Machine Learning-Assisted Identification and Quantification of Hydroxylated Metabolites of Polychlorinated Biphenyls in Animal Samples.

Laboratory studies of the disposition and toxicity of hydroxylated polychlorinated biphenyl (OH-PCB) metabolites are challenging because authentic analytical standards for most unknown OH-PCBs are not available. To assist with the characterization of these OH-PCBs (as methylated derivatives), we developed machine learning-based models with multiple linear regression (MLR) or random forest regression (RFR) to predict the relative retention times (RRT) and MS/MS responses of methoxylated (MeO-)PCBs on a gas chromatograph-tandem mass spectrometry system. The final MLR model estimated the retention times of MeO-PCBs with a mean absolute error of 0.55 min (n = 121). The similarity coefficients cos θ between the predicted (by RFR model) and experimental MS/MS data of MeO-PCBs were >0.95 for 92% of observations (n = 96). The levels of MeO-PCBs quantified with the predicted MS/MS response factors approximated the experimental values within a 2-fold difference for 85% of observations and 3-fold differences for all observations (n = 89). Subsequently, these model predictions were used to assist with the identification of OH-PCB 95 or OH-PCB 28 metabolites in mouse feces or liver by suggesting candidate ranking information for identifying the metabolite isomers. Thus, predicted retention and MS/MS response data can assist in identifying unknown OH-PCBs.

Metabolism of 3-Chlorobiphenyl (PCB 2) in a Human-Relevant Cell Line: Evidence of Dechlorinated Metabolites.

Lower chlorinated polychlorinated biphenyls (LC-PCBs) and their metabolites make up a class of environmental pollutants implicated in a range of adverse outcomes in humans; however, the metabolism of LC-PCBs in human models has received little attention. Here we characterize the metabolism of PCB 2 (3-chlorobiphenyl), an environmentally relevant LC-PCB congener, in HepG2 cells with in silico prediction and nontarget high-resolution mass spectrometry. Twenty PCB 2 metabolites belonging to 13 metabolite classes, including five dechlorinated metabolite classes, were identified in the cell culture media from HepG2 cells exposed for 24 h to 10 µM or 3.6 nM PCB 2. The PCB 2 metabolite profiles differed from the monochlorinated metabolite profiles identified in samples from an earlier study with PCB 11 (3,3'-dichlorobiphenyl) under identical experimental conditions. A dechlorinated dihydroxylated metabolite was also detected in human liver microsomal incubations with monohydroxylated PCB 2 metabolites but not PCB 2. These findings demonstrate that the metabolism of LC-PCBs in human-relevant models involves the formation of dechlorination products. In addition, untargeted metabolomic analyses revealed an altered bile acid biosynthesis in HepG2 cells. Our results indicate the need to study the disposition and toxicity of complex PCB 2 metabolites, including novel dechlorinated metabolites, in human-relevant models.

Determination of methanol partition coefficient in octanol/water system by a three-phase ratio variation headspace gas chromatographic method.

Determining the methanol partition coefficient (Kow) in octanol/water system is important to assess the risk of its impact to humans and the environment. In this paper, we report a novel method for the determination of the Kow of methanol with headspace gas chromatography (HS-GC), using a three-phase equilibrium-based phase ratio variation approach. Three headspace vials with different phase ratios [(1) 0.2 mL of water plus 3 mL of octanol, (2) 1 mL of water plus 3 mL of octanol and (3) 1 mL of water plus 10 mL of octanol] were used in the experiment. After pre-standing at 25 °C for > 10 h and equilibrating in the headspace oven at a temperature of interest for additional 25 min, the methanol signals of the vapor phase (i.e., the headspace) in these vials were measured by HS-GC, from which the Kow of methanol can be calculated based on the established equations. The results showed that the method has good precision (within 0.06 log unit in standard deviation) and acceptable accuracy (with method error within 0.5 log unit). A correlation between the Kow of methanol and temperature extrapolated the Kow values in a temperature range of interest. The present method represents a simple and in-situ approach for the determination of the Kow of methanol and is also suitable to be applied to other volatile compounds.

Characterization of the complete chloroplast genome sequence of Daphne retusa Hemsl. (Thymelaeaceae), a rare alpine plant species in northwestern China.

