Prediction of mutation-induced protein stability changes based on the geometric representations learned by a self-supervised method.

BACKGROUND: Thermostability is a fundamental property of proteins to maintain their biological functions. Predicting protein stability changes upon mutation is important for our understanding protein structure-function relationship, and is also of great interest in protein engineering and pharmaceutical design. RESULTS: Here we present mutDDG-SSM, a deep learning-based framework that uses the geometric representations encoded in protein structure to predict the mutation-induced protein stability changes. mutDDG-SSM consists of two parts: a graph attention network-based protein structural feature extractor that is trained with a self-supervised learning scheme using large-scale high-resolution protein structures, and an eXtreme Gradient Boosting model-based stability change predictor with an advantage of alleviating overfitting problem. The performance of mutDDG-SSM was tested on several widely-used independent datasets. Then, myoglobin and p53 were used as case studies to illustrate the effectiveness of the model in predicting protein stability changes upon mutations. Our results show that mutDDG-SSM achieved high performance in estimating the effects of mutations on protein stability. In addition, mutDDG-SSM exhibited good unbiasedness, where the prediction accuracy on the inverse mutations is as well as that on the direct mutations. CONCLUSION: Meaningful features can be extracted from our pre-trained model to build downstream tasks and our model may serve as a valuable tool for protein engineering and drug design.

Targeting EFHD2 inhibits interferon-γ signaling and ameliorates non-alcoholic steatohepatitis.

BACKGROUND & AIMS: The precise pathomechanisms underlying the development of non-alcoholic steatohepatitis (NASH, also known as metabolic dysfunction-associated steatohepatitis [MASH]) remain incompletely understood. In this study, we investigated the potential role of EF-hand domain family member D2 (EFHD2), a novel molecule specific to immune cells, in the pathogenesis of NASH. METHODS: Hepatic EFHD2 expression was characterized in patients with NASH and two diet-induced NASH mouse models. Single-cell RNA sequencing (scRNA-seq) and double-immunohistochemistry were employed to explore EFHD2 expression patterns in NASH livers. The effects of global and myeloid-specific EFHD2 deletion on NASH and NASH-related hepatocellular carcinoma were assessed. Molecular mechanisms underlying EFHD2 function were investigated, while chemical and genetic investigations were performed to assess its potential as a therapeutic target. RESULTS: EFHD2 expression was significantly elevated in hepatic macrophages/monocytes in both patients with NASH and mice. Deletion of EFHD2, either globally or specifically in myeloid cells, improved hepatic steatosis, reduced immune cell infiltration, inhibited lipid peroxidation-induced ferroptosis, and attenuated fibrosis in NASH. Additionally, it hindered the development of NASH-related hepatocellular carcinoma. Specifically, deletion of myeloid EFHD2 prevented the replacement of TIM4+ resident Kupffer cells by infiltrated monocytes and reversed the decreases in patrolling monocytes and CD4+/CD8+ T cell ratio in NASH. Mechanistically, our investigation revealed that EFHD2 in myeloid cells interacts with cytosolic YWHAZ (14-3-3ζ), facilitating the translocation of IFNγR2 (interferon-γ receptor-2) onto the plasma membrane. This interaction mediates interferon-γ signaling, which triggers immune and inflammatory responses in macrophages during NASH. Finally, a novel stapled α-helical peptide targeting EFHD2 was shown to be effective in protecting against NASH pathology in mice. CONCLUSION: Our study reveals a pivotal immunomodulatory and inflammatory role of EFHD2 in NASH, underscoring EFHD2 as a promising druggable target for NASH treatment. IMPACT AND IMPLICATIONS: Non-alcoholic steatohepatitis (NASH) represents an advanced stage of non-alcoholic fatty liver disease (NAFLD); however, not all patients with NAFLD progress to NASH. A key challenge is identifying the factors that trigger inflammation, which propels the transition from simple fatty liver to NASH. Our research pinpointed EFHD2 as a pivotal driver of NASH, orchestrating the over-activation of interferon-γ signaling within the liver during NASH progression. A stapled peptide designed to target EFHD2 exhibited therapeutic promise in NASH mice. These findings support the potential of EFHD2 as a therapeutic target in NASH.

Activation of α7 nicotinic acetylcholine receptors inhibits hepatic necroptosis and ameliorates acute liver injury in mice.

