The Establishment of a Primary Culture System of Proximal Tubule Segments Using Specific Markers from Normal Mouse Kidneys

The proximal tubule contains the highest expression of angiotensinogen mRNA and protein within the kidney and plays a vital role in the renal renin-angiotensin system. To study the regulation of angiotensinogen expression in the kidney in more detail, the proximal tubule needs to be accurately isolated from the rest of the nephron and separated into its three segments. The purpose of this study was to design a novel protocol using specific markers for the separation of proximal tubule cells into the three proximal tubule segments and to determine angiotensinogen expression in each segment. Kidneys were removed from C57BL/6J mice. The proximal tubules were aspirated from region of a Percoll gradient solution of the appropriate density. The proximal tubule was then separated into its three segments using segment-specific membrane proteins, after which each segment was characterized by a different specific marker (sodium-glucose transporter 2 for Segment 1; carbonic anhydrase IV for Segment 2; ecto-adenosine triphosphatase for Segment 3). The isolation of proximal tubules into three segments was successful, and angiotensinogen mRNA in Segment 2 and 3 and angiotensinogen protein in all three segments were confirmed. This protocol will be helpful for future studies of the detailed mechanisms of the intrarenal renin-angiotensin system

The Establishment of a Primary Culture System of Proximal Tubule Segments Using Specific Markers from Normal Mouse Kidneys

The proximal tubule contains the highest expression of angiotensinogen mRNA and protein within the kidney and plays a vital role in the renal renin-angiotensin system. To study the regulation of angiotensinogen expression in the kidney in more detail, the proximal tubule needs to be accurately isolated from the rest of the nephron and separated into its three segments. The purpose of this study was to design a novel protocol using specific markers for the separation of proximal tubule cells into the three proximal tubule segments and to determine angiotensinogen expression in each segment. Kidneys were removed from C57BL/6J mice. The proximal tubules were aspirated from region of a Percoll gradient solution of the appropriate density. The proximal tubule was then separated into its three segments using segment-specific membrane proteins, after which each segment was characterized by a different specific marker (sodium-glucose transporter 2 for Segment 1; carbonic anhydrase IV for Segment 2; ecto-adenosine triphosphatase for Segment 3). The isolation of proximal tubules into three segments was successful, and angiotensinogen mRNA in Segment 2 and 3 and angiotensinogen protein in all three segments were confirmed. This protocol will be helpful for future studies of the detailed mechanisms of the intrarenal renin-angiotensin system

C-ERC/mesothelin provokes lymphatic invasion of colorectal adenocarcinoma

Background Lymph node metastasis is a key event of colorectal cancer (CRC) progression. Mesothelin is expressed in various types of malignant tumor and associated with an unfavorable prognosis. The full-length mesothelin (Full-ERC) is cleaved by protease into membrane-bound C-ERC/mesothelin and N-ERC/mesothelin which is secreted into the blood. The aim of this study was to examine the biological role of mesothelin in CRC by clinicopathological analysis and in vitro lymphatic invasion assay. Methods Ninety-one cases of CRC specimens were immunohistochemically examined and the localization of mesothelin in luminal membrane and/or cytoplasm was also evaluated. Lymphatic invasion assay was also performed using the human CRC cell line, WiDr, which was transfected with Full-, N- and C-ERC/mesothelin expression plasmids (Full-WiDr, N-WiDr and C-WiDr). Results Immunohistochemically, "luminal membrane positive" of mesothelin was identified in 37.4 %, and correlated with lymphatic permeation and lymph node metastasis, but not with patients' prognosis. Interestingly, among the patients with lymph node metastasis (N = 38), "luminal membrane positive" of mesothelin significantly correlated with unfavorable patients' outcome. In addition, lymphatic invasion assay revealed that Full-WiDr and C-WiDr more significantly invaded human lymphatic endothelial cells than the Mock-WiDr (P < 0.01). Conclusion The luminal membrane expression of mesothelin was associated with unfavorable prognosis of CRC patients with lymph nodemetastasis. Moreover, this is the first report to prove the biological function of C-ERC/mesothelin associated with lymphatic invasion of cancer in vitro

