Telomerase Activity Increased and Telomere Length Shortened in Peripheral Blood Cells from Patients with Immune Thrombocytopenia

The consumption of Sechium edule (chayote) has antioxidant effect and prevents telomere attrition in older adults with metabolic syndrome

OBJECTIVE

To determine the effect of the consumption of Sechium edule (1.5 g/day) for six months on oxidative stress (OxS) and inflammation markers and its association with telomere length (TL) in older adults with metabolic syndrome (MetS).

METHODS

The study was conducted in a sample of 48 older adults: placebo (EP) and experimental (EG) groups. Lipoperoxides, protein carbonylation, 8-OHdG, total oxidant status (TOS), SOD, GPx, H₂O₂ inhibition, total antioxidant status (TAS), inflammatory cytokines (IL6, IL10, TNF-α), and TL were measured before and six months post-treatment.

RESULTS

We found a significant decrease in the levels of lipoperoxides, protein carbonylation, 8-OHdG, TOS in the EG in comparison PG. Likewise, a significante increase of TAS, IL-6, and IL-10 levels was found at six months post-treatment in EG in comparison with PG. TL showed a statistically significant decrease in PG compared to post-treatment EG.

CONCLUSIONS

Our findigns showed that the supplementation of Sechium edule has antioxidant, and anti-inflammatory effects, and diminushion of shortening of telomeric DNA in older adults with MetS. This would be the first study that shows that the intervention with Sechium edule has a possible geroprotective effect by preventing telomeres from shortening as usually happens in these patients. Therefore, suggesting a protection of telomeric DNA and genomic DNA.

Novel Biomarkers for Diagnosis and Monitoring of Immune Thrombocytopenia

Lower-than-normal platelet counts are a hallmark of the acquired autoimmune illness known as immune thrombocytopenia, which can affect both adults and children. Immune thrombocytopenia patients' care has evolved significantly in recent years, but the disease's diagnosis has not, and it is still only clinically achievable with the elimination of other causes of thrombocytopenia. The lack of a valid biomarker or gold-standard diagnostic test, despite ongoing efforts to find one, adds to the high rate of disease misdiagnosis. However, in recent years, several studies have helped to elucidate a number of features of the disease's etiology, highlighting how the platelet loss is not only caused by an increase in peripheral platelet destruction but also involves a number of humoral and cellular immune system effectors. This made it possible to identify the role of immune-activating substances such cytokines and chemokines, complement, non-coding genetic material, the microbiome, and gene mutations. Furthermore, platelet and megakaryocyte immaturity indices have been emphasized as new disease markers, and prognostic signs and responses to particular types of therapy have been suggested. Our review's goal was to compile information from the literature on novel immune thrombocytopenia biomarkers, markers that will help us improve the management of these patients.

Mediation Effect of Platelet Traits on Associations of Central Obesity with Aging Biomarkers in Rural Adults of Henan, China

Background: To assess the associations of platelet traits and obesity indices with aging biomarkers (telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN)). Methods: A cross-sectional study was performed among 5091 rural Chinese adults. Obesity indices (waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR)) and platelet traits (plateletcrit (PCT), platelet large cell ratio (P-LCR), mean platelet volume (MPV) and platelet distribution width (PDW)) were collected by physical examination. The aging biomarkers were determined by quantitative real-time polymerase chain reaction. Generalized linear regression models and mediation analysis were applied to explore the relationships between platelet traits, obesity indices, and aging biomarkers. Results: The mean age of the participants was 56 years (range: 18–79). Each one-unit increment in WC, WHR and WHtR were related to a 0.316 (95% confidence interval (CI): −0.437, −0.196), 0.323 (95% CI: −0.513, −0.134) and 0.277 (95% CI: −0.400, −0.153) decrease in relative TL; or a 0.102 (95% CI: −0.197, −0.007), 0.109 (95% CI: −0.258, −0.041) and 0.101 (95% CI: −0.199, −0.004) decrease in relative mtDNA-CN. The proportions of obesity indices with aging biomarkers mediated by platelet indices ranged from 2.85% to 10.10%. Conclusions: Increased central obesity indices in relation to shortened relative TL or decreased mtDNA-CN were mediated by platelet traits, indicating that obesity in association with the accelerated aging process may be partially attributable to abnormal platelet activity.

Stress and immunosenescence: The role of telomerase

Chronic stress is associated with the accelerated aging of the immune system and represents a potent risk factor for the development and progression of a wide range of physical and mental disorders. The elucidation of molecular pathways and mechanisms underlying the link between stress and cellular aging is an area of considerable interest and investigation. In this context, telomere biology has emerged as a particularly attractive candidate mechanism. Several studies have linked immune cell telomere length with stress-related conditions and states, and also with several physical and mental disorders. Because the cellular reverse transcriptase enzyme telomerase is the primary regulator of telomere length (by adding telomeric DNA to telomeres and thereby attenuating telomere shortening), the understanding of its regulation and regulatory functions constitutes a prime target for developing strategies to prevent, attenuate or reverse the adverse consequences of immune system aging (immunosenescence). In this review we provide an overview of the mechanistic pathways linking telomerase with stress and cellular aging, with an emphasis on the immune system. We summarize and synthesize the current state of the literature on immune cell telomerase in different stress- and aging-related disease states and provide recommendations for future research directions.

