Category Archives: Transhuman News

When it comes to attraction, the allure can begin even before she sets eyes on you. There seems to be something about the way youher dinnersmells from afar that makes you a desired target. While you are chatting with friends or overseeing the barbecue, that mosquito will go on the hunt and make you her next blood meal. But what makes you so attractive to tiny ankle biters?

This month a group of British researchers is launching a new investigation into the role of human genetics in this process. They are planning to collect smelly socks from 200 sets of identical and nonidentical twins, place the footwear in a wind tunnel with the bugs and see what happens next. The owners of the socks, the scientists hope, may naturally produce attractive or repellant chemicals that could become the basis for future mosquito control efforts. The researchers expect that studying the popularity of the garments the skeeters hone in onand analyzing both the odor compounds in them and the genetics of their ownerscould help.The study, which will include 100 twins each from the U.K. and from the Gambia, will start recruiting volunteers in the coming weeks.

We know very little about the genetics of what makes us attractive to mosquitoes, says James Logan, a medical entomologist at the London School of Hygiene and Tropical Medicine who is leading the work. Earlier studies suggest visual, olfactory and thermal (body heat) cues all help drive mosquito attraction. We hope this study will give us more insights into the mechanisms that help change our body odors to make us more or less attractive to mosquitos, he says. If we can identify important genes, perhaps we could develop a pill or medication that would allow the body to produce natural repellents to keep mosquitoes away. The findings, he adds, could also help epidemiologists improve their models for how vulnerable certain populations may be to disease-carrying mosquitoes.

Already scientists know there are differences among us that contribute to why some of us get bitten more. Those of us who exhale more carbon dioxide seem to be a natural beacon for mosquitoes, in particular. Researchers have also found a correlation with body size, with taller or larger people tending to attract more bitesperhaps because of their carbon dioxide output or body surface area. There is also some evidence women who are pregnant or at certain phases of the menstrual cycle are more attractive to mosquitoes. Other work has found that people infected with malaria are more attractive to malaria-carrying mosquitoes during their transmissible stage of infection.

But what of our individual genetics? Two years ago Logans team published a small study looking at 18 sets of identical twins and 19 sets of nonidentical twins and their attractiveness to mosquitoes. They found that identical twins were more similar in their desirability to the blood-sucking insects than the nonidentical twins. Because earlier work had found that identical twins smell more alike than nonidentical twins, the British researchers surmised genes may play a role in this mosquito attractiveness.

This new study aims to nail down some more concrete conclusions with its larger sample size and add another population into the mix. (Most research in this area has focused on European Caucasians whereas this study will also include twins from the Gambia). There are other differences that set this apart from their earlier work, too: The 2015 study had tested attractiveness among Aedes mosquitoesthose that carry dengue and Zikawhereas this study will test attractiveness among Anopheles mosquitoes, a species that can transmit malaria. The team suspects the different species will be attracted to the same volatile compounds in human odor but wants to explore this further.

This is novel work and its a good step. It will tell us if there are genetic differences or not but it wont be a complete answer about mosquito attraction because other factors like diet, wind, time of day and mosquito species can all influence that, says Zainulabeuddin Syed, a professor of biological sciences at the University of Notre Dame who studies the smell-influenced behavior and movement of insects and is not involved in the Logan project. Syeds work has found that people of various ethnic groups all seem to produce four major volatile compounds (although at varying levels) and there are some early hints that one compound in particular, called nonanal, may be particularly attractive, at least among certain species of mosquitoes.

Exactly what genes contribute to producing compounds that could possibly interest mosquitoes remains a vast unknown. Scientists that study human odors and genetics have previously suggested scent cues associated with genetics are likely controlled via the major histocompatibility complex (MHC) genes. Those genes appear to play a role in odor production and also in mammals mating choicesbecause humans and mice alike appear to prefer mates that smell less similar to themselves, which scientists have theorized may be a natural control against inbreeding. As a result, Logans team may target those odor-linked genes, but he says they are looking at all the options. In the next couple of years, he says, they hope to have some early answers. For now, and likely for many years to come, we can only slather on some bug repellant and hope for the best.

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Are You a Magnet for Mosquitoes? - Scientific American - Scientific American

The WNT1 ligand has previously been identified in bone disease, but its role in bone homeostasis, its cellular source and targets in bone have only just recently been identified.The research, led by Dr. Brendan Lee at Baylor College of Medicine, appears in the Journal of Clinical Investigation.

To determine the bone-specific function of WNT1, the mutation that has been associated with recessive forms of Osteogenesis Imperfecta (OI) and other forms of early-onset osteoporosis, Lee, chair of the Department of Molecular and Human Genetics at Baylor, generated mouse models to study the consequences of both the loss and gain of WNT1 function in a specialized bone cell called the osteocyte.

This research builds on previous work that identified WNT1s role in coordination and its known effect on brain development. Now, we understand how this molecule works in bone, and this paper tells us that WNT1 is produced by osteocytes to control the activity of the bone-forming cell, the osteoblast, said Lee, also the Robert and Janice McNair Endowed Chair and professor of molecular and human genetics at Baylor.

