Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress.

Purpose: Adhesion between calcium oxalate crystals and renal tubular epithelial cells is a vital cause of renal stone formation; however, the drugs that inhibit crystal adhesion and the mechanism of inhibition have yet to be explored. Methods: The cell injury model was constructed using nano-COM crystals, and changes in oxidative stress levels, endoplasmic reticulum (ER) stress levels, downstream p38 MAPK protein expression, apoptosis, adhesion protein osteopontin expression, and cell-crystal adhesion were examined in the presence of Laminarin polysaccharide (DLP) and sulfated DLP (SDLP) under protected and unprotected conditions. Results: Both DLP and SDLP inhibited nano-COM damage to human kidney proximal tubular epithelial cell (HK-2), increased cell viability, decreased ROS levels, reduced the opening of mitochondrial membrane permeability transition pore, markedly reduced ER Ca2+ ion concentration and adhesion molecule OPN expression, down-regulated the expression of ER stress signature proteins including CHOP, Caspase 12, and p38 MAPK, and decreased the apoptosis rate of cells. SDLP has a better protective effect on cells than DLP. Conclusions: SDLP protects HK-2 cells from nano-COM crystal-induced apoptosis by reducing oxidative and ER stress levels and their downstream factors, thereby reducing crystal-cell adhesion interactions and the risks of kidney stone formation.

MicroR-1199-5p targeting SRD5A2 promotes the biological behavior and EMT of hypospadias cells.

Hypospadias, an oft-occurring penis anomaly, ranks among neonatal's foremost birth defects. The SRD5A2 can affect male reproductive system development and is abnormally expressed in its epithelial cells. This study exploration aimed at understanding the role of SRD5A2 in the development of hypospadias from a molecular perspective. SRD5A2 levels in hypospadias primary cells were analyzed by Western blot, while targeted interaction with miR-1199-5p was ascertained by dual-luciferase gene reporter assay. In vitro biological experiments were used to confirm the biological function of SRD5A2 in hypospadias. SRD5A2 expression was significantly upregulated, and miR-1199-5p expression was significantly downregulated in hypospadias primary cells. Intervention of SRD5A2 expression can affect cell proliferation, migration, invasion, EMT, and the expression of cell cycle-related proteins. Additionally, we found that SRD5A2 is regulated by upstream miR-1199-5p and can enhance the effect of SRD5A2 on hypospadias cells. Conclusions Silencing SRD5A2 promotes cell proliferation, invasion, and migration blocks the cell cycle at the G1 phase, and simultaneously promotes EMT, cell cycle, and cell proliferation-related protein expression. The biological function of SRD5A2 in hypospadias cells is regulated by miR-1199-5p. SRD5A2 may be an effective therapeutic target for hypospadias.

Carboxymethylated Desmodium styracifolium polysaccharide reduces the risk of calcium oxalate kidney stone formation by inhibiting crystal adhesion and promoting crystal endocytosis.

The inhibition of cell surface crystal adhesion and an appropriate increase in crystal endocytosis contribute to the inhibition of kidney stone formation. In this study, we investigated the effects of different degrees of carboxymethylation on these processes. An injury model was established by treating human renal proximal tubular epithelial (HK-2) cells with 98.3 ± 8.1 nm calcium oxalate dihydrate (nanoCOD) crystals. The HK-2 cells were protected with carboxy (-COOH) Desmodium styracifolium polysaccharides at 1.17% (DSP0), 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3). Changes in biochemical indexes and effects on nanoCOD adhesion and endocytosis were detected. The protection of HK-2 cells from nanoCOD-induced oxidative damage by carboxymethylated Desmodium styracifolium polysaccharides (CDSPs) is closely related to the protection of subcellular organelles, such as mitochondria. CDSPs can reduce crystal adhesion on the cell surface and maintain appropriate crystal endocytosis, thereby reducing the risk of kidney stone formation. CDSP2 with moderate -COOH content showed the strongest protective activity among the CDSPs.

