The role of telomeres and vitamin D in cellular aging and age-related diseases

Author(s):  
Irene Pusceddu ◽  
Christopher-John L. Farrell ◽  
Angela Maria Di Pierro ◽  
Erika Jani ◽  
Wolfgang Herrmann ◽  
...  

AbstractAging is a complex biological process characterized by a progressive decline of organ functions leading to an increased risk of age-associated diseases and death. Decades of intensive research have identified a range of molecular and biochemical pathways contributing to aging. However, many aspects regarding the regulation and interplay of these pathways are insufficiently understood. Telomere dysfunction and genomic instability appear to be of critical importance for aging at a cellular level. For example, age-related diseases and premature aging syndromes are frequently associated with telomere shortening. Telomeres are repetitive nucleotide sequences that together with the associated sheltrin complex protect the ends of chromosomes and maintain genomic stability. Recent studies suggest that micronutrients, such as vitamin D, folate and vitamin B12, are involved in telomere biology and cellular aging. In particular, vitamin D is important for a range of vital cellular processes including cellular differentiation, proliferation and apoptosis. As a result of the multiple functions of vitamin D it has been speculated that vitamin D might play a role in telomere biology and genomic stability. Here we review existing knowledge about the link between telomere biology and cellular aging with a focus on the role of vitamin D. We searched the literature up to November 2014 for human studies, animal models and in vitro experiments that addressed this topic.

2020 ◽  
pp. 1-8
Author(s):  
M. Zarei ◽  
M. Zarezadeh ◽  
F. Hamedi Kalajahi ◽  
M.H. Javanbakht

Telomeres are repetitive nucleotide sequences that together with the associated sheltrin complex protect the ends of chromosomes and maintain genomic stability. Evidences from various organisms suggests that several factors influence telomere length regulation, such as telomere binding proteins, telomere capping proteins, telomerase, and DNA replication enzymes. Recent studies suggest that micronutrients, such as vitamin D, folate and vitamin B12, are involved in telomere biology and cellular aging. In particular, vitamin D is important for a range of vital cellular processes including cellular differentiation, proliferation and apoptosis. As a result of the multiple functions of vitamin D it has been speculated that vitamin D might play a role in telomere biology and genomic stability. In this study, our main goal is investigating the relationship between telomerase enzyme and vitamin D. Findings of this study suggest that higher vitamin D concentrations, which are easily modifiable through nutritional supplementation, are associated with longer LTL, which underscores the potentially beneficial effects of this hormone on aging and age-related diseases. Vitamin D may reduce telomere shortening through anti-inflammatory and anti-cell proliferation mechanisms. Significant Low levels of telomerase activity create short telomeres, which in turn signal exit from the cell cycle resulting in cell senescence and apoptosis. In follow-up examination, the patients who remained vitamin D deficient tended to have shorter telomeres than those patients whose 25-hydroxyvitamin D levels were depleted. Increasing 25-hydroxyvitamin D levels in patients with SLE may be beneficial in maintaining telomere length and preventing cellular aging. Moreover, anti-telomere antibody levels may be a promising biomarker of SLE status and disease activity.


The role of vitamin D is implicated in carcinogenesis through numerous biological processes like induction of apoptosis, modulation of immune system inhibition of inflammation and cell proliferation and promotion of cell differentiation. Its use as additional adjuvant drug with cancer treatment may be novel combination for improved outcome of different cancers. Numerous preclinical, epidemiological and clinical studies support the role of vitamin D as an anticancer agent. Anticancer properties of vitamin D have been studied widely (both in vivo and in vitro) among various cancers and found to have promising results. There are considerable data that indicate synergistic potential of calcitriol and antitumor agents. Possible mechanisms for modulatory anticancer activity of vitamin D include its antiproliferative, prodifferentiating, and anti-angiogenic and apoptic properties. Calcitriol reduces invasiveness and metastatic potential of many cancer cells by inhibiting angiogenesis and regulating expression of the key molecules involved in invasion and metastasis. Anticancer activity of vitamin D is synergistic or additive with the antineoplastic actions of several drugs including cytotoxic chemotherapy agents like paclitaxel, docetaxel, platinum base compounds and mitoxantrone. Benefits of addition of vitamin D should be weighed against the risk of its toxicity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Donita L. Garland ◽  
Eric A. Pierce ◽  
Rosario Fernandez-Godino

AbstractThe complement system plays a role in the formation of sub-retinal pigment epithelial (RPE) deposits in early stages of age-related macular degeneration (AMD). But the specific mechanisms that connect complement activation and deposit formation in AMD patients are unknown, which limits the development of efficient therapies to reduce or stop disease progression. We have previously demonstrated that C3 blockage prevents the formation of sub-RPE deposits in a mouse model of EFEMP1-associated macular degeneration. In this study, we have used double mutant Efemp1R345W/R345W:C5-/- mice to investigate the role of C5 in the formation of sub-RPE deposits in vivo and in vitro. The data revealed that the genetic ablation of C5 does not eliminate the formation of sub-RPE deposits. Contrarily, the absence of C5 in RPE cultures promotes complement dysregulation that results in increased activation of C3, which likely contributes to deposit formation even in the absence of EFEMP1-R345W mutant protein. The results also suggest that genetic ablation of C5 alters the extracellular matrix turnover through an effect on matrix metalloproteinases in RPE cell cultures. These results confirm that C3 rather than C5 could be an effective therapeutic target to treat early AMD.