Tumor budding and human chorionic gonadotropin-β expression correlate with unfavorable patient outcome in colorectal carcinoma

Tumor budding is thought to represent a manifestation of epithelial-to-mesenchymal transition (EMT) and it has been correlated with poor patient outcomes in colorectal cancer (CRC). Our group recently demonstrated that human chorionic gonadotropin-β (hCGβ) modulates EMT in CRC. In the current study, based on the likely relationships between tumor budding and hCGβ expression, we examined their clinicopathologic significance in CRC. Twenty-eight of 80 (35.0%) CRC showed tumor budding. Tumor budding significantly correlated with lymph node metastasis (P < 0.01), pathologic stage (P < 0.01), lymphatic invasion (P = 0.044), and vascular invasion (P = 0.013). Thirteen of 80 (16.3%) CRC were hCGβ positive on immunohistochemistry. More tumor buds were present in the hCGβ-positive cases (P < 0.01), and tumor budding was significantly correlated with hCGβ positivity (P < 0.01). Cases with both tumor budding and hCGβ expression had the poorest prognosis compared with all other groups (P < 0.01). In conclusion, tumor budding and hCGβ expression are closely associated with EMT, and they are independent prognostic factors in CRC. They identify patients with an "EMT phenotype" who may respond to targeted molecular therapies

Oxidative Stress/Angiotensinogen/Renin-Angiotensin System Axis in Patients with Diabetic Nephropathy

Although recent studies have proven that renin-angiotensin system (RAS) blockades retard the progression of diabetic nephropathy, the detailed mechanisms of their reno-protective effects on the development of diabetic nephropathy remain uncertain. In rodent models, it has been reported that reactive oxygen species (ROS) are important for intrarenal angiotensinogen (AGT) augmentation in the progression of diabetic nephropathy. However, no direct evidence is available to demonstrate that AGT expression is enhanced in the kidneys of patients with diabetes. To examine whether the expression levels of ROS- and RAS-related factors in kidneys are increased with the progression of diabetic nephropathy, biopsied samples from 8 controls and 27 patients with type 2 diabetes were used. After the biopsy, these patients were diagnosed with minor glomerular abnormality or diabetes mellitus by clinical and pathological findings. The intensities of AGT, angiotensin II (Ang II), 4-hydroxy-2-nonenal (4-HNE), and heme oxygenase-1 (HO-1) were examined by fluorescence in situ hybridization and/or immunohistochemistry. Expression levels were greater in patients with diabetes than in control subjects. Moreover, the augmented intrarenal AGT mRNA expression paralleled renal dysfunction in patients with diabetes. These data suggest the importance of the activated oxidative stress/AGT/RAS axis in the pathogenesis of diabetic nephropathy

Potential identification of vitamin B6 responsiveness in autism spectrum disorder utilizing phenotype variables and machine learning methods

Abstract We investigated whether machine learning methods could potentially identify a subgroup of persons with autism spectrum disorder (ASD) who show vitamin B6 responsiveness by selected phenotype variables. We analyzed the existing data from our intervention study with 17 persons. First, we focused on signs and biomarkers that have been identified as candidates for vitamin B6 responsiveness indicators. Second, we conducted hypothesis testing among these selected variables and their combinations. Finally, we further investigated the results by conducting cluster analyses with two different algorithms, affinity propagation and k-medoids. Statistically significant variables for vitamin B6 responsiveness, including combination of hypersensitivity to sound and clumsiness, and plasma glutamine level, were included. As an a priori variable, the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS) scores was also included. The affinity propagation analysis showed good classification of three potential vitamin B6-responsive persons with ASD. The k-medoids analysis also showed good classification. To our knowledge, this is the first study to attempt to identify subgroup of persons with ASD who show specific treatment responsiveness using selected phenotype variables. We applied machine learning methods to further investigate these variables’ ability to identify this subgroup of ASD, even when only a small sample size was available