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1.
Nature ; 595(7869): 730-734, 2021 07.
Article in English | MEDLINE | ID: mdl-34290403

ABSTRACT

Hepatocellular carcinoma (HCC)-the most common form of liver cancer-is an aggressive malignancy with few effective treatment options1. Lenvatinib is a small-molecule inhibitor of multiple receptor tyrosine kinases that is used for the treatment of patients with advanced HCC, but this drug has only limited clinical benefit2. Here, using a kinome-centred CRISPR-Cas9 genetic screen, we show that inhibition of epidermal growth factor receptor (EGFR) is synthetic lethal with lenvatinib in liver cancer. The combination of the EGFR inhibitor gefitinib and lenvatinib displays potent anti-proliferative effects in vitro in liver cancer cell lines that express EGFR and in vivo in xenografted liver cancer cell lines, immunocompetent mouse models and patient-derived HCC tumours in mice. Mechanistically, inhibition of fibroblast growth factor receptor (FGFR)  by lenvatinib treatment leads to feedback activation of the EGFR-PAK2-ERK5 signalling axis, which is blocked by EGFR inhibition. Treatment of 12 patients with advanced HCC who were unresponsive to lenvatinib treatment with the combination of lenvatinib plus gefitinib (trial identifier NCT04642547) resulted in meaningful clinical responses. The combination therapy identified here may represent a promising strategy for the approximately 50% of patients with advanced HCC who have high levels of EGFR.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , Phenylurea Compounds/pharmacology , Quinolines/pharmacology , Animals , Carcinoma, Hepatocellular/drug therapy , Cell Line, Tumor , Drug Resistance, Neoplasm , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , Female , Gefitinib/pharmacology , Humans , Liver Neoplasms/drug therapy , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Receptors, Fibroblast Growth Factor , Signal Transduction , Xenograft Model Antitumor Assays
2.
Nature ; 574(7777): 268-272, 2019 10.
Article in English | MEDLINE | ID: mdl-31578521

ABSTRACT

Liver cancer remains difficult to treat, owing to a paucity of drugs that target critical dependencies1,2; broad-spectrum kinase inhibitors such as sorafenib provide only a modest benefit to patients with hepatocellular carcinoma3. The induction of senescence may represent a strategy for the treatment of cancer, especially when combined with a second drug that selectively eliminates senescent cancer cells (senolysis)4,5. Here, using a kinome-focused genetic screen, we show that pharmacological inhibition of the DNA-replication kinase CDC7 induces senescence selectively in liver cancer cells with mutations in TP53. A follow-up chemical screen identified the antidepressant sertraline as an agent that kills hepatocellular carcinoma cells that have been rendered senescent by inhibition of CDC7. Sertraline suppressed mTOR signalling, and selective drugs that target this pathway were highly effective in causing the apoptotic cell death of hepatocellular carcinoma cells treated with a CDC7 inhibitor. The feedback reactivation of mTOR signalling after its inhibition6 is blocked in cells that have been treated with a CDC7 inhibitor, which leads to the sustained inhibition of mTOR and cell death. Using multiple in vivo mouse models of liver cancer, we show that treatment with combined inhibition of of CDC7 and mTOR results in a marked reduction of tumour growth. Our data indicate that exploiting an induced vulnerability could be an effective treatment for liver cancer.


Subject(s)
Apoptosis/drug effects , Cellular Senescence/drug effects , Liver Neoplasms/drug therapy , Liver Neoplasms/pathology , Molecular Targeted Therapy , Sertraline/pharmacology , Animals , Cell Cycle Proteins/antagonists & inhibitors , Cell Line, Tumor , Disease Models, Animal , Female , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Male , Mice , Mice, Inbred BALB C , Mutation , Protein Serine-Threonine Kinases/antagonists & inhibitors , Sertraline/therapeutic use , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics
3.
Mol Med ; 30(1): 58, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38720283

