The COVID-19 pandemic necessitated the rapid production of vaccines aimed at the production of neutralizing antibodies against the COVID-19 spike protein required for the corona virus binding to target cells. The best well-known vaccines have utilized either mRNA or an adenovirus vector to direct human cells to produce the spike protein against which the body produces mostly neutralizing antibodies. However, recent reports have raised some skepticism as to the biologic actions of the spike protein and the types of antibodies produced. One paper reported that certain antibodies in the blood of infected patients appear to change the shape of the spike protein so as to make it more likely to bind to cells, while other papers showed that the spike protein by itself (without being part of the corona virus) can damage endothelial cells and disrupt the blood-brain barrier. These findings may be even more relevant to the pathogenesis of long-COVID syndrome that may affect as many as 50% of those infected with SARS-CoV-2. In COVID-19, a response to oxidative stress is required by increasing anti-oxidant enzymes. In this regard, it is known that polyphenols are natural anti-oxidants with multiple health effects. Hence, there are even more reasons to intervene with the use of anti-oxidant compounds, such as luteolin, in addition to available vaccines and anti-inflammatory drugs to prevent the harmful actions of the spike protein.
Anaphylaxis is a severe multisystem reaction that occurs rapidly after the introduction of an antigen that would otherwise be a harmless substance. It is characterized by airway and respiratory problems, cardiovascular collapse, mucosal inflammation, and other complications, all severe symptoms that can cause death. IgE-dependent anaphylaxis involves mast cells (MCs) which are the main sources of biologically active mediators that contribute to the pathological and lethal phenomena that can occur in anaphylaxis. Antibody-mediated anaphylaxis can follow multiple pathways such as that mediated by MCs carrying the FcεRI receptor, which can be activated by very small amounts of antigen including a vaccine antigen and trigger an anaphylactic reaction. In addition, anaphylaxis can also be provoked by high concentrations of IgG antibodies that bind to the FcγR receptor present on basophils, neutrophils, macrophages and MCs. For this reason, the IgG concentration should be kept under control in vaccinations. Activation of MCs is a major cause of anaphylaxis, which requires immediate treatment with epinephrine to arrest severe lethal symptoms. MCs are activated through the antigen binding and cross-linking of IgE with release of mediators such as histamine, proteases, prostaglandins, leukotrienes and inflammatory cytokines. The release of these compounds causes nausea, vomiting, hives, wheezing, flushing, tachycardia, hypotension, laryngeal edema, and cardiovascular collapse. mRNA and viral vector vaccines have been cleared by the United States, Food and Drug Administration (FDA), generating hope of prevention and cure for COVID-19 around the world. Scientists advise against giving the vaccine to individuals who have had a previous history of anaphylaxis. The US Centers for Disease Control and Prevention (CDC) advises people with a previous history of any immediate allergic reaction to remain under observation for approximately 30 minutes after COVID-19 vaccination. To date, vaccines that prevent SARS-CoV-2 infection have not raised major concerns of severe allergic reactions, although, in some cases, pain and redness at the injection site and fever have occurred after administration of the vaccine. These reactions occur in the first 24-48 hours after vaccination. It has been reported that probable forms of anaphylaxis could also occur, especially in women approximately 40 years of age. But after tens of millions of vaccinations, only a few patients had this severe reaction with a low incidence. Anaphylactic and severe allergic reactions can also occur to any component of the vaccine including polysorbates and polyethylene glycol. To date, there is no precise information on allergic reactions to COVID-19 vaccines. Individuals with MCs and complement with higher activation than others may be at greater allergic risk. Moreover, the reactions called anaphylactoids, are those not mediated by IgE because they do not involve this antibody and can also occur in COVID-19 vaccination. These not-IgE-mediated reactions occur through direct activation of MCs and complement with tryptase production, but to a lesser extent than IgE-mediated anaphylaxis. However, at the moment it is not known exactly which component of the vaccine causes the allergic reaction and which vaccine causes the most side effects, including anaphylaxis. Thus, individuals who have a known allergy to any component of the vaccine should not be vaccinated. However, should an anaphylactic reaction occur, this requires immediate treatment with epinephrine to arrest severe lethal symptoms. In conclusion, the purpose of this editorial is to encourage the population to be vaccinated in order to extinguish this global pandemic that is afflicting the world population, and to reassure individuals that anaphylactic reactions do not occur with a higher incidence than other vaccinations.
