The Sequestered Actin Was Bound to Non-actin Protein(s) in the ATP-depleted Rabbit Proximal Tubules

Objective: To demonstrate whether the actin breakdown fromactin-cytoskele-ton in microvilli was bound to any non-actin protein ( s ) in 'ATP-depleted rabbitproximal tubules (PT). Methods: By using DTSSP to crosslink actin and non-actin protein (s) ininsoluble fraction of ATP-depleted PT, the crosslinked protein complexes were analysed bytwo-dimensional electrophoresis and western blotting. Results: Analysis of the crosslinked actincomplexes revealed one complex that contained actin and non-actin protein. Villin was not detected.Conclusion: The results strongly suggested that some of the sequestered actin was directly bound tonon-actin protein (s) other than was co-precipitated with villin or the nuclei as hydrophobic actinhomopolymers.

Tamoxifen induced multinucleated cells (symplasts) and distortion of seminiferous tubules in rat testis

Aim: To evaluate the effect of tamoxifen citrate on male reproductive system of rat. Methods: Groups of male rats were gavaged with tamoxifen at doses of 200 mg·kg-1·d-1, 400 mg·kg-1·d-1 or 800 mg·kg-1·d-1 in 0.1 mL olive oil for 10 consecutive days. Controls were treated with 0.1 mL olive oil. Rats were anesthetized and killed on d 3, d 15 or d 35 after the last dose. Testes were collected, processed for paraffin embedding, sectioned at 5 μm thickness, stained with H&E and analyzed microscopically. Results: There was a dose-dependent increase in the occurrence of seminiferous tubular distortion with germinal cell sloughing. The highest dose increased the number of multinucleated giant cells on d 3 and d 15. Conclusion: Tamoxifen citrate induces multinucleated giant cells and germinal epithelial sloughing in a dose-dependent manner and these changes are detrimental to male fertility.

EFFECT OF DENTIN TUBULES TO THE MECHANICAL PROPERTIES OF DENTIN.PART Ⅱ:EXPERIMENTAL STUDY

To verify the theoretical models of varying transversely isotropic stress-strain relations of dentin established in the preceding work(Part Ⅰ),we per- form a set of experiments.Because of the very fine tooth size,it usually seems to be difficult to directly measure the inhomogeneous and anisotropic parameters of dentin.In this paper,by the digital speckle correlation method,tensile experiments are made on the small dentin samples either parallel or perpendicular to the dentin tubules.With the theoretically predicted elastic stress-strain relations,an optimiza- tion method is proposed to fit the strain curve adapted to the experimental data. The results show that the theoretical elastic stress-strain relations coincides very well with the experimental observations.The determined Young's modulus and Poisson's ratio of dentin matrix are 29.5GPa and 0.44,respectively,in the optimization sense.

EFFECT OF DENTIN TUBULES ON THE MECHANICAL PROPERTIES OF DENTIN. PART Ⅰ: STRESS-STRAIN RELATIONS AND STRENGTH CRITERION

As known, there is a large number of dentin tubules in dentin. These tubules have varying radii and are shaped into radially parallel pattern. The anisotropy of microstructure of dentin shows that dentin should be treated as a ma- terial of varying transverse isotropy. In this Part, the elastic stress-strain relations and the quadratic strength criterion are established in the form of having varying transverse isotropy, in the framework of micromechanics to take into account of the effect of the microstructures-dentin tubules. Simplified forms for isotropic and ho- mogeneous cases, as well as the corresponding plane stress form of the stress-strain relations are also given. These theoretical models are very well supported by the experiments shown later in the continued paper (Part Ⅱ).

Predictors of kidney tubular dysfunction induced by adefovir treatment for chronic hepatitis B

