Heavy Metals in Surface Sediment of Plateau Lakes in Tibet, China: Occurrence, Risk Assessment, and Potential Sources.

Tibetan Plateau lakes have high ecological value and play a crucial role in maintaining ecological balance. This research aimed to study the pollution characteristics, ecological risk, and potential sources of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in the surface sediments of 12 Tibetan Plateau lakes. The results of the toxicity risk index (TRI) showed that only Gongzhu Tso (28.09) and La' ang Tso (20.25) had heavy metals that could pose a very high risk of toxicity to aquatic organisms. Hg posed the highest potential ecological risk to aquatic organisms. Based on the results of multiple analyses, we inferred that the contents of Cr, Cu, Hg, and Ni in sediments of Tibetan lakes were influenced by industrial and agricultural development; Cd, Pb, and Zn were influenced by transport and atmospheric transport; and As was derived from geothermal activity and rock weathering.

Thyroid Accumulation of 99m Tc-DTPA in Graves Disease.

ABSTRACT: 99m Tc-DTPA dynamic renal scintigraphy for evaluating glomerular filtration rate was performed in a 29-year-old woman with hyperuricemia and Graves disease. Subsequently, 99m Tc-DTPA orbital scintigraphy was conducted to determine the activity of Graves ophthalmopathy. Thyroid accumulation of 99m Tc-DTPA was incidentally identified. This should be cautiously distinguished from 99m Tc-pertechnetate uptake, considering that the salivary glands, oral cavity, and stomach were not visualized. Our case demonstrates that augmentation of blood supply, enhancement of capillary permeability, and accumulation of inflammatory exudate may be involved in the pathological process of Graves disease.

Erratum: Lentinan-functionalized Selenium Nanoparticles target Tumor Cell Mitochondria via TLR4/TRAF3/MFN1 pathway: Erratum.

[This corrects the article DOI: 10.7150/thno.46467.].

Psychologic Stress Drives Progression of Malignant Tumors via DRD2/HIF1α Signaling.

Although it is established that the sustained psychologic stress conditions under which patients with tumors often reside accelerates malignant progression of tumors, the molecular mechanism behind this association is unclear. In this work, the effect of psychologic stress on tumor progression was verified using a stress-stimulated tumor-bearing mouse model (Str-tumor). Both D2 dopamine receptor (DRD2) and hypoxia-inducible factor-1α (HIF1α) were highly expressed in the nucleus of Str-tumors. Treatment with trifluoperazine (TFP), a DRD2 inhibitor, elicited better antitumor effects in Str-tumors than the control group. These results indicate that DRD2 may mediate stress-induced malignant tumor progression. DRD2 interacted with von Hippel-Lindau (VHL) in the nucleus, and competitive binding of DRD2 and HIF1α to VHL resulted in reduced ubiquitination-mediated degradation of HIF1α, enhancing the epithelial-mesenchymal transition of tumor cells. TFP acted as an interface inhibitor between DRD2 and VHL to promote the degradation of HIF1α. In conclusion, DRD2 may promote the progression of malignant tumors induced by psychologic stress via activation of the oxygen-independent HIF1α pathway, and TFP may serve as a therapeutic strategy for stress management in patients with cancer. SIGNIFICANCE: This work identifies DRD2 regulation of HIF1α as a mechanism underlying the progression of malignant tumors stimulated by psychologic stress and suggests that DRD2 inhibition can mitigate these stress conditions in patients.See related commentary by Bernabé, p. 5144.

Sedimentary evolution of PAHs, POPs and ECs: Historical sedimentary deposition and evolution of persistent and emerging organic pollutants in sediments in a typical karstic river basin.

