Can we teach heart cells to grow up?

normal and mutant cardiomyocytes
A mutant heart muscle cell (in green) surrounded by normal cells. The mutant cell lacks Srf, a master maturation gene. It is unable to grow in size and lacks the fine membrane invaginations that help coordinate muscle contractions (appearing as vertical striations in the normal cells). (IMAGE: GUO Y; ET AL. NAT COMMS 9 #3837 (2018).]

Scientists around the world have been trying to replace damaged heart tissue using lab-made heart-muscle cells, either injecting them into the heart or applying patches laced with the cells. But results to date have been underwhelming.

“If you make cardiomyocytes in a dish from pluripotent stem cells, they will engraft in the heart and form muscle,” says William Pu, MD, director of Basic and Translational Cardiovascular Research at Boston Children’s Hospital. “But the muscle doesn’t work very well because the myocytes are stuck in an immature stage.”

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Science Seen: Using Twitter to map hospitals’ stance toward LGBT patients

Hswen Y et al. Social Science & Medicine Oct 2018. DOI: 10.1016/j.socscimed.2018.08.031  

How sensitive are hospitals to the needs of lesbian, gay, bisexual and transgender (LGBT) patients? In a 2010 survey by Lambda Legal, 70 percent of transgender patients and 56 percent of gay/lesbian/bisexual patients reported discrimination from health care providers. Clinicians refused to provide needed care, refused to touch them or used excessive precautions, blamed them for their health status, were verbally abusive or were physically violent.

A new exploratory study, published in the October issue of Social Science & Medicine, turned to social media for a view from the ground. The researchers, Yulin Hswen of Harvard T.H. Chan School of Public Health and Jared Hawkins, PhD, MMSc, of Boston Children’s Hospital’s Informatics Program, analyzed 1,856 publicly available tweets from 2015-2017.

“Information from social media and other online sources can help us gain authentic and unsolicited accounts from vulnerable patient groups, like LGBT individuals who are not typically represented,” says Hswen.

Based on the tweets, the team determined which hospitals were more supportive of LGBT patients (the blue dots in the above map) and which were less supportive (the red dots).

The identified tweets included Twitter handles from 653 hospitals and contained LGBT-related terms: LGBT, transgender, trans, intersex, sex change, transisbeautiful, tranny, drag queen, preferred pronoun, transhealth, genderodyssey, cis, gay, lesbian, queer, rainbowhealth, gender fluid, homosexual, bisexual, homo, homophob and transphobe. A tweet classed as supportive might read, “@Hospital is hosting a LGBT resource fair;” a negative tweet might read: “Having sex with men does not mean I deserve less @Hospital.”

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Getting closer to cracking HIV’s envelope protein

missing segment of HIV envelope could be target for HIV vaccine
(IMAGE: ADOBE STOCK)

For 30 years, researchers have tried to develop an HIV vaccine that would stop the virus from gaining a foothold in the body — before it attaches to T cells and slowly weakens the immune system.

“It has been extremely challenging to induce effective antibody responses against HIV-1,” says Bing Chen, PhD, who researches HIV’s molecular mechanisms at Boston Children’s Hospital.

HIV offers just one target for a vaccine to mimic to trigger protective antibodies: the envelope protein on its surface. Scientists have been struggling to capture the complex protein’s precise structure — and specifically, its structure before the virus fuses with the T-cell membrane.

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In zebrafish, a way to find new cancer therapies, targeting tumor promoters

A new study suggests the power of zebrafish as tools for cancer drug discovery (PHOTO: KATHERINE C. COHEN)

The lab of Leonard Zon, MD, has long been interested in making blood stem cells in quantity for therapeutic purposes. To test for their presence in zebrafish, their go-to research model, they turned to the MYB gene, a marker of blood stem cells. To spot the cells, Joseph Mandelbaum, a PhD candidate in the lab, attached a fluorescent green tag to MYB that made it easily visible in transparent zebrafish embryos.

“It was a real workhorse line for us,” says Zon, who directs the Stem Cell Research Program at Boston Children’s Hospital.

In addition to being a marker of blood stem cells, MYB is an oncogene. About five years ago, Zon was having lunch at a cancer meeting and, serendipitously, sat next to Jeff Kaufman, who was also interested in MYB. Kaufman was excited to hear about Zon’s fluorescing MYB zebrafish, which can be studied at scale and are surprisingly similar to humans genetically.

“Have you ever heard of adenoid cystic carcinoma?” he asked Zon.

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Super suppressor: Boosting a gene that stifles tumor growth

Researchers have packaged a tumor suppressor into a therapeutic nanoparticle.
Researchers have packaged a tumor suppressor into a therapeutic nanoparticle. IMAGE: ISLAM, ET AL.

Most of the time, cancer cells do a combination of two things: they overexpress genes that drive tumor growth and they lose normal genes that typically suppress tumors. No two tumors are exactly alike, but some combination of these two effects is usually what results in cancer. Now, for the first time, researchers have shown that it’s possible to treat cancer by delivering a gene that naturally suppresses tumors.

Researchers from Boston Children’s Hospital, Brigham and Women’s Hospital and Memorial Sloan Kettering Cancer Center combined their cancer biology and nanomaterials expertise and developed a therapeutic capable of delivering a tumor suppressor gene known as PTEN, the loss of which can allow tumors to grow unchecked.