Daphne retusa Hemsl. (Thymelaeaceae) is an evergreen shrub plant. First, we characterized the complete nucleotide sequence of chloroplast (cp) genome of D. retusa. The total length of cp genome was found to be 170,553 bp, including a large single copy (LSC) region of 84,886 bp, a small single copy (SSC) region of 2,437 bp, and a pair of inverted repeats (IRs) of 41,617 bp. The cp genome of Daphne retusa Hemsl. contains 134 genes, including 90 protein-coding genes (75 PCG species), 37 transfer RNA genes (29 tRNA species), and 6 rRNA genes (3 RNA species). A total of 13 genes (trnK-UUU, trnS-CGA, atpF, rpoC1, trnL-UAA, trnC-ACA, petD, rpl16, rpl2, ndhB, trnE-UUC, ndhA, and trnA-UGC) contain a single intron, and one gene (ycf3) contains two introns. The GC content in whole cp genome, LSC region, SSC region, and IR region was 36.75%, 34.83%, 28.19%, and 38.96% respectively, like other Thymelaeaceae plants. Phylogenetic analysis suggested that D. retusa has a close relationship with congeneric Daphne tangutica.

Characterization of the Metabolic Pathways of 4-Chlorobiphenyl (PCB3) in HepG2 Cells Using the Metabolite Profiles of Its Hydroxylated Metabolites.

The characterization of the metabolism of lower chlorinated PCB, such as 4-chlorobiphenyl (PCB3), is challenging because of the complex metabolite mixtures formed in vitro and in vivo. We performed parallel metabolism studies with PCB3 and its hydroxylated metabolites to characterize the metabolism of PCB3 in HepG2 cells using nontarget high-resolution mass spectrometry (Nt-HRMS). Briefly, HepG2 cells were exposed for 24 h to 10 µM PCB3 or its seven hydroxylated metabolites in DMSO or DMSO alone. Six classes of metabolites were identified with Nt-HRMS in the culture medium exposed to PCB3, including monosubstituted metabolites at the 3'-, 4'-, 3-, and 4- (1,2-shift product) positions and disubstituted metabolites at the 3',4'-position. 3',4'-Di-OH-3 (4'-chloro-3,4-dihydroxybiphenyl), which can be oxidized to a reactive and toxic PCB3 quinone, was a central metabolite that was rapidly methylated. The resulting hydroxylated-methoxylated metabolites underwent further sulfation and, to a lesser extent, glucuronidation. Metabolomic analyses revealed an altered tryptophan metabolism in HepG2 cells following PCB3 exposure. Some PCB3 metabolites were associated with alterations of endogenous metabolic pathways, including amino acid metabolism, vitamin A (retinol) metabolism, and bile acid biosynthesis. In-depth studies are needed to investigate the toxicities of PCB3 metabolites, especially the 3',4'-di-OH-3 derivatives identified in this study.

Disposition of PCB 11 in Mice Following Acute Oral Exposure.

PCB 11 (3,3'-dichloro-biphenyl) is an emerging environmental contaminant that represents a public health concern. Here, we investigated the distribution of PCB 11 and its metabolites in mice exposed orally to PCB 11. PCB 11 tissue levels followed the rank order adipose > lung ∼ muscle > liver > brain > blood 4 h after PCB 11 exposure, which varied from the rank order predicted with a composition-based model. We detected hydroxylated and sulfate metabolites in the liver and sulfate and glucuronide metabolites in serum. These findings lay the groundwork for future toxicity studies with PCB 11.

Atropselective Partitioning of Polychlorinated Biphenyls in a HepG2 Cell Culture System: Experimental and Modeling Results.

Cell culture models are used to study the toxicity of polychlorinated biphenyls (PCBs); however, it is typically unknown how much PCB enters the cells and, for chiral PCBs, if the partitioning is atropselective. We investigated the partitioning of racemic PCB 91, PCB 95, PCB 132, and PCB 136 in HepG2 cells following a 72 h incubation. PCBs were present in the cell culture medium (60.7-88.8%), cells (8.0-14.6%), and dishes (2.3-7.8%) and displayed atropisomeric enrichment in the cells (enantiomeric fraction [EF] = 0.55-0.77) and dishes (EF = 0.53-0.68). Polyparameter linear free energy relationships coupled with a composition-based model provided a good estimate of the PCB levels in the cells and cell culture medium. The free concentration was subsequently used to extrapolate from the nominal cell culture concentration to PCB tissue levels and vice versa. This approach can be used for in vitro-in vivo extrapolations for all 209 PCB congeners. However, this model (and modified models based on descriptors incorporating atropselective interactions, i.e., relative retention times on chiral columns) did not predict the atropselective partitioning in the cell culture system. Improved chemical descriptors that account for the atropselective binding of PCBs to biological macromolecules are, therefore, needed to predict the atropselective partitioning of PCBs in biological systems.

