Gene transfer of metalloproteinase transin induces aberrant behavior of cultured mesangial cells

Gene transfer of metalloproteinase transin induces aberrant behavior of cultured mesangial cells. The aim of the present study is to clarify whether the cellular expression of a matrix-degrading metalloproteinase, transin, alters the behavior of cultured mesangial cells (MCs). The cDNA encoding rat transin was introduced into rat MCs and transcribed under the control of a Rous sarcoma virus promoter. The resulting transfectants were then investigated for cell shape, migration, proliferation, and expression of genes associated with matrix metabolism. Northern blot analysis routinely detected the transin transcript in two separate transfectants, MeTRN2 and MeTRN5. Transin expression was strong in MeTRN2, moderate in MeTRN5, but absent in mock transfectants. Immunoblot analysis revealed that these transin transfectants synthesized 59 and 62kDa molecules, which correspond to transin gene products. Casein digestion assay detected enhanced proteolytic activity in MeTRN2 and MeTRN5. Microscopically, the transfected cells were somewhat elongated with accentuated margins compared with mock transfectants. [3H]-thymidine uptake studies revealed accelerated growth of the transfectants on a plastic substratum as well as within gel matrix. The migration of the transfectants into gel matrix was also significantly enhanced compared with that of mock transfectants. No obvious alteration, however, was found in transcripts of procollagen α1(IV), laminin B2, or the metalloproteinase inhibitor TIMP. We hypothesize that the metalloproteinase transin has a potential for affecting the behavior of MCs and contributing to the pathogenesis of glomerular injury

Mesangial cell-derived transforming growth factor-β1 reduces macrophage adhesiveness with consequent deactivation

Mesangial cell-derived transforming growth factor-β1 reduces macrophage adhesiveness with consequent deactivation. Adhesion of macrophages is a crucial event that determines the number and function of macrophages at inflammatory sites. The aim of this study was to elucidate the role of mesangial cells in the regulation of macrophage adhesiveness. J774.2 macrophages were suspended in serial dilutions of mesangial cell conditioned medium (MC medium) and seeded on plastic tissue culture plates. MC medium did not affect the initial adhesion of macrophages but induced subsequent detachment in a concentration-dependent manner. A similar effect was observed when macrophages were plated on plastic coated with laminin, collagen type IV or Matrigel. The reduced adhesiveness was reversible, and cell viability was unaffected by MC medium, indicating that the effect is not due to cytotoxicity. Conditioned media from fibroblastic, epithelial and endothelial cell lines did not induce macrophage detachment. To identify the active component in MC medium, we examined the involvement of transforming growth factor-β1 (TGF-β1) in the process. Mesangial cells constitutively expressed TGF-β1 mRNA, and MC medium contained the active form of TGF-β1. Exogenously added TGF-β1 induced macrophage detachment in a dose-dependent manner, and an anti-TGF-β1 neutralizing antibody partially abolished the activity of MC medium, indicating the involvement of TGF-β1 as an active component. Compared to adherent cells, detached macrophages showed reduced mitogenic activity and blunted induction of IL-1β and IL-6 in response to lipopolysaccharide. These data demonstrate that TGF-β1 is a mesangial cell-derived factor that impairs adhesiveness of macrophages and confers blunted responses to a specific stimulus. These findings suggest one potential mechanism for macrophage clearance from inflamed glomeruli

Real-time detection and continuous monitoring of ER stress in vitro and in vivo by ES-TRAP: evidence for systemic, transient ER stress during endotoxemia

Activity of secreted alkaline phosphatase (SEAP) produced by transfected cells is rapidly down-regulated by endoplasmic reticulum (ER) stress independent of transcriptional regulation. This phenomenon was observed in a wide range of cell types triggered by various ER stress inducers. The magnitude of the decrease in SEAP was proportional to the extent of ER stress and inversely correlated with the induction of endogenous ER stress markers grp78 and grp94. In contrast to SEAP, activity of secreted luciferase was less susceptible to ER stress. The decrease in SEAP activity by ER stress was caused by abnormal post-translational modification, accelerated degradation and reduced secretion of SEAP protein. In transgenic mice constitutively producing SEAP, systemic induction of ER stress led to reduction in serum SEAP. In these mice, administration with lipopolysaccharide caused rapid, transient decrease in serum SEAP activity, and it was correlated with up-regulation of grp78 in several organs including the spleen, lung, kidney, liver and heart. These results elucidated for the first time a possible involvement of transient, systemic ER stress in endotoxemia and provided evidence for usefulness of ER stress responsive alkaline phosphatase for real-time monitoring of ER stress in vitro and in vivo

Decreased levels of insulin-like growth factor-1 and vascular endothelial growth factor relevant to the ossification disturbance in femoral heads spontaneous hypertensive rats.

