To further elucidate the expression, regulation and function of Signaling Lymphocytic Activation Molecule Family (SLAMF) protein members in human monocytes and macrophages. Un-differentiated ...monocytic THP-1 cell (u-THP-1) and differentiated THP-1 macrophage (d-THP-1) were used as culture models in the study. Responses of cells to the differentiation agents phorbol ester (25 ng/ml) and TLR (Toll-like receptor) ligands were assessed. RT-PCR and Western blot analysis were used to determine mRNA and protein level. Pro-inflammatory cytokine mRNA expression levels and phagocytosis were used as functional markers. Data analyzed using t-test, one-way or two-way ANOVA followed by post hoc test. SLAMFs were differentially expressed in THP-1 cells. Differentiation of u-THP-1 to d-THP-1 led to significantly higher SLAMF7 mRNA and protein levels than other SLAMF. In addition, TLR stimuli increased SLAMF7 mRNA expression but not protein expression. Importantly, SLAMF7 agonist antibody and TLR ligands synergistically increased the mRNA expression levels of IL-1β, IL-6 and TNF-α, but had no effect on phagocytosis. SLAMF7 knocked-down in d-THP-1 significantly lowered TLR-induced mRNA expressions of pro-inflammatory markers. SLAM family proteins are differentially regulated by differentiation and TLRs. SLAMF7 enhanced TLR-mediated induction of pro-inflammatory cytokines in monocytes and macrophages but not phagocytosis.
More than one million copies of the approximately 300-bp Alu element are interspersed throughout the human genome, with up to 75% of all known genes having Alu insertions within their introns and/or ...UTRs. Transcribed Alu sequences can alter splicing patterns by generating new exons, but other impacts of intragenic Alu elements on their host RNA are largely unexplored. Recently, repeat elements present in the introns or 3'-UTRs of 15 human brain RNAs have been shown to be targets for multiple adenosine to inosine (A-to-I) editing. Using a statistical approach, we find that editing of transcripts with embedded Alu sequences is a global phenomenon in the human transcriptome, observed in 2674 ( approximately 2%) of all publicly available full-length human cDNAs (n = 128,406), from >250 libraries and >30 tissue sources. In the vast majority of edited RNAs, A-to-I substitutions are clustered within transcribed sense or antisense Alu sequences. Edited bases are primarily associated with retained introns, extended UTRs, or with transcripts that have no corresponding known gene. Therefore, Alu-associated RNA editing may be a mechanism for marking nonstandard transcripts, not destined for translation.
Abstract
Background
Increased inflammation has been well defined in coronavirus disease 2019 (COVID-19), while definitive pathways driving severe forms of this disease remain uncertain. Neutrophils ...are known to contribute to immunopathology in infections, inflammatory diseases, and acute respiratory distress syndrome, a primary cause of morbidity and mortality in COVID-19. Changes in neutrophil function in COVID-19 may give insight into disease pathogenesis and identify therapeutic targets.
Methods
Blood was obtained serially from critically ill COVID-19 patients for 11 days. Neutrophil extracellular trap formation (NETosis), oxidative burst, phagocytosis, and cytokine levels were assessed. Lung tissue was obtained immediately postmortem for immunostaining. PubMed searches for neutrophils, lung, and COVID-19 yielded 10 peer-reviewed research articles in English.
Results
Elevations in neutrophil-associated cytokines interleukin 8 (IL-8) and interleukin 6, and general inflammatory cytokines IFN-inducible protien-19, granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin 1β, interleukin 10, and tumor necrosis factor, were identified both at first measurement and across hospitalization (P < .0001). COVID-19 neutrophils had exaggerated oxidative burst (P < .0001), NETosis (P < .0001), and phagocytosis (P < .0001) relative to controls. Increased NETosis correlated with leukocytosis and neutrophilia, and neutrophils and NETs were identified within airways and alveoli in lung parenchyma of 40% of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–infected lungs available for examination (2 of 5). While elevations in IL-8 and absolute neutrophil count correlated with disease severity, plasma IL-8 levels alone correlated with death.
Conclusions
Literature to date demonstrates compelling evidence of increased neutrophils in the circulation and lungs of COVID-19 patients. Importantly, neutrophil quantity and activation correlates with severity of disease. Similarly, our data show that circulating neutrophils in COVID-19 exhibit an activated phenotype with enhanced NETosis and oxidative burst.
Neutrophils in the circulation of critically ill COVID-19 patients with acute respiratory distress syndrome have functional changes over the course of their disease. These neutrophils have increased antimicrobial and proinflammatory functionality, including neutrophil extracellular trap formation, phagocytosis, and oxidative burst.