Knowledge on the occurrence and distributions of organic compounds, especially PAHs, POPs and ECs, in karstic river basins is limited. This study aims to determine the depositional history and sources of PAHs, PCBs, OCPs, antibiotics, EDCs and phenolic compounds and the ecological risk they have in the Panyang River Basin, an area with a typical karstic landscape and a high-longevity population. Sediment core analysis was adopted, correlation and principal component analyses were conducted to analyze pollution sources, and lead isotope technology was implemented for dating analysis. The sediment core covered 108 years. PCBs were detected with concentrations ranging from 3.80 to 16.18 µg/kg in the core with two concentration peaks in 1950 and 2005 that were related to anthropogenic effects. Eight of the 20 targeted phenolic compounds were detected, with concentrations ranging from 0.42 to 1.10 mg/kg. All PAHs were detected in the cores, with concentrations from 12.91 to 37.80 µg/kg. They were mainly related to natural diagenetic processes and domestic and agricultural sources. The concentrations of different OCP compounds ranged from undetected to 213.43 µg/kg and were mainly related to agricultural activities and long-range transportation. These key findings can assist environmental planning and management in this river basin.

Potential type 2 diabetes mellitus drug HMPA promotes short-chain fatty acid production by improving carbon catabolite repression effect of gut microbiota.

BACKGROUND AND PURPOSE: Gut microbiota plays an important role in type 2 diabetes mellitus (T2DM) progression. From our previous work N-(4-Hydroxyphenethyl)-3-mercapto-2-methylpropanamide (HMPA) is a potential T2DM drug. We evaluated the effect of HMPA on gut microbiota and studied the molecular mechanism underlying HMPA's regulation of gut microbiota. EXPERIMENTAL APPROACH: The pseudo germ-free (PGF) T2DM model and faecal microbiota transplantation method were used to study whether gut microbiota mediates the actions of HMPA. The composition of gut microbiota was detected by using 16S rRNA sequence. Short-chain fatty acids (SCFAs) content was detected by gas chromatography. The HMPA probe was synthesised for finding and identifying the target protein of HMPA. The effect of HMPA on the utilisation of carbon sources in Bifidobacterium was evaluated. KEY RESULTS: HMPA has a slight effect on the PGF T2DM model. The gut microbiota changed by HMPA can also alleviate the symptoms of T2DM. HMPA can regulate gut microbiota structure, increase SCFAs production and reduce nitrate content in the intestinal tissues. The thickness of the mucus on colon tissues increases after HMPA treatment. The target protein of HMPA in gut microbiota is the nitrogen metabolism global transcriptional regulator (GlnR). HMPA promotes the utilisation of less preferred carbon source in the gut microbiota and increases the fermentation product of SCFAs. CONCLUSION AND IMPLICATIONS: HMPA plays a hypoglycaemic role through the gut microbiota. HMPA improves the carbon catabolite repression effect of gut microbiota and increases SCFAs production by targeting GlnR. GlnR may be a target for gut microbiota regulation.

Lentinan-functionalized Selenium Nanoparticles target Tumor Cell Mitochondria via TLR4/TRAF3/MFN1 pathway.

Rationale: Malignant ascites caused by cancer cells results in poor prognosis and short average survival time. No effective treatment is currently available for malignant ascites. In this study, the effects of lentinan (LNT)-functionalized selenium nanoparticles (Selene) on malignant ascites were evaluated. Furthermore, the mechanism of Selene targeting mitochondria of tumor cells were also investigated. Methods: Selene were synthesized and characterized by TEM, AFM and particle size analysis. The OVCAR-3 and EAC cells induced ascites models were used to evaluate the effects of Selene on malignant ascites. Proteomic analysis, immunofluorescence, TEM and ICP-MS were used to determine the location of Selene in tumor cells. Mitochondrial membrane potential, ROS, ATP content, and caspase-1/3 activity were detected to evaluate the effect of Selene on mitochondrial function and cell apoptosis. Immunofluorescence, Co-IP, pull-down, duolink, Western blot, and FPLC were used to investigate the pathway of Selene targeting mitochondria. Results: Selene could effectively inhibit ascites induced by OVCAR-3 and EAC cells. Selene was mainly located in the mitochondria of tumor cells and induced apoptosis of tumor cells. The LNT in Selene was involved in caveolae-mediated endocytosis through the interaction between toll-like receptor-4 (TLR4) and caveolin 1 (CAV1). Furthermore, the Selene in the endocytic vesicles could enter the mitochondria via the mitochondrial membrane fusion pathway, which was mediated by TLR4/TNF receptor associated factor 3 (TRAF3)/mitofusin-1 (MFN1) protein complex. Conclusion: Selene is a candidate anticancer drug for the treatment of malignant ascites. And TLR4/TRAF3/MFN1 may be a specific nano-drug delivery pathway that could target the mitochondria.

