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schistosome blood fluke

Therapy derived from parasitic worms downregulates proinflammatory pathways

schistosome blood fluke

A therapy derived from the eggs of the parasitic Schistosoma helps to protect against one of chemotherapy’s debilitating side effects by significantly downregulating major proinflammatory pathways, reducing inflammation.

A therapy derived from the eggs of parasitic worms helps to protect against one of chemotherapy’s debilitating side effects by significantly downregulating major proinflammatory pathways and reducing inflammation, indicates the first transcriptome-wide profiling of the bladder during ifosfamide-induced hemorrhagic cystitis.

The experimental model study findings were published online Feb. 7, 2019, in Scientific Reports.

With hemorrhagic cystitis, a condition that can be triggered by anti-cancer therapies like the chemotherapy drug ifosfamide and other oxazaphosphorines, the lining of the bladder becomes inflamed and begins to bleed. Existing treatments on the market carry their own side effects, and the leading therapy does not treat established hemorrhagic cystitis.

Around the world, people can become exposed to parasitic Schistosoma eggs through contaminated freshwater. Once inside the body, the parasitic worms mate and produce eggs; these eggs are the trigger for symptoms like inflammation. To keep their human hosts alive, the parasitic worms tamp down excess inflammation by secreting a binding protein with anti-inflammatory properties.

With that biological knowledge in mind, a research team led by Michael H. Hsieh, M.D., Ph.D., tested a single dose of IPSE, an Interleukin-4 inducing, Schistosoma parasite-derived anti-inflammatory molecule and found that it reduced inflammation, bleeding and urothelial sloughing that occurs with ifosfamide-related hemorrhagic cystitis.

In this follow-up project, experimental models were treated with ifosfamide to learn more about IPSE’s protective powers.

The preclinical models were given either saline or IPSE before the ifosfamide challenge. The bladders of the experimental models treated with ifosfamide had classic symptoms, including marked swelling (edema), dysregulated contraction, bleeding and urothelial sloughing. In contrast, experimental models “pre-treated” with IPSE were shielded from urothelial sloughing and inflammation, the study team found.

Transcriptional profiling of the experimental models’ bladders found the IL-1-B TNFa-IL-6 proinflammatory cascade via NFkB and STAT3 pathways serving as the key driver of inflammation. Pretreatment with IPSE slashed the overexpression of Il-1b, Tnfa and Il6 by 50 percent. IPSE drove significant downregulation of major proinflammatory pathways, including the IL-1-B TNFa-IL-6 pathways, interferon signaling and reduced (but did not eliminate) oxidative stress.

“Taken together, we have identified signatures of acute-phase inflammation and oxidative stress in ifosfamide-injured bladder, which are reversed by pretreatment with IPSE,” says Dr. Hsieh, a urologist at Children’s National Health System and the study’s senior author. “These preliminary findings reveal several pathways that could be therapeutically targeted to prevent ifosfamide-induced hemorrhagic cystitis in humans.”

When certain chemotherapy drugs are metabolized by the body, the toxin acrolein is produced and builds up in urine. 2-mercaptoethane sulfonate Na (MESNA) binds to acrolein to prevent urotoxicity. By contrast, IPSE targets inflammation at the source, reversing inflammatory changes that damage the bladder.

“Our work demonstrates that there may be therapeutic potential for naturally occurring anti-inflammatory molecules, including pathogen-derived factors, as alternative or complementary therapies for ifosfamide-induced hemorrhagic cystitis,” Dr. Hsieh adds.

In addition to Dr. Hsieh, study co-authors include Lead Author Evaristus C. Mbanefo and Rebecca Zee, Children’s National; Loc Le, Nirad Banskota and Kenji Ishida, Biomedical Research Institute; Luke F. Pennington and Theodore S. Jardetzky, Stanford University; Justin I. Odegaard, Guardant Health; Abdulaziz Alouffi, King Abdulaziz City for Science & Technology; and Franco H. Falcone, University of Nottingham.

Financial support for the research described in this report was provided by the Margaret A. Stirewalt Endowment, the National Institute of Diabetes and Digestive and Kidney Diseases under award R01DK113504, the National Institute of Allergy and Infectious Diseases under award R56AI119168 and a Urology Care Foundation Research Scholar Award.

