Bilateral telomerase-associated impacts of Spirulina platensis extracts: Activation versus inhibition

Enzymatic approaches against SARS-CoV-2 infection with an emphasis on the telomere-associated enzymes

The pandemic phase of coronavirus disease 2019 (COVID-19) appears to be over in most countries. However, the unexpected behaviour and unstable nature of coronaviruses, including temporary hiatuses, re-emergence, emergence of new variants, and changing outbreak epicentres during the COVID-19 pandemic, have been frequently reported. The mentioned trend shows the fact that in addition to vaccine development, different strategies should be considered to deal effectively with this disease, in long term. In this regard, the role of enzymes in regulating immune responses to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has recently attracted much attention. Moreover, several reports confirm the association of short telomeres with sever COVID-19 symptoms. This review highlights the role of several enzymes involved in telomere length (TL) regulation and explains their relevance to SARS-CoV-2 infection. Apparently, inhibition of telomere shortening (TS) through inhibition and/or activation of these enzymes could be a potential target in the treatment of COVID-19, which may also lead to a reduction in disease severity.

Andrographis paniculata extract as an immunity modulator against cancer via telomerase inhibition

In accordance with the importance of telomerase inhibition as a potential target in cancer therapy, and increasing reports on the association between short telomeres and severe COVID-19 symptoms as well as extensive application of Andrographis paniculata as a remedy for both cancer and SARS-CoV-2, the present study aimed at investigating the impact of the plant’s extracts on telomerase activity (as an important enzyme regulating telomere length). Telomerase inhibition in MCF-7 cells treated with the Dichloromethane, ethanol, water, and methanol extracts of A. paniculata was assessed using Telomerase Repeated Amplification Protocol (TRAP). The above-mentioned extracts inhibited telomerase by 80.3 ± 1.4%, 78.5 ± 1.35%, 77.5 ± 1.81%, and 73.7 ± 1.81%, respectively. Furthermore, the flow cytometry analysis showed that the water and methanol extracts induced higher rates of total apoptosis by 32.8% and 25%, respectively, compared with dichloromethane (10.07%) and ethanol (10.7%) extracts. The inhibitory effect of A. paniculata on telomerase activity can be considered as a potential immunity modulator in cancer therapy; however, telomerase inhibition as a safe approach to SARS-CoV-2 is arguable. Two mechanisms can be considered accordingly; (a) reducing the existing population of short telomeres via telomerase inhibition in cancer cells (arresting proliferation and finally cell death) may decrease the susceptibility against SARS-CoV-2, especially in cancer patients or patients prone to cancer, and (b) increasing the population of short telomeres via telomerase inhibition in normal/somatic cells may increase the susceptibility against SARS-CoV-2. Therefore, the telomerase inhibition of A. paniculata as an immunity modulator in cancer and COVID-19 should be investigated, carefully.

Telomerase activity, relative telomere length, and longevity in alfalfa (Medicago sativa L.)

Background

Medicago sativa L. ‘Qingshui’ is a valuable rhizomatous forage germplasm resource. We previously crossed Qingshui with the high-yielding Medicago sativa L. ‘WL168’ and obtained novel rhizomatous hybrid strains (RSA-01, RSA-02, and RSA-03). Telomere dynamics are more accurate predictors of survival and mortality than chronological age. Based on telomere analyses, we aimed to identify alfalfa varieties with increased stamina and longevity for the establishment of artificial grazing grasslands.

Methods

In this study, we performed longitudinal analysis of telomerase activity and relative telomere length in five alfalfa varieties (Qingshui, WL168, RSA-01, RSA-02, and RSA-03) at the age of 1 year and 5 years to examine the relationship among telomerase activity, rate of change in relative telomere length, and longevity. We further aimed to evaluate the longevity of the examined varieties. Telomerase activity and relative telomere length were measured using enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively.

Results

We observed significant differences in telomerase activity between plants aged 1 year and those aged 5 years in all varieties except WL168, and the rate of change in telomerase activity does not differ reliably with age. As telomerase activity and relative telomere length are complex phenomena, further studies examining the molecular mechanisms of telomere-related proteins are needed. Relative telomere lengths of Qingshui, WL168, RSA-01, RSA-02, and RSA-03 in plants aged 5 years were higher than those aged 1 year by 11.41, 11.24, 9.21, 10.23, and 11.41, respectively. Relative telomere length of alfalfa tended to increase with age. Accordingly, alfalfa varieties can be classified according to rate of change in relative telomere length as long-lived (Qingshui, WL168, and RSA-03), medium-lived (RSA-02) and short-lived (RSA-01). The differences in relative telomere length distances of Qingshui, WL168, RSA-01, RSA-02, and RSA-03 between plants aged 1 and 5 years were 10.40, 13.02, 12.22, 11.22, and 13.25, respectively. The largest difference in relative telomere length was found between Qingshui and RSA-02 at 2.20. Our findings demonstrated that relative telomere length in alfalfa is influenced by genetic variation and age, with age exerting a greater effect.