title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=749 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Expression of connexin-43 in surgical resections of primary tumor and lymph node metastases of squamous cell carcinoma and adenocarcinoma of the lung: a retrospective study link: https://peerj.com/articles/13055 last-modified: 2022-03-09 description: BackgroundConnexins are transmembrane proteins forming gap junctions between the cells, which allow intercellular communication. Significance of gap junctions and connexins in lung carcinoma is not yet understood. The objective of the study was to investigate immunohistochemical expression and the localization of connexin-43 (Cx43) in primary lung carcinoma and its lymphatic metastases.MethodsSurgical specimens of excised tumors from 88 patients (45 men and 43 women, 61.9 ± 7.4 years) with lung carcinoma (52 adenocarcinoma (AC), 36 squamous cell carcinoma (SqCC)) who were operated on at the University Hospital “Bezanijska Kosa” in a five-year period (2012–2016) were used. We conducted immunohistochemical staining for Cx43 and measured the degree of expression (percentage of positive cells and staining intensity) as well as localization of Cx43 in primary tumor and in lymphatic metastases.ResultsImmunohistochemical analysis of the primary tumors revealed that SqCC showed significantly higher percentage of tumor cells expressing Cx43 as well as higher staining intensity than AC (p < 0.001). Almost 70% of samples with SqCC showed high Cx43 expression, whereas AC showed no expression in more than 50% of cases. Localization of Cx43 expression was most often cytoplasmic (AC and SqCC) and combined membranous and cytoplasmic (SqCC) with very rare instances of nuclear localization (AC). Almost the same pattern in distribution, intensity, and localization of Cx43 expression was observed in the lymph node metastases; however, almost a third of AC cases changed the pattern of Cx43 expression in the metastasis compared to primary tumor.ConclusionThe results of this study showed that lung carcinomas express Cx43 in more than 65% of cases and that it was aberrantly localized (not membranous localization). We highlighted that SqCC expressed Cx43 more than did AC, both in primary tumor and lymphatic metastases. Further research is needed to establish whether Cx43 could be used as a prognostic biomarker in lung carcinoma. creator: Ivana Savic creator: Petar Milovanovic creator: Svetlana Opric creator: Nebojsa Ivanovic creator: Dejan Oprić uri: https://doi.org/10.7717/peerj.13055 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Savic et al. title: Environmental enrichment changes rabbits’ behavior, serum hormone level and further affects cecal microbiota link: https://peerj.com/articles/13068 last-modified: 2022-03-09 description: Many studies have shown that stress is associated with gut microbiota. Environmental enrichment (EE) could reduce stress in farm animals; however, limited information is available on the microbial community composition in rabbits raised with or without EE. This study aimed to identify EE influences on the behavior, serum hormonal levels, and cecal microbiota of rabbits. Two hundred Rex rabbits were segregated randomly within four cohorts (n = 50); reared for 76 d within standardized enclosures (non-enriched) or within cages containing a willow-stick (WS), rubber-duck (RD), or a can of beans (CB). The rabbits’ ingestive, rest, locomotion, exploratory, grooming, and abnormal behavior were observed. The serum hormone levels for rabbits were measured, and cecal specimens were sequencedfrom the V3–V4 region using 16S rRNA amplicons. Environmental enrichment increased feeding and drinking time, promoted exploratory behavior, and reduced abnormal behavior in rabbits. Insulin-like growth factor 1(IGF-1) levels of the enriched cohorts were elevated in comparison to the control cohort. Serum cortisol level for CB cohort was markedly reduced in comparison to the control cohort (p < 0.05), while dopamine levels for CB cohort peaked. Further, we found that EE mainly affected the dominant microbiota. Several families, such as Erysipelotrichaceae, Tannerellaceae, Enterobacteriaceae, Burkholderiaceae, and Prevotellaceae were markedly reduced within the CB cohort. Bacteria such as Alloprevotella, Bifidobacterium, Enterobacteriaceae, Parabacteroides, and Erysipelatoclostridium were identified as having negative associations with the presence of serum cortisol. EE influenced rabbit behavior and serum