A method for structure determination of GPCRs in various states.

G-protein-coupled receptors (GPCRs) are a class of integral membrane proteins that detect environmental cues and trigger cellular responses. Deciphering the functional states of GPCRs induced by various ligands has been one of the primary goals in the field. Here we developed an effective universal method for GPCR cryo-electron microscopy structure determination without the need to prepare GPCR-signaling protein complexes. Using this method, we successfully solved the structures of the ß2-adrenergic receptor (ß2AR) bound to antagonistic and agonistic ligands and the adhesion GPCR ADGRL3 in the apo state. For ß2AR, an intermediate state stabilized by the partial agonist was captured. For ADGRL3, the structure revealed that inactive ADGRL3 adopts a compact fold and that large unusual conformational changes on both the extracellular and intracellular sides are required for activation of adhesion GPCRs. We anticipate that this method will open a new avenue for understanding GPCR structure‒function relationships and drug development.

Synthesis of P-Stereogenic Phosphine Oxides via Nickel-Catalyzed Asymmetric Cross-Coupling of Secondary Phosphine Oxides with Alkenyl and Aryl Bromides.

A general and mild nickel-catalyzed enantioselective C(sp2 )-P cross-coupling for synthesizing P-stereogenic phosphine oxides has been developed. The asymmetric alkenylation/arylation of racemic secondary phosphine oxides with alkenyl/aryl bromides generated P-stereogenic phosphine oxides with high yields and enantioselectivities. Various functional groups were tolerated, and the applications of this method were demonstrated through late-stage functionalization and product transformations.

MiR-423-5p Regulates Cells Apoptosis and Extracellular Matrix Degradation via Nucleotide-Binding, Leucine-Rich Repeat Containing X1 (NLRX1) in Interleukin 1 beta (IL-1ß)-Induced Human Nucleus Pulposus Cells.

BACKGROUND Disc degeneration is characterized partly by the degradation in the extracellular matrix (ECM) and excess apoptosis of nucleus pulposus (NP) cells. NLRX1 (nucleotide-binding, leucine-rich repeat containing X1) is different from the other nucleotide-binding-domain and leucine-rich-repeat proteins and mainly located to the mitochondrial. It negatively regulates NF-κB (nuclear factor kappa B) and apoptosis inhibition. However, how NLRX1 is regulated and exerts effects in disc degeneration is unclear. Thus, the study aimed to analyze the effects of NLRX1 on NP cells. MATERIAL AND METHODS NLRX1 expression was detected in interleukin (IL)-1ß-induced NP cells by western blot and quantitative real-time polymerase chain reaction (qRT-PCR). Then, NLRX1 was overexpressed in IL-1ß-induced NP cells to detect apoptosis-related proteins and the extracellular matrix (ECM) by western blot, along with the detection of apoptosis levels using flow cytometry. StarBase predicted miR-423-5p target 3'UTR of NLRX1. Dual luciferase reporter assay showed that miR-423-5p could bind to the 3'UTR of NLRX1. Besides, miR-423-5p significantly affected NLRX1 levels detected by qRT-qPCR. RESULTS The miR-423-5p overexpression markedly, and negatively regulated the protective effects of NLRX1 on IL-1ß induced NP cells. Thus, our results suggested that miR-423-5p mediated the regulation of NLRX1 to affect apoptosis and ECM levels in IL-1ß induced NP cells. CONCLUSIONS miR-423-5p and NLRX1 could be potential therapeutic targets for patients with disc degeneration.

miR-4324-RACGAP1-STAT3-ESR1 feedback loop inhibits proliferation and metastasis of bladder cancer.

Considering the importance of microRNAs (miRNAs) in regulating cellular processes, we performed microarray analysis and revealed miR-4324 as one of the most differentially expressed miRNAs in bladder cancer (BCa). Then, we discovered that miR-4324 was a negative regulator of Rac GTPase activating protein 1 (RACGAP1) and that RACGAP1 functioned as an oncogenic protein in BCa. Our studies indicated that ectopic overexpression of miR-4324 in BCa cells significantly suppressed cell proliferation and metastasis and enhanced chemotherapy sensitivity to doxorubicin by repressing RACGAP1 expression. Further studies showed that estrogen receptor 1 (ESR1) increased the expression of miR-4324 by binding to its promoter, while the downregulation of ESR1 in BCa was caused by hypermethylation of its promoter. p-STAT3 induced the enrichment of DNMT3B by binding to the ESR1 promoter and then induced methylation of the ESR1 promoter. In turn, RACGAP1 induced STAT3 phosphorylation, increasing p-STAT3 expression and promoting its translocation to the nucleus. Therefore, the miR-4324-RACGAP1-STAT3-ESR1 feedback loop could be a critical regulator of BCa progression.

