Expression Pattern of α-Tubulin, Inversin and Its Target Dishevelled-1 and Morphology of Primary Cilia in Normal Human Kidney Development and Diseases.

The spatiotemporal expression of α-tubulin, inversin and dishevelled-1 (DVL-1) proteins associated with the Wnt-signaling pathway, and primary cilia morphology were analyzed in developing kidneys (14th-38th developmental weeks), healthy postnatal (1.5- and 7-years old) and pathologically changed human kidneys, including multicystic dysplastic kidneys (MCDK), focal segmental glomerulosclerosis (FSGS) and nephrotic syndrome of the Finnish type (CNF). The analysis was performed by double immunofluorescence, electron microscopy, semiquantitative and statistical methods. Cytoplasmic co-expression of α-tubulin, inversin and DVL-1 was observed in the proximal convoluted tubules (pct), distal convoluted tubules (dct) and glomeruli (g) of analyzed tissues. During kidney development, the overall expression of α-tubulin, inversin and DVL-1 decreased, while in the postnatal period slightly increased. The highest expressions of α-tubulin and inversin characterized dct and g, while high DVL-1 characterized pct. α-tubulin, inversin and DVL-1 expression pattern in MCDK, FSGS and CNF kidneys significantly differed from the healthy control. Compared to healthy kidneys, pathologically changed kidneys had dysmorphic primary cilia. Different expression dynamics of α-tubulin, inversin and DVL-1 during kidney development could indicate that switch between the canonical and noncanonical Wnt-signaling is essential for normal kidney morphogenesis. In contrast, their disturbed expression in pathological kidneys might be associated with abnormal primary cilia, leading to chronic kidney diseases.

Alteration of Cx37, Cx40, Cx43, Cx45, Panx1, and Renin Expression Patterns in Postnatal Kidneys of Dab1-/- (yotari) Mice.

Numerous evidence corroborates roles of gap junctions/hemichannels in proper kidney development. We analyzed how Dab1 gene functional silencing influences expression and localization of Cx37, Cx40, Cx43, Cx45, Panx1 and renin in postnatal kidneys of yotari mice, by using immunohistochemistry and electron microscopy. Dab1 Δ102/221 might lead to the activation of c-Src tyrosine kinase, causing the upregulation of Cx43 in the medulla of yotari mice. The expression of renin was more prominent in yotari mice (p < 0.001). Renin granules were unusually present inside the vascular walls of glomeruli capillaries, in proximal and distal convoluted tubules and in the medulla. Disfunction of Cx40 is likely responsible for increased atypically positioned renin cells which release renin in an uncontrolled fashion, but this doesn't rule out simultaneous involvement of other Cxs, such as Cx45 which was significantly increased in the yotari cortex. The decreased Cx37 expression in yotari medulla might contribute to hypertension reduction provoked by high renin expression. These findings imply the relevance of Cxs/Panx1 as markers of impaired kidney function (high renin) in yotari mice and that they have a role in the preservation of intercellular signaling and implicate connexopathies as the cause of premature death of yotari mice.

Expression and localization of DAB1 and Reelin during normal human kidney development.

AIM: To explore the spatial and temporal expression patterns of DAB1 and Reelin in the developing and postnatal healthy human kidneys as potential determinants of kidney development. METHODS: Paraffin-embedded fetal kidney tissue between the 13/14th and 38th developmental weeks (dw) and postnatal tissue at 1.5 and 7 years were stained with DAB1 and Reelin antibodies by double immunofluorescence. RESULTS: During the fetal kidney development and postnatal period, DAB1 and Reelin showed specific spatial expression pattern and diverse fluorescence intensity. During the fetal period, DAB1 was strongly expressed in the distal convoluted tubules (DCT), with strong reactivity, and diversely in the proximal convoluted tubules (PCT) and glomeruli. In the postnatal period, DAB1 expression decreased. The strongest Reelin expression in early fetal stages was observed in the PCT. In the postnatal period, Reelin expression decreased dramatically in all observed structures. These two markers were colocalized during early developmental stages, mostly in PCT, DCT, and podocytes. CONCLUSION: The appearance of DAB1 and Reelin during fetal kidney development confirms their potential significant role in the formation of kidney structure or function. High DAB1 expression in the DCT implies its regulatory role in tubular formation or function maintenance during development. Reelin was highly expressed in human kidneys at early fetal stages, mostly in the PCT, while at later fetal stages and postnatal period its expression decreased.

