Evodiamine inhibits growth of vemurafenib drug-resistant melanoma via suppressing IRS4/PI3K/AKT signaling pathway

Evodiamine, a novel alkaloid, was isolated from the fruit of tetradium. It exerts a diversity of pharmacological effects and has been used to treat gastropathy, hypertension, and eczema. Several studies reported that evodiamine has various biological effects, including anti-nociceptive, anti-bacterial, anti-obesity, and anti-cancer activities. However, there is no research regarding its effects on drug-resistant cancer. This study aimed to investigate the effect of evodiamine on human vemurafenib-resistant melanoma cells (A375/R cells) proliferation ability and its mechanism. Cell activity was assessed using the cell counting kit-8 (CCK-8) method. Flow cytometry assay was used to assess cell apoptosis and cell cycle. A xenograft model was used to analyze the inhibitory effects of evodiamine on tumor growth. Bioinformatics analyses, network pharmacology, and molecular docking were used to explore the potential mechanism of evodiamine in vemurafenib-resistant melanoma. RT-qPCR and Western blotting were performed to reveal the molecular mechanism. The alkaloid extract of the fruit of tetradium, evodiamine showed the strongest tumor inhibitory effect on vemurafenib-resistant melanoma cells compared to treatment with vemurafenib alone. Evodiamine inhibited vemurafenib-resistant melanoma cell growth, proliferation, and induced apoptosis, conforming to a dose-effect relationship and time-effect relationship. Results from network pharmacology and molecular docking suggested that evodiamine might interact with IRS4 to suppress growth of human vemurafenib-resistant melanoma cells. Interestingly, evodiamine suppressed IRS4 expression and then inhibited PI3K/AKT signaling pathway, and thus had the therapeutic action on vemurafenib-resistant melanoma.

Ginsenoside Rg1 attenuates D-galactose-induced neural stem cell senescence via the Sirt1-Nrf2-BDNF pathway

With the ageing of society's population, neurodegenerative diseases have become an important factor affecting the quality of life and mortality in the elderly. Since its physiopathological processes are complex and the authorized medications have recently been shown to have several adverse effects, the development of safe and efficient medications is urgently needed. In this study, we looked at how ginsenoside Rg1 works to postpone neural stem cell ageing and brain ageing, giving it a solid scientific foundation for use as a therapeutic therapy for neurodegenerative diseases.

High urea induces anxiety disorders associated with chronic kidney disease by promoting abnormal proliferation of OPC in amygdala

Chronic kidney disease (CKD) with anxiety disorder is of a great concern due to its high morbidity and mortality. Urea, as an important toxin in CKD, is not only a pathological factor for complications in patients with CKD, but also is accumulated in the brain of aging and neurodegenerative diseases. However, the pathological role and underlying regulatory mechanism of urea in CKD related mood disorders have not been well established. We previously reported a depression phenotype in mice with abnormal urea metabolism. Since patients with depression are more likely to suffer from anxiety, we speculate that high urea may be an important factor causing anxiety in CKD patients. In adenine-induced CKD mouse model and UT-B-/- mouse model, multiple behavioral studies confirmed that high urea induces anxiety-like behavior. Single-cell transcriptome revealed that down-regulation of Egr1 induced compensatory proliferation of oligodendrocyte progenitor cells (OPC). Myelin-related signaling pathways of oligodendrocytes (OL) were change significant in the urea accumulation amygdala. The study showed that high urea downregulated Egr1 with subsequent upregulation of ERK pathways in OPCs. These data indicate that the pathological role and molecular mechanism of high urea in CKD-related anxiety, and provide objective serological indicator and a potential new drug target for the prevention and treatment of anxiety in CKD patients.

Programmed Release METTL3-14 Inhibitor Microneedle Protects Myocardial Function by Reducing Drp1 m6A Modification-Mediated Mitochondrial Fission

M6A modification is an RNA-important processing event mediated by methyltransferases METTL3 and METTL14 and the demethylases. M6A dynamic changes after myocardial infarction (MI), involved in the massive loss of cardiomyocytes due to hypoxia, as well as the recruitment and activation of myofibroblasts. Balanced mitochondrial fusion and fission are essential to maintain intracardiac homeostasis and reduce poststress myocardial remodeling. Double-layer programmed drug release microneedle (DPDMN) breaks the limitations of existing therapeutic interventions in one period or one type of cells, and multitargeted cellular combination has more potential in MI therapy. By employing hypoxia-ischemic and TGF-β1-induced fibrosis cell models, we found that METTL3-14 inhibition effectively decreased cardiomyocyte death through the reduction of mitochondrial fragmentation and inhibiting myofibrillar transformation. DPDMN treatment of MI in rat models showed improved cardiac function and decreased infarct size and fibrosis level, demonstrating its superior effectiveness. The DPDMN delivers METTL3 inhibitor swiftly in the early phase to rescue dying cardiomyocytes and slowly in the late phase to achieve long-term suppression of fibroblast over proliferation, collagen synthesis, and deposition. RIP assay and mechanistic investigation confirmed that METTL3 inhibition reduced the translation efficiency of Drp1 mRNA by 5'UTR m6A modification, thus decreasing the Drp1 protein level and mitochondrial fragment after hypoxic-ischemic injury. This project investigated the efficacy of DPDMNs-loaded METTL3 inhibitor in MI treatment and the downstream signaling pathway proteins, providing an experimental foundation for the translation of the utility, safety, and versatility of microneedle drug delivery for MI into clinical applications.

A randomized trial of eribulin monotherapy versus eribulin plus anlotinib in patients with locally recurrent or metastatic breast cancer

BACKGROUND

Eribulin mesylate is a novel, nontaxane, microtubule dynamics inhibitor. In this study, we assessed the efficacy and safety of eribulin versus eribulin plus the oral small-molecule tyrosine kinase inhibitor anlotinib in patients with locally recurrent or metastatic breast cancer.

PATIENTS AND METHODS

In this single-center, open-label, phase II clinical study (NCT05206656) conducted in a Chinese hospital, patients with human epidermal growth factor receptor 2 (HER2)-negative, locally recurrent or metastatic breast cancer previously treated with anthracycline- or taxane-based chemotherapy were randomized (1 : 1) to receive eribulin alone or in combination with anlotinib. The primary efficacy endpoint was investigator-assessed progression-free survival (PFS).