Carboxymethylated Rhizoma alismatis polysaccharides reduces the risk of calcium oxalate stone formation by reducing cellular inflammation and oxidative stress.

This study aims to elucidate the mechanism and potential of Rhizoma alismatis polysaccharides (RAPs) in preventing oxidative damage to human renal proximal tubule epithelial cells. The experimental approach involved incubating HK-2 cells with 100 nm calcium oxalate monohydrate for 24 h to establish a cellular injury model. Protection was provided by RAPs with varying carboxyl group contents: 3.57%, 7.79%, 10.84%, and 15.33%. The safeguarding effect of RAPs was evaluated by analyzing relevant cellular biochemical indicators. Findings demonstrate that RAPs exhibit notable antioxidative properties. They effectively diminish the release of reactive oxygen species, lactate dehydrogenase, and malondialdehyde, a lipid oxidation byproduct. Moreover, RAPs enhance superoxide dismutase activity and mitochondrial membrane potential while attenuating the permeability of the mitochondrial permeability transition pore. Additionally, RAPs significantly reduce levels of inflammatory factors, including NLRP3, TNF-α, IL-6, and NO. This reduction corresponds to the inhibition of overproduced pro-inflammatory mediator nitric oxide and the caspase 3 enzyme, leading to a reduction in cellular apoptosis. RAPs also display the ability to suppress the expression of the HK-2 cell surface adhesion molecule CD44. The observed results collectively underscore the substantial anti-inflammatory and anti-apoptotic potential of all four RAPs. Moreover, their capacity to modulate the expression of cell surface adhesion molecules highlights their potential in inhibiting the formation of kidney stones. Notably, RAP3, boasting the highest carboxyl group content, emerges as the most potent agent in this regard.

Clinical characteristics and surgical treatment of children with 45, X/46, XY differences of sex development.

OBJECTIVE: This study retrospectively analyzes the clinical data of 18 children with 45,X/46,XY differences of sex development (DSD), summarizes their clinical features and explores gonadal and Müllerian duct remnants surgical treatment methods. METHODS: The clinical data of 18 children with karyotype 45,X/46,XY diagnosed in the Department of Urology of Hunan Children's Hospital from March 2011 to October 2021 were collected. All children underwent HCG stimulation testing, laparoscopic exploration, urethroscopy and bilateral gonadal biopsy. After DSD multidisciplinary team (MDT) meeting, some children underwent gonadectomy and genitalia reconstructive surgeries. RESULTS: The median age at first diagnosis was 1 year and 4 months (range: 10 months ∼ 16 years and 3 months). 5 children presented with female gender; they all maintained their gender assignment. The external masculinisation score (EMS) of patients raised as female was 1 (0∼3) [median (range)]. 13 children presented with male gender, 10 maintained a male gender, 3 were assigned a neutral gender. The EMS of the children raised as male was 5 (2-8) [median (range)], the EMS of the children raised as neutral gender was 4 (3.5-9.5) [median (range)]. The HCG stimulation test was positive in 11 cases, partially positive in 2 case, and negative in 5 cases. There was no relationship between the percentage of chimerism (45X ratio) and the appearance and severity of genital abnormalities. (t=-1.08, P=0.298). There was 1 case of complete gonadal dysgenesis (CGD), 10 cases of mixed gonadal dysgenesis (MGD), 5 cases of partial gonadal dysgenesis (PGD), 1 case of bilateral normal testes and 1 case of ovotesticular DSD (split-lateral type). No gonadal specimen showed germ cell tumor changes. Five cases selected to maintain the female gender, among which 3 cases underwent bilateral gonadectomy and genitalia reconstructive surgeries. Among the 10 children who chose to maintain the male gender, unilateral streak gonadectomy was performed in 4 (57.1%) with MGD, unilateral dysgenetic orchiectomy in 1 (25%) with PGD, and right ovariectomy in 1 with OTDSD. Nine of them underwent genitalia reconstructive surgeries. Four of them preserved their uterus and vagina did not have any complications during the follow-up period. CONCLUSION: Hypospadias combined with cryptorchidism and residual Müllerian duct structures is the most common phenotype of children with 45, X/46, XY DSD. Mixed gonadal dysgenesis (MGD) is the most common gonadal type. Gender assignment should be carefully selected after a thorough evaluation, while genitalia reconstructive surgery can be considered in selected patients. In children who choose the male gender, the Müllerian duct can be preserved.

