The SOX4/EZH2/SLC7A11 signaling axis mediates ferroptosis in calcium oxalate crystal deposition-induced kidney injury.

Epigenetic regulation is reported to play a significant role in the pathogenesis of various kidney diseases, including renal cell carcinoma, acute kidney injury, renal fibrosis, diabetic nephropathy, and lupus nephritis. However, the role of epigenetic regulation in calcium oxalate (CaOx) crystal deposition-induced kidney injury remains unclear. Our study demonstrated that the upregulation of enhancer of zeste homolog 2 (EZH2)-mediated ferroptosis facilitates CaOx-induced kidney injury. CaOx crystal deposition promoted ferroptosis in vivo and in vitro. Usage of liproxstatin-1 (Lip-1), a ferroptosis inhibitor, mitigated CaOx-induced kidney damage. Single-nucleus RNA-sequencing, RNA-sequencing, immunohistochemical and western blotting analyses revealed that EZH2 was upregulated in kidney stone patients, kidney stone mice, and oxalate-stimulated HK-2 cells. Experiments involving in vivo EZH2 knockout, in vitro EZH2 knockdown, and in vivo GSK-126 (an EZH2 inhibitor) treatment confirmed the protective effects of EZH2 inhibition on kidney injury and ferroptosis. Mechanistically, the results of RNA-sequencing and chromatin immunoprecipitation assays demonstrated that EZH2 regulates ferroptosis by suppressing solute carrier family 7, member 11 (SLC7A11) expression through trimethylation of histone H3 lysine 27 (H3K27me3) modification. Additionally, SOX4 regulated ferroptosis by directly modulating EZH2 expression. Thus, this study demonstrated that SOX4 facilitates ferroptosis in CaOx-induced kidney injury through EZH2/H3K27me3-mediated suppression of SLC7A11.

Role of Histone Modifications in Kidney Fibrosis.

Chronic kidney disease (CKD) is characterized by persistent kidney dysfunction, ultimately resulting in end-stage renal disease (ESRD). Renal fibrosis is a crucial pathological feature of CKD and ESRD. However, there is no effective treatment for this condition. Despite the complex molecular mechanisms involved in renal fibrosis, increasing evidence highlights the crucial role of histone modification in its regulation. The reversibility of histone modifications offers promising avenues for therapeutic strategies to block or reverse renal fibrosis. Therefore, a comprehensive understanding of the regulatory implications of histone modifications in fibrosis may provide novel insights into more effective and safer therapeutic approaches. This review highlights the regulatory mechanisms and recent advances in histone modifications in renal fibrosis, particularly histone methylation and histone acetylation. The aim is to explore the potential of histone modifications as targets for treating renal fibrosis.

Susceptibility of renal fibrosis in diabetes: Role of hypoxia inducible factor-1.

Diabetes may prevent kidney repair and sensitize the kidney to fibrosis or scar formation. To test this possibility, we examined renal fibrosis induced by unilateral ureteral obstruction (UUO) in diabetic mouse models. Indeed, UUO induced significantly more renal fibrosis in both Akita and STZ-induced diabetic mice than in nondiabetic mice. The diabetic mice also had more apoptosis and interstitial macrophage infiltration during UUO. In vitro, hypoxia induced higher expression of the fibrosis marker protein fibronectin in high glucose-conditioned renal tubular cells than in normal glucose cells. Mechanistically, hypoxia induced significantly more hypoxia-inducible factor-1 α (HIF-1 α) in high glucose cells than in normal glucose cells. Inhibition of HIF-1 attenuated the expression of fibronectin induced by hypoxia in high-glucose cells. Consistently, UUO induced significantly higher HIF-1α expression along with fibrosis in diabetic mice kidneys than in nondiabetic kidneys. The increased expression of fibrosis induced by UUO in diabetic mice was diminished in proximal tubule-HIF-1α-knockout mice. Together, these results indicate that diabetes sensitizes kidney tissues and cells to fibrogenesis probably by enhancing HIF-1 activation.

Lidocaine aerosol sprayed on oral and/or nasal mucosa for the rescue of acute trigeminal neuralgia exacerbations: A retrospective study.