2021 ◽  
Vol 22 (9) ◽  
pp. 4670
Author(s):  
Cinzia Buccoliero ◽  
Manuela Dicarlo ◽  
Patrizia Pignataro ◽  
Francesco Gaccione ◽  
Silvia Colucci ◽  
...  

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) is a protein that promotes transcription of numerous genes, particularly those responsible for the regulation of mitochondrial biogenesis. Evidence for a key role of PGC1α in bone metabolism is very recent. In vivo studies showed that PGC1α deletion negatively affects cortical thickness, trabecular organization and resistance to flexion, resulting in increased risk of fracture. Furthermore, in a mouse model of bone disease, PGC1α activation stimulates osteoblastic gene expression and inhibits atrogene transcription. PGC1α overexpression positively affects the activity of Sirtuin 3, a mitochondrial nicotinammide adenina dinucleotide (NAD)-dependent deacetylase, on osteoblastic differentiation. In vitro, PGC1α overexpression prevents the reduction of mitochondrial density, membrane potential and alkaline phosphatase activity caused by Sirtuin 3 knockdown in osteoblasts. Moreover, PGC1α influences the commitment of skeletal stem cells towards an osteogenic lineage, while negatively affects marrow adipose tissue accumulation. In this review, we will focus on recent findings about PGC1α action on bone metabolism, in vivo and in vitro, and in pathologies that cause bone loss, such as osteoporosis and type 2 diabetes.


Author(s):  
Sarah McCarrick ◽  
Valentin Romanovski ◽  
Zheng Wei ◽  
Elin M. Westin ◽  
Kjell-Arne Persson ◽  
...  

AbstractWelders are daily exposed to various levels of welding fumes containing several metals. This exposure can lead to an increased risk for different health effects which serves as a driving force to develop new methods that generate less toxic fumes. The aim of this study was to explore the role of released metals for welding particle-induced toxicity and to test the hypothesis that a reduction of Cr(VI) in welding fumes results in less toxicity by comparing the welding fume particles of optimized Cr(VI)-reduced flux-cored wires (FCWs) to standard FCWs. The welding particles were thoroughly characterized, and toxicity (cell viability, DNA damage and inflammation) was assessed following exposure to welding particles as well as their released metal fraction using cultured human bronchial epithelial cells (HBEC-3kt, 5–100 µg/mL) and human monocyte-derived macrophages (THP-1, 10–50 µg/mL). The results showed that all Cr was released as Cr(VI) for welding particles generated using standard FCWs whereas only minor levels (< 3% of total Cr) were released from the newly developed FCWs. Furthermore, the new FCWs were considerably less cytotoxic and did not cause any DNA damage in the doses tested. For the standard FCWs, the Cr(VI) released in cell media seemed to explain a large part of the cytotoxicity and DNA damage. In contrast, all particles caused rather similar inflammatory effects suggesting different underlying mechanisms. Taken together, this study suggests a potential benefit of substituting standard FCWs with Cr(VI)-reduced wires to achieve less toxic welding fumes and thus reduced risks for welders.


Author(s):  
Betsy Szeto ◽  
Chris Valentini ◽  
Anil K Lalwani

ABSTRACT Background The elderly are at increased risk of both hearing loss (HL) and osteoporosis. Bone mineral density (BMD) has been putatively linked to HL. However, the roles of serum calcium concentrations and vitamin D status have yet to be elucidated. Objectives The purpose of this study was to examine the relation between vitamin D status, parathyroid hormone (PTH), total calcium, BMD, and HL in a nationally representative sample of elderly adults. Methods Using the NHANES (2005–2010), audiometry and BMD data of 1123 participants aged ≥70 y were analyzed in a cross-sectional manner. HL was defined as pure tone averages &gt;25 dB HL at 500, 1000, and 2000 Hz (low frequency); 500, 1000, 2000, and 4000 Hz (speech frequency); and 3000, 4000, 6000, and 8000 Hz (high frequency) in either ear. Multivariable logistic regression was used to examine the relation between HL and total 25-hydroxyvitamin D [25(OH)D], PTH, total calcium, and BMD, adjusting for covariates. Results In multivariable analyses, total 25(OH)D &lt; 20 ng/mL was found to be associated with greater odds of low-frequency HL (OR: 2.02; 95% CI: 1.28, 3.19) and speech-frequency HL (OR: 1.96; 95% CI: 1.12, 3.44). A 1-unit decrease in femoral neck BMD (OR: 4.55; 95% CI: 1.28, 16.67) and a 1-unit decrease in total spine BMD (OR: 6.25; 95% CI: 1.33, 33.33) were found to be associated with greater odds of low-frequency HL. Serum PTH and total calcium were not found to be associated with HL. Conclusions In the elderly, low vitamin D status was associated with low-frequency and speech-frequency HL. Low vitamin D status may be a potential risk factor for age-related HL.


Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 2
Author(s):  
David Mantle ◽  
Robert A. Heaton ◽  
Iain P. Hargreaves

The ageing brain is characterised by changes at the physical, histological, biochemical and physiological levels. This ageing process is associated with an increased risk of developing a number of neurological disorders, notably Alzheimer’s disease and Parkinson’s disease. There is evidence that mitochondrial dysfunction and oxidative stress play a key role in the pathogenesis of such disorders. In this article, we review the potential therapeutic role in these age-related neurological disorders of supplementary coenzyme Q10, a vitamin-like substance of vital importance for normal mitochondrial function and as an antioxidant. This review is concerned primarily with studies in humans rather than in vitro studies or studies in animal models of neurological disease. In particular, the reasons why the outcomes of clinical trials supplementing coenzyme Q10 in these neurological disorders is discussed.


2021 ◽  
Vol 8 (1) ◽  
pp. 19-25
Author(s):  
Iwona Kusz vel Sobczuk ◽  
Anna Święch

Aim: The aim of the article was to discuss the role of balanced supplementation in diet of age-related macular degeneration patients. Methods: This review was carried out using comprehensive and systematic literature reports on the role of supplementation of vitamin D, vitamin C, vitamin E, vitamin B6, vitamin B12, zinc, lutein, zeaxanthin, omega-3 acid and folic acid in the prevention of AMD. Results: Vitamins, minerals and carotenoids are essential for the proper retinal function over an inflammation and immune response modulation. Conclusions: Vitamins, minerals and carotenoids discussed in the article have anti-inflammatory and antioxidative properties in the management of AMD progression. Accordingly, it is relevant to assure the appropriate level of these nutrients in a diet of AMD patients.


2020 ◽  
Vol 6 (43) ◽  
pp. eabb3063
Author(s):  
Wei Xu ◽  
Si-Da Han ◽  
Can Zhang ◽  
Jie-Qiong Li ◽  
Yan-Jiang Wang ◽  
...  

Progranulin (PGRN) is a secreted pleiotropic glycoprotein associated with the development of common neurodegenerative diseases. Understanding the pathophysiological role of PGRN may help uncover biological underpinnings. We performed a genome-wide association study to determine the genetic regulators of cerebrospinal fluid (CSF) PGRN levels. Common variants in region of FAM171A2 were associated with lower CSF PGRN levels (rs708384, P = 3.95 × 10−12). This was replicated in another independent cohort. The rs708384 was associated with increased risk of Alzheimer’s disease, Parkinson’s disease, and frontotemporal dementia and could modify the expression of the FAM171A2 gene. FAM171A2 was considerably expressed in the vascular endothelium and microglia, which are rich in PGRN. The in vitro study further confirmed that the rs708384 mutation up-regulated the expression of FAM171A2, which caused a decrease in the PGRN level. Collectively, genetic, molecular, and bioinformatic findings suggested that FAM171A2 is a key player in regulating PGRN production.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xue Yang ◽  
Xinan Pan ◽  
Xiaorui Zhao ◽  
Jin Luo ◽  
Mingpu Xu ◽  
...  

Background. Autophagy is a catabolic process that depends on the lysosome. It is usually used to maintain cellular homeostasis, survival and development by degrading abnormal substances and dysfunctional organelles, especially when the cell is exposed to starvation or other stresses. Increasing studies have reported that autophagy is associated with various eye diseases, of which aging is one of the important factors. Objective. To summarize the functional and regulatory role of autophagy in ocular diseases with aging, and discuss the possibility of autophagy-targeted therapy in age-related diseases. Methods. PubMed searches were performed to identify relevant articles published mostly in the last 5 years. The key words were used to retrieve including “autophagy”, “aging”, “oxidative stress AND autophagy”, “dry eye AND autophagy”, “corneal disease AND autophagy”, “glaucoma AND autophagy”, “cataract AND autophagy”, “AMD AND autophagy”, “cardiovascular diseases AND autophagy”, “diabetes AND autophagy”. After being classified and assessed, the most relevant full texts in English were chosen. Results. Apart from review articles, more than two research articles for each age-related eye diseases related to autophagy were retrieved. We only included the most relevant and recent studies for summary and discussion. Conclusion. Autophagy has both protective and detrimental effects on the progress of age-related eye diseases. Different types of studies based on certain situations in vitro showed distinct results, which do not necessarily coincide with the actual situation in human bodies completely. It means the exact role and regulatory function of autophagy in ocular diseases remains largely unknown. Although autophagy as a potential therapeutic target has been proposed, many problems still need to be solved before it applies to clinical practice.


Sign in / Sign up

Export Citation Format

Share Document