BACKGROUND: Acute liver injury (ALI) is a disease characterized by severe liver dysfunction, caused by significant infiltration of immune cells and extensive cell death with a high mortality. Previous studies demonstrated that the α7 nicotinic acetylcholine receptor (α7nAChR) played a crucial role in various liver diseases. The hypothesis of this study was that activating α7nAChR could alleviate ALI and investigate its possible mechanisms. METHODS: ALI was induced by intraperitoneal injection of lipopolysaccharide (LPS)/D-galactosamine (D-Gal) in wild type (WT), α7nAChR knockout (α7nAChR -/-) and Sting mutation (Stinggt/gt) mice in the presence or absence of a pharmacological selective α7nAChR agonist (PNU-282987). The effects of α7nAChR on hepatic injury, inflammatory response, mitochondrial damage, necroptosis and infiltration of immune cells during ALI were assessed. RESULTS: The expression of α7nAChR in liver tissue was increased in LPS/D-Gal induced ALI mice. Compared to the age-matched WT mice, α7nAChR deficiency decreased the survival rate, exacerbated the hepatic injury accompanied with enhanced inflammatory response and oxidative stress, and aggravated hepatic mitochondrial damage and necroptosis. Conversely, pharmacological activation of α7nAChR by PNU-282987 displayed the opposite trends. Furthermore, PNU-282987 significantly reduced the proportion of infiltrating monocyte-derived macrophages (CD45+CD11bhiF4/80int), M1 macrophages (CD45+CD11b+F4/80+CD86 hiCD163low), Ly6Chi monocytes (CD45+CD11b+MHCⅡ lowLy6C hi), but increased the resident Kupffer cells (CD45+CD11bintF4/80 hiTIM4 hi) in the damaged hepatic tissues caused by LPS/D-Gal. Interestingly, α7nAChR deficiency promoted the STING signaling pathway under LPS/D-Gal stimulation, while PNU-282987 treatment significantly prevented its activation. Finally, it was found that Sting mutation abolished the protective effects against hepatic injury by activating α7nAChR. CONCLUSIONS: Our study revealed that activating α7nAChR could protect against LPS/D-Gal induced ALI by inhibiting hepatic inflammation and necroptosis possibly via regulating immune cells infiltration and inhibiting STING signaling pathway.

Colchicine protects against the development of experimental abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is characterized by at least 1.5-fold enlargement of the infrarenal aorta, a ruptured AAA is life-threatening. Colchicine is a medicine used to treat gout and familial Mediterranean fever, and recently, it was approved to reduce the risk of cardiovascular events in adult patients with established atherosclerotic disease. With an AAA mice model created by treatment with porcine pancreatic elastase (PPE) and ß-aminopropionitrile (BAPN), this work was designed to explore whether colchicine could protect against the development of AAA. Here, we showed that colchicine could limit AAA formation, as evidenced by the decreased total aortic weight per body weight, AAA incidence, maximal abdominal aortic diameter and collagen deposition. We also found that colchicine could prevent the phenotypic switching of vascular smooth muscle cells from a contractile to synthetic state during AAA. In addition, it was demonstrated that colchicine was able to reduce vascular inflammation, oxidative stress, cell pyroptosis and immune cells infiltration to the aortic wall in the AAA mice model. Finally, it was proved that the protective action of colchicine against AAA formation was mainly mediated by preventing immune cells infiltration to the aortic wall. In summary, our findings demonstrated that colchicine could protect against the development of experimental AAA, providing a potential therapeutic strategy for AAA intervention in the clinic.

Prediction of tumor budding in patients with rectal adenocarcinoma using b-value threshold map.

