Tag Archives: aging

Hypothalamic Stem Cells May Reverse The Human Ageing Process

A study published in the Nature Journal by Dongsheng Cai, Albert Einstein College of Medicine, New York, talks about how stem cells, that determines how fast aging occurs in the body, can help reverse the human ageing process. Stem cells reside in Hypothalamus, a pea-sized part of the brain that contains a bundle of neurons. It is responsible for a wide array of growth, development, digestion, reproduction, and metabolism related processes in the body. As the human body starts to age, these neural stem cells in the body begins to deteriorate and accelerates the human ageing process. So, if you stop these stem cells from wearing away, you can possibly stop the human body from ageing.

The lab tests were conducted on mice, where it was observed that as the mice grew 10 months or older, the stem cells begin to deplete (earlier than the usual time for stem cells to deteriorate in mice). By the time, these mice turn two years and older, the stem cells start to disappear, causing death. However, to prove their hypothesis that stem cells deterioration truly accelerates the ageing process, scientists ‘artificially disrupted’ the stem cells in middle-aged mice, and observed that it significantly grew their rate of ageing.

Once the hypothesis that stem cells depletion leads to accelerated ageing was proved, scientists further injected the hypothalamic stem cells into the brains of older and middle-aged mice, where a sudden decrease in their ageing process was observed. This happens because the hypothalamic stem cells release molecules called microRNAs (miRNAs) which play an important role in regulation of gene expression. These miRNAs (which are bundled inside tiny particles called exosomes) released by the stem cells were then further injected into the cerebrospinal fluid of mice.

After this experiment, the ageing process significantly slowed down, in terms of tissue analysis and behavioral analysis where different changes in animals’ muscle endurance, coordination, social behavior and cognitive ability also showed signs of anti-ageing. Scientists are now looking into exploring the study further and analyze other factors related to microRNAs that might be responsible for the anti-ageing miracle!

Source: https://www.nature.com/
AND
https://in.mashable.com/

How To Fight Against Weakened Immune System When Getting Older

Scientists pinpoint metabolic pathway behind age-related immunity lossThe elderly suffer more serious complications from infections and benefit less from vaccination than the general population. Researchers have long known that a weakened immune system is to blame but the exact mechanisms behind this lagging immunity have remained largely unknownNow research led by investigators at Harvard Medical School suggests that weakened metabolism of immune T cells may be partly to blame.

The findings, published Dec. 10 in PNAS and based on experiments in mouse immune cells, pinpoint a specific metabolic pathway called one-carbon metabolism that is deficient in the aged T cells of rodents. The work also suggests possible ways to restore weakened immune function with the use of small-molecule compounds that boost T cell performance.

We believe our findings may help explain the basic malfunction that drives loss of immune defenses with age,” said senior study author Marcia Haigis, professor of cell biology in the Blavatnik Institute at Harvard Medical School. “If affirmed in further studies, we hope that our findings can set the stage for the development of therapies to improve immune function.

Source: https://scienmag.com/

Drug Encapsulation System Selectively Targets Senescent Cells

A team headed by Manuel Serrano at IRB Barcelona has designed a drug encapsulation system that selectively targets senescent cellsThe study paves the way for therapeutic approaches to eliminate senescent cells in many diseases, such as pulmonary fibrosis and cancer.

Senescent cells are damaged cells that do not perform their normal roles anymore but that are not dead –hence they are commonly known as zombi cells. These cells interfere with the functioning of the tissue in which they accumulate. Senescence is a cell program that is triggered by many types of damage and senescent cells are present in many diseases. They accumulate in diverse types of tissues during aging, thus contributing to the progressive deterioration associated to aging. Eliminating these zombi cells is one of the challenges facing science today.

In the Cellular Plasticity and Disease lab headed by the ICREA researcher Manuel Serrano at the Institute for Research in Biomedicine (IRB Barcelona) and supported by “la Caixa” Banking Foundation, the researchers devise strategies to eliminate senescent cells.  In a study published in EMBO Molecular Medicine, they present a proof of principle of a drug delivery system with selectivity for tissues that harbour senescent cells.

In collaboration with a team headed by Ramón Martínez-Máñez at the Universidad Politécnica de Valencia, the IRB Barcelona scientists have exploited a particular hallmark of senescent cells in order to design a delivery system that specifically targets them. They have demonstrated its efficacy in cells in vitro and in two experimental mouse models, namely pulmonary fibrosis and cancer. These diseases are characterized by the presence of damaged cells, and in the case of cancer this is particularly true after treatment with chemotherapy.

The figure shows two views, frontal and lateral, of the image obtained by CT of the lungs of a mouse with fibrosis (grey areas) before and after receiving nano-therapy directed at senescent cells

In these models, the senescent cells take up the carrier more efficiently than other cells and once inside the cell the casing of the carrier degrades to release the drug cargo. When the nano-vehicles contained cytotoxic compounds, the senescent cells were killed and this resulted in therapeutic improvements in mice with pulmonary fibrosis or with cancer.

This nano-carrier may pave the way for new therapeutic approaches for serious conditions, such as pulmonary fibrosis or to eliminate chemotherapy-induced senescent cells, explains Manuel Serrano. Another outcome of this study is that these nano-carriers could be used for diagnostic tests of senescence as they can transport a fluorescent compound or marker.

Source: https://www.irbbarcelona.org/