Protopanaxadiol inhibits epithelial-mesenchymal transition of hepatocellular carcinoma by targeting STAT3 pathway.

Diol-type ginsenosides, such as protopanaxadiol (PPD), exhibit antioxidation, anti-inflammation, and antitumor effects. However, the antitumor effect of these ginsenosides and the mechanism of PPD remain unclear. In this work, the antitumor effects of several derivatives, including PPD, Rg5, Rg3, Rh2, and Rh3, were evaluated in five different cancer cell lines. PPD demonstrated the best inhibitory effects on the proliferation and migration of the five cancer cell lines, especially the hepatocellular carcinoma (HCC) cell lines. Therefore, the mechanism of action of PPD in HCC cells was elucidated. PPD inhibited the proliferation, migration, and invasion ability of HepG2 and PLC/PRF/5 cells in a dose-dependent manner. Western blot and immunofluorescence assay showed that PPD can alter the expression of epithelial-mesenchymal transition markers, increase E-cadherin expression, and decrease vimentin expression. Docking and biacore experiments revealed that STAT3 is the target protein of PPD, which formed hydrogen bonds with Gly583/Leu608/Tyr674 at the SH2 domain of STAT3. PPD inhibited the phosphorylation of STAT3 and its translocation from the cytosol to the nucleus, thereby inhibiting the expression of Twist1. PPD also inhibited tumor volume and tumor lung metastasis in PLC/PRF/5 xenograft model. In conclusion, PPD can inhibit the proliferation and metastasis of HCC cells through the STAT3/Twist1 pathway.

Retrospective correction of motion-affected MR images using deep learning frameworks.

PURPOSE: Motion is 1 extrinsic source for imaging artifacts in MRI that can strongly deteriorate image quality and, thus, impair diagnostic accuracy. In addition to involuntary physiological motion such as respiration and cardiac motion, intended and accidental patient movements can occur. Any impairment by motion artifacts can reduce the reliability and precision of the diagnosis and a motion-free reacquisition can become time- and cost-intensive. Numerous motion correction strategies have been proposed to reduce or prevent motion artifacts. These methods have in common that they need to be applied during the actual measurement procedure with a-priori knowledge about the expected motion type and appearance. For retrospective motion correction and without the existence of any a-priori knowledge, this problem is still challenging. METHODS: We propose the use of deep learning frameworks to perform retrospective motion correction in a reference-free setting by learning from pairs of motion-free and motion-affected images. For this image-to-image translation problem, we propose and compare a variational auto encoder and generative adversarial network. Feasibility and influences of motion type and optimal architecture are investigated by blinded subjective image quality assessment and by quantitative image similarity metrics. RESULTS: We observed that generative adversarial network-based motion correction is feasible producing near-realistic motion-free images as confirmed by blinded subjective image quality assessment. Generative adversarial network-based motion correction accordingly resulted in images with high evaluation metrics (normalized root mean squared error <0.08, structural similarity index >0.8, normalized mutual information >0.9). CONCLUSION: Deep learning-based retrospective restoration of motion artifacts is feasible resulting in near-realistic motion-free images. However, the image translation task can alter or hide anatomical features and, therefore, the clinical applicability of this technique has to be evaluated in future studies.

Antimalarial Drug Pyrimethamine Plays a Dual Role in Antitumor Proliferation and Metastasis through Targeting DHFR and TP.

