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1.
EMBO J ; 42(15): e111951, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37334492

ABSTRACT

BRCA1 expression is highly regulated to prevent genomic instability and tumorigenesis. Dysregulation of BRCA1 expression correlates closely with sporadic basal-like breast cancer and ovarian cancer. The most significant characteristic of BRCA1 regulation is periodic expression fluctuation throughout the cell cycle, which is important for the orderly progression of different DNA repair pathways throughout the various cell cycle phases and for further genomic stability. However, the underlying mechanism driving this phenomenon is poorly understood. Here, we demonstrate that RBM10-mediated RNA alternative splicing coupled to nonsense-mediated mRNA decay (AS-NMD), rather than transcription, determines the periodic fluctuations in G1/S-phase BRCA1 expression. Furthermore, AS-NMD broadly regulates the expression of period genes, such as DNA replication-related genes, in an uneconomical but more rapid manner. In summary, we identified an unexpected posttranscriptional mechanism distinct from canonical processes that mediates the rapid regulation of BRCA1 as well as other period gene expression during the G1/S-phase transition and provided insights into potential targets for cancer therapy.


Subject(s)
Breast Neoplasms , Nonsense Mediated mRNA Decay , Humans , Female , Alternative Splicing , RNA Splicing , Breast Neoplasms/genetics , Genomic Instability , BRCA1 Protein/genetics , RNA-Binding Proteins/genetics
2.
Mol Cell ; 75(6): 1299-1314.e6, 2019 09 19.
Article in English | MEDLINE | ID: mdl-31353207

ABSTRACT

MRE11 nuclease forms a trimeric complex (MRN) with RAD50 and NBS1 and plays a central role in preventing genomic instability. When DNA double-strand breaks (DSBs) occur, MRN is quickly recruited to the damage site and initiates DNA end resection; accordingly, MRE11 must be tightly regulated to avoid inefficient repair or nonspecific resection. Here, we show that MRE11 and RAD50 form a complex (MRC) with C1QBP, which stabilizes MRE11/RAD50, while inhibiting MRE11 nuclease activity by preventing its binding to DNA or chromatin. Upon DNA damage, ATM phosphorylates MRE11-S676/S678 to quickly dissociate the MRC complex. Either excess or insufficient C1QBP impedes the recruitment of MRE11 to DSBs and impairs the DNA damage response. C1QBP is highly expressed in breast cancer and positively correlates with MRE11 expression, and the inhibition of C1QBP enhances tumor regression with chemotherapy. By influencing MRE11 at multiple levels, C1QBP is, thus, an important player in the DNA damage response.


Subject(s)
Acid Anhydride Hydrolases/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , DNA-Binding Proteins/metabolism , Homologous Recombination , MRE11 Homologue Protein/metabolism , Mitochondrial Proteins/metabolism , Multiprotein Complexes/metabolism , Nuclear Proteins/metabolism , Acid Anhydride Hydrolases/genetics , Animals , Carrier Proteins/genetics , Cell Cycle Proteins/genetics , DNA-Binding Proteins/genetics , HEK293 Cells , HeLa Cells , Humans , MRE11 Homologue Protein/genetics , Mitochondrial Proteins/genetics , Multiprotein Complexes/genetics , Nuclear Proteins/genetics , Protein Stability , Sf9 Cells , Spodoptera
3.
PLoS Pathog ; 18(2): e1010265, 2022 02.
Article in English | MEDLINE | ID: mdl-35143592

ABSTRACT

Efforts to define serological correlates of protection against COVID-19 have been hampered by the lack of a simple, scalable, standardised assay for SARS-CoV-2 infection and antibody neutralisation. Plaque assays remain the gold standard, but are impractical for high-throughput screening. In this study, we show that expression of viral proteases may be used to quantitate infected cells. Our assays exploit the cleavage of specific oligopeptide linkers, leading to the activation of cell-based optical biosensors. First, we characterise these biosensors using recombinant SARS-CoV-2 proteases. Next, we confirm their ability to detect viral protease expression during replication of authentic virus. Finally, we generate reporter cells stably expressing an optimised luciferase-based biosensor, enabling viral infection to be measured within 24 h in a 96- or 384-well plate format, including variants of concern. We have therefore developed a luminescent SARS-CoV-2 reporter cell line, and demonstrated its utility for the relative quantitation of infectious virus and titration of neutralising antibodies.