AIM:To investigate the predictors of proximal kidney tubular dysfunction(PKTD)induced by adefovir dipivoxil(ADV)treatment for chronic hepatitis B.METHODS:Seventy-nine patients(age at the evaluation of PKTD:56.9±10.7 years)with chronic hepatitis B undergoing long-term oral antiviral nucleos(t)ide analogue treatment were consecutively recruited.PKTD was defined by the presence of at least two of the following five abnormalities:phosphate diabetes,nondiabetic glucosuria,metabolic acidosis,β2-microglobulinuria,or renal hypouricemia.The single-nucleotide polymorphisms(SNPs)in the SLC22A6 gene encoding human organic anion transporter 1(h OAT1)and ABCC2 encoding multidrug resistance protein 2(MRP2)were analyzed using the Taq Man Allelic Discrimination Demonstration Kit.RESULTS:Nine(30.0%)of the 30 ADV-treated patients were diagnosed with PKTD,while no patients without ADV developed PKTD(P<0.001).Three patients with ADV were diagnosed with symptomatic osteomalacia.Among the patients who took ADV,those with PKTD were of higher age at initiation,had significantly longer treatment duration,and had a significantly lower body mass index than those without PKTD.The incidence of PKTD dramatically increased after 96 mo from the start of ADV administration.In contrast,the SNPs were not correlated with PKTD.Logistic regression analysis extracted older age at initiation(OR=5.0,95%CI:1.1-23.4;P=0.040)and longer treatment duration(OR=3.2,95%CI:1.2-8.6;P=0.020)as significant factors associated with PKTD.CONCLUSION:Our results suggest that the tubular function of the kidney of older patients undergoing longterm ADV treatment should be carefully evaluated.

Actin phosphorylation correlates with actin sequestration in ATP-depleted rabbit renal proximal tubules

Objective: To demonstrate the relation sh ip between actin phosphorylation and actin sequestration in ATP-depleted rabbi t renal proximal tubules. Methods: Using two-dimensional electr ophoreses and Western blotting to analyze the phosphorylation state of the seque stered actin in rabbit renal proximal tubules. Results: The anal ytical result of the sequestered actin indicated that nearly half of the actin w as phosphorylated on serine residue(s). Conclusion: Result sugge sted a close correlation between actin sequestration and actin phosphorylation i n ATP-depleted rabbit renal proximal tubules.

Effect of Different Irradiation Times on the Occlusion of Dentinal Tubules When Using a Nd:YAG Laser: An <i>in Vitro</i>SEM Study

Objective: To evaluate the effect of different irradiation times on the occlusion of dentinal tubules when using Nd:YAG laser. Background data: Dentin hypersensitivity is a frequent problem that has limited treatment success despite many chemical and physical therapies. Methods: Four coronal dentin disks 2 mm thick were cut with a low-speed diamond saw from four freshly extracted intact first molars. The coronal dentin surface of each disk was divided into four regions, each approximately 2 mm × 3 mm. The dentin surfaces were treated with 27% EDTA then the four regions irradiated separately in a randomized pattern with a Nd:YAG laser (120 mJ, 5 Hz), using irradiation times of 0 s, 20 s, 40 s and 60 s, representing laser energies of 0 J/cm2, 200 J/cm2, 400 J/cm2 and 600 J/cm2, respectively. SEM photomicro-graphs were taken at 1500× and 3000× to calculate the dentinal tubule orifice occlusion rates and to measure the tubule diameters, respectively. Results: For the laser irradiation times of 0 s, 20 s, 40 s and 60 s, the corresponding dentinal tubule occlusion rates were 2.05 (SD 0.29)%, 10.01 (1.71)%, 23.58 (2.51)% and 90.23 (2.24)%, respectively;and the tubule diameters were 4.18 (0.32) μm, 3.46 (0.24) μm, 1.69 (0.32) μm and 0.12 (0.02) μm, respectively. There were significant differences among all groups for both measured variables (p ≤ 0.005). Conclusions: Within the limitations of this in Vitro study, when using a Nd:YAG laser at 120 mJ and 5 Hz, an irradiation time of 60 s achieved the best sealing of the coronal dentinal tubule orifices.

MORPHOLOGICAL TRANSITION BETWEEN VESICLES AND TUBULES FOR A GLYCOPOLYMER-CONTAINING AMPHIPHILIC DIBLOCK COPOLYMER IN AQUEOUS SOLUTIONS

The morphological transition of molecular assemblies in aqueous solutions for a new amphiphilic diblock copolymer induced by changing the initial solvent conditions was studied by transmission electron microscopy (TEM). The copolymer was polystyrene(77)-b-poly[2-(beta -D-glucopyranosyloxy)ethyl acrylate (6)] (PSt(77)-b-PGEA(6)) and the solvent was a mixture of DMF and THF. PSt(77)-b-PGEA(6) yields vesicles and tubules when it is initially dissolved in THF and DMF respectively. The morphological transition between vesicles and tubules can be achieved by simply varying the amounts of THF and DMF, or changing the temperature at which the aggregates were prepared.

