Congenital anomalies of the kidney and urinary tract (CAKUT) are a major cause of pediatric renal failure, but the molecular mechanisms driving these conditions are not yet fully understood. Fibroblast Growth Factor 23 (FGF23) and its co-receptor α-KLOTHO play crucial roles in regulating calcium and phosphate homeostasis in adult kidneys, but their roles in kidney development and the pathogenesis of CAKUT remain unclear. Because of that, we analyzed the spatial and temporal expression of FGF23 and α-KLOTHO in normal fetal kidney development and CAKUT using an immunofluorescence technique. Our results demonstrate a dynamic pattern of FGF23 and α-KLOTHO expression in healthy kidney development, with FGF23 levels decreasing and α-KLOTHO levels increasing with gestational age. Also, we showed that FGF23 expression was significantly reduced in horseshoe (HKs) and duplex kidneys (DKs), while α-KLOTHO expression remained unchanged across all CAKUT conditions. Based on our results, we suggest that altered FGF23 expression in CAKUT contributes to disease pathogenesis and may represent a potential therapeutic target.

Mitochondrial dysfunction is a pivotal driver in the pathogenesis of acute kidney injury (AKI), chronic kidney disease (CKD), and congenital anomalies of the kidney and urinary tract (CAKUT). The kidneys, second only to the heart in mitochondrial density, rely on oxidative phosphorylation to meet the high ATP demands of solute reabsorption and filtration. Disrupted mitochondrial dynamics, such as excessive fission mediated by Drp1, exacerbate tubular apoptosis and inflammation in AKI models like ischemia–reperfusion injury. In CKD, persistent mitochondrial dysfunction drives oxidative stress, fibrosis, and metabolic reprogramming, with epigenetic mechanisms (DNA methylation, histone modifications, non-coding RNAs) regulating genes critical for mitochondrial homeostasis, such as PMPCB and TFAM. Epigenetic dysregulation also impacts mitochondrial–ER crosstalk, influencing calcium signaling and autophagy in renal pathology. Mitophagy, the selective clearance of damaged mitochondria, plays a dual role in kidney disease. While PINK1/Parkin-mediated mitophagy protects against cisplatin-induced AKI by preventing mitochondrial fragmentation and apoptosis, its dysregulation contributes to fibrosis and CKD progression. For instance, macrophage-specific loss of mitophagy regulators like MFN2 amplifies ROS production and fibrotic responses. Conversely, BNIP3/NIX-dependent mitophagy attenuates contrast-induced AKI by suppressing NLRP3 inflammasome activation. In diabetic nephropathy, impaired mitophagy correlates with declining eGFR and interstitial fibrosis, highlighting its diagnostic and therapeutic potential. Emerging therapeutic strategies target mitochondrial dysfunction through antioxidants (e.g., MitoQ, SS-31), mitophagy inducers (e.g., COPT nanoparticles), and mitochondrial transplantation, which mitigates AKI by restoring bioenergetics and modulating inflammatory pathways. Nanotechnology-enhanced drug delivery systems, such as curcumin-loaded nanoparticles, improve renal targeting and reduce oxidative stress. Epigenetic interventions, including PPAR-α agonists and KLF4 modulators, show promise in reversing metabolic reprogramming and fibrosis. These advances underscore mitochondria as central hubs in renal pathophysiology. Tailored interventions—ranging from Drp1 inhibition to mitochondrial transplantation—hold transformative potential to mitigate kidney injury and improve clinical outcomes. Additionally, dietary interventions and novel regulators such as adenogens are emerging as promising strategies to modulate mitochondrial function and attenuate kidney disease progression. Future research should address the gaps in understanding the role of mitophagy in CAKUT and optimize targeted delivery systems for precision therapies.

Background/Objectives: The human kallikrein-related peptidase 6 (KLK6), a serine protease with trypsin-like properties, belongs to the 15-member kallikrein (KLK) gene family and is predominantly recognized for its role in oncogenesis, neurodegenerative disorders, and skin conditions. Aquaporins (AQPs) are integral membrane proteins that facilitate water transport across cell membranes. AQP1 is constitutively active in the kidneys and plays a crucial role in reabsorbing filtered water, while AQP2 is regulated by vasopressin and is essential for maintaining body fluid homeostasis. The primary objective of the present study is to investigate the spatio-temporal expression patterns of KLK6, AQP1, and AQP2 throughout normal human nephrogenesis and congenital kidney and urinary tract (CAKUT) abnormalities: duplex kidneys, horseshoe kidneys, and dysplastic kidneys. Methods: An immunofluorescence analysis of KLK6, AQP1, and AQP2 was performed on 37 paraffin-embedded fetal kidney samples. The area percentage of KLK6 in the kidney cortex was calculated in normal developing samples during developmental phases 2, 3, and 4 and compared with CAKUT samples. Results: KLK6 exhibits distinct spatiotemporal expression patterns during human kidney development, with consistent localization in proximal tubules. Its subcellular positioning shifts from the basolateral cytoplasm in early phases to the apical cytoplasm in later stages, which may be strategically positioned to act on its substrate in either the peritubular space or the tubular fluid. KLK6 expression followed a quadratic trajectory, peaking at Ph4. This marked increase in the final developmental phase aligns with its strong expression in mature kidneys, suggesting a potential role in proximal tubule differentiation and functional maturation through facilitating extracellular matrix remodeling and activating proteinase-activated receptors, modulating the signaling pathways that are essential for tubular development. In duplex kidneys, structural abnormalities such as ureteral obstruction and hydronephrosis may upregulate KLK6 as part of a reparative response, while its downregulation could impair epithelial remodeling and cytoskeletal integrity, exacerbating dysplastic phenotypes. Conclusions: These findings highlight the potential of KLK6 involvement in normal kidney development and the pathology of CAKUT.