INTRODUCTION: Acute trigeminal neuralgia exacerbation is a common reason for frequent emergency department visits, that often occurs while waiting for surgery, but evidence on effective drugs for acute trigeminal neuralgia is scant. Whether lidocaine aerosol could be a rescue option for the treatment of acute trigeminal neuralgia exacerbations is worth exploring. Positive predictors of the analgesic effects of lidocaine aerosol also warrant further investigation. METHODS: This is a retrospective study with a total of 152 patients. We analyzed the efficacy of lidocaine aerosol for the treatment of acute trigeminal neuralgia exacerbations. A positive response was considered a decrease in the VAS score of at least 50% at 30 min of treatment. Multivariable logistic analyses were performed to identify predictive factors for lidocaine aerosol response. RESULTS: In the group of 109 responders, the VAS score decreased from 8.3 ± 1.1 cm to 0.8 ± 1.0 cm at 15 min, and 1.7 ± 1.0 cm at 30 min. The effective rate at 15 min and 30 min were 77.6% and 70.4%, respectively. Multivariate logistic analyses showed the treatment may provide better clinical outcomes in V2 trigeminal neuralgia (OR 0.01, 95%Cl 0.001-0.15, p < 0.001), V3 trigeminal neuralgia (OR 0.02, 95%Cl 0.001-0.16, p = 0.001), and V2 + V3 trigeminal neuralgia (OR 0.01, 95%Cl 0.001-0.13, p < 0.001), patients who were taking carbamazepine or oxcarbazepine with a maximum dose (OR 6.15, 95%Cl 2.11-17.93, p = 0.001) were less likely to experience immediate pain relief. CONCLUSION: Lidocaine aerosol sprayed on oral and/or nasal mucosa is beneficial for immediate pain relief in patients with acute trigeminal neuralgia exacerbations. It is expected to become a promising treatment option for patients with V2 and/or V3 trigeminal neuralgia.

STAT6 promoting oxalate crystal deposition-induced renal fibrosis by mediating macrophage-to-myofibroblast transition via inhibiting fatty acid oxidation.

OBJECTIVE AND DESIGN: Kidney stones commonly occur with a 50% recurrence rate within 5 years, and can elevate the risk of chronic kidney disease. Macrophage-to-myofibroblast transition (MMT) is a newly discovered mechanism that leads to progressive fibrosis in different forms of kidney disease. In this study, we aimed to investigate the role of MMT in renal fibrosis in glyoxylate-induced kidney stone mice and the mechanism by which signal transducer and activator of transcription 6 (STAT6) regulates MMT. METHODS: We collected non-functioning kidneys from patients with stones, established glyoxylate-induced calcium oxalate stone mice model and treated AS1517499 every other day in the treatment group, and constructed a STAT6-knockout RAW264.7 cell line. We first screened the enrichment pathway of the model by transcriptome sequencing; detected renal injury and fibrosis by hematoxylin eosin staining, Von Kossa staining and Sirius red staining; detected MMT levels by multiplexed immunofluorescence and flow cytometry; and verified the binding site of STAT6 at the PPARα promoter by chromatin immunoprecipitation. Fatty acid oxidation (FAO) and fibrosis-related genes were detected by western blot and real-time quantitative polymerase chain reaction. RESULTS: In this study, we found that FAO was downregulated, macrophages converted to myofibroblasts, and STAT6 expression was elevated in stone patients and glyoxylate-induced kidney stone mice. The promotion of FAO in macrophages attenuated MMT and upregulated fibrosis-related genes induced by calcium oxalate treatment. Further, inhibition of peroxisome proliferator-activated receptor-α (PPARα) eliminated the effect of STAT6 deletion on FAO and fibrosis-associated protein expression. Pharmacological inhibition of STAT6 also prevented the development of renal injury, lipid accumulation, MMT, and renal fibrosis. Mechanistically, STAT6 transcriptionally represses PPARα and FAO through cis-inducible elements located in the promoter region of the gene, thereby promoting MMT and renal fibrosis. CONCLUSIONS: These findings establish a role for STAT6 in kidney stone injury-induced renal fibrosis, and suggest that STAT6 may be a therapeutic target for progressive renal fibrosis in patients with nephrolithiasis.