Comparing Three Different Extraction Techniques on Essential Oil Profiles of Cultivated and Wild Lotus (Nelumbo nucifera) Flower.

Essential oil components of Nelumbo nucifera flowers from cultivated and wild lotus samples were analyzed and compared using three different extraction techniques, i.e., headspace extraction (HE), steam distillation (SD) and solvent extraction (SE), coupled with GC-MS. Forty-two peaks in the GC-MS analysis were identified as essential oil components extracted by the three methods from N. nucifera flower. The major essential oil components extracted by SD method were found to be Z,Z-10,12-hexadecadienal and E-14-hexadecenal with relative contents of 16.3% and 16.7%, respectively, which is different from that of SE method, i.e., n-hexadecanoic acid and Z,Z-9,12-octadecadienoic acid accounting for 25.8% and 26.8%, respectively. HE method demonstrated a possibility to be used as an in situ and simplest method for extracting the essential oil components from raw materials. By adding a small amount of glycerinum onto the surface of the air-dried flower sample as a solvent trap in the HE method, the volatility of the essential oil components was found to increase by two times for the first time, which could be further utilized to improve the extraction efficiency and the recovery of the essential oil components from other materials for more applications. In addition, the comparison of essential oil components between cultivated and wild samples showed that they differed only in the chemical contents but not in chemical components. This will be a comprehensive report on the chemical information of the essential oil components of N. nucifera flower and provide guidance for its further exploration as high value-added products in the food and healthcare industries.

3,3'-Dichlorobiphenyl Is Metabolized to a Complex Mixture of Oxidative Metabolites, Including Novel Methoxylated Metabolites, by HepG2 Cells.

3,3'-Dichlorobiphenyl (PCB 11) is a byproduct of industrial processes and detected in environmental samples. PCB 11 and its metabolites are present in human serum, and emerging evidence demonstrates that PCB 11 is a developmental neurotoxicant. However, little is known about the metabolism of PCB 11 in humans. Here, we investigated the metabolism of PCB 11 and the associated metabolomics changes in HepG2 cells using untargeted high-resolution mass spectrometry. HepG2 cells were exposed for 24 h to PCB 11 in DMSO or DMSO alone. Cell culture media were analyzed with ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry. Thirty different metabolites were formed by HepG2 cells exposed to 10 µM PCB 11, including monohydroxylated, dihydroxylated, methoxylated-hydroxylated, and methoxylated-dihydroxylated metabolites and the corresponding sulfo and glucuronide conjugates. The methoxylated PCB metabolites were observed for the first time in a human-relevant model. 4-OH-PCB 11 (3,3'-dichlorobiphenyl-4-ol) and the corresponding catechol metabolite, 4,5-di-OH-PCB 11 (3',5-dichloro-3,4-dihydroxybiphenyl), were unambiguously identified based on liquid and gas chromatographic analyses. PCB 11 also altered several metabolic pathways, in particular vitamin B6 metabolism. These results demonstrate that complex PCB 11 metabolite profiles are formed in HepG2 cells that warrant further toxicological investigation, particularly since catechol metabolites are likely reactive and toxic.

Selenoprotein T protects against cisplatin-induced acute kidney injury through suppression of oxidative stress and apoptosis.

Previously, selenoprotein T (SelT) expression was shown to be induced in nervous, endocrine, and metabolic tissues during ontogenetic and regenerative processes. However, whether SelT plays a critical role in renal diseases remains unclear. Here, we explored the role of SelT in cisplatin-induced acute kidney injury (AKI). Results revealed that SelT was highly expressed in renal tubules, but its expression was significantly reduced in cisplatin-induced AKI. Importantly, knocking down of SelT expression in kidney cells in vitro resulted in cisplatin-induced cell apoptosis, as indicated by the elevation of cleaved-PARP and Bax expression, Caspase-3 activity, and number of TUNEL-positive cells. Moreover, SelT silencing-induced reactive oxygen species (ROS) production, accompanied by a decrease in intracellular superoxide dismutase (SOD) and catalase (CAT) activity and increase in malondialdehyde (MDA) content. Notably, the protein and mRNA levels of Nox4 were increased in response to SelT downregulation. Furthermore, suppression of Nox4 expression by GKT137831 partially alleviated SelT knockdown-induced ROS generation and cell apoptosis in cisplatin-treated kidney cells. Taken together, our findings provide the first evidence that SelT protects against cisplatin-induced AKI by suppression of oxidative stress and apoptosis.