ABSTRACT

BACKGROUND: Vascular calcification (VC) is a complication in diabetes mellitus (DM) patients. Osteogenic phenotype switching of vascular smooth muscle cells (VSMCs) plays a critical role in diabetes-related VC. Mitophagy can inhibit phenotype switching in VSMCs. This study aimed to investigate the role of the glucagon-like peptide-1 receptor (GLP-1R) agonist exendin 4 (EX4) in mitophagy-induced phenotype switching. MATERIALS AND METHODS: The status of VC in T2DM mice was monitored using Von Kossa and Alizarin Red S (ARS) staining in mouse aortic tissue. Human aortic smooth muscle cells were cultured in high glucose (HG) and ß-glycerophosphate (ß-GP) conditioned medium. Accumulation of LC3B and p62 was detected in the mitochondrial fraction. The effect of EX4 in vitro and in vivo was investigated by knocking down AMPKα1. RESULTS: In diabetic VC mice, EX4 decreased the percentage of von Kossa/ARS positive area. EX4 inhibited osteogenic differentiation of HG/ß-GP-induced VSMCs. In HG/ß-GP-induced VSMCs, the number of mitophagosomes was increased, whereas the addition of EX4 restored mitochondrial function, increased the number of mitophagosome-lysosome fusions, and reduced p62 in mitochondrial frictions. EX4 increased the phosphorylation of AMPKα (Thr172) and ULK1 (Ser555) in HG/ß-GP-induced VSMCs. After knockdown of AMPKα1, ULK1 could not be activated by EX4. The accumulation of LC3B and p62 could not be reduced after AMPKα1 knockdown. Knockdown of AMPKα1 negated the therapeutic effects of EX4 on VC of diabetic mice. CONCLUSION: EX4 could promote mitophagy by activating the AMPK signaling pathway, attenuate insufficient mitophagy, and thus inhibit the osteogenic phenotype switching of VSMCs.


Subject(s)
AMP-Activated Protein Kinases , Exenatide , Glucagon-Like Peptide-1 Receptor , Mitophagy , Signal Transduction , Vascular Calcification , Animals , Mitophagy/drug effects , Vascular Calcification/etiology , Vascular Calcification/metabolism , Vascular Calcification/drug therapy , Signal Transduction/drug effects , Mice , Glucagon-Like Peptide-1 Receptor/agonists , Glucagon-Like Peptide-1 Receptor/metabolism , Male , AMP-Activated Protein Kinases/metabolism , Humans , Exenatide/pharmacology , Exenatide/therapeutic use , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/drug effects , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/drug therapy , Disease Models, Animal , Mice, Inbred C57BL
4.
BMC Public Health ; 24(1): 117, 2024 01 08.
Article in English | MEDLINE | ID: mdl-38191440

ABSTRACT

BACKGROUND: As global aging intensifies, older adults with chronic diseases are of increasing concern. Home and community-based services (HCBSs) have been proven to promote self-rated health (SRH) in older adults, but no research explored the associations between the use of overall HCBSs, three different types of HCBSs (health care, daily care, and social support services) and SRH among older adults with chronic diseases. Consequently, this study applies a national publicly available database to examine these associations among older adults with chronic diseases. METHODS: 8,623 older adults with chronic diseases (≥ 60 years old) were included in this study. SRH was evaluated applying a concise question with a 1 - 5 scale. HCBSs utilization was assessed through the question, "What kind of HCBSs were used in the community?". Univariate general linear regression models aimed to compare the mean values of SRH in terms of HCBSs utilization in each group. This study is a cross-sectional study design and the relationship between HCBSs utilization and SRH was assessed by multilevel linear regression. RESULTS: The mean score for SRH among the respondents was 3.19, of whom 20.55% used one or more HCBSs, 19.47% utilized health care services, 2.44% utilized social support services, and only 0.55% utilized daily care services. The use of HCBSs was found to be linked to SRH among older adults with chronic diseases (ß = 0.085, SE = 0.025, p < 0.001). SRH among older adults with chronic diseases was strongly linked to the use of health care and social support services (ß = 0.068, SE = 0.025, p < 0.001; ß = 0.239, SE = 0.063, p < 0.001, respectively). However, there was no significant association between the use of daily care services and SRH among older adults with chronic diseases. CONCLUSION: This study revealed that HCBSs utilization was positively and significantly linked to SRH in Chinese older adults with chronic diseases. Furthermore, this study supposes the low utilization of social support and daily care services may be due to a mismatch between supply and demand. The government should offer the targeted HCBSs for older adults with chronic diseases according to their unique features to enhance their health status.