Functional biochar fabricated from red mud and walnut shell for phosphorus wastewater treatment: Role of minerals.

A novel functional biochar (BC) was prepared from industrial waste red mud (RM) and low-cost walnut shell by one facile-step pyrolysis method to adsorb phosphorus (P) in wastewater. The preparation conditions for RM-BC were optimized using Response Surface Methodology. The adsorption characteristics of P were investigated in batch mode experiments, while a variety of techniques were used to characterize RM-BC composites. The impact of key minerals (hematite, quartz, and calcite) in RM on the P removal efficiency of the RM-BC composite was studied. The results showed that RM-BC composite produced at 320 °C for 58 min, with a 1:1 mass ratio of walnut shell and RM, had a maximum P sorption capacity of 15.48 mg g-1, which was more than double that of the raw BC. The removal of P from water was found to be facilitated significantly by hematite, which forms Fe-O-P bonds, undergoes surface precipitation, and exchanges ligands. This research provides evidence for the effectiveness of RM-BC in treating P in water, laying the foundation for future scaling-up trials.

RAE1 promotes nitrosamine-induced malignant transformation of human esophageal epithelial cells through PPARα-mediated lipid metabolism.

Esophageal cancer (EC) is the sixth cause of cancer-related deaths and still is a significant public health problem globally. Nitrosamines exposure represents a major health concern increasing EC risks. Exploring the mechanisms induced by nitrosamines may contribute to the prevention and early detection of EC. However, the mechanism of nitrosamine carcinogenesis remains unclear. Ribonucleic acid export 1 (RAE1), has an important role in mediating diverse cancer types, but, to date, there has been no study for any functional role of RAE1 in esophageal carcinogenesis. Here, we successfully verified the nitrosamine-induced malignant transformation cell (MNNG-M) by xenograft tumor model, based on which it was found that RAE1 was upregulation in the early stage of nitrosamine-induced esophageal carcinogenesis and EC tissues. RAE1 knockdown led to severe blockade in G2/M phase and significant inhibition of proliferation of MNNG-M cells, whereas RAE1 overexpression had the opposite effect. In addition, peroxisome proliferator-activated receptor-alpha (PPARα), was demonstrated as a downstream target gene of RAE1, and its down-regulation reduced lipid accumulation, resulting in causing cells accumulation in the G2/M phase. Mechanistically, we found that RAE1 regulates the lipid metabolism by maintaining the stability of PPARα mRNA. Taken together, our study reveals that RAE1 promotes malignant transformation of human esophageal epithelial cells (Het-1A) by regulating PPARα-mediated lipid metabolism to affect cell cycle progression, and offers a new explanation of the mechanisms underlying esophageal carcinogenesis.

Centralized health management based on hot spring resort improves physical examination indicators and sleep quality in people at high risk of chronic diseases: a randomized controlled trial.

We study the effects of centralized health management based on hot spring resorts on the physical examination index and sleep quality of people at high risk of chronic diseases. We recruited 114 volunteers at high risk of chronic diseases. We then divided them into 57 in the intervention group and 57 in the control group. The intervention group collectively received 4 weeks (28 days) of comprehensive health management interventions at Tongjing Hotspring Resort, including regular schedules, balanced diet, appropriate exercise, targeted health education, etc. The main outcomes are physical examination indicators (height, weight, waist circumference, blood pressure, lipids, and glucose) and sleep quality. Both groups underwent a questionnaire and physical examination at baseline, 2 weeks and 4 weeks. Intragroup comparisons grouped by exposure criteria showed decreases in BMI, waist circumference, triglycerides, total cholesterol, and blood glucose in the intervention group at both 2 and 4 weeks (all P < 0.05); however, in the control group, only triglycerides decreased at 4 weeks (P < 0.05). Intergroup comparisons showed BMI and waist circumference were significantly lower in the intervention group than in the control group at 4 weeks (all P < 0.05). Intragroup comparisons of insomnia severity index (ISI) scores showed a significant decrease in the intervention group at both 2 and 4 weeks (all P < 0.001) with no significant change in the control group (P > 0.05). Intergroup comparisons showed that the insomnia severity index (ISI) scores were significantly higher in the intervention group than in the control group at baseline (P = 0.006) but became significantly lower than the control group at 2 and 4 weeks (all P < 0.001). Thus, this pattern significantly improved BMI, waist circumference, triglycerides, and sleep in the intervention group. TRIAL REGISTRATION NUMBER: Chinese Clinical Trials Registry: ChiCTR2100053201, registered 14 Nov 2021. (Retroactive Registration).

