The breakdown of this brain region may accelerate aging

first_img Sign up for our daily newsletter Get more great content like this delivered right to you! Country Roger Harris/Science Source The breakdown of this brain region may accelerate aging If these sweltering summer days prompt you to reach for a cold drink, you can thank your hypothalamus, a region of the brain that helps us regulate body temperature and other internal conditions. But the region may fail us when we get older. A new study in mice suggests that the hypothalamus promotes aging, hastening physical and mental decline as its stem cells die off.“It’s a pretty stunning paper,” says Charles Mobbs, a neuroendocrinologist at the Icahn School of Medicine at Mount Sinai in New York City. The new aging mechanism “is totally novel and quite unexpected,” adds neuroendocrinologist Marianna Sadagurski of Wayne State University in Detroit, Michigan.Tucked away deep in the brain, the hypothalamus monitors and maintains our blood concentration, our body temperature, and other physiological variables. Researchers have also suspected that it plays a role in aging. The hypothalamus becomes inflamed as we get older, and 4 years ago a team led by neurodendocrinologist Dongsheng Cai of Albert Einstein College of Medicine in New York City showed that quelling this inflammation delays physical deterioration and boosts life span in mice. Email The hypothalamus, a command center deep in the brain, helps control everything from hunger to sleep. center_img In the new study, the team turned its attention to the hypothalamus’s stem cells, which in young animals divide to produce replacements for dead and damaged cells. As mice get older, the scientists found, the number of stem cells in the hypothalamus plunges. By later ages they are “basically all gone,” Cai says.To determine whether this loss promotes aging, researchers tried to speed up the process, genetically altering mice so that stem cells in the hypothalamus died when the animals were dosed with an antiviral drug. Knocking off some 70% of the cells shortened the mice’s lives by about 8%, the team reports today in Nature. The mice’s memory, coordination, and endurance also suffered. Behaviorally, they were like grumpy grandparents, less social and curious than youthful rodents. For example, when researchers put a new object into their cages, control mice spent about twice as long exploring it than did their modified counterparts.Next, the team tried to reverse this deterioration by injecting stem cells into the hypothalami of middle-aged animals. Mice that received the stem cells outlived mice injected with a different type of brain cell by more than 10%, and they retained more of their physical and mental capabilities. In humans, the extra boost could mean a few more years of healthy life, Mobbs notes.Researchers assume the loss of stem cells causes organs and tissues to wear out gradually because they can’t replenish their lost cells. But because injecting stem cells into the mice produced benefits quickly, Cai and his colleagues concluded a faster-acting mechanism was at work.Their suspicions fell on RNA molecules known as microRNAs, which stem cells manufacture and release. These microRNAs ferry messages to other cells, altering which proteins they produce. The researchers found that stem cells from the hypothalamus pump out huge amounts of microRNAs, packaged in tiny containers called exosomes. They also found that injecting mice with microRNA-rich exosomes isolated from cultures of young hypothalamus stem cells slowed the animals’ physical and cognitive breakdown almost as much as injections of stem cells.“The big question is how those microRNAs influence function,” Mobbs says. The molecules could spur other cells to curb inflammation or stress, Cai says, though he isn’t certain how they work. Where the microRNAs exert their effects is also a mystery. Their targets may be other cells in the brain or the spinal cord, but they might also slip into the bloodstream and prod cells elsewhere in the body.The work suggests that protecting or replacing the hypothalamus’s stem cells—or replicating the effects of the microRNAs—could slow aging in humans. It might also be possible to suppress the inflammation that provokes the stem cell die-off, Sadagurski says. She says some current drugs, including the diabetes treatment acarbose, curb inflammation in the hypothalamus and may be worth testing. Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe Click to view the privacy policy. Required fields are indicated by an asterisk (*) By Mitch LeslieJul. 26, 2017 , 1:00 PMlast_img

Leave a Reply

Your email address will not be published. Required fields are marked *