Subject(s)
Facilities and Services Utilization , Retirement , Humans , Aged , Middle Aged , Cross-Sectional Studies , Longitudinal Studies , Community Health Services , China , Chronic Disease
5.
Appl Environ Microbiol ; 89(6): e0066123, 2023 06 28.
Article in English | MEDLINE | ID: mdl-37289076

ABSTRACT

Maintenance of cell wall integrity is important for fungal cell morphology against external stresses and even virulence. Although the transcription factor Rlm1 is known to play major regulatory roles in the maintenance of cell integrity, the underlying mechanism of how Rlm1 contributes to cell wall integrity and virulence in phytopathogenic fungi remains unclear. Here, we demonstrated that CcRlm1 plays important roles in cell wall maintenance and virulence in the poplar canker fungus Cytospora chrysosperma. Among putative downstream targets, CcChs6 (chitin synthase) and CcGna1 (glucosamine 6-phosphate N-acetyltransferase) were found to be direct targets of CcRlm1 and shown to function in chitin synthesis and virulence. Furthermore, we found stronger induction of poplar defense responses when challenged with these gene deletion mutants. Collectively, these results suggest that CcRlm1 plays a critical role in the regulation of cell wall maintenance, stress response, and virulence by directly regulating CcChs6 and CcGna1 in C. chrysosperma. IMPORTANCE Cytospora chrysosperma causes canker diseases on woody plants, and the molecular basis of its infection is not well understood. This study shows that CcRlm1 is the major regulator of chitin synthesis and virulence of the poplar canker fungus. Our research contributes to further understanding the molecular basis of the interaction between C. chrysosperma and poplar.


Subject(s)
Populus , Transcription Factors , Transcription Factors/genetics , Gene Expression Regulation , Populus/microbiology , Cell Wall/metabolism , Chitin , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression Regulation, Fungal
6.
Cell Tissue Res ; 394(3): 455-469, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37907763

ABSTRACT

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to the intimal hyperplasia in type 2 diabetes mellitus (T2DM) patients after percutaneous coronary intervention. We aimed to investigate the role of lncRNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) in VSMC proliferation and migration, as well as the underlying mechanism. T2DM model mice with carotid balloon injury were used in vivo and mouse aortic vascular smooth muscle cells (MOVAS) stimulated by insulin were used in vitro to assess the role of CDKN2B-AS1 in VSMC proliferation and migration following vascular injury in T2DM state. To investigate cell viability and migration, MTT assay and Transwell assay were conducted. To elucidate the underlying molecular mechanisms, the methylation-specific polymerase chain reaction, RNA immunoprecipitation, RNA-pull down, co-immunoprecipitation, and chromatin immunoprecipitation were performed. In vivo, CDKN2B-AS1 was up-regulated in common carotid artery tissues. In vitro, insulin treatment increased CDKN2B-AS1 level, enhanced MOVAS cell proliferation and migration, while the promoting effect was reversed by CDKN2B-AS1 knockdown. CDKN2B-AS1 forms a complex with enhancer of zeste homolog 2 (EZH2) and DNA methyltransferase (cytosine-5) 1 (DNMT1) to regulate smooth muscle 22 alpha (SM22α) methylation levels. In insulin-stimulated cells, SM22α knockdown abrogated the inhibitory effect of CDKN2B-AS1 knockdown on cell viability and migration. Injection of lentivirus-sh-CDKN2B-AS1 relieved intimal hyperplasia in T2DM mice with carotid balloon injury. Up-regulation of CDKN2B-AS1 induced by insulin promotes cell proliferation and migration by targeting SM22α through forming a complex with EZH2 and DNMT1, thereby aggravating the intimal hyperplasia after vascular injury in T2DM.


Subject(s)
Diabetes Mellitus, Type 2 , RNA, Long Noncoding , Vascular System Injuries , Animals , Mice , Cell Movement , Cell Proliferation , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Hyperplasia , Insulin/pharmacology , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Vascular System Injuries/genetics , Vascular System Injuries/metabolism , Vascular System Injuries/pathology
7.
Mar Drugs ; 21(11)2023 Nov 16.
Article in English | MEDLINE | ID: mdl-37999418

ABSTRACT

Nanomaterials (NMs) are becoming more commonly used in microalgal biotechnology to empower the production of algal biomass and valuable metabolites, such as lipids, proteins, and exopolysaccharides. It provides an effective and promising supplement to the existing algal biotechnology. In this review, the potential for NMs to enhance microalgal growth by improving photosynthetic utilization efficiency and removing reactive oxygen species is first summarized. Then, their positive roles in accumulation, bioactivity modification, and extraction of valuable microalgal metabolites are presented. After the application of NMs in microalgae cultivation, the extracted metabolites, particularly exopolysaccharides, contain trace amounts of NM residues, and thus, the impact of these residues on the functional properties of the metabolites is also evaluated. Finally, the methods for removing NM residues from the extracted metabolites are summarized. This review provides insights into the application of nanotechnology for sustainable production of valuable metabolites in microalgae and will contribute useful information for ongoing and future practice.