BMAL1 regulates mitochondrial homeostasis in renal ischaemia-reperfusion injury by mediating the SIRT1/PGC-1α axis.

The regulation of renal function by circadian gene BMAL1 has been recently recognized; however, the role and mechanism of BMAL1 in renal ischaemia-reperfusion injury (IRI) are still unknown. The purpose of this study was to clarify the pathophysiological role of BMAL1 in renal IRI. We measured the levels of BMAL1 and mitochondrial biogenesis-related proteins, including SIRT1, PGC-1α, NRF1 and TFAM, in rats with renal IRI. In rats, the level of BMAL1 decreased significantly, resulting in inhibition of SIRT1 expression and mitochondrial biogenesis. In addition, under hypoxia and reoxygenation (H/R) stimulation, BMAL1 knockdown decreased the level of SIRT1 and exacerbated the degree of mitochondrial damage and apoptosis. Overexpression of BMAL1 alleviated H/R-induced injury. Furthermore, application of the SIRT1 inhibitor EX527 not only reduced the activities of SIRT1 and PGC-1α but also further aggravated mitochondrial dysfunction and partially reversed the protective effect of BMAL1 overexpression. Moreover, whether in vivo or in vitro, the application of SIRT1 agonist resveratrol rescued the mitochondrial dysfunction caused by H/R or IRI by activating mitochondrial biogenesis. These results indicate that BMAL1 is a key circadian gene that mediates mitochondrial homeostasis in renal IRI through the SIRT1/PGC-1α axis, which provides a new direction for targeted therapy for renal IRI.

microRNA-486-5p is implicated in the cisplatin-induced apoptosis and acute inflammation response of renal tubular epithelial cells by targeting HAT1.

The proinflammatory property of cisplatin is potentially destructive and contributes to the pathogenesis of acute kidney injury (AKI). The role and upstream regulatory mechanism of histone acetyltransferase 1 (HAT1) in acute kidney inflammation are still unknown. We performed RNA sequencing to filter differentially expressed microRNAs (miRNAs) in the kidney tissue of mice with AKI induced by cisplatin and ischemia-reperfusion. Here, we found that miR-486-5p was upregulated and that the expression of HAT1 was reduced in AKI mouse models and injured human renal proximal tubular epithelial cell (HK-2) model induced by cisplatin. miR-486-5p is implicated in cisplatin-induced kidney damage in vivo. Bioinformatics analysis predicted a potential binding site between miR-486-5p and HAT1. The Luciferase reporter assay and Western blot confirmed that miR-486-5p directly targeted the 3'-untranslated region of HAT1 mRNA and inhibited its expression in the cytoplasm of HK-2 cells. In the in vitro study, inhibiting miR-486-5p reduced apoptosis, and the expression of proinflammatory mediators was induced by cisplatin in HK-2 cells. Simultaneously, the downregulation of miR-486-5p inhibited the activation of the toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB). We further found that HAT1 could inhibit apoptosis and the activation of cisplatin on the TLR4/NF-κB pathway and that the upregulation of miR-486-5p reversed this effect. Therefore, the upregulation of miR-486-5p targeting HAT1 promoted the cisplatin-induced apoptosis and acute inflammation response of renal tubular epithelial cells by activating the TLR4/NF-κB pathway, providing a new basis to highlight the potential intervention of regulating the miR-486-5p/HAT1 axis.

Efficacy and safety of PEGylated exenatide injection (PB-119) in treatment-naive type 2 diabetes mellitus patients: a Phase II randomised, double-blind, parallel, placebo-controlled study.