hormonal levels, and CB enrichment was the most suitable for rabbits. Further, cecal microbiota composition and diversity were affected by CB enrichment. These findings suggested that CB could be considered for use in rabbit husbandry. creator: Yang Feng creator: Huimei Fan creator: Xue Liang creator: Xiaofeng Wang creator: Guoyan Gao creator: Shuangbao Gun uri: https://doi.org/10.7717/peerj.13068 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Feng et al. title: Long-term consumption of artificial sweeteners does not affect cardiovascular health and survival in rats link: https://peerj.com/articles/13071 last-modified: 2022-03-09 description: BackgroundRecent epidemiological cohort studies have suggested that consumption of artificial sweeteners (AS) is associated with adverse cardiovascular events and mortality. However, these population association studies cannot establish a causal relationship. In this study we investigated the effect of long-term (1-year) consumption of AS (Equal and Splenda, two commonly used AS) on cardiovascular health and survival in rats.MethodsAdult Sprague-Dawley rats (both sexes, 4–5 months old) were randomized into the following 3 groups: control (n = 21), AS Equal (n = 21) and Splenda (n = 18). In the AS groups, Equal or Splenda was added to the drinking water (2-packets/250 ml), while drinking water alone was used in the control rats. The treatment was administered for 12 months. Cardiovascular function and survival were monitored in all animals.ResultsIt was found that rats in the AS groups consistently consumed more sweetened water than those in the control group. AS did not affect body weight, non-fasting blood cholesterol, triglycerides, blood pressure or pulse wave velocity. There were no significant differences in left ventricular wall thicknesses, chamber dimension, cardiac function or survival. AS did not affect heart rate or atrial effective refractory period. However, rats in both Equal and Splenda groups had prolonged PR intervals (63 ± 5ms in Equal, 68 ± 6 ms in Splenda, vs 56 ± 8 ms in control, p < 0.05) and a tendency of increased atrial fibrillation inducibility.ConclusionLong-term consumption of AS does not affect cardiovascular structure, function or survival but may cause some electrophysiological abnormalities with prolonged PR intervals and a tendency of increased atrial fibrillation inducibility in rats. creator: Satvinder K. Guru creator: Ying Li creator: Olga V. Savinova creator: Youhua Zhang uri: https://doi.org/10.7717/peerj.13071 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Guru et al. title: Full-length transcriptome analysis of Adiantum flabellulatum gametophyte link: https://peerj.com/articles/13079 last-modified: 2022-03-09 description: Ferns are important components of plant communities on earth, but their genomes are generally very large, with many redundant genes, making whole genome sequencing of ferns prohibitively expensive and time-consuming. This means there is a significant lack of fern reference genomes, making molecular biology research difficult. The gametophytes of ferns can survive independently, are responsible for sexual reproduction and the feeding of young sporophytes, and play an important role in the alternation of generations. For this study, we selected Adiantum flabellulatum as it has both ornamental and medicinal value and is also an indicator plant of acidic soil. The full-length transcriptome sequencing of its gametophytes was carried out using PacBio three-generation sequencing technology. A total of 354,228 transcripts were obtained, and 231,705 coding sequences (CDSs) were predicted, including 5,749 transcription factors (TFs), 2,214 transcription regulators (TRs) and 4,950 protein kinases (PKs). The transcripts annotated by non-redundant protein sequence database (NR), Kyoto encyclopedia of genes and genomes (KEGG), eukaryotic ortholog groups (KOG), Swissprot, protein family (Pfma), nucleotide sequence database (NT) and gene ontology (GO) were 251,501, 197,474, 193,630, 194,639, 195,956, 113,069 and 197,883, respectively. In addition, 138,995 simple sequence repeats (SSRs) and 111,793 long non-coding RNAs (lncRNAs) were obtained. We selected nine chlorophyll synthase genes for qRT-PCR, and the results showed that the full-length transcript sequences and the annotation information were reliable. This study can provide a reference gene set for subsequent gene expression quantification. creator: Zeping Cai creator: Zhenyu Xie creator: Luyao Huang