Clinical Application of Ureteroscope-Assisted Laparoscopic Surgery for Prostatic Utricle in Children.

Purpose: To investigate the use of ureteroscope-assisted laparoscopic surgery (UALS) in treating symptomatic prostatic utricle (PU) in children. Materials and Methods: Data on surgically treated cases of PU at the Department of Urology in Hunan Children's Hospital between September 2014 and September 2022 were retrospectively collected and analyzed. The diagnosis was confirmed by cystourethroscopy followed by ureteroscopy, and PU was excised by ureteroscope-assisted laparoscopy. Results: A total of 21 patients with PU were enrolled in this study. The median age of the patients at surgery was 8.1 (4.6-11.5) years. Karyotyping was available for 15 children: 13 (86.7%) were 46XY, 1 (6.7%) was 45X/46XY, and 1 (6.7%) was 45X/46XY/47XYY. The median length of the PU was 5.0 (4.1-7.1) cm. Nineteen patients underwent only ureteroscope-assisted laparoscopic excision, whereas 2 also had a perineal incision. All excisions were successfully performed. The median intraoperative blood loss was 25.0 (20.0-37.5) mL. The median hospital stay and follow-up durations were 18.0 (14.5-25.0) days and 24.0 (13.5-49.0) months, respectively. The patients reported no postoperative clinical symptoms. Conclusion: UALS allows for accurate patient positioning and thorough exposure of the anatomical structures, and it is a safe, effective, and minimally invasive treatment for PU in children.

Risk-Factor Analysis and Prediction-Model Construction of Urethral Stricture after Hypospadias Surgery in Children: A Single-Centre Retrospective Study.

OBJECTIVE: This study aimed to explore the incidence of postoperative urethral stricture in children after hypospadias surgery, analyse its risk factors, and construct a prediction model. METHODS: We retrospectively analysed the clinical data of 402 children with hypospadias surgery in Hunan Children's Hospital from January 2022 to January 2023. To explore the risk factors of urethral stricture after hypospadias surgery in children, the incidence of postoperative urethral stricture in children was statistically analysed, and univariate and multivariate logistic regression analyses were adopted. A prediction model was established, and the prediction efficiency of the model was examined using a receiver operating characteristic curve. RESULTS: The incidence of postoperative urethral stricture in children after hypospadias surgery was 9.20% (37/402). On this basis, the children were divided into stricture group (SG, n = 37) and normal group (NG, n = 365). Both groups had overt differences in disease classification, urinary tract infection, indwelling-catheter time, and surgical methods (p < 0.05). Logistic regression analysis showed that urinary tract infection, surgical methods, and long indwelling-catheter time were the risk factors (p < 0.001). The prediction model constructed based on the above results had certain prediction efficiency. CONCLUSIONS: More attention should be paid to children with urinary tract infection, high-risk surgery, and long indwelling-catheter time after hypospadias surgery. Our prediction model can serve as an effective reference for evaluating the occurrence of postoperative urethral stricture.

