About this Research Topic
With a continuous increase in the elderly population, the world is going to face a “Silver Tsunami” soon. According to World Population Prospects 2019, by 2050, 1 in 6 people in the world will be over the age of 65. Aging is considered a progressive loss of physical and cognitive functions, accompanied by declining endocrine secretions and immune functioning. For example, significant decreases in hormones after menopause in women and increased susceptibility of the elderly to infectious diseases like COVID-19. The complex interactions between hormones and immune functioning have been studied for decades and there is a substantial correlation between endocrine function and immune response. This is supported by many early findings that males and females vary in immune response and that sex hormones regulate immune function.
There are continuous efforts from the scientific community to understand the molecular signals and biochemical pathways that contribute to declining endocrine functions and dysregulated immune system during aging. For example, in 1986 scientists demonstrated that transplanting pituitary adenoma cells, producing growth hormones, rejuvenated the immune system in aged rats by regenerating the thymus gland and activating proliferative T-cells. However, there is a gap in understanding the key signaling pathways that regulate interplay between hormones and immune cells during the aging process.
Aging is characterized by systemic changes in the immune system and circulating paracrine/endocrine factors resulting in a state of chronic low-grade sterile inflammation known as ‘inflammaging’. Due in part to inflammaging, the elderly population less efficiently defends against infections due to weak innate and adaptive immune functions. Furthermore, the accumulation of senescent and their secreted factors in the local and systemic milieu during aging further exacerbate this inflammatory state. The immune changes are also sex specific due to strong connection between sex-hormones and immune system, but there are not many studies exploring sex-specific immunosenescence.
Considering the significant role of paracrine, circulating, and endocrine factors and the resident immune cells in maintaining organismal homeostasis, recognizing signaling molecules involved in the immune-endocrine inflammaging axis is highly important. With the number of causalities resulting from the COVID pandemic, there is urgent need for solutions to tackle the health problems of the growing elderly population. Understanding the interplay between hormones, paracrine factors, and immune functioning can lead to better clinical interventions that can prevent serious illness in aging individuals. Hence, this Research Topic will focus on alterations in hormones and paracrine factors during aging and the effect of the endocrine system on immune functioning and vice versa.
This Research Topic will bring together research that addresses the changes in endocrine functioning and immune response during aging and disease. This topic also includes intervention studies focused on replacing hormones or rejuvenating immune function in the aging system. Understanding the interplay between these two diverse and important biological systems will lay a strong foundation for future research to identify signaling molecules and pathways as potential drug targets for therapies leading to a healthy lifespan.
This Research Topic welcomes original research articles, clinical studies, reviews, mini reviews, and perspectives towards understanding the role of the endocrine and immune systems during aging. The current Research Topic will include, but not be limited to, the following themes:
- Endocrine-related immune functioning in aging;
- Endocrine biology in aging;
- Infectious disease in aging.
Keywords: Aging, Hormones, Immunity, Senescence, Infectious disease.
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.