The influence of the initial clinical presentation of upper tract urothelial carcinoma on histopathological tumor features.

PURPOSE: To investigate the influence of the initial clinical presentation (symptomatic vs. asymptomatic) on histopathological tumor features in patients with upper tract urothelial carcinoma (UTUC). METHODS: We conducted a single-center, cross-sectional, and retrospective study that enrolled 72 adults with primary UTUC who underwent radical nephroureterectomy at our institution over a period of 4 years (April 2019-April 2023). RESULTS: Symptomatic patients exhibited significantly higher frequencies of high-grade UTUC (73.6% vs. 36.8%, p = 0.006), ≥ T2 stage UTUC (60.4% vs. 26.3%, p = 0.007), and larger tumor sizes (median 5 vs. 4 cm, p = 0.015) compared to asymptomatic patients. Multiple regression analyses demonstrated significant associations between symptomatic presentation and the presence of high-grade UTUC (OR 6.35, 95% CI 1.81-22.27, p = 0.004), ≥ T2 stage UTUC (OR 5.98, 95% CI 1.62-22.08, p = 0.007), and larger tumor size (B 3.14, 95% CI 0.62-5.66, p = 0.015). A subset of patients with hematuria was separately analyzed to assess the influence of hematuria severity (gross vs. microscopic) on UTUC characteristics. Patients with gross hematuria exhibited significantly higher frequencies of high-grade UTUC (72.9% vs. 33.3%, p = 0.048) and ≥ T2 stage UTUC (58.3% vs. 22.2%, p = 0.001). Multiple regression analyses showed significant associations between gross hematuria and the presence of high-grade UTUC (OR 6.34, 95% CI 1.15-34.95, p = 0.034) and ≥ T2 stage UTUC (OR 6.54, 95% CI 1.11-38.93, p = 0.039). CONCLUSION: Initial symptomatic presentation was independently associated with adverse histopathological UTUC characteristics, potentially attributed to earlier detection of UTUC in asymptomatic patients, before the onset of symptoms.

The Impact of the Initial Clinical Presentation of Bladder Cancer on Histopathological and Morphological Tumor Characteristics.

This study investigated the impact of the initial clinical presentation of bladder cancer on tumor characteristics. A cross-sectional, retrospective study was performed, and it involved 515 patients who underwent transurethral bladder cancer resection at the University Hospital Center Split between April 2019 and April 2023, excluding recurrent cases. The association between symptomatic versus asymptomatic presentation and bladder cancer characteristics was analyzed. A subgroup analysis compared tumor characteristics between patients with gross and microscopic hematuria. Multiple regression analyses revealed a significant association between symptomatic presentation and the detection of high-grade bladder cancer (OR 3.43, 95% CI 2.22-5.29, p < 0.001), concomitant CIS (OR 3.41, 95% CI 1.31-8.88, p = 0.012), T2 stage bladder cancer (OR 5.79, 95% CI 2.45-13.71, p < 0.001), a higher number of tumors (IRR 1.24, 95% CI 1.07-1.45, p = 0.005), and larger tumor size (B 1.68, 95% CI 1.19-2.18, p < 0.001). In the subgroup analysis, gross hematuria was associated with the detection of high-grade bladder cancer (OR 2.07, 95% CI 1.12-3.84, p = 0.020), T2 stage bladder cancer (OR 6.03, 95% CI 1.42-25.49, p = 0.015), and larger tumor size (B 1.8, 95% CI 0.99-2.6, p < 0.001). The identified associations between symptomatic presentation and unfavorable bladder cancer characteristics, likely attributed to early detection in asymptomatic cases, underscore the importance of additional research in the development of bladder cancer screening strategies.