Subject(s)
Microalgae , Nanostructures , Microalgae/metabolism , Biotechnology/methods , Biomass , Nanotechnology , Biofuels
8.
Molecules ; 28(17)2023 Aug 25.
Article in English | MEDLINE | ID: mdl-37687078

ABSTRACT

To overcome the shortcomings of the temperature sensitivity of exterior flexible facing tiles (EFFIs), a series of crosslinking carboxylic styrene-acrylate (SA) latices were prepared via the semicontinuous seed emulsion polymerization of glycidyl methacrylate (GMA), methacrylic acid (MAA), acrylic acid (AA), butyl acrylate (BA), and styrene (St), and were applied as binders to fabricate EFFTs with mineral powder. The obtained latices exhibited Bragg diffraction because of the narrow particle size distribution. Owing to the low dosage of emulsifiers and the crosslinking reaction between the epoxy group and the carboxyl group, the latex films displayed excellent water resistance, with water adsorption as low as 7.1%. The tensile test, differential scanning calorimeter (DSC) test, and dynamic mechanical analysis (DMA) indicated that at a GMA dosage of 4-6% the latex films had high mechanical strengths, which remained relatively stable in the temperature range of 10 to 40 °C. The optimal AA dosage was found in the range of 2 to 3%, at which the wet mixture exhibited good processability, conducive to forming an EFFT with a compact microstructure. Using the optimal SA latex, the obtained EFFT displayed a series of improved performances, including low water absorption, high mechanical strength, and stable self-supporting ability over a wide temperature range, exhibiting the application potential in the decoration and construction industries.

9.
Mol Plant Microbe Interact ; 35(11): 1006-1017, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35852471

ABSTRACT

Legumes acquire access to atmospheric nitrogen through nitrogen fixation by rhizobia in root nodules. Rhizobia are soil-dwelling bacteria and there is a tremendous diversity of rhizobial species in different habitats. From the legume perspective, host range is a compromise between the ability to colonize new habitats, in which the preferred symbiotic partner may be absent, and guarding against infection by suboptimal nitrogen fixers. Here, we investigate natural variation in rhizobial host range across Lotus species. We find that Lotus burttii is considerably more promiscuous than Lotus japonicus, represented by the Gifu accession, in its interactions with rhizobia. This promiscuity allows Lotus burttii to form nodules with Mesorhizobium, Rhizobium, Sinorhizobium, Bradyrhizobium, and Allorhizobium species that represent five distinct genera. Using recombinant inbred lines, we have mapped the Gifu/burttii promiscuity quantitative trait loci (QTL) to the same genetic locus regardless of rhizobial genus, suggesting a general genetic mechanism for symbiont-range expansion. The Gifu/burttii QTL now provides an opportunity for genetic and mechanistic understanding of promiscuous legume-rhizobia interactions. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.


Subject(s)
Bradyrhizobium , Lotus , Mesorhizobium , Rhizobium , Lotus/genetics , Lotus/microbiology , Rhizobium/genetics , Mesorhizobium/genetics , Bradyrhizobium/genetics , Nitrogen
10.
Biol Chem ; 403(3): 317-329, 2022 02 23.
Article in English | MEDLINE | ID: mdl-34882999

ABSTRACT

Abnormal proliferation of vascular smooth muscle cells (VSMCs) induced by insulin resistance facilitates intimal hyperplasia of type 2 diabetes mellitus (T2DM) and N6-methyladenosine (m6A) methylation modification mediates the VSMC proliferation. This study aimed to reveal the m6A methylation modification regulatory mechanism. In this study, m6A demethylase FTO was elevated in insulin-treated VSMCs and T2DM mice with intimal injury. Functionally, FTO knockdown elevated m6A methylation level and further restrained VSMC proliferation and migration induced by insulin. Mechanistically, FTO knockdown elevated Smooth muscle 22 alpha (SM22α) expression and m6A-binding protein IGF2BP2 enhanced SM22α mRNA stability by recognizing and binding to m6A methylation modified mRNA. In vivo studies confirmed that the elevated m6A modification level of SM22α mRNA mitigated intimal hyperplasia in T2DM mice. Conclusively, m6A methylation-mediated elevation of SM22α restrained VSMC proliferation and migration and ameliorated intimal hyperplasia in T2DM.