EFFECT OF DENTIN TUBULES ON THE MECHANICAL PROPERTIES OF DENTIN PART Ⅲ: NUMERICAL ANALYSIS

Imitating a real tooth and the periodontal supporting tissues, we have established a 2D finite element model and carried out a numerical analysis based on the inhomogeneous and anisotropic (IA) stress-strain relation and strength model of dentin proposed in the preceding Parts Ⅰ and Ⅱ, and the conventional homogeneous and isotropic (HI) model, respectively. Quite a few cases of loadings for a non-defected and a defected tooth are considered. The numerical results show that the stress level predicted by the IA model is remarkably higher than that by the HI model, revealing that the effect of the dentin tubules should be taken into a serious consideration from the viewpoint of biomechanics.

F-Actin Distribution Changes Provoked by Acetaminophen in the Proximal Tubule in Kidney of Adult Male Rat

Acetaminophen is a drug used to treat many conditions as headache, muscle aches, arthritis, backache, toothache, and fever between others, but collateral effects of this drug are not well known yet. Here is tested its effect on proximal tubule epithelium. Acetaminophen (APAP) at doses of 200, 500, 1000 and 1500 mg/Kg i.p. caused cell damage and changes in F-actin distribution in the proximal tubule of male Wistar rats. After 48 hours of treatment, the proximal tubule epithelium showed tumefaction and necrosis. Dose of 200 mg/kg decreased the F-actin and was observed a structure in patches in the basal cytoplasm of epithelial cells of the proximal tubule. This effect was increased depending on the administered dose. Dose of 1000 mg/kg produced the highest histological damage and changes in the actin cytoskeleton. Results of this study suggested that nephrotoxic damage produced by high doses of APAP included breakdown of cytoskeleton in proximal tubule epithelium.

Application and management of continuous glucose monitoring in diabetic kidney disease

Diabetic kidney disease(DKD)is a common complication of diabetes mellitus that contributes to the risk of end-stage kidney disease(ESKD).Wide glycemic var-iations,such as hypoglycemia and hyperglycemia,are broadly found in diabetic patients with DKD and especially ESKD,as a result of impaired renal metabolism.It is essential to monitor glycemia for effective management of DKD.Hemoglobin A1c(HbA1c)has long been considered as the gold standard for monitoring glycemia for>3 months.However,assessment of HbA1c has some bias as it is susceptible to factors such as anemia and liver or kidney dysfunction.Continuous glucose monitoring(CGM)has provided new insights on glycemic assessment and management.CGM directly measures glucose level in interstitial fluid,reports real-time or retrospective glucose concentration,and provides multiple glycemic metrics.It avoids the pitfalls of HbA1c in some contexts,and may serve as a precise alternative to estimation of mean glucose and glycemic variability.Emerging studies have demonstrated the merits of CGM for precise monitoring,which allows fine-tuning of glycemic management in diabetic patients.Therefore,CGM technology has the potential for better glycemic monitoring in DKD patients.More research is needed to explore its application and management in different stages of DKD,including hemodialysis,peritoneal dialysis and kidney transplantation.

Association of physical activity with risk of chronic kidney disease in China:A population-based cohort study

Background:Information on the association between physical activity(PA)and the risk of chronic kidney disease(CKD)is limited.We aimed to explore the associations of total,domain-specific,and intensity-specific PA with CKD and its subtypes in China.Methods:The study included 475,376 adults from the China Kadoorie Biobank aged 30-79 years during 2004-2008 at baseline.An interviewer-administered questionnaire was used to collect the information about PA,which was quantified as metabolic equivalent of task hours per day(MET-h/day)and categorized into 4 groups based on quartiles.Cox regression was used to analyze the association between PA and CKD risk.Results:During a median follow-up of 12.1 years,5415 incident CKD cases were documented,including 1159 incident diabetic kidney disease(DKD)cases and 362 incident hypertensive nephropathy(HTN)cases.Total PA was inversely associated with CKD risk,with an adjusted hazard ratio(HR,95%confidence interval(95%CI))of 0.83(0.75-0.92)for incident CKD in the highest quartile of total PA as compared with participants in the lowest quartile.Similar results were observed for risk of DKD and HTN,and the corresponding HRs(95%CIs)were 0.75(0.58-0.97)for DKD risk and 0.56(0.37-0.85)for HTN risk.Increased nonoccupational PA,low-intensity PA,and moderate-to-vigorous-intensity PA were significantly associated with a decreased risk of CKD,with HRs(95%CIs)of 0.80(0.73-0.88),0.85(0.77-0.94),and 0.85(0.76-0.95)in the highest quartile,respectively.Conclusion:PA,including nonoccupational PA,low-intensity PA,and moderate-to-vigorous-intensity PA,was inversely associated with the risk of CKD,including DKD,HTN,and other CKD,and such associations were dose dependent.

