Basic Science Tip Sheet

February 17, 2016 Categories: Scientific Conferences & Meetings, Stroke News

Tip Headlines

  • Restoring gut bacteria to youthful age linked to improved stroke recovery in mice.
  • Exosomes may be key players in two rebuilding processes after stroke.
  • Nanoparticles show early promise in reducing inflammation after brain bleed.
  • Alcohol exposure before birth may later amplify neurological problems from stroke.
  • Vaccine shows potential to protect the brain before a stroke.

Note: All Times are Pacific (PT). All tips are embargoed until the time of presentation or 3 p.m. PT/6 p.m. ET each day, whichever comes first.

Embargoed for 3 p.m. PT/6 p.m. ET, Wednesday, Feb. 17, 2016

Poster 3914/W MP45 (Hall H)

Restoring gut bacteria to youthful age linked to improved stroke recovery in mice

Restoring microorganisms in the gut to a youthful age was linked to improved stroke recovery in old mice, according to a new study presented at the American Stroke Association’s International Stroke Conference 2016.

Noting that different bacteria present in the gut change with age, researchers from the University of Connecticut in Mansfield, Connecticut, used fecal transplants to deliver a “young” set of bacteria to mice that were 18 to 20 months old as well as to mice just 3 or 4 months old, while another group of mice received an “aged” set of bacteria in each of those two age groups. The mice were first given an antibiotic to suppress their own microbial makeups and allow the new sets of gut bacteria to flourish.

Follow-up behavioral and neurological tests showed that older mice with “young” sets of bacteria recovered from the induced stroke better than their peers with “aged” bacteria. Meanwhile, death rates after the stroke were particularly high — exceeding 50 percent — in young mice with “aged” bacterial makeups, researchers said.

Michal Jandzinski, B.S., Research Assistant, University of Connecticut, Mansfield, Connecticut.

Note: Actual presentation is 5:55 p.m. PT/8:55 p.m. ET, Wednesday, Feb. 17, 2016

 

Embargoed for 3 p.m. PT/6 p.m. ET, Wednesday, Feb. 17, 2016

Poster 4324/W MP39 (Hall H)

Exosomes may be key players in two rebuilding processes after stroke

Small vesicles secreted by cells help facilitate growth and development of blood vessels and neurons in the brain following a stroke, according to a new study presented at the American Stroke Association’s International Stroke Conference 2016.

Researchers from Detroit and China, suspected that tiny vesicles, or containers called exosomes — which are secreted from cells and play a role in communication from one cell to another — might facilitate the growth and development of blood vessels (angiogenesis) and of nerve cells, or neurons (neurogenesis).

To test their hypothesis, the research team isolated cells from the brains of both healthy rats and rats whose brains had been damaged by a blood vessel blockage. Two types of cells were isolated: cerebral endothelial cells (which line blood vessels in the brain) and neural progenitor cells (which can differentiate into other types of brain cells). Exosomes were harvested from those cells and tagged with fluorescent particles. The fluorescent particles helped researchers determine if cells successfully internalized the exosomes.

Researchers first studied exosomes from endothelial cells engulfed in neural progenitor cells. They found that in rats with brain damage from a stroke, neural cells containing exosomes from endothelial cells multiplied more rapidly — and differentiated more distinctly — than neural cells with comparable exosomes from healthy rats.

Findings were similar when the experiment was conducted in reverse, applying exosomes from neural progenitor cells to endothelial cells: The exosomes from rats with the damaged brains more actively promoted growth and development of blood vessels, compared to the exosomes from healthy rats. The results suggest that exosomes may be useful in enhancing brain recovery after stroke, researchers said.

Wanlong Pan, Ph.D., Associate Professor, North Sichuan Medical University, Nanchong, China, and neurology fellow, Henry Ford Hospital, Detroit, Michigan.

Note: Actual presentation is 5:25 p.m. PT/8:25 p.m. ET, Wednesday, Feb. 17, 2016.

 

Embargoed for 3 p.m. PT/6 p.m. ET, Wednesday, Feb. 17, 2016

Poster 4326/W P265 (Hall H)

Nanoparticles show early promise in reducing inflammation after brain bleed

Nanoparticles from ceria – a rare earth metal – might lessen inflammation in the brain following a bleeding stroke (hemorrhagic stroke), according to research presented at the American Stroke Association’s International Stroke Conference 2016.

Researchers from South Korea noted that previous studies have shown that ceria nanoparticles have strong antioxidant properties as well as anti-inflammatory effects. This study investigated whether the tiny particles could reduce inflammation that occurs just after an intracerebral hemorrhage (bleeding within the brain).