The crystal structure of the Hsp90 co-chaperone Cpr7 from Saccharomyces cerevisiae.

The versatility of Hsp90 can be attributed to the variety of co-chaperone proteins that modulate the role of Hsp90 in many cellular processes. As a co-chaperone of Hsp90, Cpr7 is essential for accelerating the cell growth in an Hsp90-containing trimeric complex. Here, we report the crystal structure of Cpr7 at a resolution of 1.8Å. It consists of an N-terminal PPI domain and a C-terminal TPR domain, and exhibits a U-shape conformation. Our studies revealed the aggregation state of Cpr7 in solution and the interaction properties between Cpr7 and the MEEVD sequence from the C-terminus of Hsp90. In addition, the structure and sequence analysis between Cpr7 and homologues revealed the structure basis both for the function differences between Cpr6 and Cpr7 and the functional complements between Cns1 and Cpr7. Our studies facilitate the understanding of Cpr7 and provide decent insights into the molecular mechanisms of the Hsp90 co-chaperone pathway.

Effects of miR-1236-3p and miR-370-5p on activation of p21 in various tumors and its inhibition on the growth of lung cancer cells.

The mechanism of dsRNA-induced gene activation (RNAa) is being gradually unveiled. The plentiful evidence that it existed in mammalian species other than human demonstrated that dsRNA-mediated RNAa is a conservative phenomenon. Simultaneously, accumulating evidence suggested that microRNAs could activate gene expression by targeting promoter. Nevertheless, it is ambiguous whether microRNA-induced gene activation in different human cells is a common phenomenon. The study we performed verified that miR-1236-3p (miR-1236) and miR-370-5p can activate p21 expression in bladder cancer (BCa) T24, EJ cells, and non-small-cell lung carcinoma A549 cells, while in hepatocellular HepG2 cells both microRNAs cannot effectively induce the expression of P21WAF1/CIP1 (p21). In pancreatic cancer PANC-1 cells, only miR-370-5p had the potent abilities to induce p21 expression rather than miR-1236-3p. Unlike microRNA-mediated RNA activation, we can observe that dsP21-322 significantly activated p21 in above cells. Besides, we demonstrated that miR-1236 and miR-370 inhibited cyclin D1-CDK4/CDK6 pathway while upregulated E-cadherin expression by upregulation of p21. Overexpression of these two microRNAs in A549 induced cell-cycle arrest and cell senescence, delayed cell proliferation and colony formation, and inhibited migration and invasion. In conclusion, microRNA-mediated RNAa depends on the cell context, and miR-1236 and miR-370 can inhibit non-small-cell lung carcinoma cell growth by upregulating p21 expression in vitro.

Promoter-associated endogenous and exogenous small RNAs suppress human bladder cancer cell metastasis by activating p21 (CIP1/WAF1) expression.

Accumulating data suggest that micro RNAs (miRNAs) or double-stranded RNAs (dsRNAs) can activate gene expression by targeting promoters. The cyclin-dependent kinase inhibitor p21 (CIP1/WAF1) (p21) has also been shown to suppress epithelial-mesenchymal transition (EMT) which plays a crucial role in the early stage of tumor metastases and invasiveness. In a previous study, we have reported that miR-370-5p is low-expressed in bladder cancer (BCa) tissues and cell lines. Here, we identified that miR-370-5p and sequence homology dsRNA (dsP21-555) fully complementary to promoter hold the potent abilities to induce p21 expression. Moreover, transfection of miR-370-5p or dsP21-555 into BCa cells remarkably inverts EMT-associated genes (increases epithelial cell makers E-cadherin and ß-catenin, and decreases mesenchymal cell markers ZEB1 and Vimentin) expression mainly via regulating p21 expression. Besides, through manipulating p21, both the candidates can retard BCa cell migration and invasion. In summary, our results provide evidence that both endogenous and exogenous small RNAs may function to induce p21 expression by interacting with the similar promoter region and impede BCa metastasis.