Pyrimethamine (Pyr), an antimalarial drug that targeting plasmodium dihydrofolate reductase (pDHFR), has been proved to have antitumor activity. However, its direct target on cancer cells remains unclear. Methotrexate (MTX) is a widely used anticancer drug that blocks human dihydrofolate reductase (hDHFR). In this work, we examined the anticancer effects of Pyr in vitro and in vivo Our results showed that hDHFR and pDHFR have similar secondary and three-dimensional structures and that Pyr can inhibit the activity of hDHFR in lung cancer cells. Although Pyr and MTX can inhibit the proliferation of lung cancer cells by targeting DHFR, only Pyr can inhibit the epithelial-mesenchymal transition (EMT), metastasis and invasion of lung cancer cells. These results indicated that hDHFR is not the only target of Pyr. We further found that thymidine phosphorylase (TP), an enzyme that is closely associated with the EMT of cancer cells, is also a target protein of Pyr. The data retrieved from the Cancer Genome Atlas (TCGA) database revealed that TP overexpression is associated with poor prognosis of patients with lung cancer. In conclusion, Pyr plays a dual role in antitumor proliferation and metastasis by targeting DHFR and TP. Pyr may have potential clinical applications for the treatment of lung cancer.

Salidroside improves the hypoxic tumor microenvironment and reverses the drug resistance of platinum drugs via HIF-1α signaling pathway.

BACKGROUND: Hypoxia commonly occurs in solid tumors. The hypoxia in the center of solid tumors considerably decreases the chemosensitivity of tumor cells and induces epithelial-mesenchymal transition (EMT) as well as drug resistance of antitumor drugs. METHODS: Here, the effects of salidroside (Sal) combined with platinum drugs on human hepatocellular carcinoma were examined in vitro and in vivo. We investigated the antitumor effects of Sal by inhibiting the drug resistance and explained its mechanism in inhibiting tumor growth. FINDINGS: The results showed that Sal co-administration reverses the drug resistance of platinum drugs and suppressed metastasis induced by the hypoxic tumor microenvironment. Sal promoted the degradation of HIF-1α. In conclusion, Sal significantly increased the sensitivity to platinum drugs and inhibited hypoxia-induced EMT in hepatocellular carcinoma (HCC) through inhibiting HIF-1α signaling pathway. INTERPRETATION: Therefore, Sal may be an effective platinum drug sensitizer that can improve the chemotherapeutic efficacy in patients with HCC.

Parthenolide attenuated bleomycin-induced pulmonary fibrosis via the NF-κB/Snail signaling pathway.

BACKGROUND: Parthenolide (PTL) is a natural molecule isolated from Tanacetum parthenium that exhibits excellent anti-inflammatory and antitumor activities. Pulmonary fibrosis (PF), especially idiopathic pulmonary fibrosis (IPF), is a chronic lung disease that lacks a proven effective therapy. The present study evaluated the therapeutic effect of PTL on PF. METHODS: Serum-starved primary lung fibroblasts and HFL1 cells were treated with different doses of PTL, and cell viability and the migration rate were measured. Western blot analysis and a dual-luciferase assay were used to analyze the epithelial-mesenchymal transition (EMT)-related transcription factors influenced by PTL treatment in A549 cells and primary lung epithelial cells. Mice with bleomycin (BLM)-induced pulmonary fibrosis were treated with different doses of intragastric PTL, and pathological changes were evaluated using Hematoxylin-eosin (H&E) staining and immunohistochemical analysis. RESULTS: Our results demonstrated that PTL reduced the cell viability and migration rate of lung fibroblasts and inhibited the expression of EMT-related transcription factors in lung epithelial cells. In vivo studies demonstrated that PTL attenuated BLM-induced pulmonary fibrosis and improved the body weight and pathological changes of BLM-treated mice. We further demonstrated that PTL attenuated BLM-induced PF primarily via inhibition of the NF-κB/Snail signaling pathway. CONCLUSION: These findings suggest that PTL inhibits EMT and attenuates BLM-induced PF via the NF-κB/Snail signaling pathway. PTL is a worthwhile candidate compound for pulmonary fibrosis therapy.

Apigenin inhibits colonic inflammation and tumorigenesis by suppressing STAT3-NF-κB signaling.