Subject(s)
Diabetes Mellitus, Type 2 , Insulins , Animals , Cell Movement/physiology , Cell Proliferation , Cells, Cultured , Diabetes Mellitus, Type 2/metabolism , Hyperplasia/metabolism , Hyperplasia/pathology , Insulins/metabolism , Methylation , Mice , Muscle, Smooth, Vascular/pathology , RNA, Messenger/metabolism
11.
Hepatology ; 73(2): 644-660, 2021 02.
Article in English | MEDLINE | ID: mdl-32298475

ABSTRACT

BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor-gamma (PPARγ) coactivator-1α (PGC1α) is a key regulator of mitochondrial biogenesis and respiration. PGC1α is involved in the carcinogenesis, progression, and metabolic state of cancer. However, its role in the progression of hepatocellular carcinoma (HCC) remains unclear. APPROACH AND RESULTS: In this study, we observed that PGC1α was down-regulated in human HCC. A clinical study showed that low levels of PGC1α expression were correlated with poor survival, vascular invasion, and larger tumor size. PGC1α inhibited the migration and invasion of HCC cells with both in vitro experiments and in vivo mouse models. Mechanistically, PGC1α suppressed the Warburg effect through down-regulation of pyruvate dehydrogenase kinase isozyme 1 (PDK1) mediated by the WNT/ß-catenin pathway, and inhibition of the WNT/ß-catenin pathway was induced by activation of PPARγ. CONCLUSIONS: Low levels of PGC1α expression indicate a poor prognosis for HCC patients. PGC1α suppresses HCC metastasis by inhibiting aerobic glycolysis through regulating the WNT/ß-catenin/PDK1 axis, which depends on PPARγ. PGC1α is a potential factor for predicting prognosis and a therapeutic target for HCC patients.


Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Hepatocellular/secondary , Liver Neoplasms/pathology , Lung Neoplasms/secondary , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Biomarkers, Tumor/blood , Carcinogenesis/genetics , Carcinogenesis/pathology , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/mortality , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Disease Progression , Female , Gene Expression Regulation, Neoplastic , Humans , Liver/pathology , Liver/surgery , Liver Neoplasms/blood , Liver Neoplasms/genetics , Liver Neoplasms/mortality , Male , Middle Aged , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/pathology , PPAR gamma/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/blood , Prognosis , Pyruvate Dehydrogenase Acetyl-Transferring Kinase/metabolism , Warburg Effect, Oncologic , Wnt Signaling Pathway/genetics , Xenograft Model Antitumor Assays
12.
J Exp Bot ; 73(17): 5992-6008, 2022 09 30.
Article in English | MEDLINE | ID: mdl-35727860

ABSTRACT

Melatonin improves plant resistance to multiple stresses by participating in the biosynthesis of metabolites. Flavonoids are an important family of plant secondary metabolites and are widely recognized to be involved in resistance; however, the crosstalk between melatonin and flavonoid is largely unknown. We found that the resistance of pigeon pea (Cajanus cajan) to salt, drought, and heat stresses were significantly enhanced by pre-treatment with melatonin. Combined transcriptome and LC-ESI-MS/MS metabolomics analyses showed that melatonin significantly induced the enrichment of flavonoids and mediated the reprogramming of biosynthetic pathway genes. The highest fold-increase in expression in response to melatonin treatment was observed for the CcF3´H family, which encodes an enzyme that catalyses the biosynthesis of luteolin, and the transcription factor CcPCL1 directly bonded to the CcF3´H-5 promoter to enhance its expression. In addition, salt stress also induced the expression of CcPCL1 and CcF3´H-5, and their overexpression in transgenic plants greatly enhanced salt tolerance by promoting the biosynthesis of luteolin. Overall, our results indicated that pre-treatment of pigeon pea with melatonin promoted luteolin biosynthesis through the CcPCL1 and CcF3´H-5 pathways, resulting in salt tolerance. Our study shows that melatonin enhances plant tolerance to multiple stresses by mediating flavonoid biosynthesis, providing new avenues for studying the crosstalk between melatonin and flavonoids.