The role of osteocytes, blasts and clasts

The over- or underexpression of WNT1 is controlled by osteocytes, or bone embedded cells. The osteocytes produce WNT1 to signal to bone-forming cells called osteoblasts that reside on the surface of bone via a biochemical pathway called mTORC1. When WNT1 is overexpressed by the osteocyte, bone formation is stimulated due to an increase in osteoblast numbers and collagen production following the activation of the mTORC1 pathway in these cells.

Osteocytes are embedded in the bone, with osteoblasts and osteoclasts sitting on the surface adding or removing bone, respectively, explained Lee. It turns out, osteocytes are actually the master controllers of this balance of bone formation and resorption in part by acting as either a receiver or sender of WNT signals.

We knew previously from others work that osteocytes could inhibit bone formation by producing the protein sclerostin, which represses osteoblast function. This research brings the cycle of information full circle by showing that while sclerostin turns the osteoblasts off, WNT1 from osteocytes turns them on, Lee said.

On the other hand, loss of WNT1 function resulted in low bone mass and spontaneous fracturing, similar to that seen in patients with OI. In this case, the osteocyte is not producing WNT1. However, osteocytes also can receive WNT signals themselves, leading them to control the activity of bone-removing cells, the osteoclasts.

Therapeutic impact

Primary therapies traditionally used to treat OI have shown limited efficacy in combating WNT1-related OI and osteoporosis. However, Lee and his research team identified anti-sclerostin antibody (Scl-Ab) treatment is effective in augmenting the action of other WNT ligands to improve bone mass and to significantly decrease the number of fractures in swaying mice, a model of WNT1 related OI and osteoporosis.

The results of this study, while conducted in mice, have important implications for the treatment of OI and osteoporosis in humans down the road, Lee said. By blocking sclerostin, the bone can be repaired effectively in diseases related to loss of WNT1 suggesting a personalized therapy. This is exciting especially as a promising anti-sclerostin drug is already in clinical development.

This work was supported by the Baylor College of Medicine Intellectual and Developmental Disabilities Research Center from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the Baylor College of Medicine Advance Cores with funding from the National Institutes of Health, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the Rolanette and Berdon Lawrence Bone Disease of Texas and the Center for Skeletal Medicine and Biology at Baylor College of Medicine.

Other contributors to this work include Kyu Sang Jeong, Yi-Chien Lee, Yuqing Chen, Ming-Ming Jiang and Elda Munivez, all of whom are with Baylor, and Catherine Ambrose with the University of Texas Health Science Center at Houston.

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Research shows bone-building protein can be used in therapy - Baylor College of Medicine News (press release)

Dr. Huda Zoghbi, a neurologist whose work has revealed the molecular basis of neurological disorders, is the recipient of the 2017 Switzer Prize awarded by the David Geffen School of Medicine at UCLA for excellence in biological and biomedical sciences research.

Zoghbis lab at the Baylor College of Medicine identified a gene mutation that causes Rett syndrome, a severe genetic disorder that mostly affects girls. After a short period of apparently normal development, the disorder causes them to lose language and motor skills, typically by 18 months of age. The discovery paved the way for a genetic test to diagnose the disorder. The same gene mutation can also cause autism, juvenile-onset schizophrenia and other neuropsychiatric disorders.

Zoghbi also discovered the molecular mechanism of spinocerebellar ataxia 1, a neurodegenerative disorder in which peoples balance and coordination progressively worsens. Zoghbi and collaborator Harry Orr identified the gene mutation responsible for the disorder.

These and other discoveries by Zoghbi have opened up new areas of inquiry with the potential to advance diagnoses and treatments for Alzheimers disease, Parkinsons disease and other neurological diseases.

Dr. Zoghbis extraordinary work represents a powerful example of the direct impact that biological and biomedical research have on the lives of patients, said Dr. Kelsey Martin, dean of the Geffen School of Medicine.

Zoghbi is scheduled to deliver the Switzer Prize lecture at UCLA on Feb. 16, 2018. She will receive a $25,000 honorarium and a medallion.

Im honored to accept UCLAs Switzer Prize on behalf of the patients and the families to whom I am committed, and also on behalf of my many research collaborators and trainees, she said.

Zoghbi is a Howard Hughes Medical Institute investigator, a professor at the Baylor College of Medicine and the founding director of the Jan and Dan Duncan Neurological Research Institute at Texas Childrens Hospital in Houston. She has faculty appointments in the departments of pediatrics, molecular and human genetics, neurology and neuroscience.

A native of Beirut, Lebanon, Zoghbi fled the civil war in her home country in the mid-1970s while a medical student at the American University of Beirut. She earned a medical degree at Meharry Medical College in Nashville and went on to become chief resident in pediatrics at Baylor College of Medicine and Texas Childrens.

After years of treating patients, Zoghbi became fascinated with the origins of disease and committed to a three-year fellowship in molecular genetics to acquire research training.

She is a member of the National Academy of Sciences, the National Academy of Medicine and the American Association for the Advancement of Science.

Zoghbi is the recipient of a number of other prestigious awards, including the Breakthrough Prize in Life Sciences, the Shaw Prize in Life Science and Medicine and the Canada Gairdner International Award.

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David Geffen School of Medicine at UCLA names winner of Switzer Prize for research excellence - UCLA Newsroom