Apigenin is a naturally occurring compound with anti-inflammatory, antioxidant, and anticancer properties. Here, we investigated the effects of apigeninin inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Apigenin effectively inhibited ulcerative colitis, a type of IBD, and CAC. Apigenin decreased myeloperoxidase (MPO), inflammatory cytokine and COX-2 levels, and it attenuated inflammatory cell infiltration in treated colon tissues as compared to untreated model colon tissues. Apigenin also reduced NF-κB and STAT3 activity in vitro and in vivo, thereby inhibiting inflammation and inflammation-induced carcinogenesis. Thus apigenin appears to inhibit inflammation and inflammation-induced carcinogenesisin IBD and CAC by suppressing STAT3-NF-κB signaling.

Dihydroartemisinin inhibits EMT induced by platinum-based drugs via Akt-Snail pathway.

Artemisinin and its derivatives exhibit a high activity against a range of cancer cell types both in vitro and in vivo. In clinical practice, platinum-based anti-cancer chemotherapy is widely used to treat tumors. However, a large proportion of patients receiving these treatments will relapse because of metastasis and drug resistance. The purpose of this study is to explore the combinational anti-metastatic effect of platinum-based drugs and dihydroartemisinin (DHA). Both DDP and oxaliplatin (OXA) at low doses could induce epithelial-mesenchymal transition (EMT) in HCC. Meanwhile, co-administration of DHA could enhance DDP and OXA chemosensitivity in HCC and reverse drug resistance. DHA reversed the morphological changes induced by DDP or OXA and reversed the changes in EMT biomarkers induced by DDP and OXA in HCC in vitro and in vivo via AKT-Snail signaling. DHA significantly increased platinum-based drug sensitivity and suppressed EMT induced by platinum-based drugs via AKT-Snail signaling in HCC. DHA is expected to become the new adjuvant for chemotherapy.

Sesquiterpene binding Gly-Leu-Ser/Lys-"co-adaptation pocket" to inhibit lung cancer cell epithelial-mesenchymal transition.

Sesquiterpene lactones (SL) have a wide range of applications in anti-tumor and anti-inflammatory therapy. However, the pharmacological mechanism of such substances is not clear. In this study, parthenolide (PTL) was used as an example to explore the anti-tumor effect of natural molecules and their common mechanism. We showed that PTL inhibited the proliferation and migration by reverse EMT via the ERK2/NF-κB/Snail pathway in vivo and in vitro. Interestingly, Multiple potential targets of PTL contain a Gly-Leu-Ser/Lys-"co-adaptation pocket". This inspiring us analogies of PTL may also bind to these target proteins and play a similar function. Significantly, the Concept of co-adaptation pocket may help to increase the selectivity of drug research and development.

Dihydroartemisinin attenuates autoimmune thyroiditis by inhibiting the CXCR3/PI3K/AKT/NF-κB signaling pathway.

Dihydroartemisinin (DHA) is the first generation of naturally occurring artemisinin derivatives with antimalarial activity. Recent research showed that this drug also features immunosuppressive and anti-inflammatory properties. Autoimmune thyroiditis (AIT) is a common organ-specific autoimmune disease with no available effective drug treatment. In this study, we investigated effects of DHA on AIT in vitro and in vivo. Results showed that DHA can visibly reduce antithyroglobulin antibody and thyroid peroxidase antibody levels and regulate T helper cells (Th) 1/Th2 imbalance of experimental AIT mice. DHA also dose-dependently suppressed proliferation of lymphocytes induced by lipopolysaccharide and concanavalin A. DHA inhibited binding of C-X-C chemokine ligand 10 (CXCL10) and its receptor (C-X-C motif) receptor 3 (CXCR3), thus inhibiting calcium flow. DHA can also reduce expression levels of PI3-kinase (PI3K), p-PI3K, protein kinase B (AKT), p-AKT, nuclear factor (NF)-κB/p65, and p-NF-κB/p65. In conclusion, DHA may serve as treatment drug for AIT by inhibiting the CXCR3/PI3K/AKT/NF-kB signaling pathway.