The success of a vaccination campaign depends on the possibility of guaranteeing not only a wide distribution of effective vaccines, but also on their safety and acceptance by the population. Vaccine safety questions should be answered by correct, unbiased and evidence-based reports, and by addressing all possible problems including allergic reactions. Despite the fact that many COVID-19 vaccines are free from the majority of potentially sensitizing components, an allergic reaction can occur even in the form of a severe, life-threatening anaphylaxis. The frequency of allergic reactions against COVID vaccine is greater than that observed for other vaccinations. National and international allergology societies have proposed specific guidelines for individuals at risk of anaphylaxis by vaccine. Vaccines, like all the pharmaceutical preparations, are submitted to great safety and efficacy valuations, however, even the greatest pre-licensure experimentations are insufficient to evaluate the vaccine's potential to provoke anaphylaxis. Therefore, post-market surveillance is essential to analyze, record and characterize all adverse events. To this purpose, specific algorithms should be used as a monitoring strategy of adverse events in patients undergoing vaccination against COVID 19.
Respiratory infections (RI) significantly burden patients, their families, and society. Respiratory infection recurrence (RRI) usually depends on a defect of the immune response, which can be more or less transient and/or selective. In particular, children, older people, heavy smokers, and patients with chronic diseases, characterized by an inadequate immune response, may be at risk of developing RRI. In this context, OM- 85 could represent a valuable option in the management of RRI. OM-85 is a bacterial lysate containing the extracts of some common pathogens, including Branhamella catarrhalis, Klebsiella pneumoniae, Klebsiella ozaenae, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus viridans, and Staphylococcus aureus. Methodologically rigorous studies have documented the mechanism of action, efficacy, and safety of OM-85. OM-85 enhances the natural and acquired immune response through multifaceted mechanisms. Substantial evidence has shown that OM-85 can prevent respiratory infections, reduce the number of COPD exacerbations, and shorten the disease duration at home or in hospital. OM-85 can enhance the effectiveness of the 'flu vaccination without affecting the vaccine tolerability. The preventive use of OM-85 can reduce the use of antibiotics, contributing to contrast antibiotic resistance and saving the high cost of chronic respiratory diseases. Further studies should define the ideal candidate to OM-85 treatment.
Human Coronavirus (CoV) infections, including SARS-COV, MERS-COV, and SARS-CoV-2, usually cause fatal lower and upper respiratory tract infections due to exacerbated expression of pro-inflammatory cytokines and chemokines. We aim to summarize different aspects, such as CoV immune evasion mechanisms and host innate immune response to these infections, and their role in pathogenesis. We have also elaborated the up-to-date findings on different vaccine development strategies and progress against CoVs in both humans and non-human models. Most importantly, we have described the Phageome-human immune interaction, its therapeutic usage as anti-viral, anti-inflammatory agent, and implications for multiple vaccine development systems. The data suggest that endogenous phages might play a vital role in eliminating the infection and regulating the body's immune system. Considering the innate-immune-induced pathogenesis against CoVs and the therapeutic aptitude of phageome, we propose that the prophylactic administration of phages and phage-based vaccines could be a useful strategy to control the emerging CoV infections.
Since the spreading of Sar-CoV-2 in March 2020, many serologic tests have been developed to identify antibody responses. Indeed, different commercial kits are directed against different antigens and could utilise different methods thereby triggering confusion and criticism. Here, we compared two Food and Drug Administration (FDA)-approved automatized assays that detect IgG responses against spike or nucleocapsid protein of Sars-Cov-2 virus in 127 subjects among healthcare workers of IRCCS Policlinico San Donato (MI), Italy. We observed different kinetics of IgG responses, demonstrating the importance of timing of sampling to correctly interpret the results both for infection diagnosis and for epidemiologic studies. We observed that Anti-N response starts earlier than Anti-S1/S2 response but also decreases earlier, affecting the sensitivity of the tests at different time points. Combining two different assays, designed against different antigens, could reduce false negative results. Finally, we observed a patient who produced anti-nucleocapsid IgG, but not anti-spike IgG. In conclusion, we investigated antibody responses in Covid-19 disease, aiming to direct clinicians and laboratory scientists to correctly interpret serologic results by always paying attention to clinical history correlation, timing of sampling, methods and antigens used, to avoid false negative results and obtain relevant epidemiologic data.