OBJECTIVE: To investigate the feasibility of b-value threshold (bThreshold) map in preoperative evaluation of tumor budding (TB) in patients with locally advanced rectal cancer (LARC). METHODS: Patients with LARC were enrolled and underwent diffusion-weighted imaging (DWI). Contrast-to-noise ratio (CNR) between the lesions and normal tissues was assessed using DWI and bThreshold maps. TB was counted and scored using hematoxylin and eosin staining. Reproducibility for the apparent diffusion coefficient (ADC), bThreshold values, and region-of-interest (ROI) sizes were compared. Differences in ADC and bThreshold values with low-intermediate and high TB grades and the correlations between mean ADC and bThreshold values with TB categories were analyzed. Diagnostic performance of ADC and bThreshold values was assessed using area under the curve (AUC) and decision curve analysis. RESULTS: Fifty-one patients were evaluated. The CNR on bThreshold maps was significantly higher than that on DW images (9.807 ± 4.811 vs 7.779 ± 3.508, p = 0.005). Reproducibility was excellent for the ADC (ICC 0.933; CV 8.807%), bThreshold values (ICC 0.958; CV 7.399%), and ROI sizes (ICC 0.934; CV 8.425%). Significant negative correlations were observed between mean ADC values and TB grades and positive correlations were observed between mean bThreshold values and TB grades (p < 0.05). bThreshold maps showed better diagnostic performance than ADC maps (AUC, 0.914 vs 0.726; p = 0.048). CONCLUSIONS: In LARC patients, bThreshold values could distinguish different TB grades better than ADC values, and bThreshold maps may be a preoperative, non-invasive approach to evaluate TB grades. KEY POINTS: • Compared with diffusion-weighted images, bThreshold maps improved visualization and detection of rectal tumors. • Agreement and diagnostic performance of bThreshold values are superior to apparent diffusion coefficient in assessing tumor budding grades in patients with locally advanced rectal cancer. • bThreshold maps could be used to evaluate tumor budding grades non-invasively before operation.

Predictive value of modified MRI-based split scar sign (mrSSS) score for pathological complete response after neoadjuvant chemoradiotherapy for patients with rectal cancer.

PURPOSE: To measure the diagnostic performance of modified MRI-based split scar sign (mrSSS) score for the prediction of pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for patients with rectal cancer. METHODS: The modified MRI-based split scar sign (mrSSS) score, which consists of T2-weighted images (T2WI)-based score and diffusion-weighted images (DWI)-based score. The sensitivity, specificity, and accuracy of modified mrSSS score, endoscopic gross type, and MRI-based tumor regression grading (mrTRG) score, in the prediction of pCR, were compared. The prognostic value of the modified mrSSS score was also studied. RESULTS: A total of 189 patients were included in the study. The Kendall's coefficient of interobserver concordance of modified mrSSS score, T2WI -based score, and DWI-based score were 0.899, 0.890, and 0.789 respectively. And the maximum and minimum k value of the modified mrSSS score was 0.797 (0.742-0.853) and 0.562 (0.490-0.634). The sensitivity, specificity, and accuracy of prediction of pCR were 0.66, 0.97, and 0.90 for modified mrSSS score; 0.37, 0.89, and 0.78 for endoscopic gross type (scar); and 0.24, 0.92, and 0.77 for mrTRG score (mrTRG = 1). The modified mrSSS score had significantly higher sensitivity than the endoscopic gross type and the mrTRG score in predicting pCR. Patients with lower modified mrSSS scores had significantly longer disease-free survival (P < 0.05). CONCLUSION: The modified mrSSS score showed satisfactory interobserver agreement and higher sensitivity in predicting pCR after nCRT in patients with rectal cancer. The modified mrSSS score is also a predictor of disease-free survival.

Ferroptosis inhibitor liproxstatin-1 alleviates metabolic dysfunction-associated fatty liver disease in mice: potential involvement of PANoptosis.

