Dr. Urano’s April 2020 Update

Fumihiko “Fumi” Urano, MD

Dear Friends,

I hope you and your family are safe and well during this COVID-19 pandemic. Three things are always on my mind: Improve clinical care, Raise awareness, and Provide a cutting-edge treatment for Wolfram syndrome. As I mentioned on January 1st, I am determined to make 2020 the game-changing year for us despite this challenging time. Today, I would like to share the good news with you.

We have been testing if gene editing by CRISPR-Cas9, in combination with patient-derived induced pluripotent stem cells (iPSCs), can be utilized for the treatment of Wolfram Syndrome.I am glad to inform you that gene editing worked in Wolfram patient iPSC-derived beta cells. We were able to use these cells to cure one of the problems, making normal beta cells by correcting WFS1 gene mutation. We could cure diabetes in cells and mice. This is a proof of concept demonstrating that correcting gene defects that cause or contribute to medical problems— in this case, in the Wolfram syndrome gene — we can cure the problems. This is a major discovery in the gene therapy field, and it has been just published in a high-profile medical research journal, Science Translational Medicine.https://medicine.wustl.edu/news/diabetes-reversed-in-mice-with-genetically-edited-patient-derived-stem-cells/

Based on this discovery, it is now possible that by correcting the genetic defects in these cells, we may correct other problems Wolfram Syndrome patients experience, such as visual impairment and neurodegeneration. So, we are currently working on eye and brain cells derived from iPSCs of patients with Wolfram Syndrome to replicate this success for other problems. Many, many thanks to my patients, colleagues at Washington University and supporters in the world. Thank you, Stephanie Snow Gebel and the Snow Foundation.

As always, please feel free to contact me with any questions (urano@wustl.edu). I would like to know what you think and how you feel. Thank you again for your continued support and encouragement, especially in this very trying time, not only for our country, but the world. We will work as one team and change history together.

“That’s one small step for us today, leading to one giant leap toward a cure for Wolfram Syndrome.”

 

Sincerely,

Fumi Urano, MD, PhD

April 23, 2020

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ZOLD Gene-edited human stem cell–derived β cells from a patient with monogenic diabetes reverse preexisting diabetes in mice

Publication: Science Translational Medicine | Publication Date: April 22, 2020

Authors: Kristina G. Maxwell, Punn Augsornworawat, Leonardo Velazco-Cruz, Michelle H. Kim, Rie Asada, Nathaniel J. Hogrebe, Shuntaro Morikawa, Fumihiko Urano, Jeffrey R. Millman

Repaired β cells for replacement therapy

Wolfram syndrome is a recessive genetic disease caused by mutations in WFS1 (Wolfram syndrome 1) and can present with a multitude of symptoms including diabetes, optic atrophy, and neurological problems. There is currently no cure and patients are managed with symptomatic treatment. Maxwell et al. corrected a WFS1 pathogenic variant in patient fibroblast-derived induced pluripotent stem cells (iPSCs) that they then differentiated to pancreatic β cells. The gene-corrected β cells showed improved glucose-stimulated insulin secretion and reversed hyperglycemia for 6 months after their transplantation into diabetic mice. This study may open up the possibility of autologous β cell transplants for patients with Wolfram syndrome.

Read the entire research article here

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ZOLD Neuronal Calcium Sensor 1 (NCS1) as a Potential Drug Target for Treatment of Wolfram Syndrome

Publication: The Faseb Journal | Publication Date: April 15, 2020

Authors: Tom T. Fischer, Lien D. Nguyen, Barbara E. Ehrlich

Abstract

Wolfram syndrome (WS) is an orphan, autosomal recessive neuroendocrinological disease that affects approximately 1 in 500,000 people worldwide. Patients develop diabetes mellitus, diabetes insipidus, optical atrophy, and hearing loss and usually die in their 30s. The majority of cases are attributed to mutations in a single gene, WFS1, which encodes for the protein wolframin. Despite the known genetic cause, there is currently no direct treatment for WS. This lack of therapy is because the regular functions of wolframin, and the pathophysiological consequences following the loss of intact WFS1, remain elusive. Here, we further examined the function of WFS1 in the context of glucose toxicity, to address the earliest diagnosed symptom of WS which is the onset of diabetes mellitus near age 6. Based on a recent study, we aimed to show that WFS1 interaction with a calcium binding protein, neuronal calcium sensor 1 (NCS1), is important for its normal functions. NCS1 is known to regulate exocytosis, promote cell survival, and maintain calcium homeostasis. We showed that knocking out WFS1 in rat insulinoma (INS1) cells resulted in increased baseline calcium, reduced ATP‐evoked inositol‐trisphosphate receptor (InsP3R)‐dependent calcium response, reduced phospho‐Akt (