This study investigated whether biomarkers in the second trimester of pregnancy, including the white blood cell (WBC) count, neutrophil-lymphocyte ratio (NLR), hypersensitive C-reactive protein (hs-CRP) concentration, and procalcitonin (PCT) concentration, were associated with miscarriage during the second trimester of pregnancy. Sixty-two asymptomatic patients in their second trimester of pregnancy were included in the control group (group A). Among 67 patients diagnosed with late threatened miscarriage, 46 patients with ongoing pregnancy were included in group B and 21 patients with subsequent miscarriage were included in group C. The serum of these patients was collected and the biomarkers were analyzed. A paired-samples t-test was used for the comparison between the groups before and after the miscarriage. Statistical significance was set at p<0.05. Receiver operating characteristic curve (ROC) analysis was performed to evaluate the predictive value of different biomarkers for miscarriage during the second trimester of pregnancy. WBC count, neutrophil percentage, and hs-CRP levels were significantly higher in group C than in groups A and B (p<0.05). Lymphocyte percentage and albumin levels decreased significantly from group A to group C (p<0.05). In contrast, NLR increased significantly from group A to group C (p<0.05). There was a significant decrease in the WBC count, neutrophil percentage, hemoglobin concentration, and post-miscarriage NLR among the cases with miscarriage (p<0.05). The area under the curve of WBC count, NLR, hs-CRP, and the combination of these three factors for the prediction of late miscarriage varied from 78.0% to 82.6%. The combination of these three factors had the highest specificity of 91.1%, while hs-CRP had the highest sensitivity of 88.9%. WBC count, NLR, and hs-CRP levels are strongly associated with miscarriage during the second trimester of pregnancy, indicating that they are potential predictive biomarkers.
Chronic rhinosinusitis (CRS), especially with nasal polyps, continues to elude precise pathogenesis and effective treatment. Prior work in our laboratory demonstrated interleukin-33 (IL-33) and Substance P (SP) activation of mast cells, and inhibitory effect of interleukin-37 (IL-37). Our objective is to study the expression of these neurohormonal mediators in mast cell stimulation of nasal polyposis. This was a prospective research study involving collection of nasal lavage fluid and nasal polyp tissue from adult patients with CRS. The study was divided into two arms. First, nasal lavage fluid was collected from normal controls, and patients with allergic rhinitis, CRS, or CRS with nasal polyposis. The second arm was collection of nasal tissue from normal controls undergoing inferior turbinoplasty, or patients with nasal polyposis. Enzyme-linked immunosorbent assay and quantitative polymerase chain reaction techniques were used to determine levels in the lavage fluid and relative gene expression in the tissue of SP, IL-33, and IL-37. In total, 70 lavage and 23 tissue specimens were obtained. The level of SP was highest in patients with polyps; however, gene expression was reduced compared to normal controls. The level of IL-33 was reduced in patients with polyps as compared to patients with allergy and sinusitis, and its gene expression was not significantly different from normal controls. IL-37 was elevated in the lavage fluid of patients with nasal polyps and its gene expression was increased in the polyp tissue. Levels of SP and IL-37 were elevated in the lavage fluid of patients with nasal polyps as compared to normal controls and other sinonasal pathologies, and gene expression of IL-37 was significantly increased in the polyp tissue itself. These findings implicate these neurohormonal molecules in the pathophysiology of nasal polyposis and provide possible novel therapeutic targets.