RESULTS

From June 2020 to April 2022, a total of 80 patients were randomly assigned to either eribulin monotherapy or eribulin plus anlotinib combination therapy, with 40 patients in each group. The data cut-off was 10 August 2022. The median PFS was 3.5 months [95% confidence interval (CI) 2.8-5.5 months] for eribulin and 5.1 months (95% CI 4.5-6.9 months) for eribulin plus anlotinib (hazard ratio = 0.56, 95% CI 0.32-0.98; P = 0.04). The objective response rates were 32.5% versus 52.5% (P = 0.07), respectively, and disease control rates were 67.5% versus 92.5% (P = 0.01), respectively. Patients <50 years of age, with an Eastern Cooperative Oncology Group performance status score of 0, visceral metastasis, number of treatment lines of four or more, hormone receptor negative (triple-negative), and HER2 low expression appeared to benefit more from combined treatment. The most common adverse events in both groups were leukopenia (n = 28, 70.0%, patients in the eribulin monotherapy group versus n = 35, 87.5%, patients in the combination therapy group), aspartate aminotransferase elevations (n = 28, 70.0%, versus n = 35, 87.5%), neutropenia (n = 25, 62.5%, versus n = 31, 77.5%), and alanine aminotransferase elevations (n = 25, 62.5%, versus n = 30, 75.0%).

CONCLUSION

Eribulin plus anlotinib can be considered an alternative treatment option for HER2-negative locally advanced or metastatic breast cancer.

Geranylgeranylacetone-induced heat shock protein70 expression reduces retinal ischemia-reperfusion injury through PI3K/AKT/mTOR signaling

Retinal ischemia-reperfusion (I/R) injury is a common pathophysiological stress state connected to various diseases, including acute glaucoma, retinal vascular obstruction, and diabetic retinopathy. Recent studies have suggested that geranylgeranylacetone (GGA) could increase heat shock protein70 (HSP70) level and reduce retinal ganglion cells (RGCs) apoptosis in a rat retinal I/R model. However, the underlying mechanism remains unclear. Moreover, the injury caused by retinal I/R includes not only apoptosis but also autophagy and gliosis, and the effects of GGA on autophagy and gliosis have not been reported. Our study established a retinal I/R model by anterior chamber perfusion pressuring to 110 mmHg for 60 min, followed by 4 h of reperfusion. The levels of HSP70, apoptosis-related proteins, GFAP, LC3-II, and PI3K/AKT/mTOR signaling proteins were determined by western blotting and qPCR after treatment with GGA, HSP70 inhibitor quercetin (Q), PI3K inhibitor LY294002, and mTOR inhibitor rapamycin. Apoptosis was evaluated by TUNEL staining, meanwhile, HSP70 and LC3 were detected by immunofluorescence. Our results demonstrated that GGA-induced HSP70 expression significantly reduced gliosis, autophagosome accumulation, and apoptosis in retinal I/R injury, indicating that GGA exerted protective effects on retinal I/R injury. Moreover, the protective effects of GGA mechanistically relied on the activation of PI3K/AKT/mTOR signaling. In conclusion, GGA-induced HSP70 overexpression has protective effects on retinal I/R injury by activating PI3K/AKT/mTOR signaling.

Ganoderma lucidum polysaccharides ameliorates D-galactose-induced aging salivary secretion disorders by upregulating the rhythm and aquaporins

Longer-term deterioration in saliva secretion has been observed to occur in response to aging. The functional deterioration of the salivary gland damages swallowing and chewing abilities and consequently reduces life quality of the elderly. There are, however, only a few proven effective treatments for aging salivary secretion disorders. Ganoderma lucidum polysaccharide (GLP) has been applied to treat various diseases because of its safety, efficacy, and low cost. We investigated the protective effect of GLP on the submandibular gland (SMG) during aging. D-galactose (D-gal) was used to treat the aging mice, and the body weight, water consumption, saliva secretion, and flow rate were measured after 6 weeks of modeling. Micromorphological changes of the SMG were assessed by hematoxylin-eosin staining and transmission electron microscopy. RT-qPCR and Western blot were used to detect the expression of apoptotic proteins and inflammatory cytokines. Aquaporins (AQPs) and rhythmic protein expression were analyzed by immunohistochemistry and immunofluorescence. The results showed that GLP effectively promoted the expression of AQP5, AQP4, and AQP1, inhibited the release of TNF-α, IL-6, and Bax, and reduced inflammation and apoptosis. Further experiments showed that GLP promoted the up-regulation of core clock genes and proteins and restored the co-localized expression of CLOCK and AQP5 that were weakened during aging, helping to attenuate aging-induced weight loss, decreased salivation, and structural and functional damage. The findings of this work contribute to understanding the nature of age-related modifications in SMG by identifying changes in AQP5 expression and regulatory mechanisms linked to SMG dysfunction during aging. GLP is a potential drug for maintaining healthy salivary gland (SG) status and preventing SG deficiency in the elderly.

Activation cross sections for reactions induced by 14 MeV neutrons on natural titanium

Cross sections for the neutrons around 14 MeV interaction with natural titanium were precisely measured by neutron activation and off-line measurement technique. The fast neutrons were produced by ³H(d,n)⁴He reaction and the neutron energy was obtained by using the cross section ratio method of ⁹⁰Zr(n,2n)⁸⁹Zr to ⁹³Nb(n,2n)^92mNb reactions. Experimental cross sections have been acquired for ^natTi(n,x)⁴⁶Sc, ^natTi(n,x)⁴⁷Sc, ⁵⁰Ti(n,x)⁴⁷Ca and ⁴⁸Ti(n,x)⁴⁸Sc reactions. The measured cross section data are compared with the experimental data available in the previous literature and evaluated nuclear data from the ENDF/B-VIII.0, JEFF-3.3, JENDL-5, BROND-3.1, CENDL-3.2 and FENDL-3.2b libraries. Furthermore, excitation functions for these reactions were calculated by using the theoretical model based on Talys-1.96 code with default and adjusted parameters. Within experimental error, evaluated nuclear data are mostly consistent with experimental data. The excitation function with adjusted parameters can roughly reproduce the experimental data.

p53 inhibits the Urea cycle and represses polyamine biosynthesis in glioma cell lines

Glioma is the most common malignant tumor of the central nervous system. The urea cycle (UC) is an essential pathway to convert excess nitrogen and ammonia into the less toxic urea in humans. However, less is known about the functional significance of the urea cycle in glioma. p53 functions as a tumor suppressor and modulates several cellular functions and disease processes. In the present study, we aimed to explore whether p53 influences glioma progression by regulating the urea cycle. Here, we demonstrated the inhibitory impact of p53 on the expression of urea cycle enzymes and urea genesis in glioma cells. The level of polyamine, a urea cycle metabolite, was also regulated by p53 in glioma cells. Carbamoyl phosphate synthetase-1 (CPS1) is the first key enzyme involved in the urea cycle. Functionally, we demonstrated that CPS1 knockdown suppressed glioma cell proliferation, migration and invasion. Mechanistically, we demonstrated that the expression of ornithine decarboxylase (ODC), which determines the generation of polyamine, was regulated by CPS1. In addition, the impacts of p53 knockdown on ODC expression, glioma cell growth and aggressive phenotypes were significantly reversed by CPS1 inhibition. In conclusion, these results demonstrated that p53 inhibits polyamine metabolism by suppressing the urea cycle, which inhibits glioma progression.