Schistosoma haematobium egg

For hemorrhagic cystitis, harnessing the power of a parasite

Schistosoma haematobium egg

“Urogenital Schistosoma infestation, which is caused by S. haematobium, also causes hemorrhagic cystitis, likely by triggering inflammation when the parasite’s eggs are deposited in the bladder wall or as eggs pass from the bladder into the urinary stream. S. haematobium eggs secrete proteins, including IPSE, that ensure human hosts are not so sickened that they succumb to hemorrhagic cystitis,” says Michael H. Hsieh, M.D., Ph.D.

Every year, hundreds of thousands of U.S. patients – and even more throughout the world – are prescribed cyclophosphamide or ifosfamide. These two chemotherapy drugs can be life-saving for a wide range of pediatric cancers, including leukemias and cancers of the eyes and nerves. However, these therapies come with a serious side effect: Both cause hemorrhagic cystitis in up to 40 percent of patients. This debilitating condition is characterized by severe inflammation in the bladder that can cause tremendous pain, life-threatening bleeding, and frequent and urgent urination.

Infection with a parasitic worm called Schistosoma haematobium also causes hemorrhagic cystitis, but this organism has a fail-safe: To keep its host alive, the parasite secretes a protein that suppresses inflammation and the associated pain and bleeding.

In a new study, a Children’s-led research team harnessed this protein to serve as a new therapy for chemotherapy-induced hemorrhagic cystitis.

“Urogenital Schistosoma infestation, which is caused by S. haematobium, also causes hemorrhagic cystitis, likely by triggering inflammation when the parasite’s eggs are deposited in the bladder wall or as eggs pass from the bladder into the urinary stream. S. haematobium eggs secrete proteins, including IPSE, that ensure human hosts are not so sickened that they succumb to hemorrhagic cystitis,” says Michael H. Hsieh, M.D., Ph.D., senior author of the study published April 3, 2018, by The FASEB Journal. “This work in an experimental model is the first published report of exploiting an uropathogen-derived host modulatory molecule in a clinically relevant model of bladder disease, and it points to the potential utility of this as an alternate treatment approach.”

S. mansoni IPSE binds to Immunoglobulin E (IgE), an antibody produced by the immune system that is expressed on the surface of basophils, a type of immune cell; and mast cells, another immune cell that mediates inflammation; and sequesters chemokines, signaling proteins that alert white cells to infection sites. The team produced an ortholog of the uropathogen-derived protein. A single IV dose proved superior to multiple doses of 2-Mercaptoethane sulfonate sodium (MESNA), the current standard of care, in suppressing chemotherapy-induced bladder hemorrhaging in an experimental model. It was equally potent as MESNA in dampening chemotherapy-induced pain, the research team finds.

“The current array of medicines we use to treat hemorrhagic cystitis all have shortcomings, so there is a definite need for novel therapeutic options,” says Dr. Hsieh, a Children’s National Health System urologist. “And other ongoing research projects have the potential to further expand patients’ treatment options by leveraging other urogenital parasite-derived, immune-modulating molecules to treat inflammatory bowel diseases and autoimmune disorders.”

Future research will aim to describe the precise molecular mechanisms of action, as well as to generate other orthologs that boost efficacy while reducing side effects.

In addition to Dr. Hsieh, Children’s study co-authors include Lead Author, Evaristus C. Mbanefo; Loc Le and Luke F. Pennington; Justin I. Odegaard and Theodore S. Jardetzky, Stanford University; Abdulaziz Alouffi, King Abdulaziz City for Science and Technology; and Franco H. Falcone, University of Nottingham.

Financial support for this research was provided by National Institutes of Health under award number RO1-DK113504.

Michael Hsieh

Michael Hsieh receives grant to explore parasite proteins for pain relief

Michael Hsieh

Michael Hsieh, M.D., hopes to use parasite proteins to alleviate pain in multiple types of bladder inflammation.

Children’s National Health System Urologist Michael Hsieh, M.D., was awarded a National Institutes of Health (NIH) grant to optimize a set of parasite proteins that could alleviate pain in multiple types of bladder inflammation.

The $1 million R01 grant will fund a five-year study to exploit a parasite-derived protein, IPSE, as a candidate therapeutic. Dr. Hsieh hypothesizes that IPSE may have the ability to modulate host immune and non-immune responses to bladder injury. IPSE could be optimized for therapeutic potential, while minimizing toxicity, by generating forms that have the ability to modulate host responses via three distinct mechanisms: IL-4-binding, chemokine-binding and nuclear localization.