DNA Methylation Provides Accurate Genetic Clock To Measure Biological Age of Tissues and Organs

A scientist at the University of California- Los Angeles, has discovered a genetic biological clock that accurately measures the biological age of tissues and organs in the body. Using a ntural process called DNA methylation and monitoring 353 biological markers, the clock can measure how each part of the body and its age is comparable to others. The scientist, UCLA geneticist and biostatistician Steven Horvath, Ph.D., noted for example that a woman's breast tissue, age faster than the rest of the body.

DNA methylation is a genetic process that alters the expression of genes in cells as cells divide and differentiate from embryonic stem cells into specific tissues. As mentioned in the embedded video, DNA methylation is similar to a light dimmer switch where it can suppress a specific type of gene from expressing itself.

Using 8,000 samples of 51 types of tissue, Dr. Horvath narrowed focused on 353 biomarkers that change with age and are present throughout the body. These markers measure the biological age of the target tissue rather than its chronological age.

The next step in the research would be to find out if stopping or halting this clock can also stop aging.

Slowing Down Aging Process Through Hematopoietic Stem Cells and Molecular Protein Wnt5a

Human Stem Cell

Scientists are studying a signalling pathway that links hematopoietic stem cells and the Wnt5A protein that can slow or even reverse aging. They noted that the WNT pathway that signals the production of Wnt5a leads to the activation of another protein called Cdc42 which results in stem cell aging. By suppressing the pathway, stem cells are rejuvenated and functionally acts younger.

Stem cells are cells in the body that can transform into other higher types of cells, tissue, or even organs. The stem cell observed in this study are hematopoietic stem cells (HSC). HSCs can be found in the bone marrow and also in the umbilical cord blood, embryo or peripheral blood in the human body. They can transform into many different types of blood cells such as erythrocytes, basophils, neutrophils and B-lymphocytes.

By suppressing the Cdc42 protein through the molecular signalling pathway, HSC starts to function younger which can lead to therapies that will boost their immune systems, fight illnesses and enhance overall vitality especially for the elderly.

Protein GDF-11 Reverse Aging of the Heart

Richard T. Lee, M.D., and Amy Wagers, PhD, Harvard Stem Cell Institute Principal Faculty members, have identified a protein that can restore the enlarged, weakened hearts of aging mice to the size and functional status of the hearts of healthy young mice.
Credit: B. D. Colen/Harvard University

Researchers at the Harvard Stem Cell Institute have discovered that the protein GDF-11 have a restoring effect on the aging process of the heart. The GDF-11 protein can restore enlarged, weakened hearts back to its young and healthy status as evidenced in their experiments with hearts of young mice.

Age related disease are harder to treat since there is little or no treatment available aside from constant monitoring and regulating the targeted function. One such disease that is age related is diastolic heart failure.

Diastolic heart failure is the decline of performance of one or both ventricles of the heart during its relaxed phase (diastole). During diastole, the heart is filled with incoming blood that is being returned from the body through the inferior vena cava (IVC) and superior vena cava (SVC) to the right atrium and from lungs through pulmonary veins to the left atrium.

In Diastolic heart failure, the ventricle does not fill properly with blood because of thick and rigid walls or that the ventricle cannot relax. Age is one of the common risk factors for the disease and there is no treatment for this except for therapy targeting the affected ventricle.

With the discovery of the effect of GDF-11 to the heart, age-related heart disease such as diastolic heart failure may one day be treated.

Protein Complex NF-κB In Brain's Hypothalamus May Have Effect In Aging

Scientists are studying the relation between aging and the activation of the protein complex called NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in the hypothalamus.

The hypothalamus is the region of the brain that is responsible for homeostasis, emotions, thirst, circadian rhythms, and control of autonomic nervous systems. This region can be found under the Thalamus ('Hypo' means under).

Most of the functions governed by the hypothalamus are tiggered autonmously such as the autonomic nervous system which controls involuntary and reflexive organs such as the heart, stomach, and intestines. Circadian rhythms are functions that follow physical, mental and behavioral changes that based on a 24-hour cycle, responding primarily to light and darkness. Sleep, hunger, blood pressure, body temperature regulation are some functions that is based on the circadian rhythm.

Anti-Aging Enzyme Telomerase Successfully Mapped

Human chromosomes (grey) capped by telomeres (white)
Credit: Wikipedia

A collaboration of more than 1000 researchers have resulted in the successful mapping of the telomerase enzyme. An enzyme responsible for prolonging cellular life by protecting the chromosome.

