Objective : To investigate the effect of chromosome instability(CIN) associated gene polypeptide N-acetylgalactosaminyltransferase 7(GALNT7) on proliferation and apoptosis of HCT116 colon cancer cells. Methods : The HCT116 cell line withGALNT7knockdown was constructed by lentiviral infection. The correlation betweenGALNT7and CIN was verified by chromosome spread assay. The effect ofGALNT7on cell proliferation was detected by live cell counting, and the effect ofGALNT7on cell cycle distribution was detected by flow cytometry and Western blot. Caspase-3 activity and Western blot assays were used to detect the effect ofGALNT7on apoptosis. Results : HCT116 cells showed a slower proliferation rate upon knocking down ofGALNT7, and exhibited a more scattered karyotype distribution and a phenotype of increased degree of CIN. Inhibition ofGALNT7in HCT116 cells resulted in cell cycle arrest, upregulation of P21 and downregulation of CDK6 protein levels, as well as increased levels of Caspase-3 activity, cleaved PARP1 and PUMA protein expression, and decreased levels of BCL-2 protein expression. Conclusion TheGALNT7gene may promote proliferation and inhibit apoptosis of HCT116 colon cancer cells through the suppression of CIN generation.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

ObjectiveThis study sought to investigate the impact of exosomes derived from LoVo cells (LoVo-Exos) in colorectal cancer (CRC) on tumor angiogenesis, as well as to elucidate the potential molecular mechanisms underlying their pro-angiogenic effects. MethodsLoVo-Exos were isolated via ultracentrifugation, and their internalization into recipient human umbilical vein endothelial cells (HUVECs) was visualized using confocal microscopy. The influence of LoVo-Exos on angiogenesis was assessed through an in vitro tube formation assay. Additionally, the pro-angiogenic effects of LoVo-Exos were evaluated in vivo using a matrix gluing assay in mice. To investigate the molecular mechanisms through which LoVo-Exos facilitate angiogenesis, Western blot analysis was employed to examine the transfer of pEGFR by LoVo-Exos into recipient cells. Both Western blot and ELISA were utilized to assess the expression levels of key signaling proteins within the EGFR-ERK pathway, as well as the expression of downstream angiogenic core molecules. Furthermore, the impact of EGFR knockdown and ERK inhibitor treatment on angiogenesis was evaluated, with subsequent analysis of the expression of downstream angiogenic core molecules following these interventions. ResultsConfocal microscopy demonstrated the internalization of LoVo-Exos into HUVECs. In vitro angiogenesis assays further indicated that LoVo-Exos significantly enhanced the formation of tubular structures in HUVECs. Additionally, macroscopic examination of subcutaneous matrix plug formation in mice revealed a substantial increase in vascular-like structures within the matrix plugs following the administration of LoVo-Exos, compared to the PBS control group. Hematoxylin and eosin (HE) staining revealed the presence of erythrocyte-filled microvessels within the matrix plugs combined with LoVo-Exos. Furthermore, immunohistochemical analysis demonstrated the expression of the endothelial cell marker CD31 in these matrix plugs. The presence of CD31-positive cells in the LoVo-Exos-treated matrix plugs was associated with a significant enhancement in the formation of luminal structures. These findings suggest that LoVo-Exos facilitate the in vivo development of vascular-like structures. Subsequent investigations demonstrated that LoVo-Exos facilitated the delivery of pEGFR to HUVEC, thereby enhancing angiogenesis. Conversely, LoVo-Exos with EGFR knockdown exhibited a diminished capacity to promote angiogenesis, an effect that was further attenuated by the ERK phosphorylation inhibitor U0126. Western blot analysis assessing the activation of the EGFR-ERK signaling pathway in HUVEC indicated that LoVo-Exos augmented angiogenesis through the activation of this pathway. Furthermore, analysis of the impact of LoVo-Exos on the expression of downstream angiogenic core molecules revealed an increase in interleukin-8 (IL-8) secretion in HUVEC. The enhancement observed was diminished in LoVo-Exos following EGFR knockdown, and this reduction was counteracted by the ERK phosphorylation inhibitor U0126. ConclusionThe underlying mechanism may involve the delivery of pEGFR in LoVo-Exos to HUVECs, leading to increased IL-8 secretion via the EGFR-ERK signaling pathway, thereby enhancing the angiogenic potential of HUVECs. This finding may offer new insights into the mechanisms underlying cancer metastasis.