Subject(s)
Cajanus , Melatonin , Cajanus/genetics , Flavonoids , Gene Expression Regulation, Plant , Luteolin/pharmacology , Melatonin/metabolism , Melatonin/pharmacology , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified/metabolism , Salt Stress , Tandem Mass Spectrometry , Transcription Factors/metabolism
13.
Surg Endosc ; 36(8): 5559-5570, 2022 08.
Article in English | MEDLINE | ID: mdl-35296949

ABSTRACT

BACKGROUND: Recently, there has been a burgeoning interest in radiofrequency ablation combined with stent (RFA + Stent) for unresectable malignant biliary obstruction (MBO). This study aimed to perform a meta-analysis to evaluate the efficacy and safety of RFA + Stent compared with biliary stent alone. METHODS: We searched PubMed, Cochrane Library, Embase, and Web of Science databases from their inception dates to June 20, 2021, for studies that compared RFA + Stent and stent alone for unresectable MBO. The main outcomes were survival, patency, and adverse effects. All meta-analyses were calculated using the random-effects model. RESULTS: A total of 19 studies involving 1946 patients were included in this study. Compared with stent alone, RFA + Stent was significantly associated with better overall survival (HR 0.55; 95% CI 0.48, 0.63; P < 0.00001), longer mean survival time (SMD 2.20; 95% CI 1.17, 3.22; P < 0.0001), longer mean stent patency time (SMD 1.37; 95% CI 0.47, 2.26; P = 0.003), higher stent patency at 6 months (OR 2.82; 95% CI 1.54, 5.18; P = 0.0008). The two interventions had similar incidence of postoperative abdominal pain (OR 1.29; 95% CI 0.94, 1.78; P = 0.11), mild bleeding (OR 1.28; 95% CI 0.65, 2.54; P = 0.48), cholangitis (OR 1.09; 95% CI 0.76, 1.55; P = 0.65), pancreatitis (OR 1.39; 95% CI 0.82, 2.38; P = 0.22). Furthermore, the serum bilirubin levels and stricture diameter after operations were significantly alleviated than before operations, but the degree of alleviation between the two groups were not significantly different (all P > 0.05). CONCLUSION: Although the alleviation of serum bilirubin and stricture diameter did not differ between the two interventions, RFA + Stent can significantly improve the survival and stent patency with comparable procedure-related adverse events than stent alone. Thus, RFA + Stent should be recommended as an attractive alternative to biliary stent alone for patients with unresectable MBO.


Subject(s)
Bile Duct Neoplasms , Catheter Ablation , Cholestasis , Radiofrequency Ablation , Bile Duct Neoplasms/complications , Bile Duct Neoplasms/surgery , Bilirubin , Catheter Ablation/adverse effects , Cholestasis/etiology , Cholestasis/surgery , Constriction, Pathologic/etiology , Humans , Radiofrequency Ablation/adverse effects , Stents/adverse effects , Treatment Outcome
14.
Environ Microbiol ; 23(2): 559-571, 2021 02.
Article in English | MEDLINE | ID: mdl-31908125

ABSTRACT

Protein quality control pathways require AAA+ proteases, such as Clp and Lon. Lon protease maintains UmuD, an important component of the error-prone DNA repair polymerase (Pol V), at very low levels in E. coli. Most members of the phylum Cyanobacteria lack Lon (including the model cyanobacterium, Synechocystis sp. PCC6803), so maintenance of UmuD at low levels must employ different proteases. We demonstrate that the first 19 residues from the N-terminus of UmuD (Sug1-19 ) fused to a reporter protein are adequate to trigger complete proteolysis and that mutation of a single leucine residue (L6) to aspartic acid inhibits proteolysis. This process appears to follow the N-end rule and is mediated by ClpA/P protease and the ClpS adaptor. Additionally, mutations of arginine residues in the Sug1-19 tag suggest that the ClpX/P pathway also plays a role in proteolysis. We propose that there is a dual degron at the N-terminus of the UmuD protein in Synechocystis sp. PCC6803, which is distinct from the degron required for degradation of UmuD in E. coli. The use of two proteolysis pathways to tune levels of UmuD might reflect how a photosynthetic organism responds to multiple environmental stressors.