Collagen type Ⅲ is an important linking molecule between generated renal tubules and an artificial polyester interstitium--Reticulin as a linker between generated tubules and the interstitium

在再生医学领域,已经有很多人考虑在将来用干/祖细胞治疗急慢性肾功能衰竭。但是,要使这种治疗方案行之有效,需要了解关于患病肾脏肾小管发育的细胞生物学信息。与干/祖细胞治疗急慢性肾功能衰竭相关尚待明晰的细胞生物学问题包括:①干/祖细胞的整合。②干/祖细胞的定向分化类型。③新形成肾小管的空间构成。为了更好的了解这项技术的相关机制,文章应用了先进的培养技术在人工非细胞外基质材料界面条件下构建肾小管。将新生兔肾来源的干/祖细胞用多层聚酯纤维网覆盖,放置在灌注培养器中,用含1×10-7mol/L醛固酮的新鲜合成的在DMEM基础上改良的IMDM培养基诱导培养13d。扫描电镜下,在大豆凝集素、银染和抗Ⅲ型胶原或层粘连蛋白γ1单克隆抗体标记的全标本包埋爬片或冰冻切片上观察肾小管的生长情况。扫描电镜观察结果显示,新生成的肾小管完全被基底膜覆盖,纤维网状板有大量的纤维与生成的肾小管基底面和周围人工聚酯材料相互交联。抗Ⅲ型胶原染色和银染结果表明,在新生成的肾小管的基底膜和邻近的人工聚酯材料间有大量的纤维交织,在发育成熟的肾小管中有与新生成肾小管相同排列形式的Ⅲ型胶原纤维。以上实验结果说明,Ⅲ胶原是联系新生成的肾小管基底面和人工基质聚酯纤维的分子纽带。

Meta-analysis of the association between chronic periodontitis and chronic kidney disease

BACKGROUND Many scholars have performed several clinical studies have investigated the association between chronic periodontitis(CP)and chronic kidney disease(CKD).However,there are still differences between these research results,and there is no unified conclusion.Therefore,a systematic review is required to understand this issue fully.AIM To explore the correlation between CP and CKD.METHODS Literature on the correlation between CP and CKD,as well as the clinical attachment level(CAL)and pocket probing depth(PPD)of CKD and non-CKD,were retrieved from PubMed,Embase,the Cochrane Library,and Web of Science repositories until January 2024.After the effective data were extracted,data processing and statistics were performed using Stata 12.0.RESULTS Of the 22 studies,13 were related to CP and CKD,and 9 reported CAL and PPD in patients with CKD and healthy controls.Meta-analysis of the correlation between CP and CKD revealed that CKD probability in people with CP was 1.54 times that of healthy individuals[relative risk=1.54,95%confidence interval(CI):1.40-1.70],and CP incidence in patients with CKD was 1.98 times that of healthy individuals[overall risk(OR)=1.98,95%CI:1.53-2.57].Meta-analysis of CAL and PPD evaluations between CKD patients and healthy individuals showed that CAL and PPD levels were higher in CKD patients[standard mean difference(SMD)of CAL=0.65,95%CI:0.29-1.01;SMD of PPD=0.33,95%CI:0.02-0.63].CONCLUSION A bidirectional association exists between CP and CKD.CKD risk is increased in CP patients and vice versa.Periodontal tissue or tooth loss risks increase over time in CKD patients.