Papillary thyroid cancer (PTC) is currently one of the most common endocrine tumors worldwide. Long non-coding RNA (LncRNA) is a vital regulator in the biological processes of diverse tumors. Hence, this work aimed to clarify the role and mechanism of lncRNA OIP5-AS1 in PTC progression. OIP5-AS1 and miR-429 expression levels in PTC tissues and cells were examined using qRT-PCR. Immunohistochemical staining (IHC) was applied to detect X-linked inhibitors of apoptosis protein (XIAP) expression in PTC tissues. A dual-luciferase reporter gene experiment was employed to validate the relationship for miR-429 and XIAP, miR-429 and OIP5-AS1. The regulatory effects of OIP5-AS1 on PTC cell proliferation, migration, and invasion was detected using the MTT, BrdU, Transwell and Western blot assays. In this work we reported that OIP5-AS1 expression was up-modulated in PTC tissues and cell lines. OIP5-AS1 overexpression enhanced the proliferation and metastasis of PTC cells, but the transfection of miR-429 mimics reversed the functions of OIP5-AS1 on the proliferation, migration, and invasion of PTC cells. Additionally, OIP5-AS1 was identified as a competitive endogenous RNA (ceRNA) that repressed miR-429, thereby increasing the expression level of XIAP. Taken together, the findings confirm that OIP5-AS1 accelerates PTC progression via modulating the miR-429/XIAP axis and imply that OIP5-AS1 is likely to be a therapeutic target for PTC.
Abnormal osteoclast formation plays a significant part in rheumatoid arthritis (RA). As potent therapeutic biomarkers, microRNAs (miRNAs) have obtained increasing attention. Recently, treatment regimens regarding miRNAs have been implicated in skeletal diseases. The aim of this study is to assess the expression and function of miR-20a during osteoclast proliferation and differentiation and its correlation with bone erosion in RA mice. The expression of miR-20a was observed to be diminished in the ankle tissues of RA mice relative to that in normal controls evaluated by RT-qPCR. Hematoxylin and eosin staining, Safranin O-fast green staining, and tartrateresistant acid phosphatase staining were used to evaluate the effects of miR-20a on RA symptoms. The proliferation and differentiation of osteoclasts, and bone erosion were repressed by agomiR-20a injection. 3'UTR luciferase reporter assays were conducted to validate the putative binding between miR-20a and receptor activation of nuclear factor-κB ligand (RANKL). The protein expression and phosphorylation level of toll-like receptor4 (TLR4)/p38 pathway-related factors were detected by Western blot. miR-20a inhibited proliferation and differentiation potentials to osteoclasts partly through the TLR4/p38 pathway. The current work provides evidence that miR-20a hinders proliferation and differentiation of osteoclasts by targeting RANKL through the TLR4/p38 pathway.
The function of long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) has been revealed in injury caused by myocardial ischemia/reperfusion (I/R), however, its association with Sevoflurane (Sev), an anesthetic effective for regulating inflammation and oxidative stress, is not yet clear in I/R injury. The aim of this study was to functionally validate and elucidate the mechanism-of-action for Sev-mediated NEAT1 in myocardial I/R injury. Firstly, reduced NEAT1 was revealed in myocardial I/R injured mice treated with Sev. Moreover, restoration of NEAT1 could repress the alleviating role of Sev in cardiac function, infarct size and myocardial apoptosis in mice, while miR-140 was remarkably enhanced in myocardial tissues from mice treated with Sev. Furthermore, miR-140 was suggested and authenticated as a downstream biomolecule of NEAT1 with the help of a bioinformatics tool. Interestingly, miR-140 inhibitor played the same role as NEAT1 overexpression on the cardiac function, infarct size and apoptosis of mice. Finally, it was manifested that RhoA was a putative target of miR-140, which functioned importantly in the Sev/miR-140-mediated myocardial I/R injury. All in all, NEAT1 knockdown contributed to Sev-mediated myocardial I/R injury alleviation via the miR-140/RhoA axis.
The objective of this study was to investigate the effects of baicalein on apoptosis of HeLa human cervical cancer (CC) cells and to elucidate the underlying mechanism. HeLa cells were treated with 20, 50, 100, or 200 μmol/L baicalein for 24, 36, and 48 hours, and CCK-8 assays were used to detect cell viability, and flow cytometry was performed to assess apoptosis rate. Reverse-transcription quantitative PCR was used to measure ERK1/2, p38, and JNK mRNA levels in HeLa cells, and western blotting was performed to measure ERK1/2, p38, and JNK protein levels. The CCK-8 assay showed that the OD value of HeLa cells gradually decreased with increasing baicalein concentrations (P < 0.01) and treatment time (P < 0.01). These results indicated a negative time- and dose-dependent effect of baicalein on HeLa cells. Baicalein treatment of HeLa cells significantly increased apoptosis rate (P < 0.01). In HeLa cells treated with 50 or 200 μmol/L baicalein for 24 h, expression levels of ERK1/2 and p38 mRNA were significantly reduced, whereas that of JNK mRNA was increased (P < 0.01). The levels of phosphorylated ERK1/2 and p38 were significantly reduced, and the level of JNK protein was increased (P < 0.01). Taken together, baicalein appeared to exert anti-cancer effects on HeLa cells through induction of apoptosis and regulation of the ERK/p38/mitogen-activated protein kinase pathway.
