disruption a massive gas injection (MGI) valve is designed for the joint Texas experimental tokamak. The MGI valve is based on the eddy-current repulsion mechanism. It has a fueling volume of 30 ml. The piston of the MGI valve is made by non-ferromagnetic material, so it can be installed close to the vacuum vessel which has a strong toroidal magnetic field. A diode is use to prevent current oscillation in the discharge circuit. The drive coil of the valve is installed outside the gas chamber. The opening characteristics and the gas flow of the MGI valve have been tested by a 60 l vacuum chamber. Owing to the large electromagnetic force the reaction time of the valve is shorter than 0.3 ms. Duration for the opening of the MGI valve is in the order of 10 ms.

Sonographic Appearance of Mucinous Carcinoma of the Breast

OBJECTIVE

The aim of this study was to evaluate the sonographic and mammographic features of mucinous carcinoma and to correlate the imaging features with two histologic classifications.

MATERIALS AND METHODS

Two radiologists analyzed the mammographic and sonographic features of 33 mucinous carcinomas. Mammographic features according to the Breast Imaging Reporting and Data System (BI-RADS) and sonographic features were recorded and analyzed. The imaging features of the mass were correlated with the nuclear grade and mucin content of these 33 mucinous carcinomas. The incidence of axillary lymph nodes metastasis in different histologic grades and their detection by imaging were also assessed.

RESULTS

As many as 21.2% (7/33) of mucinous carcinomas could not be detected mammographically. When they were detected mammographically, more than 92% of the tumors presented as a mass, either oval or lobular. Microlobulations were present in 38.5% of these lesions. The margin of the lesion as seen on mammography can be used to predict the histologic grade. A circumscribed margin was associated with a favorable histologic grade (p = 0.01), whereas an indistinct margin was more commonly associated with the mixed type of lesion (p = 0.05). Sonographically, mixed cystic and solid components, distal enhancement, and microlobulated margins were commonly found in mucinous carcinomas, with an incidence of 37.5%, 43.8%, and 56.3%, respectively. Homogeneity on sonography was associated with the pure type of mucinous carcinoma and hence a better prognosis. Sonography showed a sensitivity of 50%, specificity of 89%, positive predictive value of 60%, negative predictive value of 84%, and accuracy of 79.2% in the detection of axillary lymph node metastasis.

CONCLUSION

Both sonographic and mammographic assessments are important in the correct diagnosis of mucinous carcinoma, the prediction of histologic grade, and the prognosis of the tumors.

Increased microvessel density in malignant and borderline mammary phyllodes tumours

AIMS

Tumour vascularity is considered a prognostic indicator in breast carcinoma, but its utility in mammary phyllodes tumour has not been explored. The authors report the correlation between intratumoral microvessel density and the histological grade of phyllodes tumour.

METHODS AND RESULTS

Forty cases of phyllodes tumour were reviewed for stromal cellularity, overgrowth, cytological pleomorphism, mitotic count and margin pattern. Using established criteria, these were diagnosed as benign (n=28), borderline (n=10) and malignant (n=2). Microvessel density was counted on CD31-stained slides as the number of vessels per high power field. For benign phyllodes tumour, the range was 7-26.2 (mean 13.1); for borderline phyllodes tumour the range was 17.2-32.5 (mean 22.4); for malignant phyllodes tumour the range was 25.9-33.3 (mean 29.6). The difference between the benign and borderline groups was significant (P < 0.0001) but that between the borderline and malignant groups was not, due to the small number of malignant cases.

CONCLUSIONS

There is a significant difference in stromal microvessel density between benign and borderline phyllodes tumour. Although the small number of cases of malignant phyllodes tumour limits further interpretation, we believe that microvessel density can be used as an additional objective histological parameter in the evaluation of phyllodes tumour.

Fine-needle aspiration cytology of breast carcinoma with endocrine differentiation

BACKGROUND

The value of fine-needle aspiration (FNA) in atypical proliferative to in situ to low grade invasive breast lesions remains limited due to the overlapping cytologic features of these entities. In the current study the authors review the FNA cytology of endocrine carcinoma and identify common cytologic features that allow for the diagnosis of this uncommon, low grade subtype of mammary malignancy.

METHODS

The histopathology files from the medical practices of both authors were searched between January 1996 and May 1999 and yielded six cases of endocrine carcinoma. The clinical history and all previous FNA smears were reviewed.

RESULTS

All six patients were elderly women (mean age of 72 years). Four patients presented with breast masses, one patient presented with nipple discharge, and one patient presented with both a breast mass and nipple discharge. All six surgical specimens showed endocrine ductal carcinoma in situ (E-DCIS), with four specimens showing invasive endocrine carcinoma, two of which were labeled as mucinous carcinoma. All invasive components showed the same histomorphologic and immunohistochemical profiles as the in situ components. Cytology demonstrated common features of the cellular smears with clusters and single, monomorphic plasmacytoid tumor cells that possessed moderate amounts of eosinophilic, granular cytoplasm and eccentric nuclei with fine chromatin and inconspicuous nucleoli. In four cases, additional fragments of fine and elaborate papillary fronds also were present.