Human pluripotent stem cell-derived kidney organoids:Current progress and challenges

Human pluripotent stem cell(hPSC)-derived kidney organoids share similarities with the fetal kidney.However,the current hPSC-derived kidney organoids have some limitations,including the inability to perform nephrogenesis and lack of a corticomedullary definition,uniform vascular system,and coordinated exit path-way for urinary filtrate.Therefore,further studies are required to produce hPSC-derived kidney organoids that accurately mimic human kidneys to facilitate research on kidney development,regeneration,disease modeling,and drug screening.In this review,we discussed recent advances in the generation of hPSC-derived kidney organoids,how these organoids contribute to the understanding of human kidney development and research in disease modeling.Additionally,the limitations,future research focus,and applications of hPSC-derived kidney organoids were highlighted.

Andrias davidianus bone peptides alleviates hyperuricemia-induced kidney damage in vitro and in vivo

Hyperuricemia(HUA)is a vital risk factor for chronic kidney diseases(CKD)and development of functional foods capable of protecting CKD is of importance.This paper aimed to explore the amelioration effects and mechanism of Andrias davidianus bone peptides(ADBP)on HUA-induced kidney damage.In the present study,we generated the standard ADBP which contained high hydrophobic amino acid and low molecular peptide contents.In vitro results found that ADBP protected uric acid(UA)-induced HK-2 cells from damage by modulating urate transporters and antioxidant defense.In vivo results indicated that ADBP effectively ameliorated renal injury in HUA-induced CKD mice,evidenced by a remarkable decrease in serum UA,creatinine and blood urea nitrogen,improving kidney UA excretion,antioxidant defense and histological kidney deterioration.Metabolomic analysis highlighted 14 metabolites that could be selected as potential biomarkers and attributed to the amelioration effects of ADBP on CKD mice kidney dysfunction.Intriguingly,ADBP restored the gut microbiome homeostasis in CKD mice,especially with respect to the elevated helpful microbial abundance,and the decreased harmful bacterial abundance.This study demonstrated that ADBP displayed great nephroprotective effects,and has great promise as a food or functional food ingredient for the prevention and treatment of HUA-induced CKD.

3D Reconstruction of the medullary tubular-vascular relationship in adult mouse kidneys

A close tubular vascular relationship in renal medulla is not only the structural basis for urine concentration,but is also the sensitive position for acute and chronic kidney injury.Therefore,a comprehensive understanding of spatial architecture in medulla is important for nephrologist.Serial sections were obtained from three mouse kidneys and double immunofluorescent stained for CD34 and for either AQP-1 or AQP-2.Using custom:made softwares,525 tubules and 333 vessels were traced,and ultra-structurally analyzed with EM.From corticomedullary boundary to inner medulla,descending and ascending vasa recta(DVR,AVR)closely accompanied with each and ran in the center of vascular bundle(VB).

ELABELA protects against diabetic kidney disease by activating high glucose-inhibited renal tubular autophagy

ELABELA(ELA),an endogenous ligand of the apelin receptor(also known as apelin peptide jejunum[APJ]),has been shown to decrease in the plasma of patients with diabetic kidney disease(DKD).In the current study,we explored the potential function as well as the underlying mechanisms of ELA in DKD.We first found that the ELA levels were decreased in the kidneys of DKD mice.Then,we found that ELA administration mitigated renal damage and downregulated the expression of fibronectin,collagenⅣ,and transforming growth factor-β1 in the db/db mice and the high glucose cultured HK-2 cells.Furthermore,the autophagy markers,Beclin-1 and LC3-Ⅱ/LC3-Ⅰratio,were significantly impaired in DKD,but the ELA treatment reversed these alterations.Mechanistically,the inhibitory effects of ELA on the secretion of fibrosis-associated proteins in high glucose conditions were blocked by pretreatment with 3-methyladenine(an autophagy inhibitor).In summary,these in vivo and in vitro results demonstrate that ELA effectively protects against DKD by activating high glucose-inhibited renal tubular autophagy,potentially serving as a novel therapeutic candidate for DKD.