Ossification disturbance in femoral head reportedly is seen in the Spontaneously Hypertensive rats (SHR) between ages of 10 and 20 weeks. We investigated serum and tissue levels of insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) in SHR relevant to the ossification disturbance and osteonecrosis of the femoral head. Serum levels of IGF-1 and VEGF were significantly lower in SHR than in Wistar Kyoto rats (WKY) at weeks 5, 10, 15 and 20 (p<0.005). The incidence of histological ossification disturbance of the femoral head was higher in SHR (59%) than in WKY (40%) at week 20. Lower serum and local levels of VEGF in SHR appeared to be related to the incomplete ossification of the femoral heads. Immunohistochemical study showed significantly lower numbers of IGF-1 and VEGF positive chondrocytes in the femoral epiphyseal cartilage of SHR than in those of WKY at weeks 10, 15 and 20. Our results suggest that local and/or systemic levels of IGF-1 and VEGF between ages of 5 and 20 weeks might play roles in the pathogenesis of ossifi cation disturbance of the femoral head in SHR

An objective test tool for pitch extractors' response attributes

We propose an objective measurement method for pitch extractors' responses to frequency-modulated signals. It enables us to evaluate different pitch extractors with unified criteria. The method uses extended time-stretched pulses combined by binary orthogonal sequences. It provides simultaneous measurement results consisting of the linear and the non-linear time-invariant responses and random and time-varying responses. We tested representative pitch extractors using fundamental frequencies spanning 80~Hz to 400~Hz with 1/48 octave steps and produced more than 1000 modulation frequency response plots. We found that making scientific visualization by animating these plots enables us to understand different pitch extractors' behavior at once. Such efficient and effortless inspection is impossible by inspecting all individual plots. The proposed measurement method with visualization leads to further improvement of the performance of one of the extractors mentioned above. In other words, our procedure turns the specific pitch extractor into the best reliable measuring equipment that is crucial for scientific research. We open-sourced MATLAB codes of the proposed objective measurement method and visualization procedure.Comment: 5 pages, 9 figures, submitted to Interspeech2022. arXiv admin note: text overlap with arXiv:2111.0362

Direct, Continuous Monitoring of Air Pollution by Transgenic Sensor Mice Responsive to Halogenated and Polycyclic Aromatic Hydrocarbons

BACKGROUND: The aryl hydrocarbon receptor (AhR, also called the dioxin receptor) plays crucial roles in toxicologic responses of animals to environmental pollutants, especially to halogenated and polycyclic aromatic hydrocarbons. To achieve direct, continuous risk assessment of air pollution using biological systems, we generated transgenic sensor mice that produce secreted alkaline phosphatase (SEAP) under the control of AhR. METHODS: To characterize responses of the mice to AhR agonists, sensor mice were orally administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3-methylcholanthrene (3MC), benzo[a]pyrene (B[a]P), or β-naphthoflavone (BNF), and serum levels of SEAP were evaluated. To monitor air pollution caused by cigarette smoke, we placed the mice each day in an experimental smoking room, and evaluated activity of serum SEAP for up to 4 days. Activation of AhR in individual organs was also examined by reverse transcription–polymerase chain reaction (RT-PCR) analysis of SEAP. RESULTS: In response to oral exposure to TCDD, sensor mice exhibited dramatic and sustained activation of AhR. The mice also responded sensitively to 3MC, B[a]P, and BNF. Activation of AhR was dose dependent, and the liver was identified as the main responding organ. After exposure to the smoking environment, sensor mice consistently exhibited transient, reversible activation of AhR. RT-PCR analysis of SEAP revealed that activation of AhR occurred predominantly in the lung. CONCLUSION: We are the first laboratory to demonstrate successfully direct, comprehensive monitoring of air pollution using genetically engineered mammals. The established system would be useful for real risk assessment of halogenated and polycyclic aromatic hydrocarbons in the air, especially in smoking environments. KEY WORDS: aromatic hydrocarbon, aryl hydrocarbon receptor (AhR), cigarette smoke, dioxinresponsive element (DRE), secreted alkaline phosphatase (SEAP), transgenic mouse. Enviro

Twin Rectal Tonsils Mimicking Carcinoid or Mucosa-Associated Lymphoid Tissue Lymphoma

The rectal tonsil is a rare polypoid lesion exclusively found in the rectum and is considered a reactive proliferation of the lymphoid tissue. Although this lesion is benign, we recommend that it should be differentiated from carcinoid or polypoid type of mucosa-associated lymphoid tissue lymphomas, based on gross findings. In this case report, we describe a case of rectal lesions with a unique appearance in a 41-year-old man. Colonoscopy revealed two 5-mm-sized nodules located opposite from each other on the left and right sides of the lower rectum. Endoscopic mucosal resection was conducted. Histopathologically, both lesions were mainly located in the submucosa and consisted of prominent lymphoid follicles with germinal centers of various sizes. No immunoreactivity of Bcl-2 was seen in the germinal centers. Immunohistochemical staining for kappa and lambda light chains revealed a polyclonal pattern. Therefore, these lesions were diagnosed as rectal tonsils