Subject(s)
Biosensing Techniques/methods , COVID-19 Testing/methods , COVID-19/virology , Luminescent Measurements/methods , Peptide Hydrolases/analysis , SARS-CoV-2/enzymology , Viral Proteins/analysis , COVID-19/diagnosis , Cell Line , Humans , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Replication
4.
Appl Microbiol Biotechnol ; 108(1): 380, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38888634

ABSTRACT

Obstructive sleep apnea (OSA) can lead to intestinal injury, endotoxemia, and disturbance of intestinal flora. Additionally, as a crucial component of the endocannabinoid system, some studies have demonstrated that cannabinoid 1 (CB1) receptors are closely linked to the multiple organ dysfunction triggered by OSA. However, the role of the CB1 receptor in alleviating OSA-induced colon injury remains unclear. Here, through the construction of the OSA classic model, we found that the colon tissue of chronic intermittent hypoxia (CIH)-induced mice exhibited an overexpression of the CB1 receptor. The results of hematoxylin-eosin staining and transmission electron microscopy revealed that inhibition of the CB1 receptor could decrease the gap between the mucosa and muscularis mucosae, alleviate mitochondrial swelling, reduce microvilli shedding, and promote the recovery of tight junctions of CIH-induced mice. Furthermore, CB1 receptor inhibition reduced the levels of metabolic endotoxemia and inflammatory responses, exhibiting significant protective effects on the colon injury caused by CIH. At the molecular level, through western blotting and real-time polymerase chain reaction techniques, we found that inhibiting the CB1 receptor can significantly increase the expression of ZO-1 and Occludin proteins, which are closely related to the maintenance of intestinal mucosal barrier function. Through 16S rRNA high-throughput sequencing and short-chain fatty acid (SCFA) determination, we found that inhibition of the CB1 receptor increased the diversity of the microbial flora and controlled the makeup of intestinal flora. Moreover, butyric acid concentration and the amount of SCFA-producing bacteria, such as Ruminococcaceae and Lachnospiraceae, were both markedly elevated by CB1 receptor inhibition. The results of the spearman correlation study indicated that Lachnospiraceae showed a positive association with both ZO-1 and Occludin but was negatively correlated with the colon CB1 receptor, IL-1ß, and TNF-α. According to this study, we found that inhibiting CB1 receptor can improve CIH-induced colon injury by regulating gut microbiota, reducing mucosal damage and promoting tight junction recovery. KEY POINTS: •CIH leads to overexpression of CB1 receptor in colon tissue. •CIH causes intestinal flora disorder, intestinal mucosal damage, and disruption of tight junctions. •Inhibition of CB1 receptor can alleviate the colon injury caused by CIH through regulating the gut microbiota, reducing mucosal injury, and promoting tight junction recovery.


Subject(s)
Colon , Disease Models, Animal , Intestinal Mucosa , Receptor, Cannabinoid, CB1 , Animals , Receptor, Cannabinoid, CB1/metabolism , Receptor, Cannabinoid, CB1/genetics , Mice , Colon/pathology , Colon/microbiology , Colon/metabolism , Male , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Hypoxia/metabolism , Mice, Inbred C57BL , Zonula Occludens-1 Protein/metabolism , Occludin/metabolism , Occludin/genetics , Gastrointestinal Microbiome , Tight Junctions/metabolism
5.
BMC Pregnancy Childbirth ; 24(1): 122, 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38336714

