(Press-News.org) Why do so many mothers have difficulty making enough milk to breastfeed? A new study by scientists at Cincinnati Children's Hospital Medical Center and the University of California Davis adds to their previous research implicating insulin's role in lactation success.
The study is the first to describe how the human mammary gland becomes highly sensitive to insulin during lactation. It is also the first study to get an accurate picture of how specific genes are switched on in the human mammary gland during lactation.
The researchers used next generation sequencing technology, RNA sequencing, to reveal "in exquisite detail" the blueprint for making milk in the human mammary gland, according to Laurie Nommsen-Rivers, PhD, a scientist at Cincinnati Children's and corresponding author of the study, published online in PLOS ONE, a journal of the Public Library of Science.
Nommsen-Rivers' previous research had shown that for mothers with markers of sub-optimal glucose metabolism, such as being overweight, being at an advanced maternal age, or having a large birth-weight baby, it takes longer for their milk to come in, suggesting a role for insulin in the mammary gland. The new research shows how the mammary gland becomes sensitive to insulin during lactation.
For a long time, insulin was not thought to play a direct role in regulating the milk-making cells of the human breast, because insulin is not needed for these cells to take in sugars, such as glucose. Scientists now, however, appreciate that insulin does more than facilitate uptake of sugars.
"This new study shows a dramatic switching on of the insulin receptor and its downstream signals during the breast's transition to a biofactory that manufactures massive amounts of proteins, fats and carbohydrates for nourishing the newborn baby," says Dr. Nommsen-Rivers.
"Considering that 20 percent of women between 20 and 44 are prediabetic, it's conceivable that up to 20 percent of new mothers in the United States are at risk for low milk supply due to insulin dysregulation."
Dr. Nommsen-Rivers and her colleagues were able to use a non–invasive method to capture mammary gland RNA – a chain of molecules that are blueprints for making specified proteins – in samples of human breast milk. They then created the first publicly accessible library of genes expressed in the mammary gland based on RNA-sequencing technology.
This approach revealed a highly sensitive portrait of the genes being expressed in human milk-making cells. They discovered an orchestrated switching on and off of various genes as the mammary gland transitions from secreting small amounts of immunity-boosting colostrum in the first days after giving birth to the copious production of milk in mature lactation.
In particular, the PTPRF gene, which is known to suppress intracellular signals that are usually triggered by insulin binding to its receptor on the cell surface, may serve as a biomarker linking insulin resistance with insufficient milk supply. These results lay the foundation for future research focused on the physiological contributors to mothers' milk supply difficulties.
Now that they've demonstrated the significance of insulin signaling in the human mammary gland, they are planning a phase I/II clinical trial with a drug used to control blood sugar in type 2 diabetes to determine whether it improves insulin action in the mammary gland, thus improving milk supply. While a drug is not an ideal way to solve the problem of sub-optimal glucose metabolism impairing breastfeeding, according to Dr. Nommsen-Rivers, it is excellent for establishing proof-of-concept through the use of a placebo controlled randomized clinical trial.
"The ideal approach is a preventive one," she says. "Modifications in diet and exercise are more powerful than any drug. After this clinical trial, we hope to study those interventions."
Dr. Nommsen-Rivers began her quest to understand why so many U.S. mothers today struggle with low milk supply when she was a doctoral student at the University of California Davis.
###
The lead author of the study is Danielle Lemay, PhD, of the University of California Davis Research Center.
About Cincinnati Children's
Cincinnati Children's Hospital Medical Center ranks third in the nation among all Honor Roll hospitals in U.S.News and World Report's 2013 Best Children's Hospitals ranking. It is ranked #1 for cancer and in the top 10 for nine of 10 pediatric specialties. Cincinnati Children's is one of the top two recipients of pediatric research grants from the National Institutes of Health, and a research and teaching affiliate of the University of Cincinnati College of Medicine. The medical center is internationally recognized for improving child health and transforming delivery of care through fully integrated, globally recognized research, education and innovation. Additional information can be found at http://www.cincinnatichildrens.org. Connect on the Cincinnati Children's blog, via Facebook and on Twitter.
New study reveals important role of insulin in making breast milk
2013-07-06
ELSE PRESS RELEASES FROM THIS DATE:
Caltech researcher sheds light on M.O. of unusual RNA molecules
2013-07-06
The genes that code for proteins—more than 20,000 in total—make up only about 1 percent of the complete human genome. That entire thing—not just the genes, but also genetic junk and all the rest—is coiled and folded up in any number of ways within the nucleus of each of our cells. Think, then, of the challenge that a protein or other molecule, like RNA, faces when searching through that material to locate a target gene.
Now a team of researchers led by newly arrived biologist Mitchell Guttman of the California Institute of Technology (Caltech) and Kathrin Plath of UCLA, ...
How the brain creates the 'buzz' that helps ideas spread
2013-07-06
How do ideas spread? What messages will go viral on social media, and can this be predicted?