Bumetanide Rescues Aquaporin-4 Depolarization via Suppressing β-Dystroglycan Cleavage and Provides Neuroprotection in Rat Retinal Ischemia-Reperfusion Injury

Aquaporin-4 (AQP4) regulates retinal water homeostasis and participates in retinal oedema pathophysiology. β-dystroglycan (β-DG) is responsible for AQP4 polarization and can be cleaved by matrix metalloproteinase-9 (MMP9). Retinal oedema induced by ischemia-reperfusion (I/R) injury is an early complication. Bumetanide (BU) has potential efficacy against cytotoxic oedema. Our study investigated the effects of β-DG cleavage on AQP4 and the roles of BU in a rat retinal I/R injury model. The model was induced by applying 110 mm Hg intraocular pressure to the anterior eye chamber. BU and U0126 (a selective ERK inhibitor) were intraperitoneally administered 15 and 30 min, respectively, before I/R induction. Rhodamine isothiocyanate extravasation detection, quantitative real-time PCR, transmission electron microscopy, hematoxylin-eosin staining, immunofluorescence staining, western blotting, and TUNEL staining were performed. AQP4 lost its polarization in the retinal perivascular domain as a result of β-DG cleavage. BU rescued AQP4 depolarization, suppressed AQP4 protein expression, attenuated retinal cytotoxic oedema, and downregulated β-DG and AQP4 mRNA expression. BU suppressed glial responses and mitochondria-mediated apoptotic protein expression, including that of Caspase-3 and Cyto C, raised the Bcl-2/Bax ratio, and lowered the number of apoptotic cells in the retina. Both BU and U0126 downregulated p-ERK and MMP9 expression. Thus, BU treatment suppressed β-DG cleavage, recovered AQP4 polarization partially via inhibiting ERK/MMP9 signaling pathway, and possess potential neuroprotective efficacy in the rat retinal ischemia-reperfusion injury model.

Comprehensive Analysis of Necroptosis Landscape in Skin Cutaneous Melanoma for Appealing its Implications in Prognosis Estimation and Microenvironment Status

PURPOSE

Due to poor prognosis and immunotherapy failure of skin cutaneous melanoma (SKCM), this study sought to find necroptosis-related biomarkers to predict prognosis and improve the situation with predicted immunotherapy drugs.

EXPERIMENTAL DESIGN

The Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression Program (GTEx) database were utilized to recognize the differential necroptosis-related genes (NRGs). Univariate Cox (uni-Cox) and least absolute shrinkage and selection operator (LASSO) Cox analysis were utilized for prognostic signature establishment. The signature was verified in the internal cohort. To assess the signature's prediction performance, the area under the curve (AUC) of receiver operating characteristic (ROC) curves, Kaplan-Meier (K-M) analyses, multivariate Cox (multi-Cox) regression, nomogram, and calibration curves were performed. The molecular and immunological aspects were also reviewed using single-sample gene set enrichment analysis (ssGSEA). Cluster analysis was performed to identify the different types of SKCM. Finally, the expression of the signature gene was verified by immunohistochemical staining.

RESULTS

On basis of the 67 NRGs, 4 necroptosis-related genes (FASLG, PLK1, EGFR, and TNFRSF21) were constructed to predict SKCM prognosis. The area's 1-, 3-, and 5-year OS under the AUC curve was 0.673, 0.649, and 0.677, respectively. High-risk individuals had significantly lower overall survival (OS) compared to low-risk patients. Immunological status and tumor cell infiltration in high-risk groups were significantly lower, indicating an immune system that was suppressed. In addition, hot and cold tumors could be obtained by cluster analysis, which is helpful for accurate treatment. Cluster 1 was considered a hot tumor and more susceptible to immunotherapy. Immunohistochemical results were consistent with positive and negative regulation of coefficients in signature.

CONCLUSION

The results of this finding supported that NRGs could predict prognosis and help make a distinction between the cold and hot tumors for improving personalized therapy for SKCM.

Aquaporins in Digestive System

In this chapter, we mainly discuss the expression and function of aquaporins (AQPs) expressed in digestive system. AQPs are highly conserved transmembrane protein responsible for water transport across cell membranes. AQPs in gastrointestinal tract include four members of aquaporin subfamily: AQP1, AQP4, AQP5, and AQP8, and three members of aquaglyceroporin subfamily: AQP3, AQP7, and AQP10. In the digestive glands, especially the liver, we discuss four members of aquaporin subfamily: AQP1, AQP4, AQP5, and AQP8, three members of aquaglyceroporin subfamily: AQP7, AQP9, and AQP12. In digestive system, the abnormal expression of AQPs is closely related to the occurrence and development of a variety of diseases. AQP1 is involved in saliva secretion and fat digestion and is closely related to gastric cancer and chronic liver disease; AQP3 is involved in the diarrhea and inflammatory bowel disease; AQP4 regulates gastric acid secretion and is associated with the development of gastric cancer; AQP5 is relevant to gastric carcinoma cell proliferation and migration; AQP7 is the major aquaglyceroporin in pancreatic β cells; AQP8 plays a role in pancreatic juice secretion and may be a potential target for the treatment of diarrhea; AQP9 plays considerable role in glycerol metabolism and hepatocellular carcinoma; Studies on the function of AQP10 and AQP12 are still limited. Further studies are necessary for specific locations and functions of AQPs in digestive system.

The Core-Targeted RRM2 Gene of Berberine Hydrochloride Promotes Breast Cancer Cell Migration and Invasion via the Epithelial-Mesenchymal Transition

Berberine hydrochloride (BBR) could inhibit the proliferation, migration, and invasion of various cancer cells. As the only enzyme for the de novo synthesis of ribonucleotides, RRM2 is closely related to the development of tumorigenesis. However, not much is currently known about the functional roles of RRM2 in breast cancer (BRCA), and whether BBR regulates the migration and invasion of BRCA cells by regulating the expression of RRM2 remains to be determined. We study the effects of BBR on BRCA cell proliferation in vitro and tumorigenesis in vivo by using colony formation assays, EdU assays, and xenograft models. Transcriptome sequencing, the random forest algorithm, and KEGG analysis were utilized to explore the therapeutic target genes and relative pathways. The expression of RRM2 in BRCA patients was analyzed with The Cancer Genome Atlas (TCGA) dataset, the GEPIA website tool, the Gene Expression Omnibus (GEO) database, and the UALCAN database. The survival probability of BRCA patients could be predicted by survival curve and nomogram analysis. Molecular docking was used to explore the affinity between BBR and potential targets. Gain- and loss-of-function methods were employed to explore the biological process in RRM2 participants. We comprehensively investigated the pharmacological characteristics of BBR on BRCA cell lines and discovered that BBR could inhibit the proliferation of BRCA cells in vitro and in vivo. Combining transcriptome sequencing and KEGG analysis, we found that BBR mainly affected the biological behavior of BRCA cells via HIF-1α and AMPK signal pathways. Additionally, by using bioinformatics and molecular docking, we demonstrated that RRM2 plays an oncogenic role in BRCA samples and that it acts as the hub gene of BBR on BRCA cells. Knockdown and overexpression studies indicated that RRM2 promoted BRCA cell migration as well as invasion in vitro by affecting the epithelial-to-mesenchymal transition (EMT). Our study demonstrated the significance of BBR regulating HIF-1α and AMPK signaling pathways in BRCA cells. Moreover, we revealed the carcinogenic role and potential mechanism of RRM2 as a core regulatory factor of BBR in BRCA in controlling BRCA invasion, migration, and EMT, suggesting that RRM2 may be a therapeutic target and prognostic biomarker for BRCA therapy.

