Nine-Month Trend of IgG Antibody Persistence and Associated Symptoms Post-SARS-CoV-2 Infection.

Between 2 and 8.5% of patients who recover from COVID-19 do not develop antibodies, and the durability of IgG antibodies is under scrutiny. Therefore, the presence and persistence of IgM and IgG antibodies were evaluated in a group of patients diagnosed with SARS-CoV-2 from May to August 2020. Out of 2199 suspected COVID-19 cases, 1264 were confirmed for SARS-CoV-2 by rRT-PCR; 328 consented to participate in the study, with 220 participants followed for 9 months, including 124 men (56%) and 96 women (44%). The primary symptoms were headache, dry cough, and fever. IgG antibodies developed in 95% of patients within 4 weeks post-diagnosis, and a second evaluation at 9 months showed that 72.7% still had detectable IgG antibodies. The presence of IgM in one individual (0.45%) suggested the possibility of reinfection.

Nanoparticle­based antiviral strategies to combat the influenza virus (Review).

The rapid availability of effective antiviral treatments would be beneficial during the early phases of a pandemic, as they could reduce viral loads and control serious infections until antigenic vaccines become widely available. One promising alternative therapy to combat pandemics is nanotechnology, which has the potential to inhibit a wide variety of viruses, including the influenza virus. This review summarizes the recent progress using gold, copper, silver, silicone, zinc and selenium nanoparticles, since these materials have shown remarkable antiviral capacity against influenza A virus.

Correction: Characterizing the cytotoxic effects and several antimicrobial phytocompounds of Argemone mexicana.

[This corrects the article DOI: 10.1371/journal.pone.0249704.].

Transcriptional Profile of HCV Replicon Cells after Treatment with Acetylsalicylic Acid.

OBJECTIVE: It has been demonstrated in vitro that acetylsalicylic acid (ASA) treatment halves hepatitis C virus (HCV) expression in hepatocarcinoma cells. However, the signaling pathway that promotes this ASA-induced antiviral effect has not yet been identified. AIM: The aim of this work was to identify alterations in the transcriptional profile of Huh-7-HCV-subgenomic replicon cells with vs. without ASA treatment. This comparison sheds light onto the signaling pathways and molecular mechanisms involved in the antiviral effects of ASA. METHODS: Human hepatocellular carcinoma (Huh-7) cells that express non-structural HCV proteins (Huh-7-HCV-replicon cells) were exposed to 4 mM ASA for 0, 24, 48, and 72 hours. Total RNA was isolated, and cDNA was synthesized. Transcripts were then tagged with biotin and purified. Thereafter, they were fragmented and hybridized on HG-U133 Plus 2 Gene Expression chips. Hybridization signals were captured using a GeneChip 3000 7G Scanner and analyzed via Expression Console and dChip Software. RESULTS: When exposed to ASA, hepatocarcinoma cells with non-structural HCV proteins were found to differentially regulate genes with oxidative roles in the cell. The most upregulated genes were interleukin 8 (IL-8), cytochrome P450 (CYP450), and metallothioneins (MTs), while the most downregulated genes were ribonucleotide reductases (RRs). CONCLUSION: These results show that ASA modulates the expression of genes with antioxidant functions. This suggests that ASA induces a remodeling of the antioxidant microenvironment, which may in turn interfere with the replication of HCV.

ADIPOQ-rs2241766 polymorphism is associated with changes in cholesterol levels of Mexican adolescents.

BACKGROUND: The ADIPOQ gene encodes a fat-derived protein hormone with a preponderant role in the homeostasis of glucose and fatty acids. However, previous association studies between ADIPOQ genetic variants and metabolic disorders have shown controversial results. In this study, we evaluated the effect of the ADIPOQ-rs2241766 polymorphism on diverse biochemical parameters (i.e., insulin resistance, atherogenic index, overweight and obesity) in an adolescent population from Mexico. METHODS: A cross-sectional study with convenience sampling was carried out in 356 adolescents from Northern Mexico. They were classified by sex and BMI-z score. The biochemical parameters were measured from blood samples using conventional methods. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: In low and normal weight groups, GG carriers had a significantly higher cholesterol level (P ≤ 0.05) than TG and TT carriers. However, there was no association between ADIPOQ-rs2241766 polymorphism and atherogenic index, overweight, or obesity. CONCLUSIONS: Our findings suggest that the cholesterol levels are under the influence of the ADIPOQ-rs2241766 polymorphism in Mexican adolescents and may explain how ADIPOQ variants increase the risk of developing metabolic disorders. Nevertheless, further studies are required to rule out the influence of other genetic and non-genetic factors.

