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clatharin cage viewed by electron microscopy

IPSE infiltrates nuclei through clathrin-mediated endocytosis

clatharin cage viewed by electron microscopy

IPSE, one of the important proteins excreted by the parasite Schistosoma mansoni, infiltrates human cellular nuclei through clathrin-coated vesicles, like this one.

IPSE, one of the important proteins excreted by the parasite Schistosoma mansoni infiltrates human cellular nuclei through clathrin-mediated endocytosis (a process by which cells absorb metabolites, hormones and proteins), a research team led by Children’s National Hospital reported during the American Society of Tropical Medicine and Hygiene 2019 annual meeting.

Because the public health toll from the disease this parasite causes, Schistosomiasis, is second only to malaria in global impact, research teams have been studying its inner workings to help create the next generation of therapies.

In susceptible host cells – like urothelial cells, which line the urinary tract – IPSE modulates gene expression, increasing cell proliferation and angiogenesis (formation of new blood vessels). On a positive note, neurons appear better able to fend off its nucleus-infiltrating ways.

“We know that IPSE contributes to the severity of symptoms in Schistosomiasis, which leads some patients to develop bladder cancer, which develops from the urothelial lining of the bladder. Our team’s carefully designed experiments reveal IPSE’s function in the urothelium and point to the potential of IPSE playing a therapeutic role outside of the bladder,” says Michael Hsieh, M.D., Ph.D., director of transitional urology at Children’s National and the research project’s senior author.

In addition to Dr. Hsieh, research co-authors include Evaristus Mbanefo, Ph.D.; Kenji Ishida, Ph.D.; Austin Hester, M.D.; Catherine Forster, M.D.; Rebecca Zee, M.D., Ph.D.; and Christina Ho, M.D., all of Children’s National; Franco Falcone, Ph.D., University of Nottingham; and Theodore Jardetzky, Ph.D., and Luke Pennington, M.D., Ph.D., candidate, both of Stanford University.

Financial support for research described in this post was provided by the National Institutes of Health under award No. R01-DK113504.

Hepatocytes

H-IPSE internalized by just a limited range of cells

Hepatocytes

A team led by Children’s National Hospital found that H-IPSE is internalized by just a limited range of cells, including hepatocytes.

Schistosoma mansoni is a parasite that hides out in snails, breaks free into waterways, and then infects humans, spending much of its life inside blood vessels, laying eggs and jeopardizing public health when those eggs are excreted in urine or feces. As parasitic diseases go, the ailment it causes, Schistosomiasis, is second only to malaria in global impact, according to the Centers for Disease Control and Prevention.

In order to elude the human host’s defenses, S. mansoni uses self-defense tactics that researchers are trying to better understand in order to outmaneuver the parasite. A research team led by Children’s National Hospital is trying to tease out the multiple steps that enable this parasite to reproduce and generate millions of eggs without killing its host.

The parasite’s eggs secrete a number of proteins, with IPSE as one of the most abundant, the team recently presented during the American Society of Tropical Medicine and Hygiene 2019 annual meeting. That protein binds immunoglobulin, which induces basophils and mast cells to release IL-4. After sequestering chemokines, H-IPSE infiltrates the cell nucleus (thus H-IPSE is called an infiltrin), modulating gene expression.

“H-IPSE tips the immune system balance, making it more likely to trigger a Th2 anti-inflammatory response,” says Michael Hsieh, M.D., Ph.D., director of transitional urology at Children’s National and the research project’s senior author. “It downregulates pro-inflammatory pathways, but we wanted to know more about which specific human cells it targets.”

Using Trypan Blue, a stain that selectively colors certain cells bright blue, they solved the mystery, finding that H-IPSE is internalized by just a limited range of cells. What’s more, some cell types, like urothelial cells and hepatocytes (the liver’s chief functioning cells, which activate innate immunity), are more susceptible than neurons, endothelial cells or immature dendritic cells.

In addition to Dr. Hsieh, presentation co-authors include Olivia Lamanna, Evaristus Mbanefo and Kenji Ishida, all of Children’s National; Franco Falcone, of University of Nottingham; and Theodore Jardetzky and Luke Pennington, of Stanford University.