Streptococcus pneumoniae (S. pneumoniae) pneumonia is the most common cause of community-acquired pneumonia (CAP). Previous studies have suggested the diagnostic potential of microRNAs (miRNAs) in infectious diseases. In the present study, we aimed to evaluate the potential role of miRNAs in S. pneumoniae pneumonia by using bioinformatics analysis and experimental validation. Gene Expression Omnibus (GEO) datasets including GSE97922 and GSE83615 were analyzed for identifying the differentially expressed miRNAs; the miRNA-target genes network was constructed by using miRNet and the targeted genes were subject to Gene Ontology enrichment, Kyoto Encyclopedia of Genes and Genomes and REACTOME pathway analysis; the miRNA and mRNA expression levels were determined by quantitative real-time PCR; protein concentrations were determined by enzyme-linked immunosorbent assay. Our results showed that miR-425, miR-155 and miR-33 were up-regulated in the serum from CAP patients when compared to healthy controls; whereas there was no significant difference in serum miR-222, miR-149, miR-186 and miR-132 expression levels between healthy controls and CAP patients. In vitro functional studies showed that lipopolysaccharides (LPS) induced the up-regulation of miR-425, miR-155 and miR-33 in RAW264.7 cells, and miR-425, miR-155 and miR-33 inhibition attenuated LPS-induced inflammatory responses in RAW264.7 cells. In conclusion, our results showed that miR-425, miR-155 and miR-33 were up-regulated in the serum from CAP patients by using bioinformatics analysis and experimental validation; furthermore, miR-425, miR-155 and miR-33 inhibition attenuated LPS-induced inflammatory responses in RAW264.7 cells. Nevertheless, our studies are still at the preliminary stages, and the detailed roles of miR-425, miR-155 and miR-33 in S. pneumoniae pneumonia still require further investigation.
This study aims to explore the mechanism of cyclic tensile stress (CTS) on human chondrocytes (CHs) relating to the reactive oxygen species (ROS) generation and extracellular matrix (ECM) stability in vitro. A well-established CTS model with 5%, 10%, or 20% elongation was performed for CHs stretching. After CTS, the cell viability, total ROS level, main ECM components, matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP), F-actin density, and some anti-oxidative enzymes were analyzed. Additionally, the antioxidant N-acetylcysteine (NAC) and cytochalasin D were used to suppress the ROS production and F-actin polymerization when the CHs underwent CTS, respectively. The treatment of 20% elongation-CST significantly decreased the CH viability and the expressions of collagen II, aggrecan, anti-oxidative enzymes and TIMP3/4, however, it increased the ROS accumulation, F-actin polymerization, and the expression of collagen I and MMP3/13. In contrast, the application of NAC and cytochalasin D could partly rescue the CHs from the injury caused by the high CTS. Therefore, high CTS disrupts the ECM by remodeling the F-actin cytoskeleton and promoting ROS production. Cytochalasin D and NAC are effective in rejecting F-actin cytoskeleton polymerization, and ROS accumulation through a potential synergetic process, which alleviates the ECM injury caused by High CTS.