Association between chronic kidney disease and Alzheimer's disease: an update.

It has been accepted that kidney function is connected with brain activity. In clinical studies, chronic kidney disease (CKD) patients have been found to be prone to suffering cognitive decline and Alzheimer's disease (AD). The cognitive function of CKD patients may improve after kidney transplantation. All these indicators show a possible link between kidney function and dementia. However, little is known about the mechanism behind the relation of CKD and AD. This review discusses the associations between CKD and AD from the perspective of the pathophysiology of the kidney and complications and/or concomitants of CKD that may lead to cognitive decline in the progression of CKD and AD. Potential preventive and therapeutic strategies for AD are also presented. Further studies are warranted in order to confirm whether the setting of CKD is a possible new determinant for cognitive impairment in AD.

A phase conversion headspace technique for the determination of anti-anaerobic activity of drug candidate based on the metabolic acidity change in culture medium.

Screening for anti-anaerobic drug candidates is still challenging although the anaerobic bacteria are important sources for human infections, because the method for anti-anaerobic activity testing is not readily available with low-cost and -expertise. We report a novel method for the determination of the anti-anaerobic activity of drug candidates by automated headspace-gas chromatography (HS-GC). Anaerobic bacteria were inoculated in an anaerobic atmosphere or rapidly using sterile syringe in an air-tight manner, and incubated with and without drugs for 48 h. The metabolic acidities of the cultured media were used as an indicator of cell activities and measured as end-products in place by HS-GC after being completely converted to CO2 with sodium bicarbonate. The present method is precise (relative standard deviation is below 5%) and validated by excellent agreements with a reference method on the determinations of the inhibition rates (root-mean-square error = 10%, n = 48) and half maximal inhibitory concentrations (R2 = 0.996, n = 8) of both pure drug compounds and plant extracts. Advantageously, the present method is sensitive in response to cell activity, safe with regard to cross contamination, and suitable for routine screening of diversified drug candidates for anti-anaerobic activity.

The Role of Long-Lived Plasma Cells in Antibody-Mediated Rejection of Kidney Transplantation: An Update.

BACKGROUND: Antibody-mediated rejection (ABMR) following kidney transplant is closely associated with poor prognosis of the recipients. Long-lived plasma cells (LLPCs) produce alloantibodies as long as life time and play a crucial role in ABMR. SUMMARY: LLPCs generate from germinal centers and reside in survival niches in the bone marrow as well as the inflamed tissues. They are the main and long-term source of the antibodies. LLPCs mediate ABMR via the generation of preformed antibodies in sensitized patients and de novo antibodies after transplantation. They have been acknowledged as the leading causes of ABMR; however, LLPCs are insensitive to traditional immunosuppressive therapy that removes B cells. Strategies targeting LLPCs, such as antithymocyte globulin, proteasome inhibitors as well as monoclonal antibodies, are promising methods to persistently and thoroughly clear the entire PC pool. KEY MESSAGE: LLPCs play an important role in ABMR by producing alloantibodies continually, and targeting LLPCs might be a novel and effective approach against ABMR.

Integrated Genomic Analysis Revealed Associated Genes for Alzheimer's Disease in APOE4 Non-Carriers.