ABSTRACT

BACKGROUND: According to prenatal ultrasonographic studies, single umbilical artery may be present alone or in association with other fetal abnormalities. So far, the exact pathogenesis of bladder exstrophy is unclear. Some scholars believe that bladder exstrophy and cloacal exstrophy should be regarded as a disease spectrum to explore their pathogenesis. If bladder exstrophy and cloacal exstrophy are regarded as the same disease spectrum, then we can speculate that the single umbilical artery should have the probability of being accompanied by bladder exstrophy at the same time. CASE PRESENTATION: For the first time, we report a rare case of fetal bladder exstrophy with single umbilical artery in single pregnancy. This patient underwent targeted color Doppler ultrasound at 26 weeks of pregnancy which first suspected bladder exstrophy with single umbilical artery and fetal MRI for diagnosis at 38 + 3 weeks of pregnancy which confirmed the suspicion. After the diagnosis was confirmed, the patient was scheduled for a multidisciplinary discussion. Ultimately the patient opted for induced fetal demise at 38 + 5 weeks of pregnancy and the physical appearance of the fetal demise affirmed previous ultrasound and MRI examination results. CONCLUSIONS: Our report is the first finding of single umbilical artery combined with bladder exstrophy in a singleton pregnancy. Accordingly, our case enhances the evidence that cloacal exstrophy and bladder exstrophy should be treated as the same disease spectrum. In addition, we conducted a literature review on the diagnostic progress of single umbilical artery combined with bladder exstrophy, hoping to provide useful references for the diagnosis of this disease.


Subject(s)
Bladder Exstrophy , Single Umbilical Artery , Pregnancy , Female , Humans , Bladder Exstrophy/complications , Bladder Exstrophy/diagnostic imaging , Bladder Exstrophy/pathology , Ultrasonography, Prenatal/methods , Prenatal Care , Fetal Death
6.
J Toxicol Environ Health A ; 87(10): 448-456, 2024 May 18.
Article in English | MEDLINE | ID: mdl-38557302

ABSTRACT

Cerebral ischemia-reperfusion injury (CIRI) occurs frequently clinically as a complication following cardiovascular resuscitation resulting in neuronal damage specifically to the hippocampal CA1 region with consequent cognitive impairment. Apoptosis and oxidative stress were proposed as major risk factors associated with CIRI development. Previously, glycosides obtained from Cistanche deserticola (CGs) were shown to play a key role in counteracting CIRI; however, the underlying mechanisms remain to be determined. This study aimed to investigate the neuroprotective effect of CGs on subsequent CIRI in rats. The model of CIRI was established for 2 hr and reperfusion for 24 hr by middle cerebral artery occlusion (MCAO) model. The MCAO rats were used to measure the antioxidant and anti-apoptotic effects of CGs on CIRI. Neurological function was evaluated by the Longa neurological function score test. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to detect the area of cerebral infarction. Nissl staining was employed to observe neuronal morphology. TUNEL staining was used to detect neuronal apoptosis, while Western blot determined protein expression levels of factors for apoptosis-related and PI3K/AKT/Nrf2 signaling pathway. Data demonstrated that CGs treatment improved behavioral performance, brain injury, and enhanced antioxidant and anti-apoptosis in CIRI rats. In addition, CGs induced activation of PI3K/AKT/Nrf2 signaling pathway accompanied by inhibition of the expression of apoptosis-related factors. Evidence indicates that CGs amelioration of CIRI involves activation of the PI3K/AKT/Nrf2 signaling pathway associated with increased cellular viability suggesting these glycosides may be considered as an alternative compound for CIRI treatment.


Subject(s)
Brain Ischemia , Cistanche , Neuroprotective Agents , Reperfusion Injury , Rats , Animals , Rats, Sprague-Dawley , Proto-Oncogene Proteins c-akt/metabolism , Antioxidants/pharmacology , Infarction, Middle Cerebral Artery/drug therapy , Phosphatidylinositol 3-Kinases/pharmacology , Glycosides/pharmacology , Glycosides/therapeutic use , NF-E2-Related Factor 2/pharmacology , Apoptosis , Brain Ischemia/drug therapy , Reperfusion Injury/drug therapy , Reperfusion Injury/prevention & control , Neuroprotective Agents/pharmacology
7.
J Toxicol Environ Health A ; 87(10): 436-447, 2024 May 18.
Article in English | MEDLINE | ID: mdl-38557424