Ferroptosis is a new form of regulated cell death characterized by excessive iron accumulation and uncontrollable lipid peroxidation. The role of ferroptosis in metabolic dysfunction-associated fatty liver disease (MAFLD) is not fully elucidated. In this study we compared the therapeutic effects of ferroptosis inhibitor liproxstatin-1 (LPT1) and iron chelator deferiprone (DFP) in MAFLD mouse models. This model was established in mice by feeding a high-fat diet with 30% fructose in water (HFHF) for 16 weeks. The mice then received LPT1 (10 mg·kg-1·d-1, ip) or DFP (100 mg·kg-1·d-1, ig) for another 2 weeks. We showed that both LPT1 and DFP treatment blocked the ferroptosis markers ACSL4 and ALOX15 in MAFLD mice. Furthermore, LPT1 treatment significantly reduced the liver levels of triglycerides and cholesterol, lipid peroxidation markers 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA), and ameliorated the expression of lipid synthesis/oxidation genes (Pparα, Scd1, Fasn, Hmgcr and Cpt1a), insulin resistance, mitochondrial ROS content and liver fibrosis. Importantly, LPT1 treatment potently inhibited hepatic apoptosis (Bax/Bcl-xL ratio and TUNEL+ cell number), pyroptosis (cleavages of Caspase-1 and GSDMD) and necroptosis (phosphorylation of MLKL). Moreover, LPT1 treatment markedly inhibited cleavages of PANoptosis-related caspase-8 and caspase-6 in MAFLD mouse liver. In an in vitro MAFLD model, treatment with LPT1 (100 nM) prevented cultured hepatocyte against cell death induced by pro-PANoptosis molecules (TNF-α, LPS and nigericin) upon lipid stress. On the contrary, DFP treatment only mildly attenuated hepatic inflammation but failed to alleviate lipid deposition, insulin resistance, apoptosis, pyroptosis and necroptosis in MAFLD mice. We conclude that ferroptosis inhibitor LPT1 protects against steatosis and steatohepatitis in MAFLD mice, which may involve regulation of PANoptosis, a coordinated cell death pathway that involves apoptosis, pyroptosis and necroptosis. These results suggest a potential link between ferroptosis and PANoptosis.

A therapeutic regimen of ceftazidime-avibactam for a critical patient receiving prolonged intermittent renal replacement therapy.

The present report firstly described a critically ill patient receiving a dosing regimen of ceftazidime-avibactam (CAZ-AVI) (1.875g q24h) to eliminate multidrug-resistant Klebsiella pneumoniae and a scheduled time for prolonged intermittent renal replacement therapy (PIRRT) every 48h (6h-session beginning 12h after the previous dosage on hemodialysis day). This dosing regimen for CAZ-AVI and a scheduled time for PIRRT allowed pharmacodynamic parameters of ceftazidime and avibactam to have little difference on hemodialysis and non-hemodialysis days so that we can maintain a relatively stable drug concentration. Our report highlighted not only the importance of dosing regimens in patients with PIRRT but also the significance of hemodialysis time points during the dosing interval. The innovative therapeutic plan proved to be suitable for patients infected with Klebsiella pneumoniae when on PIRRT according to the trough plasma concentrations of ceftazidime and avibactam which were maintained above the minimum inhibitory concentration during the dosing interval.

Ligustilide attenuates airway remodeling in COPD mice by covalently binding to MH2 domain of Smad3 in pulmonary epithelium, disrupting the Smad3-SARA interaction.

Airway remodeling is one of the hallmarks of chronic obstructive pulmonary disease (COPD) and is closely related to the dysregulation of epithelial-mesenchymal transition (EMT). Smad3, an important transcriptional regulator responsible for transducing TGF-ß1 signals, is a promising target for EMT modulation. We found that ligustilide (Lig), a novel Smad3 covalent inhibitor, effectively inhibited airway remodeling in cigarette smoke (CS) combined with lipopolysaccharide (LPS)-induced COPD mice. Oral administration of an alkynyl-modified Lig probe was used to capture and trace target proteins in mouse lung tissue, revealing Smad3 in airway epithelium as a key target of Lig. Protein mass spectrometry and Smad3 mutation analysis via in-gel imaging indicated that the epoxidized metabolite of Lig covalently binds to the MH2 domain of Smad3 at Cys331/337. This irreversible bonding destroys the interaction of Smad3-SARA, prevents Smad3 phosphorylation activation, and subsequently suppresses the nuclear transfer of p-Smad3, the EMT process, and collagen deposition in TGF-ß1-stimulated BEAS-2B cells and COPD mice. These findings provide experimental support that Lig attenuates COPD by repressing airway remodeling which is attributed to its suppression on the activation of EMT process in the airway epithelium via targeting Smad3 and inhibiting the recruitment of the Smad3-SARA heterodimer in the TGF-ß1/Smad3 pathway.

Magnolol alleviates pulmonary fibrosis inchronic obstructive pulmonary disease by targeting transient receptor potential vanilloid 4-ankyrin repeat domain.