AIMS/HYPOTHESIS: Glucagon-like peptide 1 receptor agonists (GLP-1 RA) such as exenatide are used as monotherapy and add-on therapy for maintaining glycaemic control in patients with type 2 diabetes mellitus. The current study investigated the safety and efficacy of once-weekly PB-119, a PEGylated exenatide injection, in treatment-naive patients with type 2 diabetes. METHODS: In this Phase II, randomised, placebo-controlled, double-blind study, we randomly assigned treatment-naive Chinese patients with type 2 diabetes in a 1:1:1:1 ratio to receive subcutaneous placebo or one of three subcutaneous doses of PB-119 (75, 150, and 200 µg) for 12 weeks. The primary endpoint was the change in HbA1c from baseline to week 12, and other endpoints were fasting plasma glucose, 2 h postprandial glucose (PPG), and proportion of patients with HbA1c < 53 mmol/mol (<7.0%) and ≤48 mmol/mol (≤6.5%) at 2, 4, 8 and 12 weeks of treatment. Safety was assessed in all patients who received at least one dose of study drug. RESULTS: We randomly assigned 251 patients to one of the four treatment groups (n = 62 in placebo and 63 each in PB-119 75 µg, 150 µg and 200 µg groups). At the end of 12 weeks, mean differences in HbA1c in the treatment groups were -7.76 mmol/mol (95% CI -9.23, -4.63, p < 0.001) (-0.72%, 95% CI -1.01, -0.43), -12.89 mmol/mol (95% CI -16.05, -9.72, p < 0.001) (-1.18%, 95% CI -1.47, -0.89) and -11.14 mmol/mol (95% CI -14.19, -7.97, p <0 .001) (-1.02%, 95% CI -1.30, -0.73) in the 75 µg, 150 µg and 200 µg PB-119 groups, respectively, compared with that in the placebo group after adjusting for baseline HbA1c. Similar results were also observed for other efficacy endpoints across different time points. There was no incidence of treatment-emergent serious adverse event, severe hypoglycaemia or death. CONCLUSIONS/INTERPRETATION: All tested PB-119 doses had superior efficacy compared with placebo and were safe and well tolerated over 12 weeks in treatment-naive Chinese patients with type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03520972 FUNDING: The study was funded by National Major Scientific and Technological Special Project for Significant New Drugs Development and PegBio.

LncRNA TUG1 attenuates ischaemia-reperfusion-induced apoptosis of renal tubular epithelial cells by sponging miR-144-3p via targeting Nrf2.

Renal ischaemia/reperfusion (I/R) injury may induce kidney damage and dysfunction, in which oxidative stress and apoptosis play important roles. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are reported to be closely related to renal I/R, but the specific molecular mechanism is still unclear. The purpose of this research was to explore the regulatory effect of lncRNA TUG1 on oxidative stress and apoptosis in renal I/R injury. This research revealed that in renal I/R injury and hypoxia/reperfusion (H/R) injury in vitro, the expression level of lncRNA TUG1 was upregulated, and oxidative stress levels and apoptosis levels were negatively correlated with the expression level of lncRNA TUG1. Using bioinformatics databases such as TargetScan and microRNA.org, microRNA-144-3p (miR-144-3p) was predicted to be involved in the association between lncRNA TUG1 and Nrf2. This study confirmed that the level of miR-144-3p was significantly reduced following renal I/R injury and H/R injury in vitro, and miR-144-3p was determined to target Nrf2 and inhibit its expression. In addition, lncRNA TUG1 can reduce the inhibitory effect of miR-144-3p on Nrf2 by sponging miR-144-3p. In summary, our research shows that lncRNA TUG1 regulates oxidative stress and apoptosis during renal I/R injury through the miR-144-3p/Nrf2 axis, which may be a new treatment target for renal I/R injury.

Novel lncRNA XLOC_032768 protects against renal tubular epithelial cells apoptosis in renal ischemia-reperfusion injury by regulating FNDC3B/TGF-ß1.

