Aging related changes of circadian rhythmicity of cytotoxic lymphocyte subpopulations

Melatonin/Sericin Wound Healing Patches: Implications for Melanoma Therapy

Melatonin and sericin exhibit antioxidant properties and may be useful in topical wound healing patches by maintaining redox balance, cell integrity, and regulating the inflammatory response. In human skin, melatonin suppresses damage caused by ultraviolet radiation (UVR) which involves numerous mechanisms associated with reactive oxygen species/reactive nitrogen species (ROS/RNS) generation and enhancing apoptosis. Sericin is a protein mainly composed of glycine, serine, aspartic acid, and threonine amino acids removed from the silkworm cocoon (particularly Bombyx mori and other species). It is of interest because of its biodegradability, anti-oxidative, and anti-bacterial properties. Sericin inhibits tyrosinase activity and promotes cell proliferation that can be supportive and useful in melanoma treatment. In recent years, wound healing patches containing sericin and melatonin individually have attracted significant attention by the scientific community. In this review, we summarize the state of innovation of such patches during 2021-2023. To date, melatonin/sericin-polymer patches for application in post-operational wound healing treatment has been only sparingly investigated and it is an imperative to consider these materials as a promising approach targeting for skin tissue engineering or regenerative dermatology.

Circadian variations in the elderly: A scoping review

The circadian clock plays important roles in several physiological processes. With aging, some of these circadian rhythms have been shown to be disrupted and suggested contributing to age-related diseases. The aim of this scoping review was to examine and map the existing evidence of circadian differences between young and older people in body fluid composition. Literature search was carried out on PubMed, Embase, Scopus and OpenGrey. The studies were screened based on inclusion and exclusion criteria by two independent reviewers and the results were summarized tabularly and narratively. The review process resulted in the identification of 1889 publications, of which 42 were eligible for inclusion. Forty-eight parameters or families of parameters were identified, including cortisol and melatonin, sex hormones, thyroid-related hormones, steroids and aldosterone. However, many were reported by only a single study. The results from the studies were heterogeneous. Even though the majority suggested the flattening of several circadian oscillations in the elderly population, this was not always observed for all the parameters analyzed, and some contradictory results were found. This review revealed a substantial number of publications that explored this research question, but further studies would be important to elucidate the clinical significance of these alterations.

Aryl hydrocarbon receptor (AhR) impairs circadian regulation: impact on the aging process

Circadian clocks control the internal sleep-wake rhythmicity of 24hours which is synchronized by the solar cycle. Circadian regulation of metabolism evolved about 2.5 billion years ago, i.e., the rhythmicity has been conserved from cyanobacteria and Archaea through to mammals although the mechanisms utilized have developed with evolution. While the aryl hydrocarbon receptor (AhR) is an evolutionarily conserved defence mechanism against environmental threats, it has gained many novel functions during evolution, such as the regulation of cell cycle, proteostasis, and many immune functions. There is robust evidence that AhR signaling impairs circadian rhythmicity, e.g., by interacting with the core BMAL1/CLOCK complex and disturbing the epigenetic regulation of clock genes. The maintenance of circadian rhythms is impaired with aging, disturbing metabolism and many important functions in aged organisms. Interestingly, it is known that AhR signaling promotes an age-related tissue degeneration, e.g., it is able to inhibit autophagy, enhance cellular senescence, and disrupt extracellular matrix. These alterations are rather similar to those induced by a long-term impairment of circadian rhythms. However, it is not known whether AhR signaling enhances the aging process by impairing circadian homeostasis. I will examine the experimental evidence indicating that AhR signaling is able to promote the age-related degeneration via a disruption of circadian rhythmicity.

The reference ranges and characteristics of lymphocyte parameters and the correlation between lymphocyte parameters and routine health indicators in adults from China

Background

Assessment of immune function is of key importance in recognition of disease or healthy status, which still faces challenge in clinical practice. We conducted a 10-center study to investigate lymphocyte parameters including the number, phenotype and IFN-γ-producing ability, and routine laboratory indicators by using the standard method.

Results

Although the heterogeneity of lymphocyte parameters was widely found, we have established the normal ranges of these parameters by using pooled data which showed no significant difference among centers. Cluster analysis of 35 parameters found 3 interesting clusters which represented different immunological status. Cluster 1 (parameters: IFN-γ⁺CD4⁺ T cell percentage and IFN-γ⁺CD8⁺ T cell percentage) represented current lymphocyte function, which was associated with indicators such as body mass index and red blood cell; Cluster 2 (parameters: NK cell number and CD45RA⁺CD4⁺ T cell percentage) represented potential of lymphocytes, which was associated with indicators such as albumin and high-density lipoprotein. Cluster 3 (parameters: HLA-DR⁺CD8⁺ T cell percentage) represented inflammatory status, which was associated with indicators such as low-density lipoprotein, globulin and age. Correlation analysis found that nutritional indicator albumin is significantly positively correlated with lymphocyte potential. Triglyceride and body mass index were positively correlated with current lymphocyte function rather than lymphocyte potential. The loss of CD8⁺ T cells was extremely pronounced with increasing age and was one of the most important factors to cause immunosenescence, which may be associated with increased glucose.