UCLA psychologists have taken a significant step toward answering these questions, identifying for the first time the brain regions associated with the successful spread of ideas, often called "buzz."
The research has a broad range of implications, the study authors say, and could lead to more effective public health campaigns, more persuasive advertisements and better ways for teachers to communicate with students.
"Our study suggests that people are regularly attuned ...
University of Akron researchers explore biomedical uses for hydrogels
2013-07-06
It's squishy, synthetic, flexible, mostly water and almost as tough as rubber.
No, it's not "flubber" — it's a hydrogel, and now scientists at The University of Akron are exploring new biomedical uses for this polymer-based product.
Dr. Jie Zheng, associate professor of chemical and biomolecular engineering, and Dr. Robert Weiss, Hezzleton E. Simmons professor and chair of polymer engineering, are among the most recent to contribute to the growing research of hydrogels, the gelatinous substance that, because of its toughness and plasticity, has several biomedical applications, ...
Satellites see ups and downs of 2 tropical Eastern Pacific systems
2013-07-06
There are two tropical cyclones in the Eastern Pacific Ocean on July 5 and one is powering up and one is powering down. NOAA's GOES-15 satellite captured Tropical Depression Dalila and Tropical Storm Erick, both off the western coast of Mexico. Because Erick is strengthening and is close to the coast, tropical storm warnings have gone into effect for Mexico.
Tropical Depression Dalila has weakened from a Category 1 hurricane status and is expected to dissipate in the next day or two. Meanwhile, Tropical Storm Erick grew from a low pressure area called System 97E into ...
Satellite quilt of wildfires, smoke throughout Canada
2013-07-06
NASA's Aqua satellite captured multiple images of fire and smoke from Canadian wildfires on July 4, 2013. The images were stitched together to form a visual quilt.
The Moderate Resolution Imaging Spectroradiometer instrument that flies aboard Aqua captured the images. MODIS has the ability to detect hot spots (fires), which appear red in the image. Plumes of smoke from various wildfires can be seen blowing across many of the Canadian provinces and out over the Atlantic Ocean.
As of July 5, the government of Saskatechewan reported 17 wildfires. British Columbia has ...
Cosmetic surgery to look whiter fails to boost women's self-esteem
2013-07-06
Many black or racially mixed women in Venezuela are undergoing nose jobs in an effort to look whiter, but the procedure only temporarily improves their self-esteem and body image in a culture that values whiteness, a Dartmouth College study finds.
Cosmetic surgery is increasingly common in many countries, including Venezuela, where an obsession with physical appearance prompts many women to get breast implants, face lifts, liposuction and other cosmetic procedures. But the trend has also sparked controversy -- the late Venezuelan President Hugo Chavez blamed cosmetic ...
Designer droplets with 'pupils' open a world of possibilities
2013-07-06
Researchers have designed droplets using a technique that could have applications for everything from extracting oil from wells to creating makeup and food.
You've seen Hollandaise sauce or mayonnaise that has separated, or that shiny layer of oil that forms on top of skin cream. This mixture of water and oil is called an emulsion, but it can be difficult to keep emulsions from separating. A special substance called an emulsifier is used to keep the mixture stable and prevent separation.
This is an ongoing problem for the food and medical industries, as well as for ...
New insights concerning the early bombardment history on Mercury
2013-07-05
The surface of Mercury is rather different from those of well-known rocky bodies like the Moon and Mars. Early images from the Mariner 10 spacecraft unveiled a planet covered by smooth plains and cratered plains of unclear origin. A team led by Dr. Simone Marchi, a Fellow of the NASA Lunar Science Institute located at the Southwest Research Institute (SwRI) Boulder, Colo., office, collaborating with the MESSENGER team, including Dr. Clark Chapman of the SwRI Planetary Science Directorate, studied the surface to better understand if the plains were formed by volcanic flows ...
New approaches to understanding infection may uncover novel therapies against influenza
2013-07-05
The influenza virus' ability to mutate quickly has produced new, emerging strains that make drug discovery more critical than ever. For the first time, researchers at Seattle BioMed, along with collaborators at the University of California, San Diego School of Medicine, St. Jude Children's Research Hospital and the University of Washington, have mapped how critical molecules regulate both the induction and resolution of inflammation during flu infection. The results are published this month in the journal Cell.
Flu is an elusive foe
The influenza virus mutates extremely ...
Grassland fencing threatens the survival of wild ungulates
2013-07-05
Ungulates like Tibetan antelope, Kiang, wild yak, Przewalski's gazelle, Tibetan gazelle, Mongolian gazelle, roam on the steppes and grasslands of Asia, need large open habitats. For examples, once millions of Mongolian gazelles migrate to the Inner Mongolian steppe in winter and return to steppes in eastern Mongolia and Durian, Russia during the breeding in summer. Hundreds of thousands of Przewalski's gazelles also roam in the Alpine steppe in Qinghai lake drainage (Fig. 1). Those wild ungulates move freely on the grasslands are animal spectacles in Eurasia.
Area of ...