Background: and Purpose Although amyloid positron emission tomography (PET) might provide a molecular diagnosis for cerebral amyloid angiopathy (CAA), it does not have sufficient specificity for this condition relative to incipient Alzheimer’s disease (AD). To identify a regional amyloid uptake pattern specific to CAA, we attempted to reduce this overlap by selecting “pure CAA” (i.e., fulfilling the criteria for probable CAA but without tau PET AD signature) and “pure AD” (i.e., positive amyloid PET and presence of tau PET AD signature, but without lobar hemorrhagic lesions). We hypothesized that occipital tracer uptake relative to the whole cortex (WC) would be higher in patients with pure CAA and may serve as a specific diagnostic marker. Methods: Patients who fulfilled these criteria were identified. In addition to the occipital region of interest (ROI), we assessed the frontal and posterior cingulate cortex (PCC) ROIs that are sensitive to AD. Amyloid PET uptake was expressed as the absolute standardized uptake value ratio (SUVR) and ROI/WC ratio. The diagnostic utility of amyloid PET was assessed using the Youden index cutoff. Results: Eighteen patients with AD and 42 patients with CAAs of comparable age were eligible. The occipital/WC was significantly higher in CAA than AD (1.02 [0.97–1.06] vs. 0.95 [0.87–1.01], P=0.001), with an area under curve of 0.762 (95% confidence interval [CI] 0.635–0.889) and a specificity of 72.2% (95% CI 46.5–90.3) at Youden cutoff (0.98). The occipital lobe, frontal lobe, PCC and WC SUVRs were significantly lower in CAA than in AD. The frontal/WC and PCC/WC ratios did not differ significantly between the groups. Conclusion Using stringent patient selection to minimize between-condition overlap, this study demonstrated the specificity of higher relative occipital amyloid uptake in CAA than in AD.

Background: and Purpose Although amyloid positron emission tomography (PET) might provide a molecular diagnosis for cerebral amyloid angiopathy (CAA), it does not have sufficient specificity for this condition relative to incipient Alzheimer’s disease (AD). To identify a regional amyloid uptake pattern specific to CAA, we attempted to reduce this overlap by selecting “pure CAA” (i.e., fulfilling the criteria for probable CAA but without tau PET AD signature) and “pure AD” (i.e., positive amyloid PET and presence of tau PET AD signature, but without lobar hemorrhagic lesions). We hypothesized that occipital tracer uptake relative to the whole cortex (WC) would be higher in patients with pure CAA and may serve as a specific diagnostic marker. Methods: Patients who fulfilled these criteria were identified. In addition to the occipital region of interest (ROI), we assessed the frontal and posterior cingulate cortex (PCC) ROIs that are sensitive to AD. Amyloid PET uptake was expressed as the absolute standardized uptake value ratio (SUVR) and ROI/WC ratio. The diagnostic utility of amyloid PET was assessed using the Youden index cutoff. Results: Eighteen patients with AD and 42 patients with CAAs of comparable age were eligible. The occipital/WC was significantly higher in CAA than AD (1.02 [0.97–1.06] vs. 0.95 [0.87–1.01], P=0.001), with an area under curve of 0.762 (95% confidence interval [CI] 0.635–0.889) and a specificity of 72.2% (95% CI 46.5–90.3) at Youden cutoff (0.98). The occipital lobe, frontal lobe, PCC and WC SUVRs were significantly lower in CAA than in AD. The frontal/WC and PCC/WC ratios did not differ significantly between the groups. Conclusion Using stringent patient selection to minimize between-condition overlap, this study demonstrated the specificity of higher relative occipital amyloid uptake in CAA than in AD.

