Comparative analysis of effects of conditioned mediums obtained from 2D or 3D cultured mesenchymal stem cells on kidney functions of diabetic rats: Early intervention could potentiate transdifferentiation of parietal epithelial cell into podocyte precursors.

AIM: The secretome of mesenchymal stem cells (MSCs) could be a potential therapeutic intervention for diabetes and associated complications like nephropathy. This study aims to evaluate the effects of conditioned mediums (CMs) collected from umbilical cord-derived MSCs incubated under 2-dimensional (2D) or 3D culture conditions on kidney functions of rats with type-I diabetes (T1D). MAIN METHODS: Sprague-Dawley rats were treated with 20 mg/kg streptozocin for 5 consecutive days to induce T1D, and 12 doses of CMs were applied intraperitoneally for 4 weeks. The therapeutic effects of CMs were comparatively investigated by biochemical, physical, histopathological, and immunohistochemical analysis. KEY FINDINGS: 3D-CM had significantly higher total protein concentration than the 2D-CM Albumin/creatinine ratios of both treatment groups were significantly improved in comparison to diabetes. Light microscopic evaluations showed that glomerular and cortical tubular damages were significantly ameliorated in only the 3D-CM applied group compared to the diabetes group, which were correlated with transmission electron microscopic observations. The nephrin and synaptopodin expressions increased in both treatment groups compared to diabetes. The WT1, Ki-67, and active caspase-3 expressions in glomeruli and parietal layers of the treatment groups suggest that both types of CMs suppress apoptosis and promote possible parietal epithelial cells' (PECs') transdifferentiation towards podocyte precursor cells by switching on WT1 expression in parietal layer rather than inducing new cell proliferation. SIGNIFICANCE: 3D-CM was found to be more effective in improving kidney functions than 2D-CM by ameliorating glomerular damage through the possible mechanism of transdifferentiation of PECs into podocyte precursors and suppressing glomerular apoptosis.

Effects of SGLT2 inhibitors on patients with diabetic kidney disease: A preliminary study on the basis of podocyturia.

BACKGROUND: The aim of this study was to investigate the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on the glomerulus through the evaluation of podocyturia in patients with diabetic kidney disease (DKD). METHODS: The study population was composed of 40 male patients with type 2 diabetes mellitus; 22 of them received SGLT2i (SGLT2i group), and the others who did not were the control. The DKD-related parameters of patients were monitored before SGLT2i initiation, and then in the third and sixth month of the follow-up period. Patients' demographic, clinical, laboratory, and follow-up data were obtained from medical charts. Microalbuminuria was measured in 24-h urine. The number of podocytes in the urine was determined by immunocytochemical staining of two different markers, namely podocalyxin (podx) and synaptopodin (synpo). Concentrations of urine stromal cell-derived factor 1a and vascular endothelial growth factor cytokines were quantified with an enzyme-linked immunosorbent assay kit. RESULTS: At the end of the follow-up period, decreases in glycosylated hemoglobin, glucose, systolic and diastolic blood pressure, uric acid level, and microalbuminuria, and improvement in body mass index level and weight loss were significant for the SGLT2i group. On the other hand, there was no significant difference in terms of these parameters in the control group. The excretion of synaptopodin-positive (synpo+ ) and podocalyxin-positive (podx+ ) cells was significantly reduced at the end of the follow-up period for the SGLT2i group, while there was no significant change for the control. CONCLUSIONS: At the end of the follow-up period, male patients receiving SGLT2i had better DKD-related parameters and podocyturia levels compared to baseline and the control group. Our data support the notion that SGLT2i might have structural benefits for glomerular health.

Identifying the optimal monopolar electrocautery output power in pedicular internal thoracic artery harvesting: 20 or 40 watts?

BACKGROUND: Monopolar electrocautery is an important tool for harvesting the pedicular internal thoracic artery (ITA) in cardiac surgery. The different power outputs of cautery may affect graft integrity and long-term patency. This study aimed to identify the optimal threshold of electrocautery power for ITA harvest. METHODS: This prospective study included 30 patients who underwent elective coronary artery bypass surgery at the Medipol Mega University Hospital. The ITA was harvested by monopolar electrocautery after a median sternotomy. The output of cautery was adjusted at 20 W in group A and 40 W in group B. Three to 4 cm of a distal ITA sample from each patient was examined under a light microscope by two independent pathologists. RESULTS: The ITA harvest time was longer in group A (21.2 ± 7.5 vs 10.3 ± 8.1 min, p < 0.001) than in group B. ITA free flow was similar in the two groups (43.6 ± 48.7 vs 51.7 ± 45.0 Ml/min, p = 0.762). Mild to moderate injury in the endothelial and sub-endothelial sample was more frequent in the low-cautery group (p = 0.0037). CONCLUSIONS: ITA endothelial integrity was found to be better preserved with 40W electrocautery. Moreover, 20W of monopolar electrocautery may not be safe in pedicular ITA harvesting.