Risk-Factor Analysis and Prediction-Model Constructionof Urethral Stricture after Hypospadias Surgery inChildren: A Single-Centre Retrospective Study

Objective: This study aimed to explore the incidence of postoperative urethral stricture in children after hypospadias surgery, analyse its risk factors, and construct a prediction model. Methods: We retrospectively analysed the clinical data of 402 children with hypospadias surgery in Hunan Children’s Hospital from January 2022 to January 2023. To explore the risk factors of urethral stricture after hypospadias surgery in children, the incidence of postoperative urethral stricture in children was statistically analysed, and univariate and multivariate logistic regression analyses were adopted. A prediction model was established, and the prediction efficiency of the model was examined using a receiver operating characteristic curve. Results: The incidence of postoperative urethral stricture in children after hypospadias surgery was 9.20% (37/402). On this basis, the children were divided into stricture group (SG, n = 37) and normal group (NG, n = 365). Both groups had overt differences in disease classification, urinary tract infection, indwelling-catheter time, and surgical methods (p < 0.05). Logistic regression analysis showed that urinary tract infection, surgical methods, and long indwelling-catheter time were the risk factors (p < 0.001). The prediction model constructed based on the above results had certain prediction efficiency. Conclusions: More attention should be paid to children with urinary tract infection, high-risk surgery, and long indwelling-catheter time after hypospadias surgery. Our prediction model can serve as an effective reference for evaluating the occurrence of postoperative urethral stricture (AU)

Risk factors for postoperative complications following one-stage proximal hypospadias repair involving the disconnection of the urethral plate: a retrospective study.

BACKGROUND: Children with hypospadias are at risk of serious physical and mental health problems, including abnormal urination, sexual dysfunction, and infertility. The sole available treatment is the surgical restoration of genital appearance and function. Proximal hypospadias (PH) correction is more challenging and carries a higher risk of complications than does distal hypospadias correction, with a higher likelihood of postoperative complications requiring additional surgery, resulting in considerable economic and psychological strain for families. Herein, we aimed to identify factors associated with complications following one-stage PH repair with urethral plate disconnection. METHODS: We retrospectively analyzed data from 236 children who underwent PH repair at our center between December 2020 and December 2022. We collected information on age, surgical procedure, length of the reconstructed urethra (LRU), glans width (GW), ventral curvature, surgical approach, preoperative androgen use, suture type, presence of prostatic utricle, body mass index, season of surgery, anesthesia type, low birth weight, preterm birth, follow-up period, and complications. Surgical complications included urethral fistulas, urethral diverticula, anastomotic strictures, urethral strictures, glans dehiscence, and penile curvature recurrences. The study population was divided into complication and no-complication groups, and univariate and multivariate analyses were conducted. RESULTS: Of the 236 patients with PH who had a median follow-up of 10.0 (8.0, 14.0) months, 79 were included (33.5%) in the complication group and 157 were included (66.5%) in the no-complication group. In the univariate analysis, age (P < 0.001), LRU (P < 0.001), degree of penile curvature (P = 0.049), and PH with prostatic utricle (P = 0.014) were significantly associated with complications after PH repair. In the multivariate logistic regression analysis, LRU (P<0.001, odds ratio [OR] = 3.396, 95% confidence interval [CI]: 2.229-5.174) and GW (P = 0.004, OR = 0.755, 95%CI: 0.625-0.912) were independent factors influencing postoperative complications. The optimal LRU threshold was 4.45 cm (area under the curve, 0.833; sensitivity, 0.873; specificity, 0.873; P<0.001, OR = 3.396, 95% CI: 2.229-5.174). CONCLUSIONS: LRU and GW are independent factors affecting PH complications. An LRU of < 4.45 cm and an increased GW can reduce the risk of complications.

Use of whole-exome sequencing to identify novel monogenic gene mutations and genotype-phenotype correlations in Chinese Han children with urolithiasis.

The incidence of urolithiasis (UL) in children has been increasing. Although the pathogenesis of pediatric UL is controversial and remains unclear, multiple monogenic causes of UL have been identified. We aim to investigate the prevalence of inherited UL causes and explore the genotype-phenotype correlation in a Chinese pediatric group. In this study, we analyzed the DNA of 82 pediatric UL patients using exome sequencing (ES). The data of metabolic evaluation and genomic sequencing were subsequently analyzed together. We detected 54 genetic mutations in 12 of 30 UL-related genes. A total of 15 detected variants were described as pathogenic mutations, and 12 mutations were considered likely pathogenic. Molecular diagnoses were made in 21 patients with pathogenic or likely pathogenic variants. Six novel mutations that were not previously reported were identified in this cohort. Calcium oxalate stones were detected in 88.9% cases (8/9) with hyperoxaluria-related mutations, while 80% of individuals (4/5) with cystinuria-causing defects were diagnosed with cystine stones. Our study highlights the significant genetic abnormalities in pediatric UL and demonstrates the diagnostic power of ES for screening patients with UL.