creator: Zixuan Wang creator: Min Pan creator: Xudong Yu creator: Shitao Xu creator: Jiajia Luo uri: https://doi.org/10.7717/peerj.13079 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Cai et al. title: Immunogenicity mechanism of mRNA vaccines and their limitations in promoting adaptive protection against SARS-CoV-2 link: https://peerj.com/articles/13083 last-modified: 2022-03-09 description: Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19) in late 2019, hundreds of millions of people have been infected worldwide. There have been unprecedented efforts in acquiring effective vaccines to confer protection against the disease. mRNA vaccines have emerged as promising alternatives to conventional vaccines due to their high potency with the capacity for rapid development and low manufacturing costs. In this review, we summarize the currently available vaccines against SARS-CoV-2 in development, with the focus on the concepts of mRNA vaccines, their antigen selection, delivery and optimization to increase the immunostimulatory capability of mRNA as well as its stability and translatability. We also discuss the host immune responses to the SARS-CoV-2 infection and expound in detail, the adaptive immune response upon immunization with mRNA vaccines, in which high levels of spike-specific IgG and neutralizing antibodies were detected after two-dose vaccination. mRNA vaccines have been shown to induce a robust CD8+T cell response, with a balanced CD4+ TH1/TH2 response. We further discuss the challenges and limitations of COVID-19 mRNA vaccines, where newly emerging variants of SARS-CoV-2 may render currently deployed vaccines less effective. Imbalanced and inappropriate inflammatory responses, resulting from hyper-activation of pro-inflammatory cytokines, which may lead to vaccine-associated enhanced respiratory disease (VAERD) and rare cases of myocarditis and pericarditis also are discussed. creator: Mohd Zulkifli Salleh creator: Mohd Nor Norazmi creator: Zakuan Zainy Deris uri: https://doi.org/10.7717/peerj.13083 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Salleh et al. title: Distinct metabolic profiling is correlated with bisexual flowers formation resulting from exogenous ethephon induction in melon (Cucumis melo L.) link: https://peerj.com/articles/13088 last-modified: 2022-03-09 description: Melon (Cucumis melo L.) is an agronomically important vegetable. Most cultivars of melon are andromonoecious and bisexual flowers only emerged from the leaf axil of lateral branches. However, the regulatory mechanism contributing to the occurrence of bisexual flowers were still obscure. In this study, ethephon was applied in two common cultivars of melon. In control without ethephon treatment, no bisexual flower was made in the main stem. However, 6.56 ± 1.42 and 6.63 ± 0.55 bisexual flowers were respectively induced in main stem of ‘Yangjiaocui-QX’ and ‘Lvbao’ after ethephon treatment, and induced bisexual flowers distributed in 12–20 nodes of main stem. During the formation of bisexual flowers, 41 metabolites were significantly up-regulated and 98 metabolites were significantly down-regulated. According to the KEGG enrichment analysis of 139 different metabolites, a total of 30 pathways were mapped and KEGG terms of “Phenylalanine, tyrosine and tryptophan biosynthesis”, “Phenylalanine metabolism” and “Flavone and flavonol biosynthesis” were significantly enriched. In three significantly enriched KEGG terms, shikimic acid, L-tryptophan, L-phenylalanine, and kaempferol were significantly up-regulated while L-tyrosine, 4-hydroxycinnami acid and luteolin were significantly down-regulated in ET compared to CK. Different metabolites were also classified depend on major class features and 14 classes were acquired. The results of metabonomics and endogenous hormone identification indicated that ethylene could enhance the concentration of salicylic acid, methyl jasmonate, ABA and IAA. This study provided an important theoretical foundation for inducing bisexual flowers in main stem and breeding new varieties of melon in future. creator: Siyu Fang creator: Yaqian Duan creator: Lanchun Nie creator: Wensheng Zhao creator: Jiahao Wang creator: Jiateng Zhao creator: Liping Zhao creator: Lei Wang uri: https://doi.org/10.7717/peerj.13088 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Fang et al. title: A bZIP transcription factor, PqbZIP1, is involved in the plant defense response of American ginseng link: https://peerj.com/articles/12939 last-modified: 