Dr. Michael Hsieh's clay shield

Innovative urologist Michael Hsieh takes unbeaten path

Dr. Michael Hsieh's clay shield

For an elementary school art project, Michael H. Hsieh, M.D., Ph.D., was instructed to fashion a coat of arms out of clay. In addition to panels for truth, justice and Taiwan, in the shield’s M.D. panel, a snake twists around a rod, like the staff for Asclepius, a Greek god associated with healing.

Children’s urologist Michael H. Hsieh, M.D., Ph.D., knew from age 10 that he would become a doctor. Proof is at his parents’ home. For an elementary school art project, students were instructed to fashion a coat of arms out of clay. In addition to panels for truth, justice and Taiwan, in the shield’s M.D. panel, a snake twists around a rod, like the staff for Asclepius, a Greek god associated with healing.

“I liked science. When I can use it to help patients, that is very rewarding,” says Dr. Hsieh, the first doctor in his family.

These days, Dr. Hsieh’s Twitter profile serves as a digital coat of arms, describing him as “tinker, tailor,” #UTI #biologist, epithelial #immunologist, helminthologist and #urologist.

Tinker/tailor is shorthand for the mystery drama, “Tinker Tailor Solider Spy,” he explains, adding that the “tinker” part also refers “to the fact that I am always questioning things, and science is about experimentation, trying to seek answers to questions.”

While still in medical school during a rotation Dr. Hsieh saw a bladder operation on a young child and thought it was “amazing.” That experience in part inspired Dr. Hsieh to become a urologist and bladder scientist. His training in immunology and study of the bladder naturally led him to study urinary tract infections and parasitic worms that affect the urinary tract. In addition, thanks to R01 funding from the National Institutes of Health (NIH), Dr. Hsieh is co-principal investigator with Axel Krieger, University of Maryland, and Jin U. Kang, Johns Hopkins, on a project to develop imaging robots for supervised autonomous surgery on soft tissue.

The $1 million in NIH funding pushes the boundaries on amazing by using multi-spectral imaging technology and improved techniques to reduce surgical complications.

Anastomosis is a technique used by surgeons to join one thing to another, whether it’s a vascular surgeon suturing blood vessels, an orthopedic surgeon joining muscles or a urologist stitching healthy parts of the urinary tract back together. Complications can set in if their stitching is too tight, prompting scar tissue to form, or too loose, letting fluid seep out.

“The human eye can see a narrow spectrum of electromagnetic radiation. These multi-spectral imaging cameras would see across greater set of wavelengths,” he says.

The project has three aims: figuring out the best way to place sutures using multi-spectral imaging, accurately tracking soft tissue as they model suturing and comparing the handicraft of a robot against anastomosis hand-sewn by surgeons.

“I like challenges, and I like new things. I am definitely not interested in doing permutations of other people’s work,” Dr. Hsieh explains. “I would much rather go on a path that hasn’t been tread. It is more difficult in some ways, but on a day-to-day basis, I know I am making a contribution.”

In another innovative research project, Dr. Hsieh leveraged a protein secreted by a parasitic worm, Schistosoma haematobium, that suppresses inflammation in hosts as a new therapeutic approach for chemotherapy-induced hemorrhagic cystitis, a form of inflammation of the bladder.

Watching his first surgery nearly 30 years ago, he had no idea robots might one day vie to take over some part of that complicated procedure, or that parasite proteins could be harnessed as drugs. However, he has a clear idea which innovations could be on the horizon for urology in the next three decades.

“My hope is 30 years from now, we will have a solid UTI vaccine and more non-antibiotic therapies. UTIs are the second-most common bacterial infection in childhood and, in severe cases, can contribute to kidney failure,” he says.

Globally, parasitic worms pose an ongoing challenge, affecting more than 1 billion worldwide – second only to malaria. People persistently infected by schistosome worms fail to reach their growth potential, struggle academically and lack sufficient energy for exercise or work.


“There is a feeling that the infection prevalence might be decreasing globally, but not as quickly as everyone hopes. In 30 years perhaps with more mass drug administration and additional drugs – including a vaccine – we’ll have it close to eliminated globally. It would become more like polio, casting a slim shadow with small pockets of infection here or there, rather than consigning millions to perpetual poverty.”