GREB1L, CRELD2 and ITGA10 expression in the human developmental and postnatal kidneys: an immunohistochemical study.

BACKGROUND: Aim of our study is to provide an insight into the genetic expression landscape of GREB1L, ITGA10 and CRELD2 which are important in human genitourinary tract development which might help elucidate the critical stages for the onset of kidney anomalies. METHODS: Morphological parameters were analyzed using immunohistochemistry on human foetal (13-38 w) and postnatal (1.5 and 7.5y) human kidney samples. RESULTS: GREB1L marker had a strong intensity and the highest rate in proximal tubules (PTC) of 1.5 years' kidney (90.25%). In the distal tubules (DCT) there were statistically significant differences in 13 w, 15 w, 16 w, 21 w, 38 w and 7.5y regarding 1.5y (Kruskal-Wallis test, p < 0.001). There was significantly more GREB1L in the glomeruli at 21 w and 38 w in regard to all other stages (Kruskal-Wallis test, p < 0.01). ITGA10 staining intensity was strongest in PCT with the highest rate in 13 w (92.75%), while the lowest rate was found in glomeruli and DCT (Kruskal-Wallis test, p < 0.001). CRELD2 had the strongest staining intensity in PCT with the highest rate in 13 w and 1.5y (92.25%) and lowest in the glomeruli of 7.5 years (24.3 %). In DCT there were statistically significant differences in CRELD2 positive cells in 13 w, 15 w, 16 w, 21 w, 38 w and 7.5y regarding 1.5y (Kruskal-Wallis test, p < 0.01). ITGA10 and CRELD2 co-localised in the postnatal period in DCT. CONCLUSION: High kidney expressions of GREB1L, ITGA10 and CRELD2 even in the postnatal period implicate their importance not only for the onset of CAKUT in the case of their mutation but also for maintenance of kidney homeostasis.

Expression of renal vitamin D receptors and metabolizing enzymes in IgA nephropathy.

AIM: One of the main causes of end-stage renal disease (ESRD) in the world is IgA nephropathy (IgAN). Since kidney is a key player in vitamin D metabolism, we investigated the expression of renal vitamin D receptors (VDR) and metabolizing enzymes in IgA nephropathy patients (IgAN-P). METHODS: The sample included twelve IgAN-P who underwent ultrasound-guided renal biopsies and five controls who underwent nephrectomy due to clear renal carcinoma. Immunofluorescent staining was used to determine the expression of VDR, 25-hydroxyvitamin D3 -alpha-hydroxylase (1alpha-OHase) and vitamin D3 24-hydroxylase (CYP24A1). RESULTS: Significant increase in expression of VDR, which was prominent in distal tubular cells (DTCs) in tissues from IgAN-P, was found in comparison to the controls (p = 0.0368). The expression of 1alpha-OHase, calcitriol synthesizing enzyme, was significantly lower in IgAN-P, in comparison with controls (p < 0.0001). The opposite, expression of CYP24A1 (vitamin D degrading enzyme), was significantly higher in IgAN-P in comparison with controls (p = 0.0003). Additionally, we found significant negative correlation between percentage of CYP24A1 immunoreactive nuclei in proximal tubular cells (PTCs) and estimated glomerular filtration rate (eGFR) in IgAN-P (r = -0.6139; p = 0.0337). CONCLUSIONS: Our research indicates substantially decreased renal calcitriol production and increased vitamin D degradation in kidneys of IgAN-P, but larger studies are needed to confirm our results.

SATB1 and PTEN expression patterns in biopsy proven kidney diseases.