Down regulation of tumour biomarkers in colon cancer cells with IRNA PFK-1 plus metformin.

PURPOSE: Metformin has been widely used for the treatment of Type 2 Diabetes Mellitus (T2DM), hyperglycemia and polycystic ovarian syndrome. Recent studies have suggested the potential of this substance as a cancer chemopreventive agent. We evaluated the antitumoral effect of iRNA-PFK-1 and the combined therapy iRNA-PFK-1 + metformin in RKO p53-positive cells. METHODS: mRNA levels of tumor suppressor genes AMPK, APC, and c-MYC, KRAS oncogenes were measured by qRT-PCR in RKO cells treated with 25 µM metformin alone or combined with iRNA-PFK-1, to evaluate the effect of both treatments. RESULTS: At 72 h after treatment with either 25 µM metformin, 150 nM iRNA-PFK-1, or the combined treatment, the transcriptional levels of these biomarkers were decreased by ~73% (p˂0.05), ~99.9%, (p˂0.01), and ~76% (p˂0.05), respectively. CONCLUSION: These in vitro results support the potential therapeutic role of metformin and PFK-1 in the treatment of colon cancer via down-modulation of the expression of several important cancer biomarkers.

Characterizing the cytotoxic effects and several antimicrobial phytocompounds of Argemone mexicana.

Commonly called the Mexican prickly poppy, Argemone mexicana is a stress-resistant member of the Papaveraceae family of plants that has been used in traditional medicine for centuries by indigenous communities in Mexico and Western parts of the United States. This plant has been exploited to treat a wide variety of ailments, with reported antimicrobial and antioxidant properties, as well as cytotoxic effects against some human cancer cell lines. Due to its various therapeutic uses and its abundance of secondary metabolites, A. mexicana has great potential as a drug discovery candidate. Herein, the germination conditions of A. mexicana are described and the cytotoxic activities of different parts (seeds, leaves, inner vs. outer roots) of the plant from methanol or hexane extracts are preliminarily characterized against cells of seven unique organisms. When comparing 1 mg of each sample normalized to background solvent alone, A. mexicana methanol outer root and leaf extracts possessed the strongest antimicrobial activity, with greatest effects against the Gram-positive bacteria tested, and less activity against the Gram-negative bacteria and fungi tested. Additionally, using the MTT colorimetric assay, the outer root methanol and seed hexane extracts displayed pronounced inhibitory effects against human colon cancer cells. Quantification of c-MYC (oncogene) and APC (tumor suppressor) mRNA levels help elucidate how the A. mexicana root methanol extract may be affecting colon cancer cells. After ultra-performance liquid chromatography coupled with mass spectrometry and subsequent nuclear magnetic resonance analysis of the root and leaf methanol fractions, two main antibacterial compounds, chelerythrine and berberine, have been identified. The roots were found to possess both phytocompounds, while the leaf lacked chelerythrine. These data highlight the importance of plants as an invaluable pharmaceutical resource at a time when antimicrobial and anticancer drug discovery has plateaued.

Inhibition of miR31 and miR92a as Oncological Biomarkers in RKO Colon Cancer Cells Treated with Kaempferol-3-O-Glycoside Isolated from Black Bean.

MicroRNAs (miRNAs) are small molecules of 19-23 nucleotides of RNA that act as regulators of the expression of proteins in eukaryotic cells. Currently, the participation of miRNAs in the development of different types of cancer has been observed. To evaluate the inhibitory effect of kaempferol-3-O-glycoside on the expression of oncological biomarkers, miR31 and miR92a in a colon cancer cell line (RKO) were analyzed. Cells were cultured and treated with 1 mM kaempferol-3-O-glycoside isolated from black bean. Expression levels of miR31 and miR92a were evaluated by real-time PCR using TaqMan probes; in addition, two oncogenes (KRAS and c-MYC) and two tumor suppressors (AMP-activated protein kinase [AMPK] and adenomatous tumors of polyposis coli [APC]) were quantified to validate the biological effects; normalization of expression levels were carried out by 2-ΔΔCt. Results were analyzed by one-way ANOVA. The expression levels of miR31, miR92a, KRAS oncogene, and the c-MYC transcription factor were subexpressed upon 72 h post-treatment with kaempferol-3-O-glycoside compared with the control without treatment (P < .05); in contrast, the tumor suppressor genes AMPK (∼4.85, P = .005) and APC (∼2.71, P = .066) tumor suppressors genes were overexpressed. Our results showed the inhibitory effect of isolated black bean flavonoid kaempferol-3-O-glycoside on cancer biomarkers: miR31 and miR92a; based on our results, this flavonoid may have interesting nutritional, therapeutic, and/or prophylactic applications to combat colon cancer.