[Effect of synthetic small double-stranded RNA on the development of bladder cancer by activating P21 expression].

OBJECTIVE: To investigate the effects of a synthetic small double-stranded RNA (dsRNA) dsP21-555 on the development of bladder cancer cell lines T24 and EJ. METHODS: According to the different treatments, bladder cancer cells were divided into three groups: negative control group (transfected with dsControl), positive control group (transfected with candidate microRNA, i.e. miR-370) and experimental group (transfected with dsP21-555). Real-time fluorescent quantitative polymerase chain reaction (qPCR) was conducted to detect the expressions of p21 mRNA and cyclin-dependent kinases 4/6 (CDK4/6) mRNA; Western blot was operated to verify the expression of P21 and CDK4/6 proteins. Cell cycle distribution was measured by flow cytometry after transfection. Cell proliferation assay was performed to evaluate the proliferative capacity of transfected cells. Colony formation assay was carried out to analyze the proliferative ability of single cancer cells. RESULTS: qPCR showed that, compared with the negative control group, dsP21-555 up-regulated the expressions of p21 mRNA by 2.46 times (P<0.01) in T24 cells and 2.60 times (P<0.01) in EJ cells; compared with the positive control group, the expression of p21 mRNA was no significantly different in the experimental group (P>0.05). Compared with the dsControl group, dsP21-555 suppressed the expressions of CDK4 mRNA by 43% (P<0.01) in T24 and 54% (P<0.01) in EJ cells, the expression of CDK6 mRNA by 39% (P<0.01) in T24 and 36% (P<0.01) in EJ cells; the differences in the expression of CDK4 and CDK6 mRNAs between the miR-370 and dsP21-555 groups were not statistically significant (P> 0.05). Western blot verified the differences of p21 and CDK4/6 genes expression among groups. Flow cytometry revealed that the G0/G1 phase cells significantly increased while S and G2/M phase cells decreased in the miR-370 and the dsP21-555 groups, compared with the dsControl group. Cell proliferation assay showed that, compared with the dsControl group, the proliferative capacities of cells transfected with miR-370 or dsP21-555 decreased significantly (both P<0.05), but the difference in proliferative capacities between the miR-370 and the dsP21-555 groups was no statistically significant (P>0.05). Colony formation assay showed that the numbers of colonies formed in the miR-370 and the dsP21-555 groups were both smaller than that in the dsControl group. CONCLUSION: dsP21-555 may activate the expression of P21 protein by RNA activation, thereby significantly inhibit the growth of bladder cancer cells.

Small activating RNA induces myogenic differentiation of rat adipose-derived stem cells by upregulating MyoD.

PURPOSE: RNA activation (RNAa) is a mechanism of gene activation triggered by promoter-targeted small double stranded RNAs (dsRNAs), also known as small activating RNAs (saRNAs). Myogenic regulatory factor MyoD is regarded as the master activator of myogenic differentiation cascade by binding to enhancer of muscle specific genes. Stress urinary incontinence (SUI) is a condition primarily resulted from urethral sphincter deficiency. It is thus expected that by promoting differentiation of adipose-derived stem cells (ADSCs) into myoblasts by activating MyoD gene through RNAa may offer benefits to SUI. MATERIALS AND METHODS: Rats ADSCs were isolated, proliferated in vitro, and identified by flow cytometry. Purified ADSCs were then transfected with a MyoD saRNA or control transfected. Real-time polymerase chain reaction (RT-PCR) and western blotting were used to detect MyoD mRNA and protein expression, respectively. Immunocytochemical staining was applied to determine the expression of desmin protein in transfected cells. Cell viability was measured by using CellTiter 96R AQueous One Solution Cell Proliferation Assay kit. RESULTS: Transfection of a MyoD saRNA (dsMyoD) into ADSCs significantly induced the expression of MyoD at both the mRNA and protein levels, and inhibited cell proliferation. Desmin protein expression was detected in dsMyoD treated ADSCs 2 weeks later. CONCLUSION: Our findings show that RNAa mediated overexpression of MyoD can promote transdifferentiation of ADSCs into myoblasts and may help treat stress urinary incontinence (SUI)-a condition primarily resulted from urethral sphincter deficiency.

Identification and functional validation of FZD8-specific antibodies.

