Inhibitory effect on SARS-CoV-2 infection of neferine by blocking Ca2+ -dependent membrane fusion.
Journal of medical virology. 2021;(10):5825-5832
The coronavirus disease 2019 (COVID-19) pandemic has focused attention on the need to develop effective therapeutics against the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and also against other pathogenic coronaviruses. In this study, we report on a kind of bisbenzylisoquinoline alkaloid, neferine, as a pan-coronavirus entry inhibitor. Neferine effectively protected HEK293/hACE2 and HuH7 cell lines from infection by different coronaviruses pseudovirus particles (SARS-CoV-2, SARS-CoV-2 [D614G, N501Y/D614G, 501Y.V1, 501Y.V2, 501Y.V3 variants], SARS-CoV, MERS-CoV) in vitro, with median effect concentration (EC50 ) of 0.13-0.41 μM. Neferine blocked host calcium channels, thus inhibiting Ca2+ -dependent membrane fusion and suppressing virus entry. This study provides experimental data to support the fact that neferine may be a promising lead for pan-coronaviruses therapeutic drug development.
Serum Calcium and Vitamin D levels: Correlation with severity of COVID-19 in hospitalized patients in Royal Hospital, Oman.
International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases. 2021;:153-163
INTRODUCTION Studies have revealed hypocalcemia and low vitamin D levels in severe covid-19 that warrant further research. OBJECTIVE Our study investigates the correlation between calcium levels at presentation as a primary endpoint and pre-existing calcium levels as a secondary endpoint to the severity of disease presentation and progression. METHOD Observational cohort study in adults admitted with COVID-19 from March utill September 2020. Multiple clinical scales and laboratory parameters were used to correlate corrected calcium and vitamin D associations with risk factors and outcomes. RESULTS Four hundred and forty five patients were included in the study. Hypocalcemic patients had more abnormal laboratory parameters and longer hospitalization duration. Hypocalcemia was in 60-75% of all age groups (p-value 0.053), for which 77.97% were ICU admissions (p-value 0.001) and 67.02% were diabetic (p-value 0.347). There were non-significant correlations between Vitamin D and almost all the parameters except for chronic respiratory diseases, which had a P-value of 0.024. CONCLUSION It can be concluded that hypocalcemia is a significant and reliable marker of disease severity and progression regardless of underlying comorbidities. Vitamin D levels fail to reflect correlation with severity of COVID-19 infections.
SARS-CoV-2 attachment to host cells is possibly mediated via RGD-integrin interaction in a calcium-dependent manner and suggests pulmonary EDTA chelation therapy as a novel treatment for COVID 19.
SARS-CoV-2 is a highly contagious virus that has caused serious health crisis world-wide resulting into a pandemic situation. As per the literature, the SARS-CoV-2 is known to exploit humanACE2 receptors (similar toprevious SARS-CoV-1) for gaining entry into the host cell for invasion, infection, multiplication and pathogenesis. However, considering the higher infectivity of SARS-CoV-2 along with the complex etiology and pathophysiological outcomes seen in COVID-19 patients, it seems that there may be an alternate receptor for SARS-CoV-2. I performed comparative protein sequence analysis, database based gene expression profiling, bioinformatics based molecular docking using authentic tools and techniques for unveiling the molecular basis of high infectivity of SARS-CoV-2 as compared to previous known coronaviruses. My study revealed that SARS-CoV-2 (previously known as 2019-nCoV) harbors a RGD motif in its receptor binding domain (RBD) and the motif is absent in all other previously known SARS-CoVs. The RGD motif is well known for its role in cell-attachment and cell-adhesion. My hypothesis is that the SARS-CoV-2 may be (via RGD) exploiting integrins, that have high expression in lungs and all other vital organs, for invading host cells. However, an experimental verification is required. The expression of ACE2, which is a known receptor for SARS-CoV-2, was found to be negligible in lungs. I assume that higher infectivity of SARS-CoV-2 could be due to this RGD-integrin mediated acquired cell-adhesive property. Gene expression profiling revealed that expression of integrins is significantly high in lung cells, in particular αvβ6, α5β1, αvβ8 and an ECM protein, ICAM1. The molecular docking experiment showed the RBD of spike protein binds with integrins precisely at RGD motif in a similar manner as a synthetic RGD peptide binds to integrins as found by other