Association of aldehyde exposure with bone mineral density in the national health and nutrition examination survey (NHANES 2013-2014)

PURPOSE

The association between aldehyde exposure and bone health in humans remains unclear. This study was to evaluate the association of serum aldehydes with bone mineral density (BMD) and osteopenia/osteoporosis.

METHODS

We analyzed the US National Health and Nutrition Examination Survey cross-sectional data from 2013 to 2014. Weighted multivariate-adjusted linear regression and logistic regression models were used to assess the association between specific aldehydes and osteopenia/osteoporosis. Associations between aldehyde combinations and BMD were also evaluated using the restricted cubic spline (RCS) method.

RESULTS

Compared with men in the first tertile, those in the third tertile of propanaldehyde concentration were negatively associated with proximal femur and lumbar spine BMD. Significant inverse associations were observed between benzaldehyde exposure and trochanter BMD in women. Benzaldehyde increased the risk of osteopenia/osteoporosis 2.75-fold [95% confidence interval (CI) = 1.06, 7.11] in the highest tertile in women compared to the lowest tertile concentration. In males, the prevalence of total femur, femur neck, and trochanter osteopenia/osteoporosis was significantly higher in the highest versus the lowest tertile of propanaldehyde exposure, with odds ratios (ORs) of 6.84 (95% CI = 2.33, 20.04), 2.72 (95% CI = 1.18, 6.27), and 3.26 (95% CI = 1.25, 8.56), respectively. RCS regression also showed decreased BMD continuously with increasing serum mixed aldehyde levels.

CONCLUSIONS

Serum aldehyde concentrations were associated with low BMD and high osteopenia/osteoporosis risk in adults, with propanaldehyde and benzaldehyde being the most critical. Co-exposure to aldehyde combinations was negatively correlated with BMD.

Monitoring isoniazid metabolism in vivo using a near-infrared fluorescent probe

As a strong nucleophilic substance, hydrazine is widely used in the fields of agriculture, industry, and medicine. Hydrazine compounds usually exist as intermediates of some drugs. Many drugs, such as isoniazid and carbidopa, produce hydrazine metabolites. Hydrazine is a genotoxic substance, which can cause DNA lesions and cancer via long-term exposure. Therefore, it is very important to monitor the level of hydrazine in the human body with high selectivity and sensitivity. Here, we synthesized a near-infrared (NIR) fluorescent probe Cy-HZ based on the hemicyanine skeleton to visualize the metabolism of the drug isoniazid in vivo. The ester group of the probe reacts with hydrazine to generate Cy-H, causing a change in fluorescence. Here, we studied its absorption and fluorescence spectra, the recognition response to hydrazine, the imaging of exogenous hydrazine in cells and the imaging in mice and further applied the probe to monitor the distribution and metabolism of isoniazid.

PPARβ down-regulation is involved in high glucose-induced endothelial injury via acceleration of nitrative stress

Endothelial injury plays a vital role in vascular lesions from diabetes mellitus (DM). Therapeutic targets against endothelial damage may provide critical venues for the treatment of diabetic vascular diseases. Peroxisome proliferator-activated receptor β (PPARβ) is a crucial regulator in DM and its complications. However, the molecular signal mediating the roles of PPARβ in DM-induced endothelial dysfunction is not fully understood. The impaired endothelium-dependent relaxation and destruction of the endothelium structures appeared in high glucose incubated rat aortic rings. A high glucose level significantly decreased the expression of PPARβ and endothelial nitric oxide synthase (eNOS) at the mRNA and protein levels, and reduced the concentration of nitric oxide (NO), which occurred in parallel with an increase in the expression of inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine. The effect of high glucose was inhibited by GW0742, a PPARβ agonist. Both GSK0660 (PPARβ antagonist) and NG-nitro-l-arginine-methyl ester (NOS inhibitor) could reverse the protective effects of GW0742. These results suggest that the activation of nitrative stress may, at least in part, mediate the down-regulation of PPARβ in high glucose-impaired endothelial function in rat aorta. PPARβ-nitrative stress may hold potential in treating vascular complications from DM.

Ganoderic acid improves 5-fluorouracil-induced cognitive dysfunction in mice

5-Fluorouracil (5-FU) is a chemotherapeutic drug with a good anti-cancer effect on various types of cancers, such as colorectal cancer and breast cancer. However, previous studies have found that 5-FU could induce cognitive deficit in clinics. As ganoderic acid, isolated from Ganoderma lucidum, has a protective effect on neurons, this study investigated the effects of ganoderic acid (GA) against 5-FU-induced cognitive dysfunction with a series of behavioral tests and related indicators. Experimental results showed that GA significantly prevented the reduction of spatial and non-spatial memory in 5-FU-treated mice. In addition, GA not only ameliorated the damage to hippocampal neurons and mitochondrial structure, but also significantly improved abnormal protein expression of mitochondrial biogenesis related marker PGC-1α, and mitochondrial dynamics related markers MFN2, DRP1 and FIS1 in the hippocampi of 5-FU-treated mice. Moreover, GA could up-regulate the expression of neuronal survival and growth-related proteins, such as BDNF, p-ERK, p-CREB, p-Akt, p-GSK3β, Nrf2, p-mTOR, and p-S6, in the hippocampi of 5-FU-treated mice. These results suggest that GA could prevent cognitive dysfunction in mice treated with 5-FU via preventing mitochondrial impairment and enhancing neuronal survival and growth, which provide evidence for GA as a promising adjunctive therapy for chemotherapy related cognitive impairment in clinics.

Serum metabolomics of end-stage renal disease patients with depression: potential biomarkers for diagnosis

Background

End-stage renal disease (ESRD) is the final stage during the development of renal failure. Depression is the most common psychiatric disorder in patients with ESRD, which in turn aggravates the progression of renal failure, however, its underlying mechanism remains unclear. This study aimed to reveal the pathogenesis and to discover novel peripheral biomarkers for ESRD patients with depression through metabolomic analysis.