Background: The main feature of osteoarthritis (OA) is the deterioration of articular cartilage, but numerous studies have demonstrated the role of synovial inflammation in the early stages of the disease, leading to further progression of OA. The WNT signaling pathway is involved in numerous activities in joint tissue, but there is a lack of evidence considering the role of WNT in OA synovitis. Our research aims to investigate the expression of WNT Family Member 5A/B (WNT5A/B), β-catenin, acetyl-α-tubulin, Dishevelled-1 (DVL-1), and Inversin (INV) in the synovial membrane of osteoarthritis (OA) hips. Methods: The immunohistochemical expressions of the aforementioned proteins in the synovial membrane were analyzed and compared with samples of control group participants with fractured femoral necks. Results: The immunoexpression of acetyl-α-tubulin was significantly increased in the intima (p < 0.0001) and subintima (p < 0.0001) of the group with OA compared with the intima and subintima of the control group. At the same time, acetyl-α-tubulin was also more highly expressed in the intima of the OA group than in the subintima of the OA group (p < 0.05); we found the same expression pattern in the control group (p < 0.0001). The differential analysis of the GEO dataset did not show significant differences between the osteoarthritis (OA) and control groups in the expression of TUBA1A. β-catenin was significantly increased in the subintima (p < 0.01) of the group with OA compared to the subintima of the control group. WNT expression has significantly higher positivity in the subintima than in the intima, especially in the control group (p < 0.01). WNT5A and WNT5B were significantly down-regulated in OA compared to the control in the differential analysis of the GEO dataset. The expression of INV and DVL-1 in our study and the differential analysis of the GEO dataset did not differ significantly between the osteoarthritis (OA) and control groups. Conclusions: Based on our results, we suggest that acetyl-α-tubulin and β-catenin might be involved in synovial membrane inflammation in OA and serve as potential therapeutic targets.

Simple Summary This research considers means of improving the early detection and treatment of colorectal cancer (CRC), a common and deadly form of cancer often identified too late for effective treatment. In our study, we examined AIFM3, VGLL4, and WNT4 in cancerous and healthy tissues at various stages of CRC. We found that these markers behave differently as the cancer advances. AIFM3 appears in healthy tissue and early cancer stages but disappears as the cancer worsens. VGLL4 increases in the affected tissues as the cancer progresses, particularly noticeable from early to more advanced stages. WNT4 is higher in cancerous tissues, but decreases in the supportive tissue surrounding cancer cells as the disease advances. Low VGLL4 levels are linked to better patient survival, unlike the other two markers. This finding suggests that VGLL4 could be useful as an indicator of CRC prognosis, potentially guiding treatment approaches.

Long-term use of topical prostaglandins might initiate chronic conjunctival inflammation, leading to poor outcomes of glaucoma surgery. The aim of this study was to evaluate the immunoexpression pattern of HSP70, CTGF, SNAIL, aSMA, cMYB, and HIFa in the conjunctiva, episclera, and deep sclera in patients with glaucoma undergoing deep sclerectomy in order to establish an association between staining intensities and prostaglandin F2 (PGF2) treatment. Double immunofluorescence (HSP70, CTGF, SNAIL, aSMA, cMYB, and HIFa) was performed on conjunctiva, episclera, and deep sclera samples, which were obtained from 23 patients treated with PGF2 and 8 patients without PGF2 treatment. When comparing the ocular tissues of patients regarding treatment with PGF2 analogs, we found a significant increase in the immunoexpression of HSP70 in the conjunctival epithelium of patients treated with PGF2 analogs compared to those without PGF2 treatment. These patients also had an increase in SNAIL immunoexpression and a decrease in aSMA immunoexpression in the deep sclera. There were no significant differences in HIFa, CTGF, or cMYB immunoexpression levels between the two groups. Further research into the regulation of these factors in ocular tissues could lead to the development of potential novel therapeutic approaches in glaucoma management.