ABSTRACT

One of the main pathological features noted in Alzheimer's disease (AD) is the presence of plagues of aggregated ß-amyloid (Aß1-42)-peptides. Excess deposition of amyloid-ß oligomers (AßO) are known to promote neuroinflammation. Sequentially, following neuroinflammation astrocytes become activated with cellular characteristics to initiate activated astrocytes. The purpose of this study was to determine whether total flavonoids derived from Dracocephalum moldavica L. (TFDM) inhibited Aß1-42-induced damage attributed to activated C8-D1A astrocytes. Western blotting and ELISA were used to determine the expression of glial fibrillary acidic protein (GFAP), and complement C3 to establish the activation status of astrocytes following induction from exposure to Aß1-42. Data demonstrated that stimulation of C8-D1A astrocytes by treatment with 40 µM Aß1-42 for 24 hr produced significant elevation in protein expression and protein levels of acidic protein (GFAP) and complement C3 accompanied by increased expression and levels of inflammatory cytokines. Treatment with TFDM or the clinically employed drug donepezil in AD therapy reduced production of inflammatory cytokines, and toxicity initiated following activation of C8-D1A astrocytes following exposure to Aß1-42. Therefore, TFDM similar to donepezil inhibited inflammatory secretion in reactive astrocytes, suggesting that TFDM may be considered as a potential compound to be utilized in AD therapy.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Lamiaceae , Humans , Amyloid beta-Peptides/pharmacology , Alzheimer Disease/drug therapy , Flavonoids/pharmacology , Complement C3/metabolism , Complement C3/pharmacology , Complement C3/therapeutic use , Neuroinflammatory Diseases , Astrocytes/metabolism , Donepezil/metabolism , Donepezil/pharmacology , Donepezil/therapeutic use , Cytokines/metabolism , Peptide Fragments/metabolism , Peptide Fragments/toxicity
8.
J Toxicol Environ Health A ; 87(11): 471-479, 2024 Jun 02.
Article in English | MEDLINE | ID: mdl-38590254

ABSTRACT

Cannabidiol (CBD), a natural component extracted from Cannabis sativa L. exerts neuroprotective, antioxidant, and anti-inflammatory effects in Alzheimer's disease (AD), a disease characterized by impaired cognition and accumulation of amyloid-B peptides (Aß). Interactions between the gut and central nervous system (microbiota-gut-brain axis) play a critical role in the pathogenesis of neurodegenerative disorder AD. At present investigations into the mechanisms underlying the neuroprotective action of CBD in AD are not conclusive. The aim of this study was thus to examine the influence of CBD on cognition and involvement of the microbiota-gut-brain axis using a senescence-accelerated mouse prone 8 (SAMP8) model. Data demonstrated that administration of CBD to SAMP8 mice improved cognitive function as evidenced from the Morris water maze test and increased hippocampal activated microglia shift from M1 to M2. In addition, CBD elevated levels of Bacteriodetes associated with a fall in Firmicutes providing morphologically a protective intestinal barrier which subsequently reduced leakage of intestinal toxic metabolites. Further, CBD was found to reduce the levels of hippocampal and colon epithelial cells lipopolysaccharide (LPS), known to be increased in AD leading to impaired gastrointestinal motility, thereby promoting neuroinflammation and subsequent neuronal death. Our findings demonstrated that CBD may be considered a beneficial therapeutic drug to counteract AD-mediated cognitive impairment and restore gut microbial functions associated with the observed neuroprotective mechanisms.


Subject(s)
Alzheimer Disease , Cannabidiol , Cognitive Dysfunction , Mice , Animals , Alzheimer Disease/drug therapy , Cannabidiol/pharmacology , Cannabidiol/therapeutic use , Brain-Gut Axis , Cognition , Cognitive Dysfunction/drug therapy , Disease Models, Animal
9.
Nucleic Acids Res ; 50(7): 3817-3834, 2022 04 22.
Article in English | MEDLINE | ID: mdl-35349706