Subject(s)
Bacterial Proteins/metabolism , DNA-Directed DNA Polymerase/metabolism , Synechocystis/enzymology , Amino Acid Motifs , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , DNA Repair , DNA-Directed DNA Polymerase/chemistry , DNA-Directed DNA Polymerase/genetics , Mutation , Proteolysis , Synechocystis/chemistry , Synechocystis/genetics , Synechocystis/metabolism
15.
Environ Microbiol ; 23(11): 6433-6449, 2021 11.
Article in English | MEDLINE | ID: mdl-34472186

ABSTRACT

Cyanobacteria have an inherited advantage in phosphonate phytoremediation. However, studies on phosphonate metabolism in cyanobacteria are rare and mostly focus on physiology and ecology. Here, C-P lyase gene cluster regulation in an undomesticated thermophilic Synechococcus OS-B' was examined in Synechocystis sp. PCC6803, a unicellular cyanobacterial model. Phylogenetic and cluster synteny analysis of C-P lyase genes revealed a closer relationship between Syn OS-B' and Thermus thermophilus, than with other cyanobacteria. Pho boxes were identified in the 5'-end-flanking region of the C-P lyase gene cluster, through which the downstream gene expression was regulated in a phosphate concentration-dependent manner. Unexpectedly, the phosphate concentration that thoroughly inhibited Pho boxes was almost two orders of magnitude higher than that of any natural or anthropogenic wastewater reported so far. The Pho boxes mediated regulation was achieved through the Pho regulon two-component system, and the absence of either SphS or SphR ablated the cell's ability to sense ambient phosphate changes. The three tandems of Pho boxes maintained inequivalent roles, of which the third tandem was not essential; however, it played a role in adjusting Pho boxes response in both positive and negative manner under phosphorus limitation.


Subject(s)
Operon , Synechocystis , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Gene Expression Regulation, Bacterial , Lyases , Operon/genetics , Phosphates/metabolism , Phylogeny , Regulon/genetics , Synechocystis/genetics , Synechocystis/metabolism
16.
New Phytol ; 230(6): 2459-2473, 2021 06.
Article in English | MEDLINE | ID: mdl-33759450

ABSTRACT

Forward and reverse genetics using the model legumes Lotus japonicus and Medicago truncatula have been instrumental in identifying the essential genes governing legume-rhizobia symbiosis. However, little information is known about the effects of intraspecific variation on symbiotic signalling. Here, we use quantitative trait locus sequencing (QTL-seq) to investigate the genetic basis of the differentiated phenotypic responses shown by the Lotus accessions Gifu and MG20 to inoculation with the Mesorhizobium loti exoU mutant that produces truncated exopolysaccharides. We identified through genetic complementation the Pxy gene as a component of this differential exoU response. Lotus Pxy encodes a leucine-rich repeat receptor-like kinase similar to Arabidopsis thaliana PXY, which regulates stem vascular development. We show that Lotus pxy insertion mutants displayed defects in root and stem vascular organisation, as well as lateral root and nodule formation. Our work links Pxy to de novo organogenesis in the root, highlights the genetic overlap between regulation of lateral root and nodule formation, and demonstrates that natural variation in Pxy affects nodulation signalling.


Subject(s)
Lotus , Mesorhizobium , Gene Expression Regulation, Plant , Lotus/genetics , Lotus/metabolism , Mesorhizobium/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Roots/genetics , Plant Roots/metabolism , Root Nodules, Plant/genetics , Root Nodules, Plant/metabolism , Symbiosis/genetics
17.
Gut ; 69(4): 727-736, 2020 04.
Article in English | MEDLINE | ID: mdl-31519701

ABSTRACT

OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the most frequent malignancies and a major leading cause of cancer-related deaths worldwide. Several therapeutic options like sorafenib and regorafenib provide only modest survival benefit to patients with HCC. This study aims to identify novel druggable candidate genes for patients with HCC. DESIGN: A non-biased CRISPR (clustered regularly interspaced short palindromic repeats) loss-of-function genetic screen targeting all known human kinases was performed to identify vulnerabilities of HCC cells. Whole-transcriptome sequencing (RNA-Seq) and bioinformatics analyses were performed to explore the mechanisms of the action of a cyclin-dependent kinase 12 (CDK12) inhibitor in HCC cells. Multiple in vitro and in vivo assays were used to study the synergistic effects of the combination of CDK12 inhibition and sorafenib. RESULTS: We identify CDK12 as critically required for most HCC cell lines. Suppression of CDK12 using short hairpin RNAs (shRNAs) or its inhibition by the covalent small molecule inhibitor THZ531 leads to robust proliferation inhibition. THZ531 preferentially suppresses the expression of DNA repair-related genes and induces strong DNA damage response in HCC cell lines. The combination of THZ531 and sorafenib shows striking synergy by inducing apoptosis or senescence in HCC cells. The synergy between THZ531 and sorafenib may derive from the notion that THZ531 impairs the adaptive responses of HCC cells induced by sorafenib treatment. CONCLUSION: Our data highlight the potential of CDK12 as a drug target for patients with HCC. The striking synergy of THZ531 and sorafenib suggests a potential combination therapy for this difficult to treat cancer.