Dilated Minute Chambers in Laryngeal Vocal Fold Polyps: Histopathological and Ultrastructural Features.

In Reinke's space of human vocal fold, type III collagen forms a three dimensional network and this contains numerous minute chambers in between these fibers. These compartments are occupied by glycosaminoglycans and glycoproteins. In laryngeal fold lesions, such as Reinke's edema and vocal fold polyps, proteoglycan (PG)/hyaluronic acid (HA) components of extracellular matrix increased. We investigated the size and quantity of the minute chambers within Reinke's space, filled with PG/HA with the aid of transmission electron microscopy. Eight vocal fold polyps and 10 mucosal biopsies (as control group) were all evaluated by light microscopy and electron microscopy. We detected that PG/HA in extracellular matrix had been increased in vocal fold lesions when compared with control group, by Alcian Blue-pH 2.5 stain. The mean volume of the chambers in Reinke's space of normal larynx was measured as 0.040233 µm2 whereas the mean volume of these chambers in vocal fold polyps was measured as 6.420221 µm2. The difference between the volumes of these chambers in vocal fold polyps and in control group was statistically significant (P = 0.001). Within these chambers PG/HA were found and PG/HA filling these chambers were increased in vocal fold polyps. We think proteoglycan and glycosaminoglycans, especially HA, play an important role in determining biochemical properties of vocal fold lesions.

In glomerular cells of puromycin aminonucleoside nephrosis rats both phosphorylated and total STAT3 levels increased during proteinuria.

Recent studies showed that JAK/STAT pathway plays role in glomerular damages. The fact that STAT3 could be activated also by oxidative stress make Puromycin Aminonucleoside (PAN) Nephrosis model very appropriate for examination of STAT3 expression changes in glomerular pathology. Along with a control group, three PAN groups sacrificed on different days were formed by the i.p. injection of PAN for 5 consecutive days. Throughout the experiment, 24-hour-urines were collected on specific days and proteinuria levels were monitored. At the end of the experiments, tissue specimens were stained immunohistochemically for both total and phosphorylated STAT3 and evaluated subjectively. They were also examined ultrastructurally in transmission electron microscope. The proteinuria levels did not increase significantly on 5th day but showed a dramatic increase on 10th and 15th days. On 20th and 25th days, urinary protein levels gradually decreased. Ultrastructural examinations showed glomerular damages such as significant decrease in slit pore number, a significant gradual increase in glomerular basement membrane thickness and podocyte hypertrophy on 5th and 15th days; besides significant increase in mesangial matrix. The first significant increases in phosphorylated and total STAT3 levels occurred in 5th day and 15th day groups respectively. These increases diminished in 25th day group. Regarding all the findings, it was deduced that STAT3 is one of the active factors in glomerular pathologies.

The relationship between glomerular function and podocyte structure of pre-proteinuria and acute nephrosis in puromycin aminonucleoside-induced rat models: a comparative electron microscopic study.

Puromycin aminonucleoside (PA) has been generally utilized as model of podocyte injury followed by massive proteinuria, severe damage on endocytotic activity of epithelial cells and postmodification of endocytosed compounds. However, total PA nephrosis (PAN) mechanism cannot be understood. We aimed to study glomerular function, foot process degeneration and transport pathways of podocytes in pre-proteinuria and acute PAN rats. Eighteen male Wistar albino rats were divided into three groups: control, pre-proteinuria and acute nephrosis groups (n=6). PA was injected into pre-proteinuria group for three times and acute group for nine times. Proteinuria levels in urine, creatinine and albumin levels in blood were detected 24 hours after PA injections. Renal cortex samples were prepared for transmission electron microscopy. Proteinuria levels in acute group significantly elevated, whereas creatinine clearance, serum albumin levels and urine volumes diminished compared to control and pre-proteinuria groups. In pre-proteinuria group, hypertrophy and structurally rich cytoplasm were detected only within podocytes. Acute group had various protein absorption granules secreted from podocyte cytoplasm to the urinary space through exocytosis after lysosomal digestion; but not observed in pre-proteinuria group. The number of slit pores in pre-proteinuria group decreased, particularly related to fusion of foot processes, subsequently leading to proteinuria. We concluded that foot process fusion begins prior to development of proteinuria although their serum albumin and creatinine clearance levels do not differ significantly. Additionally, we suggested that in acute PAN, first affected glomerular cells could be podocytes and there could be a correlation between glomerular function and number of slit pores.