Renal ischemia-reperfusion injury is a leading cause of acute kidney injury, but its underlying mechanism remains poorly understood and effective therapies are still lacking. Here, we identified lncRNA XLOC_032768 as a novel target in renal ischemia-reperfusion injury by analyzing differentially expressed genes of the transcriptome data. PCR results show that XLOC_032768 was markedly downregulated in the kidney during renal ischemia-reperfusion in mice and in cultured kidney cells during hypoxia. Upon induction in vitro, XLOC_032768 overexpression repressed the expression of fibronectin type III domain containing 3B (FNDC3B) and tubular epithelial cells apoptosis. Administration of XLOC_032768 preserved FNDC3B expression and attenuated renal tubular epithelial cells apoptosis, resulting in protection against kidney injury in mice. Knockdown of FNDC3B markedly reduced the expression of TGF-ß1 and apoptosis of renal tubular cells. Thus, XLOC_032768/FNDC3B/TGF-ß1signaling pathway in ischemia-reperfusion injury may be targeted for therapy.

[Effect of testicular autophagy on spermatogenic cells in varicocele rats].

OBJECTIVE: To study the effect of different levels of autophagy in the testis on the apoptosis of spermatogenic cells in the rat model of varicocele (VC). METHODS: We randomly divided 54 SD male rats into six groups, blank control (n = 6), rapamycin control (n = 6), chloroquine control (n = 6), VC model control (n = 12), VC + rapamycin (n = 12), and VC + chloroquine (n = 12). We observed the histomorphological changes of the testis and epididymis by HE staining, obtained the scores on spermatogenesis in the testis and epididymis, calculated the apoptosis index (AI) of the testicular spermatogenic cells by TUNEL, and determined the expressions of LC3-Ⅱ, LC3-Ⅰ, p62, Bax and Bcl-2 proteins in the testis tissue by Western blot. RESULTS: There were no significant morphological changes in the testis and epididymis of the rats in the blank control, rapamycin control and chloroquine control groups, or significant differences in the scores on testicular and epididymal spermatogenesis and AI of the testicular spermatogenic cells (P>0.05). The animals in the VC model control group exhibited significant pathological damage in the testicular and epididymal tissues, with remarkably decreased scores on spermatogenesis (P<0.01) and increased AI (P<0.01), which were markedly improved in the VC + rapamycin group and slightly aggravated in the VC + chloroquine group compared with the VC model controls. In comparison with the rats in the blank control group, those in the VC model control group showed significantly up-regulated expressions of the autophagy-related protein LC3 (including the LC3-Ⅱ/LC3-Ⅰ ratio) and the pro-apoptotic protein Bax in testicular tissue (P<0.01) but down-regulated expression of the anti-apoptotic protein Bcl-2 (P<0.01). The expressions of LC3 and Bcl-2 in the testis tissue were significantly higher in the VC + rapamycin (P<0.01) but lower in the VC + chloroquine group (P<0.01), while those of p62 and Bax remarkably lower in the VC + rapamycin (P<0.01) but higher in the VC + chloroquine group than in the VC model controls (P<0.01). CONCLUSIONS: Varicocele induces autophagy in the testis and apoptosis of spermatogenic cells in rats. Up-regulating autophagy can inhibit while blocking autophagy can promote the apoptosis of spermatogenic cells.

Tissue-specific transcriptomic profiling of Plantago major provides insights for the involvement of vasculature in phosphate deficiency responses.

The vasculature of higher plants is important with transport of both nutrient and information molecules. To understand the correspondence of this tissue in molecular responses under phosphate (Pi) deficiency, Plantago major, a model plant for vasculature biology study, was chosen in our analysis. After RNA-Seq and de novo transcriptome assembly of 24 libraries prepared from the vasculature of P. major, 37,309 unigenes with a mean length of 1571 base pairs were obtained. Upon 24 h of Pi deficiency, 237 genes were shown to be differentially expressed in the vasculature of P. major. Among these genes, only 27 have been previously identified to be specifically expressed in the vasculature tissues in other plant species. Temporal expression of several marker genes associated with Pi deficiency showed that the time period of first 24 h is at the beginning stage of more dynamic expression patterns. In this study, we found several physiological processes, e.g., "phosphate metabolism and remobilization", "sucrose metabolism, loading and synthesis", "plant hormone metabolism and signal transduction", "transcription factors", and "metabolism of other minerals", were mainly involved in early responses to Pi deficiency in the vasculature. A number of vasculature genes with promising roles in Pi deficiency adaptation have been identified and deserve further functional characterization. This study clearly demonstrated that plant vasculature is actively involved in Pi deficiency responses and understanding of this process may help to create plants proficient to offset Pi deficiency.