Immunoglobulin a vasculitis with testicular/epididymal involvement in children: A retrospective study of a ten-year period.

The clinical characteristics and risk factors for testicular/epididymal involvement in 73 children with immunoglobulin A vasculitis (IgAV) who were admitted to our hospital between January 2012 and November 2022 were reviewed. The demographic data, laboratory parameters, and follow-up data of the patients were compared to those of 146 males without testicular/epididymal involvement. A logistic regression analysis was performed to determine the variables associated with testicular/epididymal involvement. The prevalence of testicular/epididymal involvement among male patients with IgAV was 1.3% (73/5,556). Increased blood flow in the testes and/or epididymis on ultrasound was found in 71 patients. The remaining two patients underwent surgical exploration for loss or reduction of testicular blood flow. One patient underwent orchiectomy for intraoperative confirmation of complete right testicular infarction. Pathological findings revealed IgA immune complex deposition in the testis. Patient age (odds ratio [OR] = 0.792; 95% confidence interval [CI]: 0.682-0.919, p = 0.002), platelet count (OR = 1.011; 95% CI: 1.002-1.020, p = 0.013), and immunoglobulin M (IgM) levels (OR = 0.236; 95% CI: 0.091-0.608, p = 0.003) were strongly associated with the occurrence of testicular/epididymal involvement in IgAV. Therefore, young age, increased platelet count, and low IgM levels in patients with IgAV are potential risk factors for testicular/epididymal involvement. Doppler ultrasound can help differentiate IgAV from acute scrotum. Most patients with testicular/epididymal involvement have good prognoses, although serious complications such as testicular infarction may occur.

Development and validation of a prognostic model based on a single-cell RNA-seq in Wilms tumor in children.

To analyze the heterogeneity between different cell types in pediatric Wilms tumor (WT) tissue, and identify the differentially expressed genes (DEGs) of malignant tumor cells, thereby establishing a prognostic model. The single-cell sequencing data of pediatric WT tissues were downloaded from the public database. Data filtration and normalization, principal component analysis, and T-distributed stochastic neighbor embedding cluster analysis were performed using the Seurat package of R language. Cells were divided into different clusters, malignant tumor cells were extracted, and DEGs were obtained. Then, the pseudo-time trajectory analysis was performed. Prognostic biomarkers were determined by univariate and multivariate COX regression analyses and LASSO regression analysis. Kaplan-Meier survival analysis and receiver operator characteristic curve analysis were performed. Combined with the prognostic biomarkers and clinical characteristics, a nomogram was generated to predict WT prognosis. The prognostic power was validated in the external datasets. Cells in the WT tissue were divided into 10 clusters. Three prognostic biomarkers that affected the survival time of patients were screened from 215 DEGs in malignant tumor cells, and a nomogram was constructed using the three genes and clinical characteristics. The area under the curve (AUC) values of 3- and 5-year disease-free survival were 0.756 and 0.734, respectively. In the external validation dataset, the AUC value of this nomogram model was 0.826. Based on the single-cell RNA-seq, we recognized cell clusters in the WT tissue of children, identified prognostic biomarkers in malignant tumor cells, and established a comprehensive prognostic model. Our findings might provide new ideas and methods for the diagnosis and treatment of WT.

Testicular regression syndrome: A retrospective analysis of clinical and histopathological features in 570 cases.