Precision medicine is a developing trend in oncology, and it includes the prognosis and treatment of advanced-stage ccRCC. New predictive factors and therapeutic targets for this disease are steadily needed. The aim of this study was to explore the tumor expression of inversin as a potential prognostic factor and/or therapeutic target in ccRCC. We compared the expression of inversin between primary ccRCC and normal renal tissues by using immunohistochemistry and rtPCR in our cohort, and we also analyzed publicly available data from the TCGA-KIRC cohort. We found that the expression of inversin was significantly lower in primary tumor tissue, in comparison to solid normal tissue. Data from the KIRC study confirmed that a lower INVS expression level in ccRCC was significantly related with the overall and disease-specific survival, as well as with a shorter progression-free interval (p < 0.05). Four out of ten inversin interactome partners were significantly related with the overall and disease-specific survival in ccRCC. A lower expression of ANKS6 was a negative survival predictor, while a higher expression of NPHP3, DVL1, or DVL3 was related with a lower survival. The expression of INVS and its interactome partners in ccRCC was correlated with the differentiation of the tumor and metastasis. The expression of INVS and its partners was also correlated with tumor leukocyte infiltration and the expression of immune checkpoint genes. The results of this study point to inversin and a distinguished group of its interactome partners as potential prognostic factors in ccRCC, with their predominant involvement in the modulation of the inflammatory infiltration of the tumor microenvironment and a strong relationship with the metastatic potential of the tumor.

This study aimed to explore how Dab1 functional silencing influences the expression patterns of different connexins in the developing yotari (yot) mice eyes as potential determinants of retinogenesis. Using immunofluorescence staining, the protein expression of Dab1, Reelin, and connexin 37, 40, 43, and 45 (Cx37, Cx40, Cx43, and Cx45) in the wild-type (wt) and yot eyes at embryonic days 13.5 and 15.5 (E13.5 and E15.5) were analyzed. Different expression patterns of Cx37 were seen between the wt and yot groups. The highest fluorescence intensity of Cx37 was observed in the yot animals at E15.5. Cx40 had higher expression at the E13.5 when differentiation of retinal layers was still beginning, whereas it decreased at the E15.5 when differentiation was at the advanced stage. Higher expression of Cx43 was found in the yot group at both time points. Cx45 was predominantly expressed at E13.5 in both groups. Our results reveal the altered expression of connexins during retinogenesis in yot mice and their potential involvement in retinal pathology, where they might serve as prospective therapeutic targets.

In hip fracture patients, who are mostly elderly, preexisting anemia can be worsened when combined with trauma and surgery. To this date, there is no unequivocal approach about transfusion thresholds. We analyzed hemoglobin (Hb) and hematocrit (Hct) levels at three time points in surgical patients with proximal femoral fractures (PFF) to see which levels were triggers for transfusions and whether transfusions were related to mortality after hospital discharge. A total of 956 patients were operated on from 1 January 2021 to 31 December 2022 at the University Hospital of Split and included in the study. There were more women (74%); 47% patients had admission Hb < 120 g/L. Transfusion was given preoperatively to 88, intraoperatively to 74 and postoperatively to 309 patients. Transfusion thresholds were as follows: Hb 84 g/L preoperatively, 99 intraoperatively and 83 postoperatively. After hospital discharge, 10.79% of patients died within the 1st month and 23% within 6 months. In the group of non-survivors, 60% of patients had admission Hb ≤ 117 g/L and the proportion of patients transfused preoperatively was two times higher. Preoperative transfusion thresholds could be set to higher levels for patients with surgically treated PFF. However, that could increase mortality even more. Further investigation is necessary.

Melanoma is the most severe type of skin cancer and among the most malignant neoplasms in humans. With the growing incidence of melanoma, increased numbers of therapeutic options, and the potential to target specific proteins, understanding the basic mechanisms underlying the disease’s progression and resistance to treatment has never been more important. LOXL3, SNAI1, and NES are key factors in melanoma genesis, regulating tumor growth, metastasis, and cellular differentiation. In our study, we explored the potential role of LOXL3, SNAI1, and NES in melanoma progression and metastasis among patients with dysplastic nevi, melanoma in situ, and BRAF+ and BRAF− metastatic melanoma, using immunofluorescence and qPCR analysis. Our results reveal a significant increase in LOXL3 expression and the highest NES expression in BRAF+ melanoma compared to BRAF−, dysplastic nevi, and melanoma in situ. As for SNAI1, the highest expression was observed in the metastatic melanoma group, without significant differences among groups. We found co-expression of LOXL3 and SNAI1 in the perinuclear area of all investigated subgroups and NES and SNAI1 co-expression in melanoma cells. These findings suggest a codependence or collaboration between these markers in melanoma EMT, suggesting new potential therapeutic interventions to block the EMT cascade that could significantly affect survival in many melanoma patients.