ABSTRACT

Reactive oxygen species (ROS) are constantly produced in cells, an excess of which causes oxidative stress. ROS has been linked to regulation of the Hippo pathway; however, the underlying detailed mechanisms remain unclear. Here, we report that MOB1, a substrate of MST1/2 and co-activator of LATS1/2 in the canonical Hippo pathway, interacts with and is acetylated at lysine 11 by acetyltransferase CBP and deacetylated by HDAC6. MOB1-K11 acetylation stabilizes itself by reducing its binding capacity with E3 ligase Praja2 and subsequent ubiquitination. MOB1-K11 acetylation increases its phosphorylation and activates LATS1. Importantly, upstream oxidative stress signals promote MOB1 acetylation by suppressing CBP degradation, independent of MST1/2 kinase activity and HDAC6 deacetylation effect, thereby linking oxidative stress to activation of the Hippo pathway. Functionally, the acetylation-deficient mutant MOB1-K11R promotes lung cancer cell proliferation, migration and invasion in vitro and accelerates tumor growth in vivo, compared to the wild-type MOB1. Clinically, acetylated MOB1 corresponds to better prediction of overall survival in patients with non-small cell lung cancer. Therefore, as demonstrated, an oxidative stress-CBP regulatory axis controls MOB1-K11 acetylation and activates LATS1, thereby activating the Hippo pathway and suppressing YAP/TAZ nuclear translocation and tumor progression.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Chemokine CXCL10/metabolism , Hippo Signaling Pathway , Lung Neoplasms , Acetylation , Humans , Lung Neoplasms/genetics , Oxidative Stress , Protein Serine-Threonine Kinases/genetics , Reactive Oxygen Species
10.
Nano Lett ; 23(6): 2427-2435, 2023 03 22.
Article in English | MEDLINE | ID: mdl-36715488

ABSTRACT

Neurotransmitter exocytosis of living cells plays a vital role in neuroscience. However, the available amperometric technique with carbon fiber electrodes typically measures exocytotic events from one cell during one procedure, which requires professional operations and takes time to produce statistical results of multiple cells. Here, we develop a functionally collaborative nanostructure to directly measure the neurotransmitter dopamine (DA) exocytosis from living rat pheochromocytoma (PC12) cells. The functionally collaborative nanostructure is constructed of metal-organic framework (MOF)-on-nanowires-on-graphene oxide, which is highly sensitive to DA molecules and enables direct detection of neurotransmitter exocytosis. Using the microsensor, the exocytosis from PC12 cells pretreated with the desired drugs (e.g., anticoronavirus drug, antiflu drug, or anti-inflammatory drug) has been successfully measured. Our achievements demonstrate the feasibility of the functionally collaborative nanostructure in the real-time detection of exocytosis and the potential applicability in the highly efficient assessment of the modulation effects of medications on exocytosis.


Subject(s)
Dopamine , Nanostructures , Animals , Rats , Electrodes , Exocytosis/physiology , Neurotransmitter Agents
11.
J Sci Food Agric ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38953326

ABSTRACT

BACKGROUND: Giant salamander protein peptide is a peptide with rich functional properties. Giant salamander protein peptide KGEYNK (KK-6) is a peptide with both antioxidant and anti-inflammatory properties. The antioxidant and anti-inflammatory mechanisms of KK-6 are still unclear. When we studied the functional mechanism of KK-6, we found that the antioxidant property of KK-6 has a synergistic and promoting effect on anti-inflammatory properties. RESULTS: KK-6 enhances cellular resistance to LPS via the MAPK/NF-κB signaling pathway, leading to increased levels of inflammatory factors: interleukin-1ß (764.81 ng mL-1), interleukin-6 (1.06 ng mL-1) and tumor necrosis factor-α (4440.45 ng mL-1). KK-6 demonstrates potent antioxidant properties by activating the Nrf2 signaling pathway, resulting in elevated levels of antioxidant enzymes (glutathione peroxidase: 0.03 µg mL-1; superoxide dismutase: 0.589 µg mL-1) and a reduction in the concentration of the oxidative product malondialdehyde (967.05 µg mL-1). CONCLUSION: Our findings highlight the great potential of KK-6, a peptide extracted from giant salamander protein, as a remedy for intestinal inflammation. Through its dual role as an antioxidant and anti-inflammatory agent, KK-6 offers a promising avenue for alleviating inflammation-related damage and oxidative stress. This study lays the foundation for further exploration of giant salamander products and highlights their importance in health and novel food development. © 2024 Society of Chemical Industry.