Methods

Ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-MS) was used to explore changes of serum metabolites among healthy controls, ESRD patients with or without depression. The differential metabolites between groups were subjected to clustering analysis, pathway analysis, receiver operating characteristic (ROC) curve analysis.

Results

A total of 57 significant serum differential metabolites were identified between ESRD patients with or without depression, which were involved in 19 metabolic pathways, such as energy metabolism, glycerolipid metabolism, and glutamate-centered metabolism. Moreover, the area under the ROC curve of gentisic acid, uric acid, 5-hydroxytryptamine, 2-phosphoglyceric acid, leucyl-phenylalanine, propenyl carnitine, naloxone, pregnenolone, 6-thioxanthene 5'-monophosphate, hydroxyl ansoprazole, zileuton O-glucuronide, cabergoline, PA(34:2), PG(36:1), probucol and their combination was greater than 0.90.

Conclusions

Inflammation, oxidative stress and energy metabolism abnormalities, glycerolipid metabolism, and glutamate-centered metabolism are associated with the pathogenesis of ESRD with depression, which may be promising targets for therapy. Furthermore, the identified differential metabolites may serve as biomarkers for the diagnosis of ESRD patients with depression.

Expression of Urea Transporter B in Normal and Injured Brain

Urea transporter B (UT-B) is a membrane channel protein widely distributed in mammals, and plays a significant physiological role by regulating urea and water transportation in different tissues. More and more studies have found that UT-B is related to neurological diseases, including myelinopathy and depression. When urea accumulates in the brains of UT-B knockout mice, the synaptic plasticity of neurons is reduced, and the morphology and function of glial cells are also changed. However, the distribution and expression change of UT-B remain unclear. The purpose of this study is to determine the expression characteristics of UT-B in the brain. Through single-cell RNA sequencing, UT-B was found to express universally and substantially throughout the various cells in the central nervous system except for endothelial and smooth muscle cells. UT-B was detected in the third cerebral ventricular wall, granule cell layer of the dentate gyrus, and other parts of the hippocampal, cerebral cortex, substantia nigra, habenular, and lateral hypothalamic nucleus by immunohistochemistry. Compared with the membrane expression of UT-B in glial cells, the subcellular localization of UT-B is in the Golgi apparatus of neurons. Further, the expression of UT-B was regulated by osmotic pressure in vitro. In the experimental traumatic brain injury model (TBI), the number of UT-B positive neurons near the ipsilateral cerebral cortex increased first and then decreased over time, peaking at the 24 h. We inferred that change in UT-B expression after the TBI was an adaptation to changed urea levels. The experimental data suggest that the UT-B may be a potential target for the treatment of TBI and white matter edema.

Construction and validation of a pyroptosis-related gene signature in hepatocellular carcinoma based on RNA sequencing

Background

To establish a pyroptosis-related gene (PRG) signature that could be utilized to predict hepatocellular carcinoma (HCC) survival and clinical features.

Methods

The Cancer Genome Atlas (TCGA) database was utilized to identify differentially expressed PRGs. Univariate Cox and least absolute shrinkage and selection operator (LASSO) Cox regression analyses were utilized to establish the prognostic signature. The signature was verified in the International Cancer Genome Consortium cohort (ID: LIHC-US). Based on the medium-risk score, HCC samples were classified into high- or low-risk subgroups. For signature accuracy prediction, we utilized receiver operating characteristic (ROC) analysis and the Kaplan-Meier estimate (K-M). Molecular and immunological aspects were also reviewed using single-sample gene set enrichment analysis (ssGSEA). Finally, quantitative real-time PCR (qRT-PCR) was utilized to verify the expression of hub genes in vitro.

Results

On basis of the 33 PRGs, five PRGs (CASP8, GSDMC, NLRP6, NOD2, and PLCG1) were identified that could predict HCC prognosis. Individuals with high-risk scores had significantly lower overall survival (OS) compared to those with low-risk scores. To assess and confirm this signature’s prediction performance, the area under the curve (AUC) of ROC curves was utilized. In multivariate analysis, the risk score was proven to be a significant independent prognostic factor. Immunological status and tumor cell infiltration in high-risk groups were both significantly greater than in low-risk groups, indicating that the immune system was more activated. qRT-PCR analysis demonstrated that the five PRGs in HCC cell lines were differently expressed in the prognostic signature.

Conclusions

The signature could precisely predict survival outcomes and reveal immune microenvironment composition, as well as strengthen the argument for more credible clinical and functional research in HCC patients.

Discovery of novel diarylamides as orally active diuretics targeting urea transporters

Urea transporters (UT) play a vital role in the mechanism of urine concentration and are recognized as novel targets for the development of salt-sparing diuretics. Thus, UT inhibitors are promising for development as novel diuretics. In the present study, a novel UT inhibitor with a diarylamide scaffold was discovered by high-throughput screening. Optimization of the inhibitor led to the identification of a promising preclinical candidate, N-[4-(acetylamino)phenyl]-5-nitrofuran-2-carboxamide (1H), with excellent in vitro UT inhibitory activity at the submicromolar level. The half maximal inhibitory concentrations of 1H against UT-B in mouse, rat, and human erythrocyte were 1.60, 0.64, and 0.13 μmol/L, respectively. Further investigation suggested that 8 μmol/L 1H more powerfully inhibited UT-A1 at a rate of 86.8% than UT-B at a rate of 73.9% in MDCK cell models. Most interestingly, we found for the first time that oral administration of 1H at a dose of 100 mg/kg showed superior diuretic effect in vivo without causing electrolyte imbalance in rats. Additionally, 1H did not exhibit apparent toxicity in vivo and in vitro, and possessed favorable pharmacokinetic characteristics. 1H shows promise as a novel diuretic to treat hyponatremia accompanied with volume expansion and may cause few side effects.

PKCβ increases ROS levels leading to vascular endothelial injury in diabetic foot ulcers

OBJECTIVE

To explore the role and mechanism of oxidative stress injury in the diabetic foot.

METHODS

Immunohistochemistry and staining were used to detect changes in diabetic foot tissue, and the CCK-8 method was used to measure high glucose effect on cell viability. The DCFH-DA assay was used to detect the intracellular ROS content, and colorimetric methods were used to detect the activities of the CAT and SOD enzymes and the NO and MDA content in tissues and cells. In addition, the protein expression levels of PKCβ, p66shc, eNOS, ICAM-1 and NF-κB in tissues and cells were detected by Western blotting, and the distribution of p66shc and eNOS was observed by immunofluorescence.