Risk factors for cognitive impairment in patients with chronic kidney disease

BACKGROUND Chronic kidney disease(CKD)patients have been found to be at risk of concurrent cognitive dysfunction in previous studies,which has now become an important public health issue of widespread concern.AIM To investigate the risk factors for concurrent cognitive dysfunction in patients with CKD.METHODS This is a prospective cohort study conducted among patients with CKD between October 2021 and March 2023.A questionnaire was formulated by literature review and expert consultation and included questions about age,sex,education level,per capita monthly household income,marital status,living condition,payment method,and hypertension.RESULTS Logistic regression analysis showed that patients aged 60-79 years[odds ratio(OR)=1.561,P=0.015]and≥80 years(OR=1.760,P=0.013),participants with middle to high school education(OR=0.820,P=0.027),divorced or widowed individuals(OR=1.37,P=0.032),self-funded patients(OR=2.368,P=0.008),and patients with hypertension(OR=2.011,P=0.041)had a higher risk of cognitive impairment.The risk of cognitive impairment was lower for those with a college degree(OR=0.435,P=0.034)and married individuals.CONCLUSION The risk factors affecting cognitive dysfunction are age,60-79 years and≥80 years;education,primary school education or less;marital status,divorced or widowed;payment method,selffunded;hypertension;and CKD.

MicroRNA-630 alleviates inflammatory reactions in rats with diabetic kidney disease by targeting toll-like receptor 4

BACKGROUND Diabetic kidney disease(DKD)is a major complication of diabetes mellitus.Renal tubular epithelial cell(TEC)damage,which is strongly associated with the inflammatory response and mesenchymal trans-differentiation,plays a significant role in DKD;However,the precise molecular mechanism is unknown.The recently identified microRNA-630(miR-630)has been hypothesized to be closely associated with cell migration,apoptosis,and autophagy.However,the association between miR-630 and DKD and the underlying mechanism remain unknown.AIM To investigate how miR-630 affects TEC injury and the inflammatory response in DKD rats.METHODS Streptozotocin was administered to six-week-old male rats to create a hypergly cemic diabetic model.In the second week of modeling,the rats were divided into control,DKD,negative control of lentivirus,and miR-630 overexpression groups.After 8 wk,urine and blood samples were collected for the kidney injury assays,and renal tissues were removed for further molecular assays.The target gene for miR-630 was predicted using bioinformatics,and the association between miR-630 and toll-like receptor 4(TLR4)was confirmed using in vitro investigations and double luciferase reporter gene assays.Overexpression of miR-630 in DKD rats led to changes in body weight,renal weight index,basic blood parameters and histopathological changes.RESULTS The expression level of miR-630 was reduced in the kidney tissue of rats with DKD(P<0.05).The miR-630 and TLR4 expressions in rat renal TECs(NRK-52E)were measured using quantitative reverse transcription polymerase chain reaction.The mRNA expression level of miR-630 was significantly lower in the high-glucose(HG)and HG+mimic negative control(NC)groups than in the normal glucose(NG)group(P<0.05).In contrast,the mRNA expression level of TLR4 was significantly higher in these groups(P<0.05).However,miR-630 mRNA expression increased and TLR4 mRNA expression significantly decreased in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Furthermore,the levels of tumor necrosis factor-alpha(TNF-α),interleukin-1β(IL-1β),and IL-6 were significantly higher in the HG and HG+mimic NC groups than in NG group(P<0.05).However,the levels of these cytokines were significantly lower in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Notably,changes in protein expression were observed.The HG and HG+mimic NC groups showed a significant decrease in E-cadherin protein expression,whereas TLR4,α-smooth muscle actin(SMA),and collagen IV protein expression increased(P<0.05).Conversely,the HG+miR-630 mimic group exhibited a significant increase in E-cadherin protein expression and a notable decrease in TLR4,α-SMA,and collagen IV protein expression than in the HG+mimic NC group(P<0.05).The miR-630 targets TLR4 gene expression.In vivo experiments demonstrated that DKD rats treated with miR-630 agomir exhibited significantly higher miR-630 mRNA expression than DKD rats injected with agomir NC.Additionally,rats treated with miR-630 agomir showed significant reductions in urinary albumin,blood glucose,TLR4,and proinflammatory markers(TNF-α,IL-1β,and IL-6)expression levels(P<0.05).Moreover,these rats exhibited fewer kidney lesions and reduced infiltration of inflammatory cells.CONCLUSION MiR-630 may inhibit the inflammatory reaction of DKD by targeting TLR4,and has a protective effect on DKD.