Subject(s)
Anilides/pharmacology , Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/pathology , Cyclin-Dependent Kinases/antagonists & inhibitors , Liver Neoplasms/pathology , Pyrimidines/pharmacology , Sorafenib/pharmacology , Carcinoma, Hepatocellular/drug therapy , Cell Culture Techniques , Cell Line, Tumor , Humans , Liver Neoplasms/drug therapy
18.
Hepatology ; 69(2): 604-621, 2019 02.
Article in English | MEDLINE | ID: mdl-30053328

ABSTRACT

Mitochondria lie at the heart of innate immunity, and aberrant mitochondrial activity contributes to immune activation and chronic inflammatory diseases, including liver cancers. Mitophagy is a selective process for removing dysfunctional mitochondria. The link between mitophagy and inflammation in tumorigenesis remains largely unexplored. We observed that FUN14 domain-containing 1 (FUNDC1), a previously characterized mitophagy receptor, accumulates in most human hepatocellular carcinomas (HCCs), and we thus explored the role of FUNDC1-mediated mitophagy in HCC initiation and progression in a mouse model in which HCC is induced by the chemical carcinogen, diethylnitrosamine (DEN). We showed that specific knockout of FUNDC1 in hepatocytes promotes the initiation and progression of DEN-induced HCC, whereas FUNDC1 transgenic hepatocytes protect against development of HCC. Hepatocyte-specific FUNDC1 ablation results in the accumulation of dysfunctional mitochondria and triggers a cascade of events involving inflammasome activation and hyperactivation of Janus kinase/signal transducer and activator of transcription signaling. Specifically, cytosolic mitochondrial DNA (mtDNA) release and caspase-1 activation are increased in FUNDC1-depleted hepatocytes. This subsequently results in the elevated release of proinflammatory cytokines, such as interleukin-1ß (IL1ß) and hyperproliferation of hepatocytes. Conclusion: Our results suggest that FUNDC1 suppresses HCC initiation by reducing inflammasome activation and inflammatory responses in hepatocytes, whereas up-regulation of FUNDC1 expression at the late stage of tumor development may benefit tumor growth. Our study thus describes a mechanistic link between mitophagic modulation of inflammatory response and tumorigenesis, and further implies that FUNDC1-mediated mitophagy and its related inflammatory response may represent a therapeutic target for liver cancer.


Subject(s)
Carcinoma, Hepatocellular/etiology , Liver Neoplasms, Experimental/etiology , Membrane Proteins/metabolism , Mitochondrial Proteins/metabolism , Mitophagy , Animals , Carcinoma, Hepatocellular/metabolism , Caspase 1/metabolism , Diethylnitrosamine , Hepatocytes/metabolism , Humans , Inflammasomes/metabolism , Liver Cirrhosis/etiology , Liver Cirrhosis/metabolism , Liver Neoplasms, Experimental/metabolism , Male , Mice, Inbred C57BL , Mice, Knockout
19.
Plant Physiol ; 181(2): 804-816, 2019 10.
Article in English | MEDLINE | ID: mdl-31409696

ABSTRACT

During the legume-rhizobium symbiotic interaction, rhizobial invasion of legumes is primarily mediated by a plant-made tubular invagination called an infection thread (IT). Here, we identify a gene in Lotus japonicus encoding a Leu-rich repeat receptor-like kinase (LRR-RLK), RINRK1 (Rhizobial Infection Receptor-like Kinase1), that is induced by Nod factors (NFs) and is involved in IT formation but not nodule organogenesis. A paralog, RINRK2, plays a relatively minor role in infection. RINRK1 is required for full induction of early infection genes, including Nodule Inception (NIN), encoding an essential nodulation transcription factor. RINRK1 displayed an infection-specific expression pattern, and NIN bound to the RINRK1 promoter, inducing its expression. RINRK1 was found to be an atypical kinase localized to the plasma membrane and did not require kinase activity for rhizobial infection. We propose RINRK1 is an infection-specific RLK, which may specifically coordinate output from NF signaling or perceive an unknown signal required for rhizobial infection.


Subject(s)
Lotus/enzymology , Plant Proteins/metabolism , Protein Kinases/metabolism , Root Nodules, Plant/growth & development , Lotus/growth & development , Lotus/microbiology , Rhizobium/physiology , Root Nodules, Plant/microbiology
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