Conclusions

We have established the normal ranges of lymphocyte parameters in different areas. This study elucidates the key indicators used to reflect the current function or potential of lymphocytes, which may provide a valuable clue for how to keep immunity healthy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-022-00298-5.

Morphofunctional and signaling molecules overlap of the pineal gland and thymus: role and significance in aging

Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, AANAT, CGRP, VIP, chromogranin A); cell renovation markers (p53, AIF, Ki67), matrix metalloproteinases (MMP2, MMP9) and lymphocytes markers (CD4, CD5, CD8, CD20). Pineal melatonin is decreased, as is one of the melatonin pathway synthesis enzymes in the thymic gland. A further similarity is the increased MMPs levels evident over age in both glands. Significant differences are evident in cell renovation processes, which deteriorate more quickly in the aged thymus versus the pineal gland. Decreases in the number of pineal B-cells and thymic T-cells were also observed over aging. Collected data indicate that cellular involution of the pineal gland and thymus show many commonalities, but also significant changes in aging-associated proteins. It is proposed that such ageing-associated alterations in these two glands provide novel pharmaceutical targets for the wide array of medical conditions that are more likely to emerge over the course of ageing.

Age and gender leucocytes variances and references values generated using the standardized ONE-Study protocol

Flow cytometry is now accepted as an ideal technology to reveal changes in immune cell composition and function. However, it is also an error-prone and variable technology, which makes it difficult to reproduce findings across laboratories. We have recently developed a strategy to standardize whole blood flow cytometry. The performance of our protocols was challenged here by profiling samples from healthy volunteers to reveal age- and gender-dependent differences and to establish a standardized reference cohort for use in clinical trials. Whole blood samples from two different cohorts were analyzed (first cohort: n = 52, second cohort: n = 46, both 20-84 years with equal gender distribution). The second cohort was run as a validation cohort by a different operator. The "ONE Study" panels were applied to analyze expression of >30 different surface markers to enumerate proportional and absolute numbers of >50 leucocyte subsets. Indeed, analysis of the first cohort revealed significant age-dependent changes in subsets e.g. increased activated and differentiated CD4(+) and CD8(+) T cell subsets, acquisition of a memory phenotype for Tregs as well as decreased MDC2 and Marginal Zone B cells. Males and females showed different dynamics in age-dependent T cell activation and differentiation, indicating faster immunosenescence in males. Importantly, although both cohorts consisted of a small sample size, our standardized approach enabled validation of age-dependent changes with the second cohort. Thus, we have proven the utility of our strategy and generated reproducible reference ranges accounting for age- and gender-dependent differences, which are crucial for a better patient monitoring and individualized therapy. © 2016 International Society for Advancement of Cytometry.

Cortisol as a marker for increased mortality in patients with incidental adrenocortical adenomas

CONTEXT

Incidental benign adrenocortical adenomas, adrenal incidentalomas are found in 4.5% of abdominal computed tomography scans, with the incidence increasing to 10% in patients older than 70 years of age. These incidentalomas frequently show evidence of excess cortisol secretion but without overt Cushing's syndrome. The mortality rate is increased in Cushing's syndrome.

OBJECTIVE

This study sought to investigate whether patients with adrenal incidentalomas have an increased mortality.

DESIGN

This was a retrospective, longitudinal cohort study.

SETTING

The study was carried out in an Endocrine Investigation Unit in a University Teaching Hospital.

PATIENTS

Two hundred seventy-two consecutive patients with an incidental adrenal mass underwent a dedicated diagnostic protocol, which included dexamethasone testing for hypercortisolism between 2005 and 2013. Overall survival was assessed in 206 patients with a benign, adrenocortical adenoma.

MAIN OUTCOME MEASURES

Survival analysis was carried out by using Kaplan-Meier curves and the effect of dexamethasone cortisol estimated by Cox-regression analysis. Cause-specific mortality was ascertained from death certificates and compared with local and national data.

RESULTS

Eighteen of 206 patients died and the mean time (SD) from diagnosis to death was 3.2 (1.7) years. Seventeen of 18 patients who died had a post dexamethasone cortisol >1.8 μg/dL and there was a significant decrease in survival rate with increasing dexamethasone cortisol levels (P = .001). Compared with the <1.8 μg/dL group, the hazard ratio (95% confidence interval) for the 1.8-5 μg/dL group was 12.0 (1.6-92.6) whereas that of the >5 μg/dL group was 22.0 (2.6-188.3). Fifty percent and 33% of deaths were secondary to circulatory or respiratory/infective causes, respectively.