Elucidation of the Mechanisms of Long-Distance mRNA Movement in a Nicotiana benthamiana/Tomato Heterograft System.

Recent heterograft analyses showed that large-scale messenger RNA (mRNA) movement takes place in the phloem, but the number of mobile transcripts reported varies widely. However, our knowledge of the mechanisms underlying large-scale mRNA movement remains limited. In this study, using a Nicotiana benthamiana/tomato (Solanum lycopersicum) heterograft system and a transgenic approach involving potato (Solanum tuberosum), we found that: (1) the overall mRNA abundance in the leaf is not a good indicator of transcript mobility to the root; (2) increasing the expression levels of nonmobile mRNAs in the companion cells does not promote their mobility; (3) mobile mRNAs undergo degradation during their movement; and (4) some mRNAs arriving in roots move back to shoots. These results indicate that mRNA movement has both regulated and unregulated components. The cellular origins of mobile mRNAs may differ between herbaceous and woody species. Taken together, these findings suggest that the long-distance movement of mRNAs is a complex process and that elucidating the physiological roles associated with this movement is challenging but remains an important task for future research.

Ursolic acid inhibits epithelial-mesenchymal transition in vitro and in vivo.

CONTEXT: Ursolic acid (UA; 3ß-hydroxy-urs-12-en-28-oic acid), one of the pentacyclic triterpenoids found in various plants and herbs, possesses some beneficial effects under pathological conditions, including combating hepatic fibrosis. OBJECTIVE: This study investigates the effects of UA on renal tubulointerstitial fibrosis in vivo and in vitro. MATERIALS AND METHODS: In vivo, 24 male C57BL6 mice were divided into four groups. Eighteen mice were subjected to unilateral ureteral obstruction (UUO) and the remaining six sham-operated mice served as control. UUO mice received either vehicle or UA (50 or 100 mg/kg) by gastric gavage for 6 days. In vitro, HK-2 cells were treated with 10 or 50 µM UA and 10 ng/mL recombinant human transforming growth factor-ß1 (TGF-ß1). The molecular mechanisms of fibrosis were investigated. RESULTS: UUO induced marked interstitial collagen I and fibronectin deposition and epithelial-mesenchymal transition (EMT), as evidenced by increased α-smooth muscle actin (α-SMA) and decreased E-cadherin. However, UA treatment significantly reduced collagen I and fibronectin accumulation in the fibrotic kidney. UA treatment also decreased α-SMA and preserved E-cadherin in vivo. In vitro, TGF-ß1-treated HK-2 cells demonstrated elevated α-SMA, snail1, slug, TGF-ß1, and p-smad3, as well as diminished E-cadherin. UA pretreatment prevented E-cadherin loss and diminished α-SMA expression in HK-2 cells. UA downregulated mRNA expression of snail1 and slug. UA also lowered TGF-ß1 protein expression and p-Smad3 in HK-2 cells. CONCLUSIONS: UA attenuated renal tubulointerstitial fibrosis by inhibiting EMT, and such inhibition may be achieved by decreasing profibrotic factors. UA may be a novel therapeutic agent for renal fibrosis.

Distinct Mechanisms of the ORANGE Protein in Controlling Carotenoid Flux.

ß-Carotene adds nutritious value and determines the color of many fruits, including melon (Cucumis melo). In melon mesocarp, ß-carotene accumulation is governed by the Orange gene (CmOr) golden single-nucleotide polymorphism (SNP) through a yet to be discovered mechanism. In Arabidopsis (Arabidopsis thaliana), OR increases carotenoid levels by posttranscriptionally regulating phytoene synthase (PSY). Here, we identified a CmOr nonsense mutation (Cmor-lowß) that lowered fruit ß-carotene levels with impaired chromoplast biogenesis. Cmor-lowß exerted a minimal effect on PSY transcripts but dramatically decreased PSY protein levels and enzymatic activity, leading to reduced carotenoid metabolic flux and accumulation. However, the golden SNP was discovered to not affect PSY protein levels and carotenoid metabolic flux in melon fruit, as shown by carotenoid and immunoblot analyses of selected melon genotypes and by using chemical pathway inhibitors. The high ß-carotene accumulation in golden SNP melons was found to be due to a reduced further metabolism of ß-carotene. This was revealed by genetic studies with double mutants including carotenoid isomerase (yofi), a carotenoid-isomerase nonsense mutant, which arrests the turnover of prolycopene. The yofi F2 segregants accumulated prolycopene independently of the golden SNP Moreover, Cmor-lowß was found to inhibit chromoplast formation and chloroplast disintegration in fruits from 30 d after anthesis until ripening, suggesting that CmOr regulates the chloroplast-to-chromoplast transition. Taken together, our results demonstrate that CmOr is required to achieve PSY protein levels to maintain carotenoid biosynthesis metabolic flux but that the mechanism of the CmOr golden SNP involves an inhibited metabolism downstream of ß-carotene to dramatically affect both carotenoid content and plastid fate.