Transient receptor potential vanilloid 4 (TRPV4) plays a role in regulating pulmonary fibrosis (PF). While several TRPV4 antagonists including magnolol (MAG), have been discovered, the mechanism of action is not fully understood. This study aimed to investigate the effect of MAG on alleviating fibrosis in chronic obstructive pulmonary disease (COPD) based on TRPV4, and to further analyze its mechanism of action on TRPV4. COPD was induced using cigarette smoke and LPS. The therapeutic effect of MAG on COPD-induced fibrosis was evaluated. TRPV4 was identified as the main target protein of MAG using target protein capture with MAG probe and drug affinity response target stability assay. The binding sites of MAG at TRPV4 were analyzed using molecular docking and small molecule interaction with TRPV4-ankyrin repeat domain (ARD). The effects of MAG on TRPV4 membrane distribution and channel activity were analyzed by co-immunoprecipitation, fluorescence co-localization, and living cell assay of calcium levels. By targeting TRPV4-ARD, MAG disrupted the binding between phosphatidylinositol 3 kinase γ and TRPV4, leading to hampered membrane distribution on fibroblasts. Additionally, MAG competitively impaired ATP binding to TRPV4-ARD, inhibiting TRPV4 channel opening activity. MAG effectively blocked the fibrotic process caused by mechanical or inflammatory signals, thus alleviating PF in COPD. Targeting TRPV4-ARD presents a novel treatment strategy for PF in COPD.

Exerkine fibronectin type-III domain-containing protein 5/irisin-enriched extracellular vesicles delay vascular ageing by increasing SIRT6 stability.

AIMS: Exercise confers protection against cardiovascular ageing, but the mechanisms remain largely unknown. This study sought to investigate the role of fibronectin type-III domain-containing protein 5 (FNDC5)/irisin, an exercise-associated hormone, in vascular ageing. Moreover, the existence of FNDC5/irisin in circulating extracellular vesicles (EVs) and their biological functions was explored. METHODS AND RESULTS: FNDC5/irisin was reduced in natural ageing, senescence, and angiotensin II (Ang II)-treated conditions. The deletion of FNDC5 shortened lifespan in mice. Additionally, FNDC5 deficiency aggravated vascular stiffness, senescence, oxidative stress, inflammation, and endothelial dysfunction in 24-month-old naturally aged and Ang II-treated mice. Conversely, treatment of recombinant irisin alleviated Ang II-induced vascular stiffness and senescence in mice and vascular smooth muscle cells. FNDC5 was triggered by exercise, while FNDC5 knockout abrogated exercise-induced protection against Ang II-induced vascular stiffness and senescence. Intriguingly, FNDC5 was detected in human and mouse blood-derived EVs, and exercise-induced FNDC5/irisin-enriched EVs showed potent anti-stiffness and anti-senescence effects in vivo and in vitro. Adeno-associated virus-mediated rescue of FNDC5 specifically in muscle but not liver in FNDC5 knockout mice, promoted the release of FNDC5/irisin-enriched EVs into circulation in response to exercise, which ameliorated vascular stiffness, senescence, and inflammation. Mechanistically, irisin activated DnaJb3/Hsp40 chaperone system to stabilize SIRT6 protein in an Hsp70-dependent manner. Finally, plasma irisin concentrations were positively associated with exercise time but negatively associated with arterial stiffness in a proof-of-concept human study. CONCLUSION: FNDC5/irisin-enriched EVs contribute to exercise-induced protection against vascular ageing. These findings indicate that the exerkine FNDC5/irisin may be a potential target for ageing-related vascular comorbidities.

Modulating the Structures and Magnetic Properties of Dy(III) Single-Molecule Magnets through Acid-Base Regulation.

Chemical modulation on the structures and physical properties of the coordination complexes is of great interest for the preparation of new functional materials. By changing the acidity or basicity of the reaction medium, the deprotonation degree of a multidentate ligand with multiple active protons, H4daps (H4daps = N',N'″-((1E,1'E)-pyridine-2,6-diylbis(ethan-1-yl-1-ylidene))bis(2-hydroxybenzohydrazide)), can be regulated on purpose. With this ligand of different deprotonation and charges, three new DyIII complexes ([Dy(H3daps)(CH3COO)2(EtOH)]·CH3COOH (1Dy), [Dy2(H2daps)2(EtOH)2(H2O)2(MeOH)2](CF3SO3)2·(H2O)2 (2Dy), and [Dy3(H1daps)2(H2daps)(µ3-OH)(EtOH)(H2O)] (3Dy)) of different nuclearities (mono-, di-, and trinuclear for 1Dy to 3Dy, respectively) have been synthesized and characterized structurally and magnetically. Analyses on the related bond lengths and resulting hydrogen bond modes in the complexes provide the details of the deprotonation position and the charge of the ligands, which can be in the form of H3daps-, H2daps2-, and H1daps3-. Interestingly, the more deprotonated ligand can act as a bridging ligand between the DyIII centers using the phenol and/or carbonyl oxygen atoms, which leads to the multinuclear structures. Magnetic studies on these complexes revealed that complex 1Dy is a field-induced single-molecule magnet (SMM), while complexes 2Dy and 3Dy show SMM behavior under a zero dc field.

