A new discovery about the spatial orientation and physical interactions of our genes provides a promising step forward in our ability to design custom antibodies. This, in turn, could revolutionize the fields of vaccine development and infection control.
Recent years of research by Alt and others in the field of molecular biology have revealed that it’s not just our genes themselves that determine health and disease states. It’s also the three-dimensional arrangement of our genes that plays a role in keeping genetic harmony. Failure of these structures may trigger genetic mutations or genome rearrangements leading to catastrophe.
The importance of genetic loops
Crammed inside the nucleus, chromatin, the chains of DNA and proteins that make up our chromosomes, is arranged in extensive loop arrangements. These loop configurations physically confine segments of genes that ought to work together in a close proximity to one another, increasingly their ability to work in tandem.
“All the genes contained inside one loop have a greater than random chance of coming together,” says Suvi Jain, PhD, a postdoctoral researcher in Alt’s lab and a co-first author on the study.
Meanwhile, genes that ought to stay apart remain blocked from reaching each other, held physically apart inside our chromosomes by the loop structures of our chromatin.
But while many chromatin loops are hardwired into certain formations throughout all our cells, it turns out that some types of cells, such as certain immune cells, are more prone to re-arrangement of these loops. …
For decades, cardiac researcher James McCully, PhD, has been spellbound by the idea of using mitochondria, the “batteries” of the body’s cells, as a therapy to boost heart function. Finally, a clinical trial at Boston Children’s Hospital is bringing his vision — a therapy called mitochondrial transplantation — to life.
Mitochondria, small structures inside all of our cells, synthesize the essential energy that our cells need to function. In the field of cardiac surgery, a well-known condition called ischemia often damages mitochondria and its mitochondrial DNA inside the heart’s muscle cells, causing the heart to weaken and pump blood less efficiently. Ischemia, a condition of reduced or restricted blood flow, can be caused by congenital heart defects, coronary artery disease and cardiac arrest.
For the smallest and most vulnerable patients who are born with severe heart defects, a heart-lung bypass machine called extracorporeal membrane oxygenation (ECMO) can help restore blood flow and oxygenation to the heart. But even after blood flow has returned, the mitochondria and their DNA remain damaged.
“In the very young and the very old, especially, their hearts are not able to bounce back,” says McCully.
Ischemia can be fatal for the tiniest patients
After cardiac arrest, for instance, a child’s mortality rate jumps to above 40 percent because of ischemia’s effects on mitochondria. If a child’s heart is too weak to function without the support of ECMO, his or her risk of dying increases each additional day spent connected to the machine.
But what if healthy mitochondria could come to the rescue and replace the damaged ones? …
First in a two-part series on transplant tolerance.
Although organ transplant recipients take drugs to suppress the inflammatory immune response, almost all eventually lose their transplant. A new approach, perhaps added to standard immunosuppressant treatment, could greatly enhance people’s long-term transplant tolerance, report researchers at Boston Children’s Hospital.
The approach, which has only been tested in mice as of yet, works by maintaining a population of T cells that naturally temper immune responses. It does so by turning on a gene called DEPTOR, which itself acts as a genetic regulator. In a study published July 3 in the American Journal of Transplantation, boosting DEPTOR in T cells enabled heart transplants to survive in mice much longer than usual. …
Research tells us that the “good” bacteria that inhabit our intestines help to regulate our metabolism. A new study in fruit flies shows one of the ways in which these commensal microbes keep us metabolically fit.
The findings, published today in Cell Metabolism, suggest that innate immune pathways, our first line of defense against bacterial infection, have a side job that’s equally important.
The intestine’s digestive cells use an innate immune pathway to respond to harmful bacteria by producing antimicrobial peptides. But other intestinal cells, enteroendocrine cells, use the same pathway, known as IMD, to respond to “good” bacteria — by fine-tuning body metabolism to diet and intestinal conditions.
“What’s most interesting to me is that some innate immune pathways aren’t just for innate immunity,” says Paula Watnick, MD, PhD, of the Division of Infectious Diseases at Boston Children’s Hospital. “Innate immune pathways are also listening to the ‘good’ bacteria – and responding metabolically.” …
Since the late 1970s, biologists have known that blood develops in a specific body location. But they’ve wondered why different creatures house their blood stem cells in different places. In humans and other mammals, they’re in the bone. In fish, they’re in the kidney. Why?
