Aging is a complex process of damage accumulation, and has been viewed as experimentally and medically intractable. The process of aging leads to marked malfunction of multiple cellular and molecular events that ultimately get translated into various chronic ailments and diseases such as Type 2 diabetes mellitus (T2DM), Alzheimer’s disease (AD), and osteoporosis, Parkinson’s disease, atherosclerosis and cancer. Aging-related diseases are related to a deficiency of the immune system, which results from an aged thymus and bone marrow cells. Intra bone marrow-bone marrow transplantation (IBM-BMT) is a useful method to treat intractable diseases. This review summarizes findings that IBM-BMT can improve and treat aging-related diseases, including T2DM, osteoporosis and AD, in animal models.
T2DM is induced by obesity, a sedentary lifestyle and nutritional factors, while there are also genetic factors that appear to impact the interaction of multiple genes during the development of T2DM. T2DM is not considered to be an autoimmune disease, but some autoantibodies such as islet-cell antibodies and glutamic acid decarboxylase antibodies have been reported to be positive in some young T2DM patients. Therapies for T2DM mainly include lifestyle changes and oral drugs to reduce the hyperglycemia and improve insulin sensitivity. However, these measures fail to maintain blood glucose levels in the normal range all the time. Recent research into cell based-stem cell therapies has been focused on T2DM.
Osteoporosis is one of the most common bone disorders and is now classified into primary and secondary types. Though primary osteoporosis usually occurs in both sexes at all ages, it is often observed in postmenopausal women and even in men later in life. A review of current therapies indicates that bisphosphonates, anti-receptor activator of NF-kb ligand, and anti-sclerostin antibodies are used to counter osteoporosis.
AD is a kind of neurological disorder that causes a decrease in cognitive ability, resulting from the deposition of beta-amyloid plaque, neurofibrillary tangles and neurodegeneration . The role of tau has become the focus of attention in AD therapy, because current drug treatment using cholinesterase inhibitors or NMDA antagonists has proven to be only modestly successful (Medina and Avila).
Animal models are useful for basic studies, and the senescence-accelerated mouse (SAM) strain was established as a novel murine model of senescence acceleration and age-associated disorders. This strain includes SAM-prone, short-lived mice (SAMP) and SAM-resistant, long-lived mice (SAMR). The respective SAMP models, with their characteristic pathological phenotypes, show similar age-associated disorders, including osteoporosis and AD, to those often observed in elderly humans.
Immune dysfunction, including defective T cells and B cells may accelerate the aging process in the diabetic mice and SAMP mice. IBM-BMT has been shown to be a valuable strategy for the treatment of aging-related disorders in experimental models of T2DM, osteoporosis and AD. Future studies will focus on related mechanisms through which IBM-BMT improves aging-related diseases. Additionally, we will attempt to determine whether IBM-BMT can prevent or treat other aging-related diseases such as Parkinson’s disease and atherosclerosis.