Quantification of nitric oxide by high-performance liquid chromatography-fluorometric method in subgenomic hepatitis C virus-replicon expressing Huh7 cells upon treatment with acetylsalicylic acid.

As nitric oxide (NO) expression levels are lower in hepatocytes compared with other cell types, it is difficult to quantify this compound via Griess assay. The aim of the present study was to quantify NO concentration in the cell culture medium from a subgenomic hepatitis C virus (HCV)-replicon expressing Huh-7 cell system using a high-performance liquid chromatography (HPLC)-fluorescence detector in the presence or absence of acetylsalicylic acid (ASA) treatment. HCV-replicon cells were incubated with ASA (4 mM) for 24, 48 and 72 h. Thereafter, the medium was collected to measure nitrites (NO2-) as an indirect indicator of NO levels using diaminonaphtalene as a derivate agent. NO levels were significantly higher (1.7-fold) in Huh-7 replicon cells treated with ASA (72 h post-treatment) than untreated cells (P<0.05); NO inhibitor reduced ~30% the level of NO in Huh-7 replicon cells treated with ASA (48 h post-treatment; P<0.05). The findings suggested that the HPLC-fluorescence method provided an accurate and efficient measurement of NO production in Huh-7-HCV-replicon cells culture medium.

Microsatellite instability and protein expression of MLH1 and MSH2 genes in young Mexican patients less than 50 years of age diagnosed with colorectal cancer.

Diagnosis of colorectal cancer in patients under 45 years old should alert us to possible hereditary forms of this neoplasia. Most cases of hereditary colorectal cancer correspond to Lynch syndrome which is caused by mutations in DNA mismatch repair genes, particularly MLH1 and MSH2. The dysfunction is associated with microsatellite instability which occurs in 95% cases of this syndrome and in 15% of sporadic colorectal cancer. In sporadic colon tumors, downregulation of MLH1 is observed in cases with the BRAF V600E variant, which induces hypermetylation of the MLH1 promoter. Mutation screening for hereditary cancer has impacted the diagnosis, genetic counseling, and early tumor detection in families affected by hereditary colorectal cancer syndromes but mutation screening technologies are seldom available in public health care centers in developing countries. This study aimed to describe immunohistochemistry and microsatellite instability abnormalities in tumor samples archived in a public hospital in Mexico. Paraffin-embedded samples of patients with colorectal cancer, diagnosed at under 50 years old, were studied to analyze correlations among clinical variables, MLH1 and MSH2 protein expression (immunohistochemistry), microsatellite instability (fluorescent PCR-based assay), and BRAF V600E variant (real time PCR). Forty-seven tumor specimens from patients with TNM stage II and above were analyzed. Tumors were mainly located in the proximal colon segment and displayed histologic intestinal variety and infiltration to serosa. Twenty samples showed decreased expression of mismatch repair proteins and 10 of these presented microsatellite instability (7 high and 3 low instability patterns, respectively). There were no instances of BRAF V600E mutation found. Altered MLH1 or MSH2 expression was found in 42.5% of the samples and microsatellite instability was observed in 21.3% of the tumors. These results suggested that about a fifth of the patients were candidates for family assessment and genetic counseling.

The 482Ser of PPARGC1A and 12Pro of PPARG2 Alleles Are Associated with Reduction of Metabolic Risk Factors Even Obesity in a Mexican-Mestizo Population.