In several preclinical models, their PTENboosting therapeutic was able to inhibit tumor growth. Their findings were published yesterday in Nature Biomedical Engineering.

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Self-sacrificing cells hold clues to improving treatment of MRSA, sepsis

Image of neutrophils
During infection, white blood cells called neutrophils eject their own DNA strands outward to block bacteria from spreading. IMAGE: ADOBE STOCK

Over the last several years, scientists have made great headway in our understanding of how self-sabotaging immune cells play a role in our ability to fight infection. So far, we know that when white blood cells called neutrophils are triggered by bacterial infection, they self-combust and eject their own DNA strands outward like spider webs. Sacrificing themselves, the exploded neutrophils and their outreaching DNA tentacles form sunburst-shaped neutrophil extracellular traps (NETs).

“NET formation is an innate immune response that our body has when it recognizes the presence of pathogens,” says Ben Croker, PhD, a researcher in the Division of Hematology/Oncology at Boston Children’s Hospital. “Once formed, NETs restrict pathogen movement and proliferation and alert the rest of the immune system to the invader’s presence.”

Now, Croker and a team of researchers at Boston Children’s have identified a critical element of NET formation and how it enables the body to fight off infections like methicillin-resistant Staphylococcus aureus (MRSA). Their findings, recently published in Science Signaling, could someday have clinical implications for tough-to-treat infections and even sepsis.

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Genomic sequencing for newborns: Are parents receptive?

BabySeqCasie Genetti, MS, CGC is a licensed genetic counselor with the Manton Center for Orphan Disease Research at Boston Children’s Hospital. She is first author of a recently published paper on the BabySeq Project.

The idea of genomic sequencing for every newborn has many in the scientific community buzzing with excitement, while leaving others wary of the ethical and social implications. But what do the parents think? The BabySeq Project has been exploring parental motivations and concerns while assessing their willingness to participate in a pilot newborn sequencing study.

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Neurons from the brain amplify touch sensation. Could they be targeted to treat neuropathic pain?

neuropathic pain amplification circuit
CREDIT: ALBAN LATREMOLIERE/BOSTON CHILDREN’S HOSPITAL/JOHNS HOPKINS

Neuropathic pain is a hard-to-treat chronic pain condition caused by nervous system damage. For people affected, the lightest touch can be intensely painful. A study in today’s Nature may open up a new angle on treatment — and could help explain why mind-body techniques can sometimes help people manage their pain.

“We know that mental activities of the higher brain — cognition, memory, fear, anxiety — can cause you to feel more or less pain,” notes Clifford Woolf, MB, BCh, PhD, director of the F.M. Kirby Neurobiology Center at Boston Children’s Hospital. “Now we’ve confirmed a physiological pathway that may be responsible for the extent of the pain. We have identified a volume control in the brain for pain — now we need to learn how to switch it off.”

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Typing medulloblastoma: From RNA to proteomics and phospho-proteomics

medulloblastoma proteomics study
Medulloblastoma (CREDIT: ARMED FORCES INSTITUTE OF PATHOLOGY/WIKIMEDIA)

Medulloblastoma is one of the most common pediatric brain tumors, accounting for nearly 10 percent of cases. It occurs in the cerebellum, a complex part of the brain that controls balance, coordination and motor function and regulates verbal expression and emotional modulation. While overall survival rates are high, current therapies can be toxic and cause secondary cancers. Developing alternative therapeutics is a priority for the field.

As early as the 1990s, the lab of Scott Pomeroy, MD, PhD, neurologist-in-chief at Boston Children’s Hospital, discovered molecules in medulloblastoma tumors that could predict response to therapies. In 2010, Pomeroy and colleagues uncovered four distinct molecular subtypes of medulloblastoma.

The World Health Organization updated the brain tumor classification scheme in 2016 to include these molecular and genetic features. In the new scheme, tumor subtypes with a good molecular prognosis receive less radiation and chemotherapy. But the creation of targeted therapeutics has remained a challenge, since some of the genetic pathways implicated in these subtypes are found in non-cancerous cells.

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Blood filtration device could provide personalized care for sepsis

Artistic image of cytokines
Could cell-signaling proteins called cytokines be modulated to tame inflammation? IMAGE: ADOBE STOCK

Cytokines are small proteins produced by the body’s cells that have a big impact on our immune system. Researchers at Boston Children’s Hospital believe that modulating their presence in our bodies could be the key to improving outcomes in life-threatening cases of trauma, hemorrhage and many other conditions including sepsis, which alone impacts nearly one million Americans each year.

The reason? Cells essentially use cytokines to talk to one another. In response to their surroundings, cells release different types of cytokines that encourage inflammatory or anti-inflammatory effects on the body. Infection or trauma causes cells to pump out more cytokines that produce inflammation. Altogether, an escalating chorus of cytokines can sometimes tip a person’s body into overwhelming inflammation that can turn fatal, which is what happens during sepsis.

But what if scientists could remove the problematic cytokines to bring the choir into perfect tune, allowing the immune system to respond with just the right amount of inflammation for healing?

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