Background: and Purpose Although amyloid positron emission tomography (PET) might provide a molecular diagnosis for cerebral amyloid angiopathy (CAA), it does not have sufficient specificity for this condition relative to incipient Alzheimer’s disease (AD). To identify a regional amyloid uptake pattern specific to CAA, we attempted to reduce this overlap by selecting “pure CAA” (i.e., fulfilling the criteria for probable CAA but without tau PET AD signature) and “pure AD” (i.e., positive amyloid PET and presence of tau PET AD signature, but without lobar hemorrhagic lesions). We hypothesized that occipital tracer uptake relative to the whole cortex (WC) would be higher in patients with pure CAA and may serve as a specific diagnostic marker. Methods: Patients who fulfilled these criteria were identified. In addition to the occipital region of interest (ROI), we assessed the frontal and posterior cingulate cortex (PCC) ROIs that are sensitive to AD. Amyloid PET uptake was expressed as the absolute standardized uptake value ratio (SUVR) and ROI/WC ratio. The diagnostic utility of amyloid PET was assessed using the Youden index cutoff. Results: Eighteen patients with AD and 42 patients with CAAs of comparable age were eligible. The occipital/WC was significantly higher in CAA than AD (1.02 [0.97–1.06] vs. 0.95 [0.87–1.01], P=0.001), with an area under curve of 0.762 (95% confidence interval [CI] 0.635–0.889) and a specificity of 72.2% (95% CI 46.5–90.3) at Youden cutoff (0.98). The occipital lobe, frontal lobe, PCC and WC SUVRs were significantly lower in CAA than in AD. The frontal/WC and PCC/WC ratios did not differ significantly between the groups. Conclusion Using stringent patient selection to minimize between-condition overlap, this study demonstrated the specificity of higher relative occipital amyloid uptake in CAA than in AD.

ObjectiveTo study the regulatory effect of the partial sequence within the 3’ untranslated region （3’UTR） of slit guidance ligand 1 （Slit1） （Slit1-3’UTR） on the fibrotic phenotypes of cardiac fibroblasts （CFs） and its potential mechanism. MethodsThe adenovirus vector was used to overexpress the 1526nt sequence of Slit1-3’UTR in ICR neonatal mouse CFs （mCFs）. The expression of fibrosis-related genes in mCFs， such as collagen type 1 alpha1（COL1A1）， collagen type 3 alpha3 （COL3A1） and alpha smooth muscle actin （α-SMA） were detected by Western blot assay. The effect of Slit1-3’UTR 1526nt on the proliferation and migration of mCFs was assessed by EdU staining and Trans-well assays. Angiotensin Ⅱ （Ang Ⅱ） was used to treat mCFs， and the impact of Slit1-3’UTR 1526nt on the fibrotic phenotypes of Ang Ⅱ-induced mCFs was evaluated. After overexpression of Slit1-3’UTR 1526nt， miR-34a-5p mimic was transfected into mCFs， followed by actinomycin D treatment to detect the mRNA stability of Slit1-3’UTR 1526nt， and the levels of miR-34a-5p and its target gene SIRT1（si-SIRT1） in mCFs were determined. The effects of miR-34a-5p and small interfering RNA targeting SIRT1 on the Slit1-3’UTR 1526nt-mediated regulation of fibrotic phenotypes were also determined. ResultsAdenovirus-mediated overexpression of Slit 1-3’UTR 1526nt was achieved in mCFs. Overexpression of Slit 1-3’UTR 1526nt markedly inhibited the expression of the fibrosis-related genes， proliferation and migration of mCFs and fibrotic phenotypes of Ang Ⅱ. The results of actinomycin D assay showed that miR-34a-5p inhibited the stability of Slit1-3’UTR 1526nt in mCFs， while the level of miR-34a-5p was reduced in mCFs with overexpression of Slit1-3’UTR 1526nt. Transfection of miR-34a-5p promoted the fibrotic phenotypes， and reversed the inhibitory effect of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. Overexpression of Slit1-3’UTR 1526nt significantly increased the level of miR-34a-5p target gene SIRT1 in mCFs. Transfection of miR-34a-5p and si-SIRT1 consistently reversed the inhibitory effects of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. ConclusionSlit1-3’UTR1526nt inhibits the fibrotic phenotypes of mCFs by binding to miR-34a-5p and increasing the expression of its target gene of SIRT1.