Oral all-trans retinoic acid plus danazol versus danazol as second-line treatment in adults with primary immune thrombocytopenia: a multicentre, randomised, open-label, phase 2 trial

BACKGROUND

Primary immune thrombocytopenia is a severe bleeding disorder. About 50-85% of patients achieve initial remission from first-line therapies, but optimal second-line treatment remains a challenge. All-trans retinoic acid (ATRA) has an immunomodulatory effect on haemopoiesis, making it a possible treatment option. We aimed to evaluate the efficacy and safety of ATRA plus danazol versus danazol in non-splenectomised patients with corticosteroid-resistant or relapsed primary immune thrombocytopenia.

METHODS

We did a multicentre, randomised, open-label, phase 2 study of adult patients (≥18 years) with primary immune thrombocytopenia from five different tertiary medical centres in China. Those eligible were non-splenectomised, resistant to corticosteroid treatment or relapsed, and had a platelet count less than 30 × 10⁹ per L. Masked statisticians used simple randomisation to assign patients (1:1) to receive oral ATRA (10 mg twice daily) plus oral danazol (200 mg twice daily) or oral danazol monotherapy (200 mg twice daily) for 16 weeks. Neither clinicians nor patients were masked to group assignments. All patients were assessed every week during the first 8 weeks of treatment, and at 2-week intervals thereafter. The primary endpoint was 12-month sustained response defined as platelet count of 30 × 10⁹ per L or more and at least a doubling of baseline platelet count (partial response), or a platelet count of 100 × 10⁹ per L or more (complete response) and the absence of bleeding without rescue medication at the 12-month follow-up. All randomly allocated patients, except for those who withdrew consent, were included in the modified intention-to-treat population and efficacy assessment, and all patients who received at least one dose of the study agents were included in the safety analysis. Study enrolment was stopped early because the trial results crossed the interim analysis efficacy boundary for sustained response. This trial is registered with ClinicalTrials.gov, number NCT01667263.

FINDINGS

From June 1, 2012, to July 1, 2016, we screened 130 patients for eligibility; 34 were excluded and 96 were randomly assigned. 93 patients were included in the modified intention-to-treat analysis: 45 in the ATRA plus danazol group and 48 in the danazol group. At the 12-month follow-up, sustained response was achieved more frequently in patients receiving ATRA plus danazol than in those receiving danazol monotherapy (28 [62%] of 45 vs 12 [25%] of 48; odds ratio 4·94, 95% CI 2·03-12·02, p=0·00037). Only two grade 3 adverse events were reported: one (2%) patient receiving ATRA plus danazol with dry skin, and one (2%) patient receiving danazol monotherapy with liver injury. There was no grade 4 or worse adverse event or treatment-related death in either group.

INTERPRETATION

Patients with primary immune thrombocytopenia given ATRA plus danazol had a rapid and sustained response compared with danazol monotherapy. This finding suggests that ATRA represents a promising candidate for patients with corticosteroid-resistant or relapsed primary immune thrombocytopenia.

FUNDING

National Natural Science Foundation of China, Beijing Natural Science Foundation, Beijing Municipal Science and Technology Commission, and the National Key Research and Development Program of China.

Transgenic rat model of childhood-onset dermatitis by overexpressing telomerase reverse transcriptase (TERT)

Childhood-onset dermatitis is one of the most common skin disorders in children. Although various mouse models that mirror aspects of dermatitis have become available, there is still a need for an animal model that develops dermatitis in childhood and is more suitable for performing tissue transplantation experiments. There is emerging evidence that peripheral blood T lymphocytes from patients with dermatitis have significantly increased telomerase activity. Here, we developed telomerase reverse transcriptase (TERT)-expressing transgenic (Tg) rats that spontaneously developed eczematous skin inflammation in childhood. Newborn TERT-Tg rats developed visible dermatitis in 56 % of cases, and the skin lesions microscopically showed spongiosis and acanthosis with infiltration of lymphocytes, eosinophils and mast cells. TERT-Tg rats with dermatitis exhibited increased CD4 (2.5-fold) and CD8 (fivefold) T cell numbers compared with dermatitis-free TERT-Tg rats. Stronger TERT activity was observed in the peripheral lymphocytes of dermatitis-positive TERT-Tg rats than those of dermatitis-free TERT-Tg rats. RT-PCR analysis revealed that IL-4 was markedly elevated in the spleen of dermatitis-positive TERT-Tg rats, and that interferon-gamma was increased in the dermatitis lesions. Moreover, skin grafting of TERT-Tg rats with dermatitis onto T cell-deficient nude rats demonstrated that the inflamed skin lesions could not be maintained. Taken together, the results suggest that TERT activation in T lymphocytes is one of the potential predisposing factors for dermatitis. Moreover, our results demonstrated that the TERT-Tg rats mirror aspects of human childhood-onset dermatitis and that these animals represent a potential animal model system for studying childhood-onset dermatitis.