The Wnt pathway is an evolutionarily conserved pathway involved in stem cell homeostasis and tissue regeneration. Aberrant signaling in the Wnt pathway is highly associated with cancer. Developing antibodies to block overactivation of Frizzled receptors (FZDs), the main receptors in the Wnt pathway, is one of the viable options for treating cancer. However, obtaining isoform-specific antibodies is often challenging due to the high degree of homology among the ten FZDs. In this study, by using a synthetic library, we identified an antibody named pF8_AC3 that preferentially binds to FZD8. Guided by the structure of the complex of pF8_AC3 and FZD8, a second-generation targeted library was further constructed, and finally, the FZD8-specific antibody sF8_AG6 was obtained. Cell-based assays showed that these antibodies could selectively block FZD8-mediated signaling activation. Taken together, these antibodies have the potential to be developed into therapeutic drugs in the future.

Washout CYFRA 21-1: A tool to improve diagnostic accuracy of fine needle aspiration in the diagnosis of metastatic lymph nodes in papillary thyroid cancer.

Thyroid carcinoma has an increasing incidence of endocrine system cancers. Fine needle aspiration cytology (FNAC) and thyroglobulin (Tg) are the primary diagnostic modalities employed for assessing metastatic lymph nodes (LNs) in thyroid cancer. Due to the limited accuracy, rare patients benefited from these procedures. In this research, we aimed to discover a dependable biomarker that could increase the accuracy of FNAC's ability to diagnose metastatic LNs among patients suffering from papillary thyroid cancer (PTC). From March 2021 to July 2023, 99 LNs from PTC patients who had thyroid ultrasonography suspicions of metastases were examined. All patients underwent FNAC, washout Tg and CYFRA 21-1 measurements. Surgical histology and a subsequent FNAC were utilized to validate the outcomes of LNs. In our study, the optimal cut-off value for CYFRA 21-1 washout fluid was 1.145 ng/mL, with a specificity of 94.00 % (slightly lower than Tg and FNAC at 98 %). However, CYFRA 21-1 demonstrated significantly higher diagnostic sensitivity (85.71 %) and accuracy (86.41 %) compared to Tg (71.43 %, 81.55 %) and FNAC (69.39 %, 80.58 %). Furthermore, FNAC plus washout CYFRA 21-1 performed better in diagnosing the metastatic LNs in PTC than FNAC plus Tg, which may indicate a novel solution for metastatic LNs diagnosis in PTC.

An epitope-directed selection strategy facilitating the identification of Frizzled receptor selective antibodies.

The lack of incorporating epitope information into the selection process makes the conventional antibody screening method less effective in identifying antibodies with desired functions. Here, we developed an epitope-directed antibody selection method by designing a directed library favoring the target epitope and a precise "counter" antigen for clearing irrelevant binders in the library. With this method, we successfully isolated an antibody, pF7_A5, that targets the less conserved region on the FZD2/7 CRD as designed. Guided by the structure of pF7_A5-FZD2CRD, a further round of evolution was conducted together with the "counter" antigen selection strategy, and ultimately, an FZD2-specific antibody and an FZD7-preferred antibody were obtained. Because of targeting the predefined functional site, all these antibodies exhibited the expected modulatory activity on the Wnt pathway. Together, the method developed here will be useful in antibody drug discovery, and the identified FZD antibodies will have clinical potential in FZD-related cancer therapy.

Engineering a modular double-transmembrane synthetic receptor system for customizing cellular programs.

Implementation of designer receptors in engineered cells confers them to sense a particular physiological or disease state and respond with user-defined programs. To expand the therapeutic application scope of engineered cells, synthetic receptors realized through different strategies are in great demand. Here, we develop a synthetic receptor system that exerts dual control by incorporating two transmembrane helices for the signal chain. Together with a sensor-actuator device with minimal background signals and a positive loop circuit, this receptor system can sensitively respond to extracellular protein signals. We demonstrate that this synthetic receptor system can be readily adapted to respond to various inputs, such as interleukin-1 (IL-1), programmed death ligand 1 (PD-L1), and HER2, and release customized outputs, including fluorescence signals and the therapeutic molecule IL-2. The robust signaling ability and generality of this receptor system promise it to be a useful tool in the field of cell engineering for fundamental research and translational applications.