CONCLUSIONS

The cytologic smear diagnosis of endocrine carcinoma is assisted by the presence of plasmacytoid tumor cells and arborizing papillary fronds.

Peripheral chemoreceptors in congenital central hypoventilation syndrome

Congenital central hypoventilation syndrome (CCHS) is a rare disorder of unknown etiology, characterized by failure of the autonomic control of respiration. The primary defect is believed to involve central respiratory control; however, no specific lesion has been identified. We report two cases of CCHS (one female, 3 mo of age and one male 2 yr of age) in which there was detailed examination of the neural, muscular, and chemoreceptor components of respiratory control. Although no specific abnormalities were identified in the central nervous system (CNS) or muscles of respiration, striking changes were observed in arterial chemoreceptors, carotid bodies (CB), and airway chemoreceptors, neuroepithelial bodies (NEB). In both cases, CB were small (< 50% of control), with a marked decrease in the number of glomus cells identified by immunostaining for tyrosine hydroxylase and serotonin. Ultrastructural analysis of glomus cells in Case 1 showed a marked decrease in the frequency of dense core vesicles (< 20% of control), the storage site of amine and peptide neurotransmitters. Immunostaining for S100 protein, a marker of sustentacular or Type II cells, was increased up to twofold compared with controls. In the lung, the frequency and size of NEB immunostained for bombesin was increased twofold in both cases, suggesting compensatory hyperplasia of airway chemoreceptors. Since intact peripheral chemoreceptors are essential for respiratory control, especially the response to hypoxia, abnormalities in CB and NEB may contribute to the pathophysiology of CCHS and related conditions such as sudden infant death syndrome (SIDS).

Spontaneous rupture of thoracic aorta through an atheromatous plaque: case report and literature review

Spontaneous rupture of thoracic aorta without aneurysm formation is extremely rare. A case of spontaneous rupture through an atheromatous plaque in an 82-year-old woman is reported. She presented with atypical chest pain, and chest radiography revealed no evidence of aneurysm. She died suddenly in the hospital within 24 h after admission. At autopsy, there was an intimal tear and rupture of the descending aorta through an atheromatous plaque, resulting in massive hemothorax. The previous reported cases of spontaneous aortic rupture were reviewed. The pathology of spontaneous aortic rupture are discussed with emphasis on the dating of the rupture, which may have significant medicolegal importance.

Narcolepsy secondary to fourth ventricular subependymoma

BACKGROUND

Secondary (symptomatic) narcolepsy is rare. We report a subependymoma of the fourth ventricle associated with narcolepsy. The patient was a 50-year old woman with a long history of narcolepsy who died of colonic carcinoma with no cerebral metastasis. She was positive for HLA-DR2. At autopsy there was a tumour dorsal to the fourth ventricle which involved the midbrain tectum and rostral pons. Histologic examination of the tumour confirmed it to be a subependymoma.

METHODS

Review of the previous cases of secondary narcolepsy was made with particular reference to the anatomical location of the lesions.

RESULTS

Most of the lesions were found around the third ventricle and rostral brainstem.

CONCLUSIONS

Knowing the anatomical localization of the pathological changes in secondary narcolepsy could be important in improving our understanding of its pathogenesis.

Cytologic features of Kimura's disease in fine-needle aspirates. A study of eight cases

Kimura's disease is a chronic inflammatory disorder of unknown etiology, presenting usually as painless subcutaneous swellings in the head and neck region or in the salivary glands. The cytologic features of fine-needle aspirates of eight cases of Kimura's disease were studied with reference to the histologic appearance of the subsequent surgical specimens. In the cytologic smears, the prominent feature was the presence of significant numbers of eosinophils in a background of lymphoid cells. Fragments of collagenous tissue and Warthin-Finkeldey polykaryocytes occasionally were seen. In the cell block, vascular proliferation and fibrosis were useful features, providing further support to the diagnosis. The constellation of these features is characteristic of Kimura's disease and should suggest this diagnosis in the appropriate clinical setting. For initial diagnosis, excisional biopsy is important for the exclusion of malignant lymphoma, histiocytosis X, angiolymphoid hyperplasia with eosinophilia and other reactive lymphadenopathies. Nonetheless, fine-needle aspiration cytology may be valuable in the diagnosis of recurrent lesions of Kimura's disease and may spare the patient from repeated biopsies.

Fine needle aspiration diagnosis of angiomyolipoma of the liver using a cell block with immunohistochemical study. A case report

Fine needle aspiration diagnosis of hepatic angiomyolipoma has been reported rarely. Below we report one such case diagnosed by examination of a cell block. The presence of epithelioid smooth muscle cells, mature adipocytes, thick-walled vessels and extramedullary hematopoiesis established the diagnosis. It was further substantiated by positive staining of the epithelioid cells for muscle-specific actin (HHF-35). The epithelioid cells were also immunoreactive with a melanocytic marker, HMB-45, but not with desmin, vimentin, cytokeratin or S-100 protein. HMB-45 might prove to be a sensitive marker for the epithelioid smooth muscle component of the tumor. The advantage of the routine use of a cell block in fine needle aspiration is emphasized.