By Kelsey Calhoun

Chronic pain gets a fair amount of attention from researchers, but chronic itch, such as eczema or psoriasis, can cause just as much distress. Chronic itch can result from a variety of skin, nervous system or systemic disorders, and many drugs, including some antidepressants, can cause terrible itch as a side effect. There are few effective treatments for such intense and chronic itching, despite being a relatively common affliction: Eczema alone affects nearly 10 percent of people worldwide.

But good news may be on the horizon. A team of scientists, including faculty and students in the MBL Neurobiology Course, have identified a new gene that promotes itching, suggesting a way forward to a better understanding and, perhaps, to powerful new therapies.

Dr. Diana Bautista

MBL Neurobiology Course faculty member Diana Bautista of University of California, Berkeley. Credit: MarkJosephStudio.com

To identify genes that mediate itch, the team, led by Diana Bautista of the University of California, Berkeley, and Rachel Brem at the Buck Institute for Research on Aging, studied itch behavior across genetically distinct mouse strains.  Just as eczema and allergic itch can run in families, they found that some mouse strains were more likely to develop chronic itch and could pass this trait onto their progeny. They then compared gene expression levels in the itch-prone and itch-resistant mice, specifically in the sensory neurons that innervate the skin and mediate itch sensations.

They discovered that mice naturally expressing high levels of a particular gene, HTR7, were exceptionally itchy. This caught their attention, because HTR7 codes for a serotonin receptor, and “high levels of serotonin in the skin have long been known to correlate with itch severity in a variety of human chronic itch disorders,” Bautista says. They also discovered, in a mouse model of eczema, that activation of HTR7 triggered itch-evoked scratching while ablation of HTR7 significantly diminished itch.   

Some of the key work on the paper was done by three students in the MBL Neurobiology Course in 2014. Anne Olsen, Michael Kienzler, and Kyle Lyman worked with Bautista, a faculty member in the course, to identify some of the mechanisms by which activation of HTR7 promotes chronic itch signaling in the nervous system.  All three students appear as co-authors on the paper.

Understanding the molecular mechanisms underlying chronic itch is of significant clinical interest and there is much more to learn. “Abnormal behavior of three cell types mediate chronic itch,” says Bautista, “skin cells, neurons, and immune system cells. We want to discover the mechanisms that promote itch, and also what long-term changes in these cell types maintain chronic conditions.” In the meantime, the HTR7 receptor offers an exciting potential drug target for new medications seeking to sooth intense itchiness.

Citation: Morita T et al (2015). HTR7 Mediates Serotonergic Acute and Chronic Itch. Neuron, DOI: 10.1016/j.neuron.2015.05.044

Summer at MBL is busy, beautiful, and quickly over, but time is still devoted to planning for the future. Students and early-career scientists looking for their next steps don’t have to go far for advice, because each Wednesday during lunch,the SUCCESS program tackles an important aspect of career planning.

From crafting a resumé to getting funded to choosing a mentor, different career topics are addressed each week by a panel of successful scientists.. The atmosphere is informal, so attendees are comfortable asking questions and sparking discussion.

A quick survey of attendees at last week’s SUCCESS workshop proved roughly half were undergraduates, a quarter were graduate students, and a quarter were post-docs, with a few research technicians and assistants as well. The panel discussion on “Choosing Your Career: Academia and Other Not-for-Profitsoffered something for everyone to consider, regardless of career stage.

Panelist Steve Zottoli, MBL’s Co-Director of Education, stressed the importance of mentors. “Finding the right mentor is so critical. You have to take an active role in finding the right mentor who believes in you so much that they take you to the next level,” he said. As students and early-career scientists find their mentors and their places in the scientific community, the SUCCESS series makes sure they are not without good advice.

SUCCESS workshops are held on Wednesdays through July 29 in the Meigs Room, Swope Center, with lunch beginning at 11:30 AM. The full schedule is here: http:/www.mbl.edu/SUCCESS/

The SUCCESS series (Shaping and Understanding Career Choices in Education, Science, and Self) is a project of a dedicated, MBL community-wide committee led by Bill Reznikoff, MBL Director of Education.

The MBL’s collecting boat, the Gemma, has had a few passengers from Woods Hole Oceanographic Institution of late: Aran Mooney, a biologist, and Casey Zakroff, an MIT-WHOI Joint Program graduate student. Mooney and Zakaroff are studying the impact of ocean acidification on squid, using data they collected with the help of the Gemma’s captain and crew. (Ocean acidification is the ongoing decrease in the pH of the Earth’s oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.)

Along with being a key species in the oceanic food web, squid have a multimillion-dollar impact on the human food industry. They are a vital component to the marine ecosystem’s wellbeing, as well as ours, making it crucial to monitor any risks that threaten healthy growth.

In the film, Is Ocean Acidification Affecting Squid?, produced by Daniel Cojanu, Mooney and Zakroff show how rising pH levels may be impacting a local and much prized marine species.

 

Kristin Gribble, assistant research scientist in the MBL’s Bay Paul Center, was awarded the “Runner-Up Best Paper Prize 2014” by the journal Aging Cell and the Council of the Anatomical Society. The award recognizes her paper, “Maternal caloric restriction partially rescues the deleterious effects of advanced maternal age on offspring” (Gribble K.E., G. Jarvis, M. Bock and D.B. Mark Welch Aging Cell 13: 623-630, 2014).

Gribble and colleagues discovered that advanced maternal age reduces the lifespan, fecundity, and size of offspring in the rotifer (B. manjavacas), a tiny aquatic animal that is becoming established as a model organism for aging research. However, the researchers were able to reduce the severity of some of these effects by putting the mothers on a calorie-restricted diet. More information is here.

female-Brachionus-manjavacas--rotifer-with-egg-by-Kristin-Gribble

By Hunt Willard
MBL President and Director

It’s now been five days since the tragic earthquake struck Nepal. The official death toll has passed 5,000, but this doesn’t begin to tell the story of devastation in Nepal and neighboring regions of China and India that has affected millions of people in the region, wiped out entire villages, and destroyed ancient landmarks of cultural, religious and historic significance.

Kathmandu Valley, April 25. Credit: UNDP Nepal

Kathmandu Valley, April 25. Credit: UNDP Nepal

From the other side of the world, where we finally welcome spring to Woods Hole, it is difficult to grasp the scope of this disaster and the scale of suffering. This is why we tend to focus on specific events or images – the video of avalanches on Mt. Everest, or the neurosurgeon/journalist Sanjay Gupta performing brain surgery on an injured child, or a woman in Kathmandu who was pulled alive from the rubble, 36 hours after her 5-story apartment building came crashing down on top of her. Those images help us stay connected to the story, but ultimately fail to convey the massive scale of suffering, when three stories so quickly blur to become 3,000 and then 3 million.

Science – no less than the world around us – is increasingly a global enterprise. This is especially so at the MBL, where we regularly welcome scientists, staff, students and visitors from around the world.

And this is why we should pause – even for just a moment – to think about our colleagues and friends, some of whom, even unknown to us, have relatives, extended family members, classmates or neighbors who come from Nepal and the regions so affected by this tragedy. Today, we can all be Nepalese, and they can all be part of the MBL community.

Thank you for your thoughts and for what you do.

 

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