12.
Opt Express ; 31(6): 9657-9668, 2023 Mar 13.
Article in English | MEDLINE | ID: mdl-37157530

ABSTRACT

Although tunable Fabry-Perot (F-P) filters are widely acknowledged as fiber Bragg grating (FBG) demodulators, F-P filters exhibit drift error when subjected to ambient temperature and piezo-electrical transducer (PZT) hysteresis. To address the drift issue, the majority of the existing literature makes use of additional devices like the F-P etalon and gas chamber. In this study, a novel drift calibration method based on two-stage decomposition and hybrid modeling is proposed. The initial drift error sequences are broken down into three frequency components using the variational mode decomposition (VMD), and the medium-frequency components are further broken down using the secondary VMD. The initial drift error sequences are significantly simplified by the two-stage VMD. On this foundation, the long short-term memory (LSTM) network and polynomial fitting (PF) are used to forecast the low-frequency and high-frequency drift errors, respectively. The LSTM enables the prediction of intricate nonlinear local behaviors, while the PF method predicts the overall trend. The benefits of LSTM and PF can be effectively utilized in this manner. Compared to the single-stage decomposition, two-stage decomposition achieves superior results. The suggested method is an affordable and effective alternative to the current drift calibration techniques.

13.
Org Biomol Chem ; 21(45): 8984-8988, 2023 Nov 22.
Article in English | MEDLINE | ID: mdl-37937487

ABSTRACT

A metal-free and efficient approach for the synthesis of structurally important nicotinates through 4-HO-TEMPO-mediated [3 + 3] annulation of cyclopropanols with ß-enamine esters is presented. This protocol features high atom efficiency, green waste, simple operation and broad substrate scope. Moreover, the experiments of gram-scale synthesis and recovery of oxidants make this strategy more sustainable and practical.

14.
Org Biomol Chem ; 21(25): 5171-5175, 2023 Jun 28.
Article in English | MEDLINE | ID: mdl-37288792

ABSTRACT

An efficient, practical and regioselective synthesis of (E)-alkenylphosphine oxides has been developed starting from alkenes under copper catalysis and 4-HO-TEMPOH oxidation. Preliminary mechanistic studies clearly reveal that a phosphinoyl radical is involved in this process. Moreover, this method features mild reaction conditions, good functional group tolerance, and excellent regioselectivity and also promises to be efficient for the late-stage functionalization of drug molecular skeletons. The reaction will create an opportunity for the synthesis of complex phosphorus containing bioactive molecules.

15.
Arch Insect Biochem Physiol ; 114(4): e22050, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37622383

ABSTRACT

Chitin plays an important role in the development and molting of insects. The key genes involved in chitin metabolism were considered promising targets for pest control. In this study, two splice variants of chitin deacetylase 2 (CDA2) from Diaphorina citri were identified, including DcCDA2a and DcCDA2b. Bioinformatics analysis revealed that DcCDA2a and DcCDA2b encoded 550 and 544 amino acid residues with a signal peptide, respectively. Spatio-temporal expression patterns analysis showed that DcCDA2a and DcCDA2b were highly expressed in D. citri wing and nymph stages. Moreover, DcCDA2a and DcCDA2b expression levels were induced by 20-hydroxyecdysone (20E). Silencing DcCDA2a by RNA interference (RNAi) significantly disrupted the D. citri molting and increased D. citri mortality and malformation rate, whereas inhibition of DcCDA2b resulted in a semimolting phenotype. Furthermore, silencing DcCDA2a and DcCDA2b significantly suppressed D. citri chitin and fatty acid metabolism. Our results indicated that DcCDA2 might play crucial roles in regulating D. citri chitin and fatty acid metabolism, and it could be used as a potential target for controlling D. citri.