CONCLUSIONS

PATIENTS with adrenal incidentalomas and a post-dexamethasone serum cortisol >1.8 μg/dL have increased mortality, mainly related to cardiovascular disease and infection.

Aging affects the proportions of T and B cells in a group of elderly men in a developing country--a pilot study from Pakistan

Immune status is different in the elderly and the young, but whether age-associated differences are similar in developing and industrialized countries is unclear. To approach this question, peripheral blood immune cell phenotypes were analyzed by polychromatic flow cytometry in 50 young and 50 elderly men in a pilot study in a rural area of Pakistan. As a group, the elderly had a significantly lower CD4:CD8 ratio, a lower percentage of CD8+ naïve T cells, and significantly higher percentage of late-differentiated memory cells than the young. No age-associated differences were seen in B cells or NK cells. CD8+ cells as a percentage of CD3+ T cells were positively associated with plasma CRP levels but not other factors. We conclude that there are differences between the peripheral immune cell phenotypes of young and elderly Pakistani men and that these seem broadly similar to those more extensively documented in industrialized countries, despite the marked societal, nutritional, and many other differences in these populations.

Biological variability of lymphocyte subsets of human adults' blood

BACKGROUND

Alterations in lymphocyte subpopulations are present in several immune diseases, and clinicians and researchers recognise the importance of investigating the distribution and changes in lymphocyte subsets over relatively long periods of time in order to evaluate the effectiveness of treatment and follow the course of disease. Yet further insight is required on the biological variability (BV) of lymphocyte subsets, which is crucial to the correct interpretation of longitudinal changes and provides essential information for setting desirable quality specifications and defining the usefulness of reference values.

METHODS

Four-colour-flow cytometry was used to investigate the BV of lymphocyte populations (LP) in the peripheral blood of 20 healthy adults recruited from our laboratory staff and followed for three months. The total lymphocyte count was measured, and the relative frequencies determined for T-cells (CD3+), T-helper cells (CD3+CD4+), cytolytic T-cells (CD3+CD8+), B-cells (CD3-CD19+), NK-cells (CD3-CD16+/56+), non-MHC restricted cytolytic T-cells (CD3+CD56+) and activated T-cells (CD3+HLA-DR+).

RESULTS AND CONCLUSIONS

Data on the components of BV were applied to set quality specifications for allowable precision, bias and total error. Analytical performances were established, and they were more than desirable for all the markers considered in our study. By comparing within-subject and between-subjects BV, we were able to define the uselessness of reference ranges in the evaluation of changes in CD serial results. Data on within-subject BV and analytical precision were thus used to determine the reference change values, in order to identify the significance of changes in serial results. The findings made in the present study provide further evidence of the relevance of BV in the evaluation of immunological markers of LP.

Recreational physical activity and risk of head and neck cancer: a pooled analysis within the international head and neck cancer epidemiology (INHANCE) Consortium

Increasing evidence suggests that physical activity could prevent cancer, but scanty data is available on head and neck cancer (HNC). The aim of our study is to clarify the effect of recreational physical activity (rPA) on HNC. We analyzed data from four case-control studies, including 2,289 HNC cases and 5,580 controls. rPA was classified as: none/low (reference group), moderate and high. We calculated summary Odds Ratios (ORs) by pooling study-specific ORs. Overall, moderate rPA was associated with 22% lower risk of HNC compared to those with none or very low rPA levels [OR = 0.78, 95% Confidence Interval (95% CI): 0.66, 0.91]. Moderate rPA is associated with reduced risk of oral (OR = 0.74, 95% CI: 0.56, 0.97) and pharyngeal cancer (OR = 0.67, 95% CI: 0.53, 0.85), as well as high rPA levels (OR = 0.53, 95% CI: 0.32, 0.88 for oral cavity, OR = 0.58, 95% CI: 0.38, 0.89 for pharynx). High rPA levels, however, is associated with higher risk of laryngeal cancer (OR = 1.73, 95% CI: 1.04, 2.88). Stratified analyses showed that such inverse association between moderate rPA and HNC was more evident among males (OR = 0.75, 95% CI: 0.62, 0.90), subjects ≥45 years (OR = 0.78, 95% CI: 0.66, 0.93), and ever smokers and ever drinkers (OR = 0.72, 95% CI: 0.59, 0.88). High rPA significantly reduces HNC risk among subject ≥45 years (OR = 0.66, 95% CI: 0.48, 0.91). Promoting rPA might be inversely associated with HNC.