The aim of this study was to investigate the relationship between functional polymorphisms Gly482Ser in PPARGC1A and Pro12Ala in PPARG2 with the presence of obesity and metabolic risk factors. We included 375 individuals characterized as Mexican-Mestizos and classified by the body mass index (BMI). Body dimensions and distribution of body fat were measured. The HOMA-IR and adiposity indexes were calculated. Adipokines and metabolic profile quantification were performed by ELISA and routine methods. Genetic polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism analysis. A difference between obese and nonobese subjects in polymorphism PPARGC1A distribution was observed. Among obese individuals, carriers of genotype 482Gly/Gly were observed to have decreased body fat, BMI, and body fat ratio versus 482Ser/Ser carriers and increased resistin and leptin levels in carriers Gly+ phenotype versus Gly- phenotype. Subjects with PPARG2 Ala- phenotype (genotype 12Pro/Pro) showed a decreased HOMA-IR index versus individuals with Ala+ phenotype (genotypes 12Pro/Ala plus 12Ala/Ala). We propose that, in obese Mexican-Mestizos, the combination of alleles 482Ser in PPARGC1A and 12Pro in PPARG2 represents a reduced metabolic risk profile, even when the adiposity indexes are increased.

Downregulation of inducible nitric oxide synthase (iNOS) expression is implicated in the antiviral activity of acetylsalicylic acid in HCV-expressing cells.

Previously, we described that acetylsalicylic acid (ASA) decreases HCV expression, but the mechanisms involved have not been clearly established. We evaluated the participation of inducible nitric oxide synthase (iNOS) in the regulation of HCV-RNA induced by ASA. Huh7 cells expressing non-structural HCV proteins were exposed to 4 mM ASA and incubated at the same times we reported HCV downregulation (24-72 h), and iNOS mRNA and protein levels were then measured by real-time PCR and Western blot, respectively. Nitric oxide levels were measured at the same time. Inhibition of iNOS mRNA by small interfering RNAs (siRNA) and activation of the iNOS gene promoter by ASA treatment were evaluated. In Huh7 replicon cells treated with ASA, we found decreased levels of iNOS mRNA, iNOS protein and nitrosylated protein levels at 48-72 h. ASA exposure also reduced the transactivation of the iNOS promoter in HCV replicon cells at 48 h, and this was partly due to the decrease in the affinity of transcription factor C/EBP-ß for its binding site in the iNOS promoter. siRNA silencing of iNOS decreased HCV-RNA expression (65 %) and potentiated the antiviral effect (80 %) of ASA compared with control cells. ASA reduces iNOS expression by downregulating promoter activity, mRNA and protein levels at the same time that it decreases HCV expression. These findings suggest that the antiviral activity of ASA is mediated partially through the modulation of iNOS.

Use of proteomic analysis tools to identify HCV-proteins down-regulated by acetylsalicylic acid.

Background and aim. Acetylsalicylic acid (ASA) has been shown to downregulate HCV expression; however, the involved mechanisms are unknown. We used proteomic analysis to compare protein expression profiles between human hepatocarcinoma cells (Huh7) and Huh7-HCV cells harboring expression of non-structural HCV proteins, to elucidate the mechanism(s) involved in ASA-mediated downregulation of HCV replication. Material and methods. Both cell lines were treated or untreated with 4 mM ASA and harvested at 0, 24, 48 and 72 h to isolate total proteins, which were resolved by two-dimensional gel electrophoresis (2DE) to separate them by isoelectric point (pI), followed by fractionation by molecular weight (MW). Gels were scanned and analyzed with PD-Quest software V8.0.1, and proteins were elucidated by the specific pI and MW using TAGIDENT software. Statistics analysis included the t-test. esults and Discussion. Different protein patterns among hepatocytes expressing HCV-proteins in ASA treated and untreated cells were found. Among proteins differentially expressed in Huh7-HCV cells, we found proteins related to cell proliferation (MTMR6, FAM22, HDGF and HCF-1) after 24 h of ASA treatment; and upregulation of angiostatin, PI4KA and STAT-1 after 48 h of treatment. Finally, at 72 h of ASA exposure, we identified overexpression of adenylsuccinate synthase, 2'-3'-di-deoxyadenosine, ubiquitin-protein-ligase E6A, adenylosuccinate-lyase and nibrin (NBN). Conclusion. We found that ASA induces different protein patterns in Huh7-HCV cells promoting activation of proteins involved in cell progression, repair of double strand breaks, proliferation, inhibition of apoptosis and growth stimulation at the same time that it decreased HCV expression.