2022-03-08 description: American ginseng (Panax quinquefolius L.) is a perennial medicinal plant that has a long usage history in China. However, root rot, which is mainly caused by Fusarium solani can severely reduce the yield and quality of American ginseng, but no disease-resistant variety of American ginseng exists, and the resistance against this disease is not yet well understood. Thus, it is very urgent to analyze the interaction mechanism regulating the interactions between American ginseng and F. solani to mine disease resistance genes. Using transcriptome data and quantitative polymerase chain reaction (qPCR), we screened the transcription factor PqbZIP1 in response to induction by chitin. Yeast self-activation and subcellular localization experiments proved that PqbZIP1 showed transcriptional activity and was localized in the plant nucleus. In addition, qPCR showed that the highest relative expression level was in the roots, wherein chitin and F. solani inhibited and activated the expression of PqbZIP1, respectively, in American ginseng. Additionally, PqbZIP1 significantly inhibited the growth of the Pseudomonas syringae pv. tomato D36E strain in Nicotiana benthamiana, where expressing PqbZIP1 in N. benthamiana increased the jasmonic acid, salicylic acid, and abscisic acid content. Furthermore, PqbZIP1 expression was continually increased upon inoculation with F. solani. Hence, this study revealed that the PqbZIP1 transcription factor might mediate multiple hormonal signaling pathway to modulate root rot disease resistance in American ginseng, and provided important information to breed disease-resistant American ginseng. creator: Shanshan Yang creator: Xiaoxiao Zhang creator: Ximei Zhang creator: Yanmeng Bi creator: Weiwei Gao uri: https://doi.org/10.7717/peerj.12939 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Yang et al. title: Associations between the rs5498 (A > G) and rs281432 (C > G) polymorphisms of the ICAM1 gene and atherosclerotic cardiovascular disease risk, including hypercholesterolemia link: https://peerj.com/articles/12972 last-modified: 2022-03-08 description: BackgroundAtherosclerotic cardiovascular disease (ASCVD) originates from complex risk factors, including age, gender, dyslipidemia, obesity, race, genetic and genetic variation. ICAM1 gene polymorphisms are a significant risk factor for ASCVD. However, the impact of the rs5498 and rs281432 polymorphisms on the prevalence of hypercholesterolemia (HCL) has not been reported. Therefore, we determine the relationships between single nucleotide polymorphisms (SNPs), including rs5498 and rs281432 on Intercellular adhesion molecule 1 gene (ICAM1) and ASCVD susceptibility in patients with HCL.MethodsThe clinical characteristics of 278 participants were assessed, and classified to groups having HCL and without HCL. ICAM1 SNPs genotyping was performed by DNA sequencing, and ICAM1 expression was measured using real-time PCR.ResultsPositive dominant model rs5498 participants had twice the risk of HCL (95% confidence interval (CI): [1.24–3.23], P = 0.005). The frequency of the G allele in rs5498 was 1.69 times higher in participants with HCL than in controls (95% CI [1.15–2.47], P = 0.007). Participants with the rs5498 AG or GG variants and high ICAM1 mRNA expression (≥3.12) had 2.49 times the risk (95% CI [1.42–4.38], P = 0.001), and those with a high LDL-C concentration (≥3.36 mmol/L) had 2.09 times the risk (95% CI [1.19–3.66], P = 0.010) of developing ASCVD compared with those with low ICAM1 mRNA and LDL-C levels. Interestingly, participants carrying the rs5498 AG or GG variants who had tachycardia (resting heart rates (RHRs) >100 beats/min) had a 5.02-times higher risk than those with a lower RHR (95% CI [1.35–18.63], P = 0.016).ConclusionsIt may consider the G allele in ICAM1rs5498 is associated with a higher risk of ASCVD in Thai people with HCL, and is also positively associated with ICAM1 mRNA expression, LDL-C concentration, and RHR. creator: Naruemon Wechjakwen creator: Amornrat Aroonnual creator: Pattaneeya Prangthip creator: Ngamphol Soonthornworasiri creator: Pornpimol Panprathip Phienluphon creator: Jirayu Lainampetch creator: Karunee Kwanbunjan uri: https://doi.org/10.7717/peerj.12972 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Wechjakwen et al. title: Microbial community spatial structures in Luzhou-flavored liquor pit muds with different brewing materials link: https://peerj.com/articles/12987 last-modified: 2022-03-08 description: BackgroundAlthough