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.

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.

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.

MON-680 Might Podocyturia Be an Early Marker for Diabetic Nephropathy in Males

Renal involvement can develop before detection of microalbuminuria in type 2 diabetes. There is an interest in finding biomarkers to detect diabetic nephropathy (DN) earlier and identify progression risk. Podocyturia emerge as a marker for early kidney damage however standardization problems hamper its widespread use. We aimed to investigate the value of podocyturia for the detection of early DN. Herein we report our preliminary results.

Our study population was composed of three type 2 diabetic patient groups and a healthy control group. Diabetic groups were defined as follows; group 1: patients without microalbuminuria who had HbA1c <7%; group 2: patients without microalbuminuria who had HbA1c> 8.5%; group 3: patients with diabetic retinopathy who had proteinuria >1g/day and/or microalbuminuria >300 mg/day and group 4: healthy volunteers without any known disease. Patients with glomerular filtration rate (GFR) below 30 ml/min were excluded.

GFR was calculated using the abbreviated MDRD formula. Microalbuminuria was measured in 24 hour urine. Number of podocytes in the urine was determined by immunocytochemical staining of podocalyxin. Due to the known expression of podocalyxin in the female genital tract, only males were included. Statistical analyses were carried out using Statistical Package for the Social Sciences version (SPSS) 24.0 and statistical significance was set as p<0.05.

We examined a total of 119 patients (mean age 57.35 ± 12.75 yrs.). Patient distribution in each group was as follows; group 1: 24(20%); group 2: 26(22%); group 3: 24(20%) and group 4: 45(38%) patients. There was no significant difference in mean age (p=0.582) and duration of diabetes (p=0.517) between the diabetic groups. The mean GFR was significantly lower in group 3 than in group 1 and 2 (p<0.001, p:0.007; respectively). The median podocyte measurement in urine was 0,25 (IQR: 0- 2.68) podx/ml in group 1; 0,37 (IQR: 0-2.12) podx/ml in group 2; 1,37 (IQR: 0.56-5.18) podx/ml in group 3; 0.0 (IQR: 0-0.75) podx/ml in group 4. The mean number of podocytes in urine was significantly different between the 4 groups (p=0.001). In posthoc analysis with Bonferoni correction, the mean podocytes measurement was significantly higher in group 3 than in group 1 and 4 (p=0.033, p=0.001; respectively).

According to our preliminary results; podocyturia assessed by podocalyxin immunostaining does not seem to be increased in male diabetic patients without proteinuria. Further studies on larger patient groups and using different podocyte markers might clarify the value of podocyturia as an early marker of DN.

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.

What is the cause of hypertrophia in asymmetric tonsils?

OBJECTIVES

Asymmetric tonsillar hypertrophy is a condition, confirmed by physical examination, that can be found in every age group. The aim of this study was to compare each tonsil through macroscopic and microscopic assessment of specimens and reveal the reasons that cause one tonsil to grow more than the other.

METHODOLOGY

The study was carried out with 93 patients who wereindicated for tonsillectomy in the authors' Clinic. Of these 93 patients, seven cases who had clinically asymmetric but pathologically symmetric tonsils were excluded from the study. The presence of microscopicintraepithelial abscess, Helicobacter pylori with Giemsa stain, Coccobacillus, fungus, Actinomyces with Pas-Grocott stain, dysplasia or hyperplasia, malignancy and reactive changes in the epithelium were evaluated.

RESULTS

The study was conducted with 86 patients aged between two and 35, of whom 32 were women (37.2%) and 54 were men (62.8%). The mean age of cases was 8.37 ± 5.95. The mean difference between two tonsils ranged from 1 to 12 mm, mean 3.67 ± 2.56 mm. When the findings were examined, the presence of H. pylori, Coccobacillus, fungus and Actinomyces, reactive changes in the epithelium, pattern of hyperplasia, intraepithelial abscess and macroscopic presence of pus did not reveal any statistically significant changes.

CONCLUSION

The reasons behind asymmetric tonsil hypertrophies and how they are related to malignancies have not yet been clarified. There is no statistically significant difference between the evaluated parameters in the present study. This study has brought a new point of view to the subject by comparing different-sized tonsils in the same person, thus paving the way for future studies with a broader scope.