Subject(s)
Citrus , Hemiptera , Animals , Hemiptera/physiology , Alternative Splicing , Chitin , Fatty Acids
16.
Proc Natl Acad Sci U S A ; 117(45): 28239-28250, 2020 11 10.
Article in English | MEDLINE | ID: mdl-33109719

ABSTRACT

Aberrant programmed cell death protein 1 (PD-1) expression on the surface of T cells is known to inhibit T cell effector activity and to play a pivotal role in tumor immune escape; thus, maintaining an appropriate level of PD-1 expression is of great significance. We identified KLHL22, an adaptor of the Cul3-based E3 ligase, as a major PD-1-associated protein that mediates the degradation of PD-1 before its transport to the cell surface. KLHL22 deficiency leads to overaccumulation of PD-1, which represses the antitumor response of T cells and promotes tumor progression. Importantly, KLHL22 was markedly decreased in tumor-infiltrating T cells from colorectal cancer patients. Meanwhile, treatment with 5-fluorouracil (5-FU) could increase PD-1 expression by inhibiting the transcription of KLHL22. These findings reveal that KLHL22 plays a crucial role in preventing excessive T cell suppression by maintaining PD-1 expression homeostasis and suggest the therapeutic potential of 5-FU in combination with anti-PD-1 in colorectal cancer patients.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Homeostasis , Programmed Cell Death 1 Receptor/metabolism , T-Lymphocytes/immunology , Adaptor Proteins, Signal Transducing/drug effects , Adaptor Proteins, Signal Transducing/genetics , Animals , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/immunology , Fluorouracil , HEK293 Cells , Humans , Immune Checkpoint Proteins , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Proteolysis , Signal Transduction , Transcriptome , Tumor Microenvironment/immunology , Ubiquitin-Protein Ligases/metabolism
17.
BMC Musculoskelet Disord ; 24(1): 479, 2023 Jun 13.
Article in English | MEDLINE | ID: mdl-37312078

ABSTRACT

PURPOSE: The changes in the lower limb alignment were vitally important after high tibial osteotomy (HTO). Therefore, the purpose of present study was to analyze the characteristics of plantar pressure distribution after HTO, and to investigate the effect of plantar pressure distribution on postoperative limb alignment. METHODS: Between May 2020 and April 2021, varus knee patients undergoing HTO were evaluated in the present study. The peak pressure of plantar regions, medial-lateral pressure ratio (MLPR), foot progression angle (FTA), anteroposterior COP (AP-COP), lateral symmetry of COP (LS-COP), and the radiographic parameters were evaluated preoperatively and at the final follow-up. Compared among the slight valgus (SV), moderate valgus (MV) and large valgus (LV) groups at the final follow-up, the peak pressure of HM, HC and M5 regions, and the MLPR were compared; the Knee Injury and Osteoarthritis Outcome Score4 (KOOS4) including four subscales, and the American of orthopedic foot and ankle society (AOFAS) were evaluated. RESULTS: The WBL%, HKA and TPI angle changed significantly after HTO (P < 0.001). The preoperative group exhibited a lower peak pressure in the HM region (P < 0.05) and higher peak pressure in the M5 region (P < 0.05); the pre- and postoperative groups exhibited a lower peak pressure in the HC region (P < 0.05); the rearfoot MLPR was significantly lower and LS-COP was significantly higher in the preoperative group (P = 0.017 in MLPR and 0.031 in LS-COP, respectively). Comparison among the SV, MV and LV groups, the SV group indicated a lower peak pressure in the HM region (P = 0.036), and a lower MLPR in the rearfoot (P = 0.033). The KOOS Sport/Re score in the MV and LV groups increased significantly compared with the SV group (P = 0.042). CONCLUSION: Plantar pressure distribution during the stance phase in patients with varus knee OA following HTO exhibited a more medialized rearfoot plantar pressure distribution pattern than that before surgery. Compared with the small valgus alignment, a moderate to large valgus alignment allows patients to walk with a more even medial and lateral plantar pressure distribution, which is more similar to healthy adults.


