Genes Encoding ACE2, TMPRSS2 and Related Proteins Mediating SARS-CoV-2 Viral Entry are Upregulated with Age in Human Cardiomyocytes

Age is an independent risk factor for adverse outcome in patients following COVID-19 infection. We hypothesised that differential expression of genes encoding proteins proposed to be required for entry of SARS-Cov-2 in aged compared to younger cardiomyocytes might contribute to the susceptibility of older individuals to COVID-19-associated cardiovascular complications.We generated strand-specific RNA-sequencing libraries from RNA isolated from flow-sorted cardiomyocyte nuclei from left ventricular tissue. RNASeq data were compared between five young (19-25yr) and five older (63-78yr) Caucasian males who had not been on medication or exhibited evidence of cardiovascular disease post-mortem.Expression of relevant genes encoding ACE2, TMPRSS2, TMPRS11D, TMPRS11E, FURIN, CTSL, CTSB and B0AT1/SLC6A19 were upregulated in aged cardiomyocytes and the combined relative cardiomyocyte expression of these genes correlated positively with age. Genes encoding proteins in the RAAS and interferon/interleukin pathways were also upregulated such as ACE, AGTR1, MAS1 and IL6R.Our results highlight SARS-CoV-2 related genes that have higher expression in aged compared with young adult cardiomyocytes. These data may inform studies using selective enzyme inhibitors/antagonists, available as experimental compounds or clinically approved drugs e.g. remdesivir that has recently been rapidly accepted for compassionate use, to further understand the contribution of these pathways in human cardiomyocytes to disease outcome in COVID-19 patients.Competing Interest StatementThe authors have declared no competing interest.View Full Text

Activation of NF-κB in Synovium versus Cartilage from Patients with Advanced Knee Osteoarthritis: A Potential Contributor to Inflammatory Aspects of Disease Progression.

The aim was to assess the activation and association of the NF-κB system across synovial membrane (SM) and articular cartilage (AC) in patients with knee osteoarthritis (OA) and ascertain its potential effects on catabolic mediator expression in advanced OA. SM and AC were obtained from 40 OA patients undergoing total knee arthroplasty and from 19 postmortem control subjects. NF-κB subunit RelA in nuclear and cytosolic fractions and NF-κB1-DNA binding in nuclear extracts was assessed by ELISA, whereas NFKB1, RELA, IL-8, IL-6, and MMP3 gene expression were analyzed by reverse transcriptase-quantitative PCR in tissues. We observed higher SM nuclear RelA protein levels and upregulated NF-κB1-DNA binding in OA patients compared with postmortem controls. However, in AC, lower nuclear RelA levels were observed compared with cytosolic extracts in patients. Nuclear RelA levels correlated positively with NF-κB1-DNA binding in SM and AC in patients. SM RELA and MMP3 mRNA levels were upregulated, whereas IL-8 and IL-6 as well as AC RELA were downregulated in patients compared with controls. In SM, nuclear RelA levels correlated positively with MMP3 gene expression in patients. A negative correlation was observed between SM nuclear RelA levels and AC NF-κB1-DNA binding, and SM nuclear NF-κB1-DNA binding correlated negatively with AC MMP3 and NFKB1 mRNA levels in patients. These findings highlight NF-κB-triggered cross-talk and feedback mechanisms between SM and AC in OA. Further, our findings strongly support a role for an activated NF-κB system in the transcriptional mechanism of inflammatory processes, especially in SM of patients with advanced OA.

Comorbidities in relation to fatality of first myocardial infarction.

INTRODUCTION: Present knowledge concerning potential associations between comorbidities and the fatality of a first myocardial infarction (MI) is limited. AIM: To identify comorbidities in 45-70-year-old individuals who suffered a first MI and died within 7 days in Stockholm County from 1992-1994. In addition, to assess how each of the comorbidities identified, as well as the number of hospitalizations during the 10-year period prior to the MI, was associated with MI fatality. METHODS: The data collected on our inception cohort of 1984 first MI, of which 524 were fatal within 7 days, were primarily self-reported, proxy-reported by questionnaire and/or extracted from comprehensive national registers. Comorbidities among fatal cases with a prevalence >2% were identified. Risk ratios (with 95% confidence intervals) for the association of MI fatality with number of prior hospitalizations and specific comorbidities were calculated using binomial regression with log link. A structured review of autopsy reports on fatal cases was performed in order to identify additional indicators of comorbidities. RESULTS: After adjusting for sex, age and disposable income, the number of previous hospitalizations was associated with 7-day MI fatality. Of the comorbidities identified as prevalent in fatal cases, the following were associated with 7-day fatality in crude analysis: epilepsy, heart failure, stroke, alcoholism, cancer, renal diseases, asthma, psychiatric diseases, diabetes, and rheumatoid arthritis. Indicators of comorbidities identified from autopsy data included a silent MI, severe atherosclerosis of the abdominal aorta, and hepatic steatosis. Adjustments for sex and age (although not possible for epilepsy and alcoholism), did not substantially alter results. CONCLUSIONS: Our current findings indicate that in connection with a first MI, particular attention should be paid to those with repeated prior hospitalizations and/or epilepsy, heart failure, stroke, alcoholism, cancer, renal diseases, asthma, psychiatric diseases, diabetes and rheumatoid arthritis.