BACKGROUND: APOE4 is the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD). LOAD patients carrying or not carrying APOE4 manifest distinct clinico-pathological characteristics. APOE4 has been shown to play a critical role in the pathogenesis of AD by affecting various aspects of pathological processes. However, the pathogenesis involved in LOAD not-carrying APOE4 remains elusive. OBJECTIVE: We aimed to identify the associated genes involved in LOAD not-carrying APOE4. METHODS: An integrated genomic analysis of datasets of genome-wide association study, genome-wide expression profiling and genome-wide linkage scan and protein-protein interaction network construction were applied to identify associated gene clusters in APOE4 non-carriers. The role of one of hub gene of an APOE4 non-carrier-associated gene cluster in tau phosphorylation was studied by knockdown and western blot. RESULTS: We identified 12 gene clusters associated with AD APOE4 non-carriers. The hub genes associated with AD in these clusters were MAPK8, POU2F1, XRCC1, PRKCG, EXOC6, VAMP4, SIRT1, MME, NOS1, ABCA1 and LDLR. The associated genes for APOE4 non-carriers were enriched in hereditary disorder, neurological disease and psychological disorders. Moreover, knockdown of PRKCG to reduce the expression of protein kinase Cγ isoform enhanced tau phosphorylation at Thr181 and Thr231 and the expression of glycogen synthase kinase 3ß and cyclin-dependent kinase 5 in the presence of APOE3 but not APOE4. CONCLUSION: The study provides new insight into the mechanism of distinct pathogenesis of LOAD not carrying APOE4 and prompts the functional exploration of identified genes based on APOE genotypes.

Development of a multiplex polymerase chain reaction assay for the parallel detection of harmful algal bloom-forming species distributed along the Chinese coast.

Harmful algal blooms (HABs) have adverse effects on the marine ecological environment, public health, and marine economy. Thus, methods for the accurate and rapid identification of harmful algal species are urgently needed for the effective monitoring of the occurrence of HABS. A method for the parallel detection of harmful algal species must be established because various HAB-forming algal species coexist in the marine environment. This work developed a multiplex PCR (mPCR) method that can simultaneously detect six common HAB-forming microalgal species distributed along the coast of China: Karlodinium veneficum (Kv), Chattonella marina (Cm), Skeletonema spp., Scrippsiella trochoidea (St), Karenia mikimotoi (Km), and Prorocentrum donghaiense (Pd). Specific mPCR primers were designed from the internal transcribed spacer rDNA or large subunit rDNA gene of the target algal species. The mPCR conditions were optimized. Each mPCR primer was subjected to a cross-reactivity test with other microalgae to confirm the specificity of the developed mPCR system. The results of the system stability test indicated that the background concentration of DNA tested did not affect the performance of the established mPCR system. The results of the sensitivity test showed that the detection limit of the proposed mPCR system for Kv, Cm, Km, and Pd was 0.6 ng µL-1 and that for Skeletonema spp. and St was 0.06 ng µL-1. Additional mPCR analysis with spiked field samples revealed that the detection limit of the mPCR system for Km, Pd, and Kv was 60 cells, whereas that for Cm, Skeletonema spp., and St was 6 cells. The convenience and accuracy of the established mPCR assay were further validated through tests with field samples. The proposed mPCR assay is characterized by parallel analysis, strong specificity, and stability and can be used to supplement morphology-based detection methods for algal species.

In-situ headspace analysis of metabolic carbon dioxide of aerobic bacteria for assessing antimicrobial activity of natural products.

Headspace analysis of the volatile metabolites has been used as a good strategy for monitoring the microbial growth in several applications, but never been established for the evaluation of the activity of microbial inhibitor in the field of drug screening from natural products. We report on a new method for the determination of antimicrobial activity of drug compounds or crude extracts from natural products by measuring the amount of metabolic carbon dioxide produced in the drug-bacteria incubation system. 2 mL of medium containing bacteria and drug of interest was incubated at 37 °C for 24 h. The amount of metabolic carbon dioxide partitioned in the headspace was measured to evaluate the drug antimicrobial activity using headspace gas chromatography (HS-GC) coupled with thermal conductive detector (TCD). The principle and the standard procedure of the present method have been developed and verified. As a result, the precision of the present method was less than 4% (expressed as relative standard deviation), and an excellent agreement was found on both inhibition rate (R2 = 0.935) and the half inhibition concentration (R2 = 0.994) between the present method and a reference method (optical density method). By comparison, the present method is simpler and safer regarding the microorganism contamination due to the in-situ incubation and detection in the closed system, and suitable for the routine analysis of antimicrobial activity of natural products with high flexibility in both bacterial strains and sample properties.

Volatile fingerprints and biomarkers of three representative kiwifruit cultivars obtained by headspace solid-phase microextraction gas chromatography mass spectrometry and chemometrics.