Photoinduced Copper-Catalyzed C(sp3)-P Bond Formation by Coupling of Secondary Phosphines with N-(Acyloxy)phthalimides and N-Fluorocarboxamides.

A photoinduced copper-catalyzed C(sp3)-P bond formation has been developed by using N-(acyloxy)phthalimides as radical precursors and secondary phosphine boranes as coupling partners. A variety of alkyl carboxylic acid derivatives can be readily transformed into the corresponding phosphines with high reaction efficiency and structural diversity. Besides, utilizing the 1,5-HAT of the N-centered radical process, the δ C(sp3)-H bond can be coupled with secondary phosphines, which provides a novel method for the regioselective formation of C(sp3)-P bonds.

S-phase kinase-associated protein 2 impairs the inhibitory effects of miR-1236-3p on bladder tumors.

We have previously demonstrated that miR-1236-3p has the robust ability to up-regulate p21 expression by targeting the p21 promoter, thus inhibiting bladder cancer progression. Microarray experiments displayed that miR-1236-3p significantly increased the expression of the oncogenic F-box protein S-phase kinase-associate protein 2 (Skp2) while activating p21 expression in bladder cancer cells. Here, we confirmed that Skp2 was over-expressed following transfection with miR-1236-3p. Further, we demonstrated that miR-1236-3p and its sequence homology dsRNA, dsRNA-245 (which is completely complementary to the p21 promoter), both are able to potently induce p21 expression. We found that dsRNA-245 did not induce changes in Skp2 expression, while miR-1236-3p could increase Skp2 expression; this influence was independent of p21 activation. Moreover, transfection of miR-1236-3p or dsRNA-245 into bladder cancer cells significantly inhibited cell proliferation and clonegenesis and induced cell cycle arrest mainly by regulating p21 expression. However, the growth inhibition caused by dsRNA-245 was more effective than that caused by miR-1236-3p. This difference in effect size is mainly related to the miR-1236-3p-induced expression of Skp2. In summary, our results provided evidence that both endogenous and exogenous small RNAs might function to induce p21 expression by interacting with the same promoter region, therefore impeding bladder cancer cell growth. Additionally, our results indicated that microRNA activation can activate the expression of some tumor suppressor genes as well as some oncogenes. This indicated the need for the further study of clinical applications of RNA activation.

Upregulation of E­cadherin expression mediated by a novel dsRNA suppresses the growth and metastasis of bladder cancer cells by inhibiting ß-catenin/TCF target genes.

Low expression levels of E­cadherin are correlated with poor prognosis in patients with bladder cancer (BCa). A small activating RNA (saRNA) targeting a specific promoter region can activate gene expression. In the present study, two small double-stranded RNAs (dsRNAs) targeting the promoter region of human E­cadherin were designed and synthesized, and the regulatory role of saRNAs in E­cadherin expression was investigated. The results of reverse transcription-quantitative polymerase chain reaction and western blotting demonstrated that transfection of dsEcad­346 into the BCa cell lines T24 and 5637 significantly activated E­cadherin expression. Furthermore, transfection of dsEcad­346 and miR­373 induced cell cycle arrest in G0/G1 phase, promoted apoptosis and significantly inhibited migration and invasion of BCa cells. Results of immunofluorescence and western blotting indicated that ß-catenin was redistributed from the nucleus to the cell membrane following transfection of dsEcad­346 and miR­373. Additionally, the expression of ß-catenin/T-cell factor complex (TCF) target genes (c­MYC, matrix metallopeptidase 2, cyclin D1) was suppressed following transfection of BCa cells with saRNA. Silencing of E­cadherin expression blocked the inhibitory effect of dsEcad­346 and miR­373 on BCa cells. In conclusion, a novel designed dsEcad­346 can activate the expression of E­cadherin in BCa cells. saRNA-mediated activation of E­cadherin expression inhibited the growth and metastasis of BCa cells by promoting the redistribution of ß-catenin from nucleus to cell membrane and inhibiting the ß-catenin/TCF target genes.

CIRBP is a novel oncogene in human bladder cancer inducing expression of HIF-1α.