A new study adds to a growing body of evidence that mothers’ experiences affect their babies’ chromosomes. For the first time, it also shows a gender difference — with male babies more susceptible to maternal influence. And it even implicates experiences dating back to the mother’s own childhood.
The researchers enrolled 151 socioeconomically diverse mothers and their infants, all born at Beth Israel Deaconess Medical Center in Boston. The mothers completed in-depth interviews during pregnancy. Cord blood was collected from the newborns so that their chromosomes could be examined — and in particular, the little caps at their tips known as telomeres. …
In adults, end-stage renal disease, or ESRD, is most commonly a complication of diabetes or hypertension. In children, teens and young adults, it’s a different picture entirely. New research finds that more than half of people needing a kidney transplant before age 25 have a congenital anomaly of the kidney or urinary tract, and that 40 percent have an identifiable genetic cause of ESRD. Knowing these genetic underpinnings can inform better care for patients with kidney disease, says study leader Friedhelm Hildebrandt, MD, chief of the Division of Nephrology at Boston Children’s Hospital.
Hildebrandt and his colleagues drew on 263 families whose child received a new kidney at Boston Children’s between 2007 and 2017, before the age of 25. In 68 families, the team was able to perform whole-exome sequencing, comparing their DNA with a normal reference sample. …
Stem cell researchers at Boston Children’s Hospital have, for the first time, profiled a highly elusive kind of stem cell in the early embryo – a cell so fleeting that it makes its entrance and exit within a 12-hour span. They describe this “poised pluripotent” cell in the journal Cell Stem Cell.
In mice, poised cells appear 4.75 to 5.25 days after egg and sperm join to form the embryo, right at the time when the embryo stops floating around and implants itself in the uterine wall.
“People have had a hard time capturing the peri-implantation period because it’s really hard to define,” says Richard Gregory, PhD, who led the research. “It’s a very dynamic stage. Everything happens within a few hours, which is quite remarkable considering the extent of the changes occurring in the properties of the cells.” …
For more than 15 years, pediatric neuro-oncologist Mariella Filbin, MD, PhD, has been on a scientific crusade to understand DIPG (diffuse intrinsic pontine glioma). She hopes to one day be able to cure a disease that has historically been thought of as an incurable type of childhood brain cancer.
“While I was in medical school, I met a young girl who was diagnosed with DIPG,” Filbin recalls. “When I heard that there was no treatment available, I couldn’t believe that was the case. It really made a huge impression on me and since then, I’ve dedicated all my research to fighting DIPG.”
Her mission brought her to Boston Children’s Hospital for her medical residency program and later, to do postdoctoral research at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. Now, she’s starting her own research laboratory focused on DIPG — which has also been called diffuse midline glioma (DMG) in recent years — and continuing to treat children with brain tumors at the Dana-Farber/Boston Children’s pediatric brain tumor treatment center. She’s also a scientist affiliated with the Broad Institute Cancer Program.
This year, Filbin has made new impact in the field by leveraging the newest single-cell genetic sequencing technologies to analyze exactly how DIPG develops in the first place. Her latest research, published in Science, entailed profiling more than 3,300 individual brain cells from biopsies of six different patients.
Using what’s known as a single-cell RNA sequencing approach to interrogate the makeup of DIPG/DMG tumors, Filbin was able to identify a particularly problematic type of brain cell that acts forever young, constantly dividing over and over again in a manner similar to stem cells. …
In our early days as embryos, before we had brains, we had a neural fold, bathed in amniotic fluid. Sometime in the early-to-mid first trimester, the fold closed to form a tube, capturing some of the fluid inside as cerebrospinal fluid. Only then did our brains begin to form.
In 2015, a team led by Maria Lehtinen, PhD, Kevin Chau, PhD and Hanno Steen, PhD, at Boston Children’s Hospital, showed that the profile of proteins in the fluid changes during this time. They further showed that these proteins “talk” to the neural stem cells that form the brain.