This study aimed to analyze the clinical features and pathological findings of the largest reported case series of testicular regression syndrome (TRS). Data, including age, affected side, color Doppler ultrasound results, surgical methods, intraoperative conditions, and pathological examinations, of children with unilateral TRS who were treated in our center from December 2012 to November 2021 were retrospectively analyzed. A total of 570 patients were included in this study. The mean age at surgery was 38 (range, 5-193) months. There were 457 cases (80.2%) of left TRS. Preoperative color Doppler ultrasonography found nubbins in 172 cases (30.2%). The long diameter of the contralateral testis was 17.11 (±4.22) mm, and the volume was 0.81 (±1.15) ml. The long diameter was ≥1.6 cm in 62.0% of the patients (240/387) aged ≤3 years. Laparoscopy was performed as the initial surgical step in 513 cases, of which 96.7% of the children had closed internal rings. One or more lesions of fibrosis, hemosiderin, and calcification were found in 92.4% (474/513) of the excised remnants. Germ cells were present in 16 cases (3.1%). In conclusion, TRS is more common on the left side and is usually accompanied by a closed internal ring and compensatory hypertrophy of the contralateral testis. Germ cells are only present in cases where the spermatic vessels enters the internal ring. We recommend that further exploration and excision of the remnants may not be applicable in cases where only the vas deferens has entered the internal ring.

Clinical Efficacy of Laparoscopic Orchiopexy With the Modified Prentiss Maneuver for Non-palpable Testis Near the Internal Ring.

Objective: To compare the clinical efficacy and safety of laparoscopic orchiopexy with the modified Prentiss maneuver (LOMPM) and laparoscopic trans-inguinal orchiopexy (LTIO) for the treatment of non-palpable testis (NPT) <1 cm from the internal ring. Methods: Children with unilateral NPT who underwent laparoscopic orchiopexy at our center between February 2018 and January 2021 were retrospectively analyzed. According to the surgical method, they were divided into LOMPM and LTIO groups. The operation time, postoperative pain degree, postoperative complications and follow-up results were compared between the two groups. Results: A total of 98 patients were included in this study, including 41 cases in the LOMPM group and 57 cases in the LTIO group. All patients underwent successful surgery. The LOMPM group was superior to the LTIO group in terms of postoperative testicular position (lower scrotm: 90.2 vs. 71.9%, P = 0.026). There were no significant differences in operation time, postoperative pain score, and complications between the two groups. Preoperative testicular volume, postoperative testicular volume, and testicular growth rate in the LOMPM group were comparable to those in the LTIO group. There were no testicular atrophy, inguinal hernia and hydrocele in both groups after operation. Conclusions: LOMPM was comparable in safety to LTIO, but LOMPM had a good post-operative testicular position, and was suitable for the treatment of NPT near the internal ring.

Clinical Analysis of Pyocele of Tunica Vaginalis in 56 Newborns.

OBJECTIVE: This study aimed to explore the clinical characteristics, treatment methods, and prognosis of neonatal pyocele of tunica vaginalis and to provide a reference for the clinical treatment. METHODS: A total of 56 newborns with pyocele of tunica vaginalis were admitted to our hospital due to the scrotal emergency from January 2015 to January 2020. Our study retrospectively analyzed these 56 cases. Of the 56 cases, including 32 full-term infants and 24 premature infants, age ranged from 1 to 27 days. Initially, conservative treatment (intravenous antibiotic treatment) was applied to 42 cases, and surgery to 14 cases. Then, 7 underwent surgical exploration during the conservative treatment, and 2 cases with initial surgical treatment experienced orchiectomy because of complete necrosis. For 56 cases, the average follow-up time was 18 months. RESULTS: The clinical recovery time of cases with conservative treatment ranged from 8 to 17 days, with an average of 11.02 ± 2.31 days. The clinical recovery time of cases with surgery ranged from 6 to 15 days, with an average of 9.28 ± 2.78 days. During the follow-up, for 56 cases, except for the 2 cases with orchiectomy, the testicular position and Doppler flow both went back to normal, of the 42 cases with initial conservative treatment, 1 case experienced testicular retardation, of the 14 cases with initial surgical treatment, 2 cases experienced testicular retardation, and hydrocele of 42 cases were self-healed. CONCLUSIONS: Neonatal pyocele of tunica vaginalis is mostly secondary to intra-abdominal infection. Color Doppler ultrasound is helpful for the diagnosis. The percutaneous aspiration is a way of collecting pathogenic bacteria during the conservative treatment. If the color Doppler suggests testicular involvement, surgical exploration should be performed.