Cold-inducible RNA binding protein (CIRBP) has been reported to be associated with distinct tumorigenesis. In this study, we investigated the role of CIRBP in human bladder cancer (BCa), indicating that CIRBP is overexpressed in BCa tissues and cell lines to promote proliferation and migration. Moreover, CIRBP could induce expression of HIF-1α via binding to the 3'-UTR of its mRNA to increase the mRNA stability in BCa cells. Furthermore, we demonstrated that PTGIS is a HIF-1α targeted gene, a major regulator in hypoxic cancer progression by activating transcription of various oncogenes. Our results also suggested that overexpression of HIF-1α may suppress the expression of PTGIS in BCa cells, by binding to HRE sequence at the promoter region of PTGIS. In addition, we found a strongly downregulation of PTGIS in BCa tissue and transcriptionally inhibited by HIF-1α in BCa cells, which could be triggered by its DNA methylation. Further result suggested that knockdown of CIRBP could promote the expression of PTGIS, meanwhile knockdown of PTGIS could partially rescue CIRBP-deficiency induced inhibition of migration and proliferation in BCa cells. Taken together, our study indicated that CIRBP could be a novel oncogene in human bladder cancer inducing transcription of HIF-1α, which could inhibit expression of methylated PTGIS.

Short- and long-term outcomes of laparoscopic versus open surgery for rectal cancer: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: The present meta-analysis aimed to evaluate the short- and long-term outcomes of laparoscopic surgery (LS) versus open surgery (OS) for rectal cancer. METHODS: PubMed, Web of Science, and Cochrane Library, were searched for eligible randomized controlled trials (RCTs) published up to June 2017. Operation related index, postoperative complication, and long-term survival rate and disease-free survival rate were evaluated by meta-analytical techniques. RESULT: Nine RCTs enrolling 4126 patients were included in the present meta-analysis. Compared to OS, LS had similar positive circumferential resection margin (CRM) and number of lymph nodes extracted (LNE) as well as long term 5 years survival rate and disease-free survival rate, but of which the risk tendency was higher in LS group. The short-term outcomes of major and total postoperative complication were lower in LS group. CONCLUSIONS: LS for rectal cancer was as safe and effective as OS in terms of long-term outcomes, but with lower postoperative complication.

The suppressive effects of miR-1180-5p on the proliferation and tumorigenicity of bladder cancer cells.

In our previous research, we have reported that a candidate microRNA (miR-1180-5p) has the capacity to induce overexpression of tumor suppressor gene p21 and inhibit the growth of human bladder cancer (BCa) cell lines in vitro. However, the exact mechanism as to how miR-1180-5p suppresses BCa cell proliferation remains unknown, and the inhibitory effect of miR-1180-5p in vivo also need to be investigated. In the present study, we found that the expression level of miR-1180-5p was lower in BCa cells than in normal human urothelial cells. Furthermore, we found that overexpression of p21, activated by miR-1180-5p, interfered with cell cycle progress by inhibiting the cell cycle related proteins (CDK4, CDK6, Cyclin D1 and Cyclin A2), and thereby suppressed BCa cell proliferation. In addition, miR-1180-5p also suppressed the tumor growth in vivo significantly. Taken together, our study provides evidence that up-regulation of p21 is mainly responsible for the suppressive effect of miR-1180-5p on BCa cells and miR-1180-5p can significantly inhibit tumorigenicity in vivo.

History of kidney stones and risk of chronic kidney disease: a meta-analysis.

BACKGROUND: Although the relationship between a history of kidney stones and chronic kidney disease (CKD) has been explored in many studies, it is still far from being well understood. Thus, we conducted a meta-analysis of studies comparing rates of CKD in patients with a history of kidney stones. METHODS: PubMed, EMBASE, and the reference lists of relevant articles were searched to identify observational studies related to the topic. A random-effects model was used to combine the study-specific risk estimates. We explored the potential heterogeneity by subgroup analyses and meta-regression analyses. RESULTS: Seven studies were included in this meta-analysis. Pooled results suggested that a history of kidney stones was associated with an increased adjusted risk estimate for CKD [risk ratio (RR), 1.47 95% confidence interval (CI) [1.23-1.76])], with significant heterogeneity among these studies (I2 = 93.6%, P < 0.001). The observed positive association was observed in most of the subgroup analyses, whereas the association was not significant among studies from Asian countries, the mean age ≥50 years and male patients. CONCLUSION: A history of kidney stones is associated with increased risk of CKD. Future investigations are encouraged to reveal the underlying mechanisms in the connection between kidney stones and CKD, which may point the way to more effective preventive and therapeutic measures.