This study aimed to screen the key immune-related genes (IRGs) in head and neck squamous cell carcinoma (HNSC) and construct the IRGs-related prognostic model to predict the overall survival (OS) of patients with HNSC. The RNA-seq data and clinical data were downloaded from The Cancer Genome Atlas database, and IRGs were obtained from the Immunology Database and Analysis Portal. Differentially expressed genes (DEGs) between HNSC and normal samples were identified, followed by integration with IRGs to screen differentially expressed IRGs. After univariate and multivariate proportional hazard regression analyses, an IRG-based risk model was constructed. Meanwhile, data chip of GSE65858 as the validation set to assess the predicted performance of established model. Next, univariate and multivariate Cox regression analyses were performed to identify the independent prognostic factor of HNSC, and the Nomogram model was developed to predict patient outcome. Furthermore, the correlation between immune cell infiltration and risk score was analyzed. A total of 65 differently expressed IRGs associated with prognosis of HNSC were screened, and finally a 26-gene IRG signature was identified to construct a prognostic prediction model. The AUC of ROC curve was 0.750. Survival analysis showed that patients in the high-risk group had a worse prognosis. Independent prognostic analysis showed that risk score could be considered as an independent predictor for HNSC prognosis. Nomogram assessment showed that the model had high reliability for predicting the survival of patients with HNSC in 1, 2, 3 years. Ultimately, the abundance of B cells and CD4+ T cell infiltration in HNSC showed negative correlations with risk score. Our IRG-based prognostic risk model may be used to estimate the prognosis of HNSC patients.
Chronic obstructive pulmonary disease (COPD) represents a chronic inflammatory disorder of the airways induced mainly by cigarette smoking. In the current study, cigarette smoke extract (CSE) was used to develop an in vitro COPD model using human bronchial epithelium (HBE) cells to expound the possible role of microRNA-29b (miR-29b) in COPD. Firstly, miR-29b and interleukin (IL)-22 expression was assessed in serum of 20 healthy non-smokers, 20 healthy smokers and 20 COPD patients as well as CSE-treated HBE cells. Then, miR-29b and IL-22 expression was altered to evaluate their functions in Th17/Treg ratio. miR-29b inhibited Th17/Treg ratio and levels of IL-22; whereas overexpression of IL-22 reversed these trends. Moreover, rescue experiments found that IL-22 neutralized the repressive effects of miR-29b on Th17/Treg ratio and inflammatory response. Finally, we found that miR-29b blocked the JAK/STAT3 pathway in CSE-treated HBE cells. These data highlighted that miR-29bs modulated Th17/Treg imbalance in CSE-induced experimental COPD through inhibition of IL-22-dependent JAK/STAT3 pathway.
The aim of this study was to investigate the mechanism of interleukin-17 (IL-17) gene in renal tissues of rats suffering from adriamycin (ADM) nephropathy and its effect on the expression level of characteristic proteins, such as Podocalyxin and Nephrin, in podocytes. Sprague-Dawley (SD) rats were randomly divided into a control group (treated with normal saline) and an ADM group (treated with adriamycin). ADM model rats were transfected with lentivirus and divided into a transfection group (transfected with recombinant plasmid IL-17-shRNA) and a negative control group (transfected with plasmid shNC). Coomassie brilliant blue G-250 (CBB) method was adopted to detect the levels of albumin in urine to validate the model. The ultrastructure of rat glomeruli was observed, and the ratio of T helper 17 cells/regulatory T cells (Th17/Treg) was measured by flow cytometry (FCM). The expression levels of IL-17, forkhead box P3 (Foxp3), Nephrin, and Podocalyxin were detected by real-time quantitative PCR (RT-qPCR) and western blot analysis. Results of the study showed that the proteinuria content of the ADM group was significantly higher than that of the control group (P<0.05). In the ADM group, the glomerular basement membrane had uneven thickness and incomplete structure, which showed foot process fusion and electron dense accumulation. However, the glomerular basal membrane in the transfected rats was thin and intact, and a small amount of epithelial foot process fusion and electron density accumulation were observed. The percentages of Th17 cells and IL-17 levels in the ADM group were significantly higher than those in the control group, while the percentages of Treg cells, Foxp3, Nephrin, and Podocalyxin levels were significantly lower than those in the control group (P<0.05). The percentages of Th17 cells, IL-17, Nephrin, and Podocalyxin in the transfection group were significantly higher than those in the ADM group and the negative control group, while the percentages of Treg cells and Foxp3 were significantly lower than those in the ADM group and the negative control group (P<0.05). The results of this study showed that abnormal activation of Th17/IL-17 cells caused podocyte injury and promoted the occurrence and progression of ADM nephropathy. In addition, inhibition of IL-17 gene expression could improve the imbalance of number of Th17 and Treg cells, which may be potentially applied in treatment of patients with primary nephrotic syndrome (PNS).