Subject(s)
Orthopedics , Osteoarthritis, Knee , Adult , Humans , Osteoarthritis, Knee/diagnostic imaging , Osteoarthritis, Knee/surgery , Lower Extremity , Osteotomy/adverse effects , Foot/diagnostic imaging
18.
Proc Natl Acad Sci U S A ; 117(10): 5472-5477, 2020 03 10.
Article in English | MEDLINE | ID: mdl-32086392

ABSTRACT

Studies on myotonic dystrophy type 1 (DM1) have led to the RNA-mediated disease model for hereditary disorders caused by noncoding microsatellite expansions. This model proposes that DM1 disease manifestations are caused by a reversion to fetal RNA processing patterns in adult tissues due to the expression of toxic CUG RNA expansions (CUGexp) leading to decreased muscleblind-like, but increased CUGBP1/ETR3-like factor 1 (CELF1), alternative splicing activities. Here, we test this model in vivo, using the mouse HSALR poly(CUG) model for DM1 and recombinant adeno-associated virus (rAAV)-mediated transduction of specific splicing factors. Surprisingly, systemic overexpression of HNRNPA1, not previously linked to DM1, also shifted DM1-relevant splicing targets to fetal isoforms, resulting in more severe muscle weakness/myopathy as early as 4 to 6 wk posttransduction, whereas rAAV controls were unaffected. Overexpression of HNRNPA1 promotes fetal exon inclusion of representative DM1-relevant splicing targets in differentiated myoblasts, and HITS-CLIP of rAAV-mycHnrnpa1-injected muscle revealed direct interactions of HNRNPA1 with these targets in vivo. Similar to CELF1, HNRNPA1 protein levels decrease during postnatal development, but are elevated in both regenerating mouse muscle and DM1 skeletal muscle. Our studies suggest that CUGexp RNA triggers abnormal expression of multiple nuclear RNA binding proteins, including CELF1 and HNRNPA1, that antagonize MBNL activity to promote fetal splicing patterns.


Subject(s)
Alternative Splicing , Heterogeneous Nuclear Ribonucleoprotein A1/genetics , Heterogeneous Nuclear Ribonucleoprotein A1/metabolism , Myotonic Dystrophy/genetics , Animals , CELF1 Protein/genetics , DNA-Binding Proteins/metabolism , Disease Models, Animal , Fetus , Humans , Mice , Mice, Transgenic , Myotonic Dystrophy/metabolism , Myotonic Dystrophy/pathology , RNA-Binding Proteins/metabolism
19.
Org Biomol Chem ; 20(46): 9127-9131, 2022 11 30.
Article in English | MEDLINE | ID: mdl-36377719

ABSTRACT

An Fe-catalyzed unprotected hydroxylamine mediated Heck-type coupling between sulfinic acids and alkenes for the regioselective synthesis of (E)-vinyl sulfones has been developed. Mechanism studies indicated for the first time that a radical process may be involved and that hydroxylamines play multiple roles, including those of a mild oxidant and an in situ base. It was found for the first time that this transformation not only realizes C-S bond construction promoted by unprotected hydroxylamines, but also provides a practical and complementary method for the preparation of structurally important (E)-vinyl sulfones.


Subject(s)
Hydroxylamines , Iron , Hydroxylamines/chemistry , Iron/chemistry , Catalysis , Sulfones/chemistry
20.
Anal Bioanal Chem ; 414(24): 7123-7141, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35962791

ABSTRACT

Exosomes are extracellular vesicles with a diameter ranging from 30 to 150 nm, which are an important medium for intercellular communication and are closely related to the progression of certain diseases. Therefore, exosomes are considered promising biomarkers for the diagnosis of specific diseases, and thereby, treatments based on exosomes are being widely examined. For exosome-related research, a rapid, simple, high-purity, and recovery isolation method is the primary prerequisite for exosomal large-scale application in medical practice. Although there are no standardized methods for exosome separation and analysis, various techniques have been established to explore their biochemical and physicochemical properties. In this review, we analyzed the progress in exosomal isolation strategies and proposed our views on the development prospects of various exosomal isolation techniques.


Subject(s)
Exosomes , Biomarkers/analysis , Exosomes/chemistry
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