Overexpression of SGLT2 in the kidney of a P. gingivalis LPS-induced diabetic nephropathy mouse model

Background: The overexpression of sodium-glucose cotransporter 2 (SGLT2) in diabetic kidneys has been reported. It has also been established that the diabetic glomerular endothelium expresses the toll-like receptors TLR2 and TLR4. The present study aims to examine the renal SGLT2 induction by the TLR2/4 ligand Porphyromonas (P.) gingivalis lipopolysaccharide (Pg-LPS) in mouse diabetic nephropathy. Methods: Immunohistochemical study and tissue RT-PCR analyses were performed on mouse kidneys in streptozotocin (STZ)-induced diabetic ICR mice (STZ-ICR), in healthy ICR mice administered Pg-LPS (LPS-ICR), and in diabetic ICR mouse kidneys with Pg-LPS-induced nephropathy (LPS-STZ). Results: In the quantitative analysis of blood sugar levels, the mean time to reach 600 mg/dl was shorter in the LPS-STZ than in the STZ-ICR kidneys. The rise in blood glucose levels was significantly steeper in the LPS-STZ than in the STZ-ICR kidneys. According to these data the LPS-STZ model suggests a marked glucose intolerance. The expression of SGLT2 was significantly stronger in the whole of the renal parenchyma of the LPS-STZ than in the LPS-ICR or in the STZ-ICR. The expression of SGLT2 was observed both in the renal tubules and around the renal tubules, and in the glomeruli of the LPS-STZ kidneys. In the analysis by tissue real-time PCR and cell ELISA, the expression of the SGLT2 gene and protein was significantly stronger in the LPS-STZ than in the LPS-ICR or in the STZ-ICR. There were no differences in the renal SGLT2 production in the LPS-ICR and the STZ-ICR kidneys. Conclusions: Abnormally high renal expression of SGLT2 occurs in diabetic kidneys with P. gingivalis LPS. Periodontitis may be an exacerbating factor in diabetic nephropathy as well as in diabetes

Immunohistochemical study for the expression of leukocyte adhesion molecules, and FGF23 and ACE2 in P. gingivalis LPS-induced diabetic nephropathy

Objective The present study aims to examine the expression of leukocyte adhesion molecules and renal metabolic factors in diabetic mouse kidneys with periodontal pathogen Pg-LPS-induced nephropathy. Background We recently reported that the glomerular endothelium expresses toll-like receptor (TLR)2 and TLR4 in diabetic environments and TLR2/4 ligand Porphyromonas (P.) gingivalis lipopolysaccharides (Pg-LPS) induce nephropathy in diabetic mice. It is thought that Pg-LPS promotes the chronic inflammation with the overexpression of leukocyte adhesion molecules and renal-specific metabolic enzymes by the recognition of Pg-LPS via TLR in the diabetic kidneys. There have been no reports of the effects of periodontopathic bacteria on the expression of leukocyte adhesion molecules and the accumulation of physiologically active substances in the kidney. Methods The immunohistochemical investigation was performed on diabetic mouse kidney with Pg-LPS-induced nephropathy with glomerulosclerosis in glomeruli. Results There were no vessels which expressed vascular cell adhesion molecule-1 (VCAM-1), E-selectin, or fibroblast growth factor (FGF) 23 in streptozotocin (STZ)-induced diabetic ICR mice (STZ-ICR), or in healthy ICR mice administered Pg-LPS (LPS-ICR). However, in diabetic ICR mouse kidneys with Pg-LPS-induced nephropathy (LPS-STZ) the expression of VCAM-1 and the accumulation of FGF23 were observed in renal tubules and glomeruli, and the expression of E-selectin was observed in renal parenchyma and glomeruli. The angiotensin-converting enzyme 2 (ACE2) was detected in the proximal tubules but not in other regions of ICR, STZ-ICR, or LPS-ICR. In LPS-STZ ACE2 was detected both in renal tubules as well as in glomeruli. The Mac-1 and podoplanin-positive cells increased in the renal parenchyma with diabetic condition and there was the distribution of a large number of Mac-1-positive cells in LPS-STZ. Conclusions The Pg-LPS may induce diabetic renal inflammation such as glomerulosclerosis and tubulitis with infiltration of Mac-1/podoplanin positive macrophages via glomerular overexpression of VCAM-1 and E-selectin, resulting in accumulation of both ACE2 and FGF23 which were unmetabolized with the inflammation-induced kidney damage under the diabetic condition. Periodontitis may be a critical factor in the progress of nephropathy in diabetic patients