In a lab experiment, researchers studied a type of white blood cell called macrophages taken from the brains of rats and applied ceria nanoparticles to them. Compared with untreated macrophages, the macrophages treated with the nanoparticles secreted fewer inflammation-promoting chemicals.

In a second experiment, researchers injected ceria nanoparticles in 10 rats with brain bleeds. Compared with 10 untreated rats, the treated rats had less damage at the stroke site and less water accumulation, suggesting less inflammation in the area of the stroke, researchers said.

Chi Kim, M.D., Research Fellow, and Seung-Hoon Lee, M.D., Associate Professor, Seoul National University Hospital, Seoul, Korea.

Note: Actual presentation is 6:15 p.m. PT/9:15 p.m. ET, Wednesday, Feb. 17, 2016.

 

Embargoed for 3 p.m. PT/6 p.m. ET, Wednesday, Feb. 17, 2016

Abstract 4236/131 (Room 515 B)

Alcohol exposure before birth may later amplify neurological problems from stroke

Exposure to alcohol before birth might impair kidney blood flow in adulthood and heighten neurological problems caused by a stroke, according to an animal study presented at the American Stroke Association’s International Stroke Conference 2016.

A research team from Texas A&M Health Science Center, College of Medicine, administered ethanol to six pregnant mice twice daily for four days, from gestational day 12 through 15, and administered water to six other pregnant mice. At 12 days of gestation, the mice were in a stage of pregnancy comparable to late in the first trimester for humans, researchers said.

Using ultrasound testing, the team measured blood flow in both male and female offspring of the mice at 3 months of age, a period equivalent to young adulthood in humans. Blood flow analysis showed evidence for increased arterial resistance within the kidneys — a sign of possible early onset renal hypertension — in the male offspring that were exposed to alcohol before birth.

Researchers then assessed neurological damage caused by stroke in both male and female offspring and found greater levels of impairment in the six female and six male mice that had fetal alcohol exposure, compared with the dozen that were not exposed to alcohol.

Measurements of the stroke-damaged area of the brain were correlated to scores on neurological testing in the females, but not the males, with fetal alcohol exposure. “The finding indicates that in mice exposed to alcohol before birth, sex appears to play some role in whether the volume of damaged tissue in the brain correlates with functional and neurological impairment,” said lead researcher Shameena Bake, Ph.D., and assistant professor at Texas A&M Health Science Center in Bryan, Texas.

Shameena Bake, Ph.D., Assistant Professor, Texas A&M Health Science Center, Bryan, Texas.

Note: Actual presentation is 9:33 a.m. PT/12:33 p.m. ET, Thursday, Feb. 18, 2016.

 

Embargoed for 3 p.m. PT/6 p.m. ET, Thursday, Feb. 18, 2016

Poster 3172/T P269 (Hall H)

Vaccine shows potential to protect the brain before a stroke

A type of vaccine previously studied to treat high blood pressure may have the potential to protect the brain when administered before a stroke, according to an animal study presented at the American Stroke Association’s International Stroke Conference 2016.

Japanese researchers tested a peptide vaccine targeting the hormone angiotensin II (Ang II) a key player in high blood pressure. Members of the research team previously had found that their peptide vaccine decreased blood pressure in a mouse model of hypertension, while the blood pressure of mice with normal readings was unaffected. The hormone also has been linked to patients’ prognosis after a ischemic (clot-caused) stroke.

In the new study, researchers injected 53 male rats with the vaccine three times, at ages 4, 6 and 7 weeks old, and administered a second group of 41 with saline at the same intervals. Stroke was induced in vaccinated rats and rats that were given saline.

The team then measured levels of anti-Ang II antibody in the blood and brains of the rats that received the vaccine and had a stroke. Compared with rats that had low blood levels of antibody, the animals with high levels in the blood had more anti-Ang II antibodies in functional tissue at the side of the brain where the stroke occurred. Researchers also noted that vaccinated rats that produced high blood levels of antibody had less damage to the brain and fewer degenerated neurons.

Because the Ang II peptide vaccine is long-lasting, has anti-inflammatory effects and appears able to protect the brain after a blood vessel blockage, it has potential to be a therapy for high blood pressure and stroke prevention, researchers said.

Kouji Wakayama, M.D., Project Assistant Professor, University of Tokyo, Japan.

Note: Actual presentation is 6:15 p.m. PT/9:15 p.m. ET, Thursday, Feb. 18, 2016.

Additional Resources:

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