In 2009, three doctors received the Nobel Prize for Medicine (Physiology) for the discovery of the telomerase enzyme. Telomerase is an enzyme that is believed to have a rejuvenating effect on normal cells.

Telomerase works on the telomeres which are found at the tips of cellular chromosomes. Telomeres protect the chromosome strand. These telomeres shorten after each division of the cell until it is consumed. Although normal cell division affects the telomeres, other factors such as stress, unbalanced diet, and lifestyle also can affect them.

As the telomeres shorten, the cell starts to deteriorate and may result in loss of the ability of the cell to divide, disease, and tissue/organ deterioration. A short telomere is said to be an effective biomarker (in combination with other biomarkers) for health and disease risk.

Telomerase, the enzyme, protects the telomeres and maintains it, increasing telomere length. It helps elongate telomeres after each cell replication.

No Health Benefits For Middle-Aged Women Taking Resveratrol

A study conducted on resveratrol has revealed it does not offer any health benefits on healthy middle-aged women.

The compound resveratrol is found in high concentration in the skin of grapes. Resveratrol is produced naturally by several plants, including grapes, when pathogens such as bacteria or fungi form a threat to the plant.

According to proponents of resveratrol, it activates the sirtuin gene. The sirtuin gene is an inactive gene. It is believed that when activated, it starts a survival process that extends life by slowing down aging.

Aside from increasing longevity, it is also thought to improve insulin sensitivity and reduce risk of heart disease. There are studies that suggest that drinking red wine lowers the risk of health problems. Red wine is said to have two times more average resveratrol concentration than the equivalent commercial juices.

Studying Cell Senescence And Its Relation To The Aging Of the Brain

Senescence is the change in the form and biology of a cell or organism as it ages past its maturity. When a cell loses its ability to divide, this is called cellular senescence. It must be noted that with cellular senescence, the affected cell is still metabolically active. These are called senescent cells.

Senescent cells exhibit changes in form and function which may lead to age-related changes such as wrinkles and surface dryness. Some cells become senescent after an average of 50 cycles of replication or division. Other cells become senescent because of exposure to toxins or DNA damage.

Senescence is an irreversible process and scientists are studying this phenomenon in relation to aging and the growth of cancerous tumors.

Scientists discover how the brain ages

The ageing process has its roots deep within the cells and molecules that make up our bodies. Experts have previously identified the molecular pathway that react to cell damage and stems the cell's ability to divide, known as cell senescence.

However, in cells that do not have this ability to divide, such as neurons in the brain and elsewhere, little was understood of the ageing process. Now a team of scientists at Newcastle University, led by Professor Thomas von Zglinicki have shown that these cells follow the same pathway.

This challenges previous assumptions on cell senescence and opens new areas to explore in terms of treatments for conditions such as dementia, motor neuron disease or age-related hearing loss.

Declining Testosterone Levels Due More To Health and Behavior Than Age

Testosterone is a male steroid hormone which plays a major role in the development of the male reproductive organs and emergence of secondary male sexual characteristics such as facial hair, a deeper voice and muscles.

Both men and women produce this hormone. In men, the hormone is produced in the testes and adrenal glands. In women, it is produced in the ovaries and adrenal glands. Men have about 20 times more testosterone than women. On average, men produce 4mg to 10 mg of testosterone per day.

Testosterone is an anabolic steroid. Anabolic steroids increase protein synthesis within cells. This leads to the buildup of cellular tissue (anabolism), especially in muscles. Testosterone also has androgenic (virilising) properties which means that it affects the development and maintenance of masculine characteristics.

Declining testosterone levels in men not part of normal aging, study finds

A new study finds that a drop in testosterone levels over time is more likely to result from a man's behavioral and health changes than by aging. The study results will be presented Monday at The Endocrine Society's 94th Annual Meeting in Houston.

"Declining testosterone levels are not an inevitable part of the aging process, as many people think," said study co-author Gary Wittert, MD, professor of medicine at the University of Adelaide in Adelaide, Australia. "Testosterone changes are largely explained by smoking behavior and changes in health status, particularly obesity and depression."

Many older men have low levels of the sex hormone testosterone, but the cause is not known. Few population-based studies have tracked changes in testosterone levels among the same men over time, as their study did, Wittert said.