Okicamelliaside targets the N-terminal chaperone pocket of HSP90 disrupts the chaperone protein interaction of HSP90-CDC37 and exerts antitumor activity.

Heat shock protein 90 (HSP90) has been recognized as a crucial target in cancer cells. However, various toxic reactions targeting the ATP binding site of HSP90 may not be the best choice for HSP90 inhibitors. In this paper, an ellagic acid derivative, namely, okicamelliaside (OCS), with antitumor effects was found. To identify potential anti-cancer mechanisms, an OCS photosensitive probe was applied to target fishing and tracing. Chemical proteomics and protein-drug interaction experiments have shown that HSP90 is a key target for OCS, with a strong binding affinity (KD = 6.45 µM). Mutation analysis of the target protein and molecular dynamics simulation revealed that OCS could competitively act on the key Glu-47 site at the N-terminal chaperone pocket of HSP90, where the co-chaperone CDC37 binds to HSP90, affect its stability and reduce the ∆Gbind of HSP90-CDC37. It was demonstrated that OCS destroys the protein-protein interactions of HSP90-CDC37; selectively affects downstream kinase client proteins of HSP90, including CDK4, P-AKT473, and P-ERK1/2; and exerts antitumor effects on A549 cells. Furthermore, tumor xenograft experiments demonstrated high antitumor activity and low toxicity of OCS in the same way. Our findings identified a novel N-terminal chaperone pocket natural inhibitor of HSP90, that is, OCS, which selectively inhibits the formation of the HSP90-CDC37 protein complex, and provided further insight into HSP90 inhibitors for anti-cancer candidate drugs.

Activating α7nAChR ameliorates abdominal aortic aneurysm through inhibiting pyroptosis mediated by NLRP3 inflammasome.

Abdominal aortic aneurysm (AAA) is defined as a dilated aorta in diameter at least 1.5 times of a normal aorta. Our previous studies found that activating α7 nicotinic acetylcholine receptor (α7nAChR) had a protective effect on vascular injury. This work was to investigate whether activating α7nAChR could influence AAA formation and explore its mechanisms. AAA models were established by angiotensin II (Ang II) infusion in ApoE-/- mice or in wild type and α7nAChR-/- mice. In vitro mouse aortic smooth muscle (MOVAS) cells were treated with tumor necrosis factor-α (TNF-α). PNU-282987 was chosen to activate α7nAChR. We found that cell pyroptosis effector GSDMD and NLRP3 inflammasome were activated in abdominal aorta, and inflammatory cytokines in serum were elevated in AAA models of ApoE-/- mice. Activating α7nAChR reduced maximal aortic diameters, preserved elastin integrity and decreased inflammatory responses in ApoE-/- mice with Ang II infusion. While α7nAChR-/- mice led to aggravated aortic injury and increased inflammatory cytokines with Ang II infusion when compared with wild type. Moreover, activating α7nAChR inhibited NLRP3/caspase-1/GSDMD pathway in AAA model of ApoE-/- mice, while α7nAChR deficiency promoted this pathway. In vitro, N-acetylcysteine (NAC) inhibited NLRP3 inflammasome activation and NLRP3 knockdown reduced GSDMD expression, in MOVAS cells treated with TNF-α. Furthermore, activating α7nAChR inhibited oxidative stress, reduced NLRP3/GSDMD expression, and decreased cell pyroptosis in MOVAS cells with TNF-α. In conclusion, our study found that activating α7nAChR retarded AAA through inhibiting pyroptosis mediated by NLRP3 inflammasome. These suggested that α7nAChR would be a potential pharmacological target for AAA.