RESULTS

The results of clinical specimens experiments showed that the DFU group exhibited disordered morphology and increased glucose metabolism, decreased activities of the enzymes CAT and SOD in tissues, and increased MDA and NO contents compared to those in the CON group. Furthermore, protein levels of the p-PKCβ, p-p66shc, ICAM-1, and p-NF-κB were increased, and eNOS protein level was decreased; these results were consistent in clinical specimens and in vitro experiments.

CONCLUSIONS

High glucose levels may induce oxidative stress injury in cells and tissues by activating the PKCβ-p66shc signaling pathway.

Atomically dispersed Ni in cadmium-zinc sulfide quantum dots for high-performance visible-light photocatalytic hydrogen production

Catalysts with a single atom site allow highly tuning of the activity, stability, and reactivity of heterogeneous catalysts. Therefore, atomistic understanding of the pertinent mechanism is essential to simultaneously boost the intrinsic activity, site density, electron transport, and stability. Here, we report that atomically dispersed nickel (Ni) in zincblende cadmium-zinc sulfide quantum dots (ZCS QDs) delivers an efficient and durable photocatalytic performance for water splitting under sunlight. The finely tuned Ni atoms dispersed in ZCS QDs exhibit an ultrahigh photocatalytic H₂ production activity of 18.87 mmol hour^-1 g^-1. It could be ascribed to the favorable surface engineering to achieve highly active sites of monovalent Ni(I) and the surface heterojunctions to reinforce the carrier separation owing to the suitable energy band structures, built-in electric field, and optimized surface H₂ adsorption thermodynamics. This work demonstrates a synergistic regulation of the physicochemical properties of QDs for high-efficiency photocatalytic H₂ production.

MFN2 contributes to metabolic disorders and inflammation in the aging of rat chondrocytes and osteoarthritis

OBJECTIVE

Metabolic disorders and inflammation of chondrocytes are major pathological changes in aging cells and osteoarthritis (OA). Recent studies demonstrated age-related mitochondrial dysfunction may be a key contributing factor in the development of OA. Mitofusin 2 (MFN2) is a key regulator of mitochondrial fusion, cell metabolism, autophagy and apoptosis. This study was performed to ascertain whether MFN2 was involved in the aging of chondrocytes and OA.

METHODS

Metabolic measurements were taken in rat chondrocytes between different ages (3-week, 5-month, 12-month). MFN2 activity was detected in both human and rat chondrocytes during aging and OA. Then, knockdown of MFN2 with small interfering RNA (siRNA) was performed to confirm whether MFN2 contributes to metabolic changes. Lentiviruses were used to establish MFN2-overexpression/knockdown OA models both in vivo and in vitro to confirm whether MFN2 contributes to OA progress. Further, regulatory mechanism of MFN2 was assessed and interaction between MFN2 and PARKIN was performed.

RESULTS

A metabolic shift to mitochondrial respiration was confirmed in rat chondrocytes during aging. MFN2 expression was elevated in both human and rat chondrocytes during aging and OA. Knockdown of MFN2 with siRNA reversed the age-related metabolic changes in rat chondrocytes. Overexpression of MFN2 exacerbated inflammation and OA progress, while knockdown of MFN2 ameliorated inflammation and OA progress. Further, MFN2 could be ubiquitinated by PARKIN, declined PARKIN expression during aging and OA might result in elevated MFN2 expression.

CONCLUSIONS

Elevated MFN2 contributes to metabolic changes and inflammation during aging of rat chondrocytes and osteoarthritis.

Highly Stretchable Sheath-Core Yarns for Multifunctional Wearable Electronics

Flexible electronic devices with strain sensing and energy storage functions integrated simultaneously are urgently desirable to detect human motions for potential wearable applications. This paper reports the fabrication of a cotton/carbon nanotube sheath-core yarn deposited with polypyrrole (PPy) for highly multifunctional stretchable wearable electronics. The microscopic structure and morphology of the prepared sheath-core yarn were characterized by scanning electron microscopy and Fourier transform infrared spectrometry. A mechanical experiment demonstrated its excellent stretchable capacity because of its unique spring-like structure. We demonstrate that the sheath-core yarn can be used as wearable strain sensors, exhibiting an ultrahigh strain sensing range (0-350%) and excellent stability. The sheath-core yarn can be used in highly sensitive real time monitoring toward both subtle and large human motions under different conditions. Furthermore, the electrochemical performance of the sheath-core yarn was characterized by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The measured areal capacitance was 761.2 mF/cm² at the scanning rate of 1 mV/s. The method of spinning technology may lead to new exploitation of CNTs and PPy in future wearable electronic device applications.

High urea induces depression and LTP impairment through mTOR signalling suppression caused by carbamylation

BACKGROUND

Urea, the end product of protein metabolism, has been considered to have negligible toxicity for a long time. Our previous study showed a depression phenotype in urea transporter (UT) B knockout mice, which suggests that abnormal urea metabolism may cause depression. The purpose of this study was to determine if urea accumulation in brain is a key factor causing depression using clinical data and animal models.

METHODS

A meta-analysis was used to identify the relationship between depression and chronic diseases. Functional Magnetic Resonance Imaging (fMRI) brain scans and common biochemical indexes were compared between the patients and healthy controls. We used behavioural tests, electrophysiology, and molecular profiling techniques to investigate the functional role and molecular basis in mouse models.

FINDINGS

After performing a meta-analysis, we targeted the relevance between chronic kidney disease (CKD) and depression. In a CKD mouse model and a patient cohort, depression was induced by impairing the medial prefrontal cortex. The enlarged cohort suggested that urea was responsible for depression. In mice, urea was sufficient to induce depression, interrupt long-term potentiation (LTP) and cause loss of synapses in several models. The mTORC1-S6K pathway inhibition was necessary for the effect of urea. Lastly, we identified that the hydrolysate of urea, cyanate, was also involved in this pathophysiology.

INTERPRETATION

These data indicate that urea accumulation in brain is an independent factor causing depression, bypassing the psychosocial stress. Urea or cyanate carbamylates mTOR to inhibit the mTORC1-S6K dependent dendritic protein synthesis, inducing impairment of synaptic plasticity in mPFC and depression-like behaviour. CKD patients may be able to attenuate depression only by strict management of blood urea.

T2 mapping in dermatomyositis/polymyositis and correlation with clinical parameters

AIM

To explore the T2-mapping signal characteristics of the thigh muscles in patients with dermatomyositis/polymyositis (DM/PM) and to investigate the correlation between thigh muscle T2 values, clinical parameters, and serum creatinine kinase (CK).

MATERIALS AND METHODS

Forty-two patients with DM/PM proven by diagnostic criteria were enrolled in the study along with 13 healthy control subjects. Both T2-mapping and conventional magnetic resonance imaging (MRI) images were obtained in the thigh musculature of all subjects. The T2 values of thigh muscles were compared between the DM/PM patients and control groups. Thirty-one DM/PM patients were evaluated with manual muscle testing (MMT) and serum CK levels. A Spearman correlation coefficient model was used to correlate the mean T2 values and clinical assessments. The Kruskal-Wallis test and receiver operating characteristic (ROC) curves were also utilised. p-Values <0.05 reflected statistical significance.