Inhibition of Calcium Oxalate Formation and Antioxidant Activity of Carboxymethylated Poria cocos Polysaccharides.

Three carboxymethylated Poria cocos polysaccharides (PCP-C1, PCP-C2, and PCP-C3) with -COOH contents of 6.13%, 10.24%, and 16.22%, respectively, were obtained by carboxymethylation of the original polysaccharide (PCP-C0), which has a molecular weight of 4 kDa and a carboxyl (-COOH) content of 2.54%. The structure of the PCP-Cs was characterized by FT-IR, 1H NMR, and 13C NMR spectra. The four PCP-Cs exhibited antioxidant activity, and their ability to scavenge radicals (hydroxyl and DPPH) and chelate ferrous ions was positively correlated with the degree of carboxymethylation. As the content of -COOH groups in the PCP-Cs increases, their ability to regulate the growth of calcium oxalate (CaOx) crystals was enhanced, thus inhibiting the growth of calcium oxalate monohydrate (COM) crystals and inducing the formation of more calcium oxalate dihydrate (COD) crystals. The formed CaOx crystal was more round and blunt, the absolute value of the Zeta potential on the crystal surface increased, and the aggregation between crystals was inhibited. Thermogravimetric analysis curves showed that the proportions of PCP-C0, PCP-C1, PCP-C2, and PCP-C3 incorporated into the crystal were 20.52%, 15.60%, 10.65%, and 9.78%, respectively, in the presence of 0.4 g/L PCP-Cs. PCP-C protection resisted oxidative damages of human kidney proximal tubular epithelial cells (HK-2) caused by oxalate, resulting in increased cell viability and superoxide dismutase activity and decreased reactive oxygen species levels, malondialdehyde content, and 8-hydroxy-deoxyguanosine expression. Hence, PCP-Cs, especially PCP-C3, can inhibit the formation of CaOx crystals and may have the potential to be an alternative antistone drug.

Protective Effect of Degraded Porphyra yezoensis Polysaccharides on the Oxidative Damage of Renal Epithelial Cells and on the Adhesion and Endocytosis of Nanocalcium Oxalate Crystals.

The protective effects of Porphyra yezoensis polysaccharides (PYPs) with molecular weights of 576.2 (PYP1), 105.4 (PYP2), 22.47 (PYP3), and 3.89 kDa (PYP4) on the oxidative damage of human kidney proximal tubular epithelial (HK-2) cells and the differences in adherence and endocytosis of HK-2 cells to calcium oxalate monohydrate crystals before and after protection were investigated. Results showed that PYPs can effectively reduce the oxidative damage of oxalic acid to HK-2 cells. Under the preprotection of PYPs, cell viability increased, cell morphology improved, reactive oxygen species levels decreased, mitochondrial membrane potential increased, S phase cell arrest was inhibited, the cell apoptosis rate decreased, phosphatidylserine exposure reduced, the number of crystals adhered to the cell surface reduced, but the ability of cells to endocytose crystals enhanced. The lower the molecular weight, the better the protective effect of PYP. The results in this article indicated that PYPs can reduce the risk of kidney stone formation by protecting renal epithelial cells from oxidative damage and reducing calcium oxalate crystal adhesion, and PYP4 with the lowest molecular weight may be a potential drug for preventing kidney stone formation.

Preprotection of Tea Polysaccharides with Different Molecular Weights Can Reduce the Adhesion between Renal Epithelial Cells and Nano-Calcium Oxalate Crystals.