Optimization of microsatellite genotyping system used for genetic diversity evaluation of Ailuropoda melanoleuca.

Microsatellite DNA is one of the most widely used genetic markers of giant panda, especially in population size estimation, paternity testing, and genetic diversity analysis. However, there are few reports on the physical locations of microsatellite markers on the chromosomes of the giant panda (Ailuropoda melanoleuca) and research on the performance of microsatellite in genotyping system and the PCR amplification conditions. In this study, we analyzed the chromosomal locations and evaluated the application values of 34 microsatellite markers, based on the giant panda genome reference sequence (ASM200744v2). We optimized the PCR reaction systems and amplification procedures for these 34 microsatellite markers. We found the low value of the microsatellite marker of Ame-µ10 in genetic application, and the necessity in redesigning the primers for gpz-6. Our research helps to improve the reproducibility and reliability of genotyping results and is of great significance for promoting the establishment and standardized application of the "A Regulation for Giant Panda Population Genetic Archives" in giant panda conservation.

[Abdominal Aortic Aneurysm:Pathological Mechanism and Animal Model].

Abdominal aortic aneurysm is defined as a dilated aorta with a diameter at least 1.5 times of the normal aorta.There is no effective drug for AAA.We summarized the high-risk factors,pathologic features,current therapies,and animal models in the pre-clinical study to gain comprehensive understanding of AAA.With this review,we aim to provide scientific support for the mining of therapeutic targets for AAA.

Differentiating T1a-T1b from T2 in gastric cancer lesions with three different measurement approaches based on contrast-enhanced T1W imaging at 3.0 T.

BACKGROUND: To explore the diagnostic value of three different measurement approaches in differentiating T1a-T1b from T2 gastric cancer (GC) lesions. METHODS: A total of 95 consecutive patients with T1a-T2 stage of GC who performed preoperative MRI were retrospectively enrolled between January 2017 and November 2020. The parameters MRI T stage (subjective evaluation), thickness, maximum area and volume of the lesions were evaluated by two radiologists. Specific indicators including AUC, optimal cutoff, sensitivity, specificity, accuracy, positive likelihood ratio (PLR), negative likelihood ratio (NLR), positive predictive value (PPV) and negative predictive value (NPV) of MRI T stage, thickness, maximum area and volume for differentiating T1a-T1b from T2 stage lesions were calculated. The ROC curves were compared by the Delong test. Decision curve analysis (DCA) was used to evaluate the clinical benefit. RESULTS: The ROC curves for thickness (AUC = 0.926), maximum area (AUC = 0.902) and volume (AUC = 0.897) were all significantly better than those of the MRI T stage (AUC = 0.807) in differentiating T1a-T1b from T2 lesions, with p values of 0.004, 0.034 and 0.041, respectively. The values corresponding to the thickness (including AUC, sensitivity, specificity, accuracy, PPV, NPV, PLR and NLR) were all higher than those corresponding to the MRI T stage, maximum area and volume. The DCA curves indicated that the parameter thickness could provide the highest clinical benefit if the threshold probability was above 35%. CONCLUSIONS: Thickness may provide an efficient approach to rapidly distinguish T1a-T1b from T2 stage GC lesions.

Evaluating treatment response to neoadjuvant chemoradiotherapy in rectal cancer using various MRI-based radiomics models.

BACKGROUND: To validate and compare various MRI-based radiomics models to evaluate treatment response to neoadjuvant chemoradiotherapy (nCRT) of rectal cancer. METHODS: A total of 80 patients with locally advanced rectal cancer (LARC) who underwent surgical resection after nCRT were enrolled retrospectively. Rectal MR images were scanned pre- and post-nCRT. The radiomics features were extracted from T2-weighted images, then reduced separately by least absolute shrinkage and selection operator (LASSO) and principal component analysis (PCA). Four classifiers of Logistic Regression, Random Forest (RF), Decision Tree and K-nearest neighbor (KNN) models were constructed to assess the tumor regression grade (TRG) and pathologic complete response (pCR), respectively. The diagnostic performances of models were determined with leave-one-out cross-validation by generating receiver operating characteristic curves and decision curve analysis. RESULTS: Three features related to the TRG and 11 features related to the pCR were obtained by LASSO. Top five principal components representing a cumulative contribution of 80% to overall features were selected by PCA. For TRG, the area under the curve (AUC) of RF model was 0.943 for LASSO and 0.930 for PCA, higher than other models (P < 0.05 for both). As for pCR, the AUCs of KNN for LASSO and PCA were 0.945 and 0.712, higher than other models (P < 0.05 for both). The DCA showed that LASSO algorithm was clinically superior to PCA. CONCLUSION: MRI-based radiomics models demonstrated good performance for evaluating the treatment response of LARC after nCRT and LASSO algorithm yielded more clinical benefit.