RESULTS

The T2 value of all oedematous muscles was greater on average than that of the unaffected muscles of the DM/PM patients (p<0.05) and the muscles of healthy volunteers (p<0.05). The T2 value of unaffected muscles in DM/PM patients was also greater than that of the normal muscles in healthy volunteers (p<0.05). The area under the curves (AUCs) for T2 relaxation time values was 0.72 with respective sensitivity and specificity of 72.6% and 65.4%. The mean T2 relaxation time of the 31 patients group and the MMTs (p<0.05) was correlated without serum CK levels (p>0.05).

CONCLUSION

T2 mapping is not only quantitatively used for subclinical muscle involvement in DM/PM, but also be used to demonstrate severity of damaged muscles in DM/PM.

Growing ZnO Nanoparticles on Polydopamine-Templated Cotton Fabrics for Durable Antimicrobial Activity and UV Protection

This work aims to develop durable functional cotton fabrics by growing zinc oxide (ZnO) nanoparticles on polydopamine (PDA) templates. ZnO nanoparticles were grown on the PDA-templated cotton fabrics by the hydrothermal method at room temperature. The surface morphology, chemical composition, and crystalline structure of the ZnO-coated cotton fabrics were characterized by scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The ZnO nanoparticles were found to disperse evenly on the surface of cotton fabrics. The ultraviolet (UV) protection factor (UPF) value of the ZnO-coated cotton fabrics was maintained at 122.5, and 99% reduction in bacterial load was observed against Gluconobacter cerinus even after five cycles of laundering. The PDA was found to be effective in fixing the ZnO seeds tightly on the surface of cotton fabrics, resulting in excellent durability of the coating of ZnO nanoparticles.

miRNA-320a inhibits glioma cell invasion and migration by directly targeting aquaporin 4

Glioma is the most aggressive and malignant type of primary intracranial tumor. In recent decades, despite the rapid development of modern surgery and therapeutic strategies available for brain tumors, the prognosis of glioma remains poor and the median survival time is <15 months. In this study, we found that the levels of miRNA-320a were significantly decreased in patients with glioma, and that elevated miRNA-320a expression was associated with a better prognosis. In addition, aquaporin 4 (AQP4) was identified as a direct target of miRNA-320a. Overexpression of miRNA-320a led to the inhibition of cell invasion and migration via targeting of AQP4. Therefore, our results suggested that miRNA-320a could suppress the aggressive capacity of tumors by targeting AQP4, and that miRNA-320a could serve as a new effective therapeutic target for glioma surgical and therapeutic strategies.

Statistically optimal estimation of Greenland Ice Sheet mass variations from GRACE monthly solutions using an improved mascon approach

We present an improved mascon approach to transform monthly spherical harmonic solutions based on GRACE satellite data into mass anomaly estimates in Greenland. The GRACE-based spherical harmonic coefficients are used to synthesize gravity anomalies at satellite altitude, which are then inverted into mass anomalies per mascon. The limited spectral content of the gravity anomalies is properly accounted for by applying a low-pass filter as part of the inversion procedure to make the functional model spectrally consistent with the data. The full error covariance matrices of the monthly GRACE solutions are properly propagated using the law of covariance propagation. Using numerical experiments, we demonstrate the importance of a proper data weighting and of the spectral consistency between functional model and data. The developed methodology is applied to process real GRACE level-2 data (CSR RL05). The obtained mass anomaly estimates are integrated over five drainage systems, as well as over entire Greenland. We find that the statistically optimal data weighting reduces random noise by 35-69%, depending on the drainage system. The obtained mass anomaly time-series are de-trended to eliminate the contribution of ice discharge and are compared with de-trended surface mass balance (SMB) time-series computed with the Regional Atmospheric Climate Model (RACMO 2.3). We show that when using a statistically optimal data weighting in GRACE data processing, the discrepancies between GRACE-based estimates of SMB and modelled SMB are reduced by 24-47%.

Aquaporins in Digestive System

In this chapter, we mainly discuss the expression and function of aquaporins (AQPs ) expressed in digestive system . AQPs in gastrointestinal tract include four members of aquaporin subfamily: AQP1, AQP4, AQP5 and AQP8, and a member of aquaglyceroporin subfamily: AQP3. In the digestive glands, especially the liver, we discuss three members of aquaporin subfamily: AQP1, AQP5 and AQP8, a member of aquaglyceroporin subfamily: AQP9. AQP3 is involved in the diarrhea and inflammatory bowel disease; AQP5 is relevant to gastric carcinoma cell proliferation and migration; AQP9 plays considerable role in glycerol metabolism , urea transport and hepatocellular carcinoma. Further investigation is necessary for specific locations and functions of AQPs in digestive system.

Functional inhibition of urea transporter UT-B enhances endothelial-dependent vasodilatation and lowers blood pressure via L-arginine-endothelial nitric oxide synthase-nitric oxide pathway

Mammalian urea transporters (UTs), UT-A and UT-B, are best known for their role in urine concentration. UT-B is especially distributed in multiple extrarenal tissues with abundant expression in vascular endothelium, but little is known about its role in vascular function. The present study investigated the physiological significance of UT-B in regulating vasorelaxations and blood pressure. UT-B deletion in mice or treatment with UT-B inhibitor PU-14 in Wistar-Kyoto rats (WKYs) and spontaneous hypertensive rats (SHRs) reduced blood pressure. Acetylcholine-induced vasorelaxation was significantly augmented in aortas from UT-B null mice. PU-14 concentration-dependently produced endothelium-dependent relaxations in thoracic aortas and mesenteric arteries from both mice and rats and the relaxations were abolished by N(ω)-nitro-L-arginine methyl ester. Both expression and phosphorylation of endothelial nitric oxide synthase (eNOS) were up-regulated and expression of arginase I was down-regulated when UT-B was inhibited both in vivo and in vitro. PU-14 induced endothelium-dependent relaxations to a similar degree in aortas from 12 weeks old SHRs or WKYs. In summary, here we report for the first time that inhibition of UT-B plays an important role in regulating vasorelaxations and blood pressure via up-regulation of L-arginine-eNOS-NO pathway, and it may become another potential therapeutic target for the treatment of hypertension.

Syntenin is expressed in human gliomas and may correlate with tumor migration

INTRODUCTION

Invasion is usually recognized as the main reason for the high recurrence and death rates of gliomas. Therefore, properly understanding the molecular mechanisms of migration and invasion of human gliomas has become a focus and will be helpful for the treatment of gliomas. Syntenin has been demonstrated to be implicated in the migration, invasion and metastasis of many types of malignant tumors. Therefore, we investigated the expression of syntenin in human gliomas and its relationship with glioma migration.