Crystal adhesion is an important link in the formation of kidney stones. This study investigated and compared the adhesion differences between nano-calcium oxalate monohydrate (COM) and human renal proximal tubule epithelial (HK-2) cells before and after treatment with tea polysaccharides (TPSs) TPS0, TPS1, TPS2, and TPS3 with molecular weights of 10.88, 8.16, 4.82, and 2.31 kDa, respectively. TPS treatment effectively reduced the damage of COM to HK-2 cells, thereby resulting in increased cell activity, decreased release of lactate dehydrogenase, cell morphology recovery, decreased level of reactive oxygen species, increased mitochondrial membrane potential, increased lysosomal integrity, decreased expression of adhesion molecule osteopontin and eversion of phosphatidylserine, and decreased crystal adhesion. Among the TPSs, TPS2 with moderate molecular weight had the best protective effect on cells and the strongest effect on the inhibition of crystal adhesion. Thus, TPS2 may be a potential anticalculus drug.

Repair of Tea Polysaccharide Promotes the Endocytosis of Nanocalcium Oxalate Monohydrate by Damaged HK-2 Cells.

Endocytosis is a protective mechanism of renal epithelial cells to eliminate retained crystals. This research investigated the endocytosis of 100 nm calcium oxalate monohydrate crystals in human kidney proximal tubular epithelial (HK-2) cells before and after repair by four kinds of tea polysaccharides with molecular weights (MWs) of 10.88 (TPS0), 8.16 (TPS1), 4.82 (TPS2), and 2.31 kDa (TPS3), respectively. When HK-2 cells were repaired by TPSs after oxalic acid injury, the cell viability, wound healing ability, mitochondrial membrane potential, percentage of cells with endocytosed crystals, and dissolution rate of the endocytosed crystals increased; the cell morphology recovered; and the reactive oxygen level and lactate dehydrogenase release decreased. Most of the endocytosed crystals were found in the lysosomes. The repair effects of the four TPSs were ranked in the following order: TPS2>TPS1>TPS3>TPS0. TPS2 with moderate MW presented the optimal repair ability and strongest ability to promote endocytosis.

Genetic and Clinical Analyses of 13 Chinese Families With Cystine Urolithiasis and Identification of 15 Novel Pathogenic Variants in SLC3A1 and SLC7A9.

BACKGROUND: Cystinuria is a rare genetic disorder characterized by defective renal reabsorption of cystine, ornithine, arginine, and lysine. The increased urinary excretion of cystine results in the development of cystine urolithiasis (CU). The mutated SLC3A1 and SLC7A9 genes are the cause of CU, a global disorder. Its frequency and mutation spectrum vary between different populations. In Asia, the data for CU are limited. METHOD: Urinary stones were collected from patients of a single center over a five-year period and analyzed via Fourier transform infrared spectroscopy. Genomic DNA was isolated from 13 patients with CU and their parents and from 26 controls affected by calcium oxalate dihydrate stones. The coding regions and the exon-intron boundaries of SLC3A1 and SLC7A9 were subjected to PCR amplification and then sequenced via traditional Sanger sequencing. Genetic variants were functionally annotated using the InterVar, ClinVar, gnom AD, and HGMD databases. RESULTS: From the 232 samples of urinary stones, we identified 13 patients with CU (10 males and 3 females). The onset age was from 7 months to 9 years. The CU stones varied from 0.26 cm3 to 18.67 cm3. Sanger sequencing detected a total of 14 SLC3A1 (nine were novel) and 10 SLC7A9 (six were novel) rare variants from the 13 CU families. All variants, including 15 novel variants, were pathogenic, disease-causing, or damaging. CONCLUSION: All 13 pediatric CU families harbored SLC3A1 or/and SLC7A9 rare variants. A total of 15 novel pathogenic variants in SLC3A1 and SLC7A9 were identified. This study expanded the known mutational spectrum of CU in the Chinese population.