MRI-based nomogram analysis: recognition of anterior peritoneal reflection and its relationship to rectal cancers.

BACKGROUND: This study is aimed to explore the factors influencing the visualization of the anterior peritoneal reflection (APR) and evaluated the feasibility of measuring the distance from the anal verge to APR (AV-APR), the tumor height on MRI and the accuracy of determining the tumor location with regard to APR. METHODS: We retrospectively analyzed 110 patients with rectal cancer. A univariate and multivariate logistic regression was performed to identify the independent factors (age, sex, T stage, the degree of bladder filling, pelvic effusion, intraoperative tumor location, BMI, uterine orientation, the distance from seminal vesicle/uterus to rectum) associated with the visualization of the APR on MRI. The nomogram diagram and receiver operating characteristic curve (ROC curve) were established. Intraclass correlation coefficient (ICC) was used to evaluate the consistency of the distance of AV-APR. The Pearson correlation coefficient was used to characterize the agreement between measurements of the tumor height by colonoscopy and MRI. The Kappa statistics was used to evaluate the value of MRI in the diagnosis of the tumor location with regard to the APR. RESULTS: Multivariate logistic regression showed that BMI (P = 0.031, odds ratio, OR = 1.197), pelvic effusion (P = 0.020, OR = 7.107) and the distance from seminal vesicle/uterus to the rectum (P = 0.001, OR = 3.622) were correlated with the visualization of APR. The cut-off point of BMI and the distance from seminal vesicle/uterus to the rectum is 25.845 kg/m2 and 1.15 cm. The area under curve (AUC) (95% Confidence Interval, 95% CI) of the combined model is 0.840 (0.750-0.930). The favorable calibration of the nomogram showed a non-significant Hosmer-Lemeshow test statistic (P = 0.195). The ICC value (95% CI) of the distance of AV-APR measured by two radiologists was 0.981 (0.969-0.989). The height measured by MRI and colonoscopy were correlated with each other (r = 0.699, P < 0.001). The Kappa value was 0.854. CONCLUSIONS: BMI, pelvic effusion, and the distance from seminal vesicle/uterus to rectum could affect the visualization of APR on MRI. Also, it's feasible to measure the distance of AV-APR, the tumor height, and to evaluate the tumor location with regard to APR using MRI.

Effects of low-level mercury exposure on brain-derived neurotrophic factor in preschool children.

OBJECTIVES: Mercury (Hg), a ubiquitous heavy metal, could affect the neurodevelopment of the children, however, these associations are still equivocal. Brain derived neurotrophic factor (BDNF) plays an essential role in the central nervous system development in children. This study aimed to investigate the effects of low-level mercury exposure on serum BDNF levels and the influence of sex and dietary intake on these relationships in children. METHODS: In this cross-sectional study, a total of 541 pre-school children were recruited, the blood mercury concentrations and serum BDNF levels were measured. The background information on demographic characteristics and dietary habits of the children was collected through questionnaires. Multivariable linear models after adjustment for potential confounders were used to evaluate the associations between mercury exposure and levels of BDNF in children. RESULTS: The GMs of blood mercury concentrations and serum BDNF levels were 1.06 µg/L, 20.4 ng/mL, respectively. A significant positive association between blood mercury concentrations and serum BDNF levels was found. After stratification by sex, the blood mercury concentrations in children were positive associated with serum BDNF levels in girls but not in boys. However, these associations were attenuated when we further adjusted the children's dietary intake variables. CONCLUSIONS: Our findings suggest that low-levels of mercury exposure may have sex-specific effects on BDNF levels in young children and that dietary intake may be potential confounders in these relationships. However, further studies are warranted to investigate the role of BDNF in the effects of mercury on neurodevelopment.