Annexin A1 (AnxA1, also known as lipocortin-1), is a calcium-dependent phospholipid binding protein with diverse functions. Previous studies have indicated that AnxA1 is associated with age-related β-cell dysfunction and aging, which lead to decreased β-cell proliferation capacity. However, it has been uncertain whether AnxA1 affects the proliferation of pancreatic beta (β) cells. In the present study, we reduced AnxA1 expression in the MIN6 islet β-cell line using small interfering RNA (AnxA1-siRNA), then measured cell cycle distribution and cellular proliferation. We also measured the expression levels of cell cycle-related proteins such as cyclin D1, cyclin E, and cyclin-dependent kinase 2 (CDK2) by Western blot analysis. We investigated the phosphatidylinositol 3-kinase (PI3K)/ serine/threonine protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway to explore the potential mechanism underlying the observed effects. Knockdown of AnxA1 expression using siRNA reduced the rates of MIN6 cell proliferation. The proportions of cells in S and G2/M phases also decreased upon inhibition of AnxA1. Moreover, AnxA1 protein expression in MIN6 cells was positively related to the protein levels of cyclin D1, cyclin E, and CDK2. Activation of the PI3K/Akt/mTOR signaling pathway by AnxA1 may be involved in the signaling cascade to regulate cell proliferation. This study identified a positive correlation between AnxA1 protein and pancreatic β-cell proliferation. AnxA1 protein expression might affect the proliferation of MIN6 cells via regulation of cyclin D1, cyclin E, and CDK2 proteins, as well as the PI3K/Akt/mTOR signaling pathway.
This study aimed to investigate the roles of hsa_circRNA_103801 in the progression of osteosarcoma (OS) cells. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to detect the expression level of circRNA_103801 in OS cells. Cell count kit-8 and Transwell migration and invasion assays were employed to detect the proliferation, migration, and invasion abilities of OS cells. The effects of circRNA_103801 on the apoptosis of OS cells were identified by flow cytometry. The binding relationship between circRNA_103801 and miR-338-3p was verified by bioinformatics analysis. MiR-338-3p level in OS cell lines was detected by RT-qPCR. Additionally, Western blotting was utilized to detect the expression levels of HIF-1, Rap1, PI3K, and Akt in OS cells. The results showed that the expression level of circRNA_103801 was significantly up-regulated in OS patients' tissues. Inhibiting the expression level of circRNA_103801 could attenuate the proliferation, migration, and invasion abilities of OS cells. In addition, the down-regulated expression level of circRNA_103801 could induce cell apoptosis. The results of the luciferase reporter assay suggested that circRNA_103801 could be combined with miR-338-3p, and the RT-qPCR revealed that the miR-338-3p level in OS cells after knockdown of circRNA_103801 was elevated compared with the control group. The results of Western blotting suggested that the expression levels of HIF-1, Rap1, PI3K, and Akt were elevated in OS cells. In conclusion, the circRNA_103801-miR-3388-3p-HIF-1/Rap1/PI3K-Akt pathway could be a therapeutic target of OS.
Proliferation of vascular smooth muscle cells (VSMCs) participates in multiple cardiovascular disorders, while the mechanism remains unclear. This study aims to investigate the effects of insulin on VSMC. Insulin was used to stimulate rat VSMCs, and the effects on cell cycle and proliferation were subsequently analyzed using flow cytometry. Furthermore, AP-1 and SM-α overexpression vectors were constructed and transfected into VSMCs. AP-1 and SM-α were inhibited by SR11302 and SM-α siRNA, respectively. The mRNA and protein expression levels were subsequently detected using the reversetranscription quantitative polymerase chain reaction and western blotting, respectively. AP-1 and SM-α gene promoter binding sites were determined using luciferase and chromatin immunoprecipitation assays. As a result, we found that high dose of insulin promoted proliferation of VSMCs and increased the percentage of cells in the S phase by downregulating AP-1. AP-1 was identified to bind to the SM-α gene promoter at locus 2-177 to upregulate SM-α gene expression. Inhibition of AP-1 led to the decrease of SM-α expression. Overexpression of SM-α directly suppressed proliferation of VSMCs, while knocking it down promoted the process. Therefore, this study revealed that insulin downregulated the expression of the SM-α gene by inhibiting AP-1, which in turn facilitated proliferation of VSMCs.