studies have shown that Bacteroidetes, Clostridiales, and Lactobacillales are the main components of the microbial community in pit mud during the brewing of Luzhou-flavored liquor, little is known about the effect of brewing materials on spatial structures of this microbiome.MethodsHigh-throughput sequencing of the V4–V5 region of prokaryotic 16S rRNA gene was performed to analyze the microbial community diversity and spatial heterogeneity in Luzhou-flavored liquor pit muds with different brewing ingredients. The structural characteristics and heterogeneous spatial distribution of the pit mud microbial communities were examined using bioinformatics and multivariate statistical analysis methods.ResultsOur results showed that Euryarchaeota, Actinobacteria, Bacteroidetes, Chlorobi, Chloroflexi, Firmicutes, Proteobacteria, Synergistetes, Tenericutes, and WWE1 were the dominant phyla in the pit mud microbiome. The Shannon and Simpson indices of the pit mud microbiome with three grains (M3G) in the upper layer were significantly lower than those in middle layer and bottom, whereas those of the pit mud microbiome with five grains (M5G) in bottom were significantly lower than those in middle layer (p < 0.05). There were significant differences in the microbial community compositions between the pit muds with different brewing ingredients and locations in the same pit (p < 0.05). T78 of Anaerolinaceae, Butyrivibrio, Dehalobacter_Syntrophobotulus, Desulfosporosinus, Asteroleplasma, and vadinCA02 of Synergistaceae were significantly enriched in M3G, whereas Prevotella, Vagococcus, Caldicoprobacter, Butyrivibrio, Coprococcus, Dorea, Sporanaerobacter, Tepidimicrobium, TissierellaSoehngenia, RFN20 of Erysipelotrichaceae, Sutterella, 125ds10 of Alteromonadales, Vibrio, and Sphaerochaeta were significantly enriched in M5G. This study provides a theoretical basis for exploring the influence of brewing ingredients in pit muds on the production of Luzhou-flavored liquor and the specific influence of pit mud microorganisms in different locations on liquor production. creator: Jinjin Li creator: Hongzhao Sun creator: Qian Wang creator: Yunfei Cai creator: Zhu Shi creator: Jianlei Jia creator: Lei Zheng creator: Ru Jiang creator: Lingmei Gao uri: https://doi.org/10.7717/peerj.12987 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Li et al. title: Abubidentin A, New Oleanane-type Triterpene Ester from Abutilon bidentatum and its antioxidant, cholinesterase and antimicrobial activities link: https://peerj.com/articles/13040 last-modified: 2022-03-08 description: BackgroundThis work describes the phytochemical and biological investigation of aerial parts of Abutilon bidentatum Hochst. Of Saudi origin.MethodologyPetroleum ether fraction of ethanolic extract A. bidentatum was fractionated on a silica gel column and further purified with different chromatographic procedures for the isolation of chemical compounds. The chemical structures of all the pure isolated compounds were elucidated by the interpretation of their spectral data using IR, UV, 1H, 13C NMR, and MS spectroscopy and chemical methods (alkaline hydrolysis) as well as comparison with data reported in the literature. The extract and isolated compounds were evaluated for antioxidant, cholinesterase inhibitory, and antimicrobial activities.ResultsA new oleanane-type triterpene ester, namely abubidentin A (3) (α, 3β, 30-trihydroxy-29-carboxy-olean-9(11), 12-diene-3-dotriacontanoate), along with two known compounds: 2-hydroxydocosanoic acid (1) and stigmasta-22-ene-3-β-ol (2) were isolated from the aerial parts of Abutilon bidentatum Hochst. (Malvaceae). Concerning the biological potential, the abubidentinA displayed antioxidant, cholinesterase inhibitory and antimicrobial activities. AbubidentinA possessed strong antioxidant activity against DPPH and ABTS+ radical scavenging assays. This new triterpene exhibited high inhibition against acetylcholinesterase (IC50 38.13 ± 0.07 µgmL−1) and butyrylcholinesterase (IC50 32.68 ± 0.37 µgmL−1). Abubidentin A displayed promising antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus (125–150 µgmL−1).ConclusionThese findings suggest A. bidentatum can contribute as a source of new biologically active compounds, especially antioxidants and antimicrobial agents. creator: Gadah A. Al-Hamoud creator: Nawal M. Al-Musayeib creator: Musarat Amina creator: Sabrin R.M. Ibrahim uri: https://doi.org/10.7717/peerj.13040 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Al-Hamoud et al.