Volatile aroma of kiwifruit is a mixture of complicated and time-dependent compounds, and thereby the study of these compounds required distinguished analytical techniques as well as robust data analysis techniques. In this work, we report on the volatile fingerprints and biomarkers of three representative kiwifruit cultivars with commercial importance using headspace solid-phase microextraction gas chromatography-mass spectrometric (HS-SPME-GC-MS) coupled with multivariate analysis. As a result, 95 volatiles have been analyzed from the fingerprints, and ultimately six of which were identified as volatile biomarkers of the kiwifruit cultivars studied, which are formic acid octyl ester, 2-Methylbicyclo[4.3.0]non-1(6)-ene, 1-ethoxy-2,4-hexadiene, and 2-methyl-5-(1-methylethyl)-bicyclo[3.1.0]hex-2-ene for Jintao (A. chinensis), and 1-methoxy-2-methyl-benzene and (E,E)-2,4-heptadienal for Cuiyu (A. deliciosa), respectively. Since the samples of each cultivar were in various maturities, these compounds could be taken as the maturity-independent volatile biomarkers for the kiwifruit cultivars, which would be valuable for marker-assisted flavour breeding in the kiwifruit production.

Rapid and sensitive detection of Amphidinium carterae by loop-mediated isothermal amplification combined with a chromatographic lateral-flow dipstick.

Frequent outbreaks of toxic algal blooms devastate marine ecosystems, marine fisheries, and public health. Monitoring toxic algae is crucial to reduce losses caused by imminent algal blooms. However, traditional detection techniques relying on morphological examination are tedious and time-consuming. Therefore, the development of convenient strategies to detect toxin-producing microalgae is necessary. In this study, a novel method for the rapid, sensitive detection of Amphidinium carterae by loop-mediated isothermal amplification (LAMP) combined with a chromatographic lateral-flow dipstick (LFD) was established. The partial internal transcribed spacer gene was PCR amplified, cloned, and sequenced to design four LAMP primers and a detection probe for A. carterae detection. The LAMP detection conditions were optimized, and the optimum parameters were determined to be the following: dNTP concentration, 1.2 mM; betaine concentration, 1.2 M; magnesium ion concentration, 8 mM; ratio of inner primer to outer primer, 8:1; amplification temperature, 59 °C; and amplification time, 60 min. The specificity of LAMP-LFD was confirmed by cross-reactivity tests with other algal species. LAMP-LFD was 100 times more sensitive than regular PCR and similarly sensitive as LAMP and SYBR Green I. LAMP-LFD can be completed within 70 min and did not require special detection equipment. The convenience of the established LAMP-LFD assay was further validated by tests with simulated field-water samples. In conclusion, the developed LAMP-LFD assay can be used as a reliable and simple method of detecting A. carterae.

IL-6 increases podocyte motility via MLC-mediated focal adhesion impairment and cytoskeleton disassembly.

The disturbance of podocyte motility is an essential pathogenic mechanisms of foot process effacement during proteinuric diseases, and myosin light chain (MLC) is a pivotal component in regulating the motility of podocytes. Inflammatory cytokine interleukin-6 (IL-6) has been reported to induce podocyte abnormalities by various mechanisms, however, whether aberrant cell motility contributes to the IL-6-induced podocyte injury remains unknown. Here, by wound healing, transwell, and cell migration assays, we confirmed that IL-6 accelerates the motility of podocyte. Simultaneously, the phosphorylation of MLC is elevated along with perturbed focal adhesion (FAs) and cytoskeleton. Next, via genetic and pharmacologic interruption of MLC or its phosphorylation we revealed that the activation of MLC is implicated in IL-6-mediated podocyte hypermotility as well as the disassembly of FAs and F-actin. By using stattic, an inhibitor for STAT3 phosphorylation, we uncovered that STAT3 activation is the upstream event for MLC phosphorylation and the following aberrant motility of podocytes. Additionally, we found that calcitriol markedly attenuates podocyte hypermotility via blocking STAT3-MLC. In conclusion, our study demonstrated that IL-6 interrupts FAs dynamic, cytoskeleton organization, and eventually leads to podocyte hypermotility via STAT3/MLC, whereas calcitriol exerts its protective role by inhibiting this pathway. These findings enrich the mechanisms accounting for IL-6-mediated podocyte injury from the standpoint of cell motility and provide a novel therapeutic target for podocyte disorders.