MATERIAL AND METHODS

Immunohistochemistry, Western blot and real time-polymerase chain reaction (RT-PCR) were performed to detect the expression of syntenin in human gliomas. Phosphorylated FAK in human gliomas was examined by western blot.

RESULTS

Scattered syntenin positive glioma cells were detected by immunohistochemistry in normal tissue. Syntenin expression in grade II, III and IV gliomas increased with the degree of tumor malignancy, and no syntenin expression was detected in grade I gliomas. The level of phosphorylated FAK at the tyrosine 397 site also elevated with the degree of tumor malignancy. There was a positive correlation between the syntenin level and the pathological grade of gliomas (r s = 0.896, p < 0.05). Phosphorylated FAK was also upregulated along with the stage of glioma progression and the increase of syntenin expression.

CONCLUSIONS

Our results indicate that the enhanced expression of syntenin and phosphorylated FAK may correlate with the increase of the malignancy of human gliomas. Syntenin may promote human glioma migration through interaction with FAK.

Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters

Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na(+), K(+), or Cl(-) levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics.

Clinical aspects of urea transporters

Jk antigens, which were identified as urea transporter B (UT-B) in the plasma membrane of erythrocytes, and which determine the Kidd blood type in humans, are involved in transfusion medicine, and even in organ transplantation. The Jk(a-b-) blood type is a consequence of a silent Slc14A1 gene caused by various mutations related to lineage. In addition, the specific mutations related to hypertension and metabolic syndrome cannot be ignored. Genome-wide association studies established Slc14A1 as a related gene of bladder cancer and some genotypes are associated with higher morbidity. This chapter aims to introduce the clinical significance of urea transporters.

Urea transporter UT-B deletion induces DNA damage and apoptosis in mouse bladder urothelium

BACKGROUND

Previous studies found that urea transporter UT-B is abundantly expressed in bladder urothelium. However, the dynamic role of UT-B in bladder urothelial cells remains unclear. The objective of this study is to evaluate the physiological roles of UT-B in bladder urothelium using UT-B knockout mouse model and T24 cell line.

METHODOLOGY/PRINCIPAL FINDINGS

Urea and NO measurement, mRNA expression micro-array analysis, light and transmission electron microscopy, apoptosis assays, DNA damage and repair determination, and intracellular signaling examination were performed in UT-B null bladders vs wild-type bladders and in vitro T24 epithelial cells. UT-B was highly expressed in mouse bladder urothelium. The genes, Dcaf11, MCM2-4, Uch-L1, Bnip3 and 45 S pre rRNA, related to DNA damage and apoptosis were significantly regulated in UT-B null urothelium. DNA damage and apoptosis highly occurred in UT-B null urothelium. Urea and NO levels were significantly higher in UT-B null urothelium than that in wild-type, which may affect L-arginine metabolism and the intracellular signals related to DNA damage and apoptosis. These findings were consistent with the in vitro study in T24 cells that, after urea loading, exhibited cell cycle delay and apoptosis.

CONCLUSIONS/SIGNIFICANCE

UT-B may play an important role in protecting bladder urothelium by balancing intracellular urea concentration. Disruption of UT-B function induces DNA damage and apoptosis in bladder, which can result in bladder disorders.

Cytogenetic and molecular analysis of infertile Chinese men: karyotypic abnormalities, Y-chromosome microdeletions, and CAG and GGN repeat polymorphisms in the androgen receptor gene

Chromosome abnormalities, Y-chromosome microdeletions, and androgen receptor gene CAG and GGN repeat polymorphisms in infertile Chinese men featuring severe oligospermia and azoospermia were analyzed. Ninety-six fertile men and 189 non-obstructive infertile men, including 125 patients with azoospermia and 64 with severe oligozoospermia, were studied. Seventeen infertile men (9.0%) carried a chromosome abnormality. Twenty (10.6%) carried a Y-chromosome microdeletion. In the remainder of the patients and controls, GGN and CAG repeats were sequenced. Short GGN repeats (n < 23) appeared to be associated with defective spermatogenesis, with the number of GGN repeats strongly correlated with sperm counts. No significant difference in CAG repeats was found between patients and controls, nor were CAG repeats correlated with sperm counts. However, for CAG repeats ranging between 24 and 25, there was a >2.5-fold risk (OR = 2.539, 95%CI = 1.206-5.344, P < 0.05) of severe oligospermia and azoospermia. Our results confirmed the significant role of chromosome abnormalities, Y-chromosome microdeletions, and GGN repeats in Chinese male infertility.

Isolation and characterization of twelve polymorphic microsatellite loci in the buff-throated partridge (Tetraophasis szechenyii)

Twelve polymorphic microsatellite markers were isolated from an AC-enriched genomic library of Buff-throated partridge (Tetraophasis szechenyii). The allele number of these loci ranged from three to 13 (average 7.75 per locus) in tested individuals. Polymorphism information content ranged from 0.532 to 0.882 with an average of 0.721. Average observed and expected heterozygosities were 0.559 (range from 0.240 to 0.792) and 0.772 (range from 0.621 to 0.910), respectively. These microsatellite markers will be useful for the assessment of genetic diversity, relatedness identification of family and analysis of population structure in wild buff-throated partridge.

[Estimation of insulin secretion rate in multiple sampled intravenous glucose tolerance test]

OBJECTIVE

To measure and calculate insulin secretion rate(ISR) in multiple sampled intravenous glucose tolerance test (FSIVGTT) according to the two compartment model and standard parameters of the kinetics of connecting peptide (C-P) in vivo.

METHODS

15 subjects with normal glucose tolerance and 11 type 2 diabetic patients took part in the study. Oral glucose tolerance test (OGTT) and FSIVGTT were performed. Glucose concentrations were measured by hexokinase method. Insulin (INS) and C-P concentrations were measured by radioimmunoassay. A computer procedure devised by our laboratory was used to calculate the value of ISR at each time point.

RESULTS

In the control group, serum INS and C-P concentrations reached the peak at 4 min, the second peak was not obvious. In type 2 diabetes, only 5 subjects had a small peak within 4 min, two curves reached its peak between 60 and 80 min. In the control group, ISR reached its peak 2 min after injection of glucose, that was earlier than INS and C-P curves in time sequence (P = 0.000), the second obvious peak was shown at 22 min. In type 2 diabetes, an obvious but small peak of ISR was shown at 2 min and all the patients had this peak.

CONCLUSIONS

It is necessary to take the process of metabolic clearance of INS and C-P into consideration, when blood concentration of INS and C-P were used as indexes to evaluate the secretion function of beta-cells. The ISR profile is more sensitive for investigation of the second phase of insulin secretion in the control group and the first phase in type 2 diabetes group.