Slit2 ameliorates renal inflammation and fibrosis after hypoxia-and lipopolysaccharide-induced epithelial cells injury in vitro.

Hypoxic acute kidney injury (AKI) is often incompletely repaired and leads to chronic kidney disease (CKD), which is characterized by tubulointerstitial inflammation and fibrosis. The Slit2 family of secreted glycoproteins is expressed in the kidney, it has been shown to exert an anti-inflammatory activity and prevent ischemic renal injury in vivo. However, whether Slit2 reduces renal fibrosis and inflammation after hypoxic and inflammatory epithelial cells injury in vitro remains unknown. In this study, we aimed to evaluate whether Slit2 ameliorated fibrosis and inflammation in two renal epithelial cells line challenged with hypoxia and lipopolysaccharide (LPS). Renal epithelial cells were treated with hypoxia and LPS to induce cell injury. Hoechst staining and Western blot analysis was conducted to examine epithelial cells injury. Immunofluorescence staining and Western blot analysis was performed to evaluate tubulointerstitial fibrosis. Real-time polymerase chain reaction (PCR) tested the inflammatory factor interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, and Western blot analysis determined the hypoxia-inducible factor (HIF)-1α, Toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB. Results revealed that hypoxia induced epithelial cells apoptosis, inflammatory factor IL-1ß and TNF-α release and tubulointerstitial fibrosis. LPS could exacerbate hypoxia -induced epithelial cells apoptosis, IL-1ß and TNF-α release and fibrosis. Slit2 reduced the expression of fibronectin, the rate of epithelial cell apoptosis, and the expression of inflammatory factor. Slit2 could also inhibit the expression of TLR4 and NF-κB, but not the expression of HIF-1α. Therefore, Slit2 attenuated inflammation and fibrosis after LPS- and hypoxia-induced epithelial cells injury via the TLR4/NF-κB signaling pathway, but not depending on the HIF-1α signaling pathway.

Physiological and transcriptomic responses of reproductive stage soybean to drought stress.

KEY MESSAGE: The dynamic alterations of the physiological and molecular processes in reproductive stage soybean indicated the dramatic impact caused by drought. Drought is a major abiotic stress that limits soybean (Glycine max) production. Most prior studies were focused on either model species or crops that are at their vegetative stages. It is known that the reproductive stage of soybean is more susceptible to drought. Therefore, an understanding on the responsive mechanisms during this stage will not only be important for basic plant physiology, but the knowledge can also be used for crop improvement via either genetic engineering or molecular breeding. In this study, physiological measurements and RNA-Seq analysis were used to dissect the metabolic alterations and molecular responses in the leaves of soybean grown at drought condition. Photosynthesis rate, stomata conductance, transpiration, and water potential were reduced. The activities of SOD and CAT were increased, while the activity of POD stayed unchanged. A total of 2771 annotated genes with at least twofold changes were found to be differentially expressed in the drought-stressed plants in which 1798 genes were upregulated and 973 were downregulated. Via KEGG analysis, these genes were assigned to multiple molecular pathways, including ABA biogenesis, compatible compound accumulation, secondary metabolite synthesis, fatty acid desaturation, plant transcription factors, etc. The large number of differentially expressed genes and the diverse pathways indicated that soybean employs complicated mechanisms to cope with drought. Some of the identified genes and pathways can be used as targets for genetic engineering or molecular breeding to improve drought resistance in soybean.