Modulation of the immune system by cancer protective food bioactives has preventive and therapeutic importance in prostate cancer, but the mechanisms remain largely unclear. The current study tests ...the hypothesis that the diet-derived cancer protective compounds, indole-3-carbinol (I3C) and 3,3'-diindolylmethane (DIM), affect the tumor microenvironment by regulation of inflammatory responses in monocytes and macrophages. We also ask whether I3C and DIM act through the aryl hydrocarbon (AHR)-dependent pathway or the signaling lymphocyte activation molecule (SLAM) family protein CD84-mediated pathway. The effect of I3C and DIM was examined using the human THP-1 monocytic cell in its un-differentiated (monocyte) and differentiated (macrophage) state. We observed that I3C and DIM inhibited lipopolysaccharide (LPS) induction of IL-1β mRNA and protein in the monocyte form but not the macrophage form of THP-1. Interestingly, CD84 mRNA but not protein was inhibited by I3C and DIM. AHR siRNA knockdown experiments confirmed that the inhibitory effects of I3C and DIM on IL-1β as well as CD84 mRNA are regulated through AHR-mediated pathways. Additionally, the AHR ligand appeared to differentially regulate other LPS-induced cytokines expression. Hence, cross-talk between AHR and inflammation-mediated pathways, but not CD84-mediated pathways, in monocytes but not macrophages may contribute to the modulation of tumor environments by I3C and DIM in prostate cancer.
Resveratrol is a phytochemical that has been under consideration for use as a prostate cancer chemopreventive agent. However, the efficacy, as well as the mechanisms of action of resveratrol on ...prostate cancer prevention, remains largely unknown. This study seeks to address these questions and examine the cancer preventive effects of resveratrol using complementary human LNCaP prostate cancer cell culture and xenograft models. In cultured LNCaP cells, we found that resveratrol inhibited cell growth. The growth inhibitory effects of resveratrol appeared to be through modulation of both androgen- and estrogen-mediated events. Global gene expression analysis using microarrays identified androgen-responsive genes as a group of genes universally affected by resveratrol in LNCaP cells in vitro. The effect of resveratrol on expression of these genes appeared to be through inhibition of both androgen- and estrogen-mediated transcription. In a xenograft model, resveratrol delayed LNCaP tumor growth and inhibited expression of a marker for steroid hormone responses. However, exposure to resveratrol also led to increased angiogenesis and inhibition of apoptosis in the xenograft. In summary, resveratrol may act through modulation of steroid hormone-dependent pathways to inhibit prostate cancer cell growth in both culture and xenografts, but exposure in vivo may be of concern.
Stilbenes are phytoalexins that become activated when plants are stressed. These compounds exist in foods and are widely consumed. Resveratrol is a grape-derived stilbene, which possesses a wide ...range of health-promoting activities, including anticancer properties. Several other stilbenes structurally similar to resveratrol are also available in food, but their biological activities remain largely unknown. In this study, we compared the effects of resveratrol and its natural derivatives pterostilbene, trans-resveratrol trimethylether, trans-pinostilbene and trans-desoxyrhapontigenin on androgen-responsive human prostate cancer LNCaP cells. We found that these compounds exert differential effects on LNCaP cell growth, cell cycle and apoptosis. Trans-resveratrol trimethylether appeared to be the most potent compound among the stilbenes tested. Treatment of LNCaP cells with trans-resveratrol trimethylether resulted in G2/M blockage while other compounds, including resveratrol, induced G1/S arrest. Moreover, different from other compounds, trans-resveratrol trimethylether induced apoptosis. At the molecular level, the effects of these compounds on cell cycle correlated with induction of the cyclin-dependent kinase inhibitor 1A and B mRNA levels. Additionally, these compounds also inhibited both androgen- as well as estrogen-mediated pathways. These results provide mechanistic information on how resveratrol and its methylether analogs may act to contribute to potential antiprostate cancer activity.
COVID-19 is initiated by binding the SARS-CoV-2 spike protein to angiotensin-converting enzyme 2 (ACE2) on host cells. Food factors capable of suppressing the binding between the SARS-CoV-2 spike ...protein and ACE2 or reducing the ACE2 availability through ACE2 inhibitions may potentially reduce the risk of SARS-CoV-2 infection and COVID-19. In this study, the chemical compositions of clove water and ethanol extracts were investigated, along with their potentials in suppressing SARS-CoV-2 spike protein–ACE2 binding, reducing ACE2 availability, and scavenging free radicals. Thirty-four compounds were tentatively identified in the clove water and ethanol extracts, with six reported in clove for the first time. Clove water and ethanol extracts dose-dependently suppressed SARS-CoV-2 spike protein binding to ACE2 and inhibited ACE2 activity. The water extract had stronger inhibitory effects than the ethanol extract on a dry weight basis. The clove water extract also had more potent free radical scavenging activities against DPPH• and ABTS•+ (536.9 and 3525.06 μmol TE/g, respectively) than the ethanol extract (58.44 and 2298.01 μmol TE/g, respectively). In contrast, the ethanol extract had greater total phenolic content (TPC) and relative HO• scavenging capacity (HOSC) values (180.03 mg GAE/g and 2181.08 μmol TE/g, respectively) than the water extract (120.12 mg GAE/g and 1483.02 μmol TE/g, respectively). The present study demonstrated the potential of clove in reducing the risk of SARS-CoV-2 infection and COVID-19 development.
Background and Aim
Dedicated studies evaluating the impact of COVID‐19 on outcomes of pancreatobiliary IgG4 related disease (IgG4‐RD) patients are scarce. Whether COVID‐19 infection or vaccination ...would trigger IgG4‐RD exacerbation remains unknown.
Methods
Pancreatobiliary IgG4‐RD patients ≥ 18 years old with active follow‐up since January 2020 from nine referral centers in Asia, Europe, and North America were included in this multicenter retrospective study. Outcome measures include incidence and severity of COVID‐19 infection, IgG4‐RD disease activity and treatment status, interruption of indicated IgG4‐RD treatment. Prospective data on COVID‐19 vaccination status and new COVID‐19 infection during the Omicron outbreak were also retrieved in the Hong Kong cohort.
Results
Of the 124 pancreatobiliary IgG4‐RD patients, 25.0% had active IgG4‐RD, 71.0% were on immunosuppressive therapies and 80.6% had ≥ 1 risk factor for severe COVID. In 2020 (pre‐vaccination period), two patients (1.6%) had COVID‐19 infection (one requiring ICU admission), and 7.2% of patients had interruptions in indicated immunosuppressive treatment for IgG4‐RD. Despite a high vaccination rate (85.0%), COVID‐19 infection rate has increased to 20.0% during Omicron outbreak in the Hong Kong cohort. A trend towards higher COVID‐19 infection rate was noted in the non‐fully vaccinated/unvaccinated group (17.6% vs 33.3%, P = 0.376). No IgG4‐RD exacerbation following COVID‐19 vaccination or infection was observed.
Conclusion
While a low COVID‐19 infection rate with no mortality was observed in pancreatobiliary IgG4‐RD patients in the pre‐vaccination period of COVID‐19, infection rate has increased during the Omicron outbreak despite a high vaccination rate. No IgG4‐RD exacerbation after COVID‐19 infection or vaccination was observed.
NDC80 complex (NDC80C) is composed of four subunits (SPC24, SPC25, NDC80, and NUF2) and is vital for kinetochore-microtubule (KT-MT) attachment during mitosis. Paradoxically, NDC80C also functions in ...the activation of the spindle-assembly checkpoint (SAC). This raises an interesting question regarding how mitosis is regulated when NDC80C levels are compromised. Using a degron-mediated depletion system, we found that acute silencing of SPC24 triggered a transient mitotic arrest followed by mitotic slippage. SPC24-deficient cells were unable to sustain SAC activation despite the loss of KT-MT interaction. Intriguingly, our results revealed that other subunits of the NDC80C were co-downregulated with SPC24 at a posttranslational level. Silencing any individual subunit of NDC80C likewise reduced the expression of the entire complex. We found that the SPC24-SPC25 and NDC80-NUF2 subcomplexes could be individually stabilized using ectopically expressed subunits. The synergism of SPC24 downregulation with drugs that promote either mitotic arrest or mitotic slippage further underscored the dual roles of NDC80C in KT-MT interaction and SAC maintenance. The tight coordinated regulation of NDC80C subunits suggests that targeting individual subunits could disrupt mitotic progression and provide new avenues for therapeutic intervention.
These results highlight the tight coordinated regulation of NDC80C subunits and their potential as targets for antimitotic therapies.
Second forward view (SFV) examination of the right colon (RC) in colonoscopy was suggested to improve the adenoma detection rate (ADR), but multicenter data to inform its routine use remain limited. ...We performed an international multicenter randomized trial comparing SFV vs a standard single forward view examination of the RC on adenoma detection.
Asymptomatic individuals undergoing screening or surveillance colonoscopies from 6 Asia Pacific regions were invited for study. A forward view examination of the RC was first performed in all patients, followed by randomization at the hepatic flexure to either SFV examination of the RC and standard withdrawal examination from the hepatic flexure to rectum, or a standard withdrawal colonoscopy (SWC) examination from the hepatic flexure to rectum. The primary outcome was RC ADR.
Between 2016 and 2019, there were 1011 patients randomized (SFV group, 502 patients; SWC group, 509 patients). Forty-five endoscopists performed the colonoscopies. The RC ADR was significantly higher in the SFV group than in the SWC group (27.1% vs 21.6%; P = .042). The whole-colon ADR was high in both groups (49.0% vs 45.0%; P =.201). The SFV examination identified 58 additional adenomas in 49 patients (9.8%), leading to a change in surveillance recommendations in 15 patients (3.0%). The median overall withdrawal time was 1.5 minutes longer in the SFV group (12.0 vs 10.5 min; P < .001). Older age, male sex, ever smoking, and longer RC withdrawal time were independent predictors of right-sided adenoma detection.
In this multicenter trial, SFV examination significantly increased the RC ADR in screening and surveillance colonoscopies. Routine RC SFV examination should be considered. ClinicalTrials.gov ID: NCT03121495.
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