BACKGROUND: In present study we investigated expression pattern of the special tissue markers. SATB1 and PTEN to evaluate possible influence in pathophysiology and development of various biopsy proven kidney diseases. METHODS: The 32 kidney biopsy samples were analysed using light, immunofluorescence and electron microscopy. There were 19 samples in proliferative and 13 samples in non- proliferative group of renal diseases. As control group, 9 specimens of healthy kidney tissue taken after surgery of kidney tumour were used. SATB1 and PTEN markers were used for immunofluorescence staining. Analysed tissue structures were glomeruli, proximal convoluted tubules (PCT) and distal convoluted tubules (DCT). The number of SATB1 and PTEN cells were calculated and the data compared between kidney structures, disease groups and control specimens. RESULTS: Both markers were positive in all investigated kidney structures, with expression generally, more prominent in tubular epithelial cells than in glomeruli, with the highest staining intensity rate as well as highest rate of both markers in DCT of proliferative diseases group (SATB1 64.5 %, PTEN 52 %). There was statistically significant difference in SATB1 expression in all tissue structures of interest in proliferative as well as non- proliferative group compared to control group (p < 0.01-p < 0.0001). PTEN expression were found significantly decreased in PCT of both disease groups in regard to control (PTEN 25.3 % and 23.8 % vs. 41.1 % (p < 0.01 and p < 0.001 respectively). CONCLUSION: SATB1 and PTEN could be considered as markers influenced in kidney disease development. SATB1/PTEN expression should be further investigated as useful markers of kidney disease activity as well as potential therapeutic target.

Expression of apoptotic and proliferation factors in gastric mucosa of patients with systemic sclerosis correlates with form of the disease.

Despite high prevalence of patients with gastric disease in systemic sclerosis (SSc), its pathogenesis is still poorly understood. We immunohistochemically analysed biopsies of gastric mucosa (GM) in 5 controls and 15 patients with different forms of SSc: limited cutaneous (lc), diffuse cutaneous moderate (sys1) and severe (sys2). The number of positive cells was analysed by a Kruskall-Wallis test, P < 0.05 was considered statistically significant. Percentage of proliferating (Ki-67 positive) cells was highest in sys1 (3% in superficial and 4,6% in deeper parts of GM), which dropped to 1% in sys2. Percentage of α-smooth muscle actin (α-SMA) positive cells was 5% in controls, 9% in superficial GM, while in deeper GM rose from 7% to 19% in sys1 and sys2, thus indicating increased myofibroblast population. Caspase-3 positive apoptotic cells characterized 1,5-2% of controls, 8% of superficial and 6% of deeper GM cells in sys1. In sys2, apoptosis affected 50% of surface epithelial and gland cells and 30% of deeper glands, and correlated with increased fibrosis and decreased syndecan-1 expression. Our data demonstrate that sys1 is the most "active" proliferating form of SSc. Sys2 characterize collagen deposition, surface epithelium defects, extensive apoptosis and low proliferation, GM atrophy and loss of function.

Transparency and public accessibility of clinical trial information in Croatia: how it affects patient participation in clinical trials.

INTRODUCTION: Despite increased visibility of clinical trials through international trial registries, patients often remain uninformed of their existence, especially if they do not have access to adequate information about clinical research, including the language of the information. The aim of this study was to describe the context for transparency of clinical trials in Croatia in relation to countries in Central and Eastern Europe, and to assess how informed Croatian patients are about clinical trials and their accessibility. MATERIALS AND METHODS: We assessed the transparency of clinical trials from the data available in the public domain. We also conducted an anonymous survey on a convenience sample of 257 patients visiting two family medicine offices or an oncology department in south Croatia, and members of national patients' associations. RESULTS: Despite legal provisions for transparency of clinical trials in Croatia, they are still not sufficiently visible in the public domain. Among countries from Central and Eastern Europe, Croatia has the fewest number of registered trials in the EU Clinical Trials Registry. 66% of the patients in the survey were aware of the existence of clinical trials but only 15% were informed about possibilities of participating in a trial. Although 58% of the respondents were willing to try new treatments, only 6% actually participated in a clinical trial. Only 2% of the respondents were aware of publicly available trial registries. CONCLUSIONS: Our study demonstrates that there is low transparency of clinical trials in Croatia, and that Croatian patients are not fully aware of clinical trials and the possibilities of participating in them, despite reported availability of Internet resources and good communication with their physicians. There is a need for active policy measures to increase the awareness of and access to clinical trials to patients in Croatia, particularly in their own language.