Fibulin-4 and -5, but not Fibulin-2, are Associated with Tropoelastin Deposition in Elastin-Producing Cell Culture

Elastic system fibers consist of microfibrils and tropoelastin. During development, microfibrils act as a template on which tropoelastin is deposited. Fibrillin-1 is the major component of microfibrils. It is not clear whether elastic fiber-associated molecules, such as fibulins, contribute to tropoelastin deposition. Among the fibulin family, fibulin-2, -4 and -5 are capable of binding to tropoelastin and fibrillin-1. In the present study, we used the RNA interference (RNAi) technique to establish individual gene-specific knockdown of fibulin-2, -4 and -5 in elastin-producing cells (human gingival fibroblasts; HGF). We then examined the extracellular deposition of tropoelastin using immunofluorescence. RNAi-mediated down-regulation of fibulin-4 and -5 was responsible for the diminution of tropoelastin deposition. Suppression of fibulin-5 appeared to inhibit the formation of fibrillin-1 microfibrils, while that of fibulin-4 did not. Similar results to those for HGF were obtained with human dermal fibroblasts. These results suggest that fibulin-4 and -5 may be associated in different ways with the extracellular deposition of tropoelastin during elastic fiber formation in elastin-producing cells in culture

Graft Duodenal Perforation due to Internal Hernia after Simultaneous Pancreas-Kidney Transplantation: Report of a Case

Although complications including graft thrombosis, graft pancreatitis, and rejection have been well documented after pancreas transplantation, the occurrence of graft duodenal perforation is uncommon. In this article, we report a case of graft duodenal perforation due to internal hernia after simultaneous pancreas-kidney transplantation (SPK). A patient with type I diabetes mellitus and diabetic nephropathy had undergone SPK from a cadaveric donor. One year later, she was admitted to our hospital for severe lower abdominal pain with preshock status. She was immediately examined by abdominal computed tomography and both peripancreas graft fluid accumulation and severe dilatation of the ileum were detected. On emergency operation, two punched holes located at the graft duodenal side near the suture line and an obstruction of herniated bowel behind the graft pancreas were detected. These holes were repaired and the internal hernia was reduced. However, a control of the intraabdominal infection was very difficult despite intensive treatment with antibiotics and additional abdominal drainage. Finally, a graft pancreatectomy was unavoidably required. When complications, including symptomatic intraabdominal infection, require re-laparotomy after pancreas transplantation, the therapeutic focus should be switched from salvaging the graft to the preservation of life

Immunohistochemical Examination on the Distribution of Cells Expressed Lymphatic Endothelial Marker Podoplanin and LYVE-1 in the Mouse Tongue Tissue

The clinical study for lingual disease requires the detailed investigation of the lingual lymphatic network and lymphatic marker-positive cells. Recently, it has been reported that several tissue cells and leukocytes express lymphatic markers, LYVE-1 and podoplanin. This study was aimed to clarify the lingual distribution of cells expressing LYVE-1 and podoplanin. In the mouse tongue, podoplanin is expressed in nerve sheaths, lingual gland myoepithelial cells, and lymphatic vessels. LYVE-1 is expressed in the macrophage marker Mac-1-positive cells as well as lymphatic vessels, while factor-VIII was detected in only blood endothelial cells. α-SMA was detected in vascular smooth muscle and myoepithelial cells. Therefore, identification of lymphatic vessels in lingual glands, the combination of LYVE-1 and factor-VIII, or LYVE-1 and Mac-1 is useful because myoepithelial cells express podoplanin and α-SMA. The immunostaining of factor-VIII on lymphatic vessels was masked by the immunostaining to LYVE-1 or podoplanin because lymphatic vessels express factor-VIII to a far lesser extent than blood vessels. Therefore, except for the salivary glands, the combination of podoplanin and α-SMA, or factor-VIII is useful to identify lymphatic vessels and blood vessels with smooth muscle, or blood capillaries

Expression of SARS‐CoV‐2 entry factors in human oral tissue

The distribution of cells expressing SARS‐CoV‐2 entry factor angiotensin‐converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in human oral tissues were tested. The investigation was conducted with normal flesh tissue and paraffin‐embedded specimens. The ACE2 and TMPRSS2 expression was detected with all subjects in the normal mucosa of the keratinized stratified squamous epithelia of the tongue and non‐keratinized stratified squamous epithelia of the lip and cheek. It was found that ACE2 is expressed in the cytoplasm and on the cell membrane mainly in the stratum granulosum of the epithelia while the TMPRSS2 is strongly expressed on the cell membrane mainly in the stratum granulosum and stratum spinosum, but not in the stratum basale. Antibodies’ reactions for ACE2 and TMPRSS2 were not observed in the nuclei or keratin layer. The expression of ACE2 and TMPRSS2 in the oral epithelia appears to be general, and the expression was also observed in the mucous and serous acini of the labial glands. The SARS‐CoV‐2 may transiently attach to the oral mucosa and the minor salivary glands which are present under all of the oral mucosa. The oral cavity can be considered an important organ for SARS‐CoV‐2 attachment and may provide a preventive medical avenue to guard against COVID‐19 by preventing saliva from scattering

Altered dynamics in the renal lymphatic circulation of type 1 and type 2 diabetic mice.

The dynamics of the renal lymphatic circulation in diabetic nephropathy is not fully elucidated. The present study evaluated the effect of diabetic nephropathy on the renal lymphatic circulation in streptozotocin (STZ)-induced type 1 diabetic mice (ICR-STZ) and in type 2 diabetic KK/Ta mice which were fed a high fat diet (KK/Ta-HF). The diabetic mouse kidneys developed edema because of the nephropathy. In control mice renal lymphatic vessels distributed in the cortex but rarely in the medulla while in ICR-STZ and KK/Ta-HF mice, there were many lymphatic vessels with small lumen in both cortex and medulla. Total numbers and areas of renal blood vessels in the diabetic mice were similar to those in the controls while the total numbers and areas of renal lymphatic vessels were larger in diabetic mice than in the controls. There were statistically significant differences in the numbers of lymphatic vessels with diameters of 50-100 µm between the ICR-STZ and the control ICR mice, and in the numbers of lymphatic capillaries with diameters smaller than 50 µm between the KK/Ta-HF and the control KK/Ta mice. The diabetic nephropathy may induce the lymphangiogenesis or result in at least the renal lymphatic vessel expansion.福岡歯科大学2013年

Distribution of podoplanin-expressing cells in the mouse nervous systems.

Podoplanin is a mucin-type glycoprotein which was first identified in podocytes. Recently, podoplanin has been successively reported as a marker for brain and peripheral nerve tumors, however, the distribution of podoplanin-expressing cells in normal nerves has not been fully investigated. This study aims to examine the podoplanin-expressing cell distribution in the mouse head and nervous systems. An immunohistochemical study showed that the podoplanin-positive areas in the mouse peripheral nerve and spinal cord are perineurial fibroblasts, satellite cells in the dorsal root ganglion, glia cells in the ventral and dorsal horns, and schwann cells in the ventral and dorsal roots; in the cranial meninges the dura mater, arachnoid, and pia mater; in the eye the optic nerve, retinal pigment epithelium, chorioidea, sclera, iris, lens epithelium, corneal epithelium, and conjunctival epithelium. In the mouse brain choroid plexus and ependyma were podoplanin-positive, and there were podoplanin-expressing brain parenchymal cells in the nuclei and cortex. The podoplanin-expressing cells were astrocyte marker GFAP-positive and there were no differences in the double positive cell distribution of several portions in the brain parenchyma except for the fornix. The results suggest that podoplanin may play a common role in nervous system support cells and eye constituents.福岡歯科大学2013年