researchers. SARS-CoV-2 spike protein has a number of phosphorylation sites that can induce cAMP, PKC, Tyr signaling pathways. These pathways either activate calcium ion channels or get activated by calcium. In fact, integrins have calcium & metal binding sites that were predicted around and in vicinity of RGD-integrin docking site in our analysis which suggests that RGD-integrins interaction possibly occurs in calcium-dependent manner. The higher expression of integrins in lungs along with their previously known high binding affinity (~KD = 4.0 nM) for virus RGD motif could serve as a possible explanation for high infectivity of SARS-CoV-2. On the contrary, human ACE2 has lower expression in lungs and its high binding affinity (~KD = 15 nM) for spike RBD alone could not manifest significant virus-host attachment. This suggests that besides human ACE2, an additional or alternate receptor for SARS-CoV-2 is likely to exist. A highly relevant evidence never reported earlier which corroborate in favor of RGD-integrins mediated virus-host attachment is an unleashed cytokine storm which causes due to activation of TNF-α and IL-6 activation; and integrins role in their activation is also well established. Altogether, the current study has highlighted possible role of calcium and other divalent ions in RGD-integrins interaction for virus invasion into host cells and suggested that lowering divalent ion in lungs could avert virus-host cells attachment.
Low serum calcium and phosphorus and their clinical performance in detecting COVID-19 patients.
Journal of medical virology. 2021;(3):1639-1651
BACKGROUND This study aimed to evaluate the clinical performance of low serum calcium and phosphorus in discriminative diagnosis of the severity of patients with coronavirus disease 2019 (COVID-19). We conducted a single-center hospital-based study and consecutively recruited 122 suspected and 104 confirmed patients with COVID-19 during January 24 to April 25, 2020. Clinical risk factors of COVID-19 were identified. The discriminative power of low calcium and phosphorus regarding the disease severity was evaluated. Low calcium and low phosphorus are more prevalent in severe or critical COVID-19 patients than moderate COVID-19 patients (odds ratio [OR], 15.07; 95% confidence interval [CI], 1.59-143.18 for calcium; OR, 6.90; 95% CI, 2.43-19.64 for phosphorus). The specificity in detecting the severe or critical patients among COVID-19 patients reached 98.5% (95% CI, 92.0%-99.7%) and 84.8% (95% CI, 74.3%-91.6%) by low calcium and low phosphorus, respectively, albeit with suboptimal sensitivity. Calcium and phosphorus combined with lymphocyte count could obtain the best discriminative performance for the severe COVID-19 patients (area under the curve [AUC] = 0.80), and combined with oxygenation index was promising (AUC = 0.71). Similar discriminative performances of low calcium and low phosphorus were found between suspected and confirmed COVID-19 patient. Low calcium and low phosphorus could indicate the severity of COVID-19 patients, and may be utilized as promising clinical biomarkers for discriminative diagnosis.
Influence of anti-osteoporosis treatments on the incidence of COVID-19 in patients with non-inflammatory rheumatic conditions.
Coronavirus disease 19 (COVID-19) is currently a global pandemic that affects patients with other pathologies. Here, we investigated the influence of treatments for osteoporosis and other non-inflammatory rheumatic conditions, such as osteoarthritis and fibromyalgia, on COVID-19 incidence. To this end, we conducted a cross-sectional study of 2,102 patients being treated at the Rheumatology Service of Hospital del Mar (Barcelona, Spain). In our cohort, COVID-19 cumulative incidence from March 1 to May 3, 2020 was compared to population estimates for the same city. We used Poisson regression models to determine the adjusted relative risk ratios for COVID-19 associated with different treatments and comorbidities. Denosumab, zoledronate and calcium were negatively associated with COVID-19 incidence. Some analgesics, particularly pregabalin and most of the studied antidepressants, were positively associated with COVID-19 incidence, whereas duloxetine presented a negative association. Oral bisphosphonates, vitamin D, thiazide diuretics, anti-hypertensive drugs and chronic non-steroidal anti-inflammatory drugs had no effect on COVID-19 incidence in the studied population. Our results provide novel evidence to support the maintenance of the main anti-osteoporosis treatments in COVID-19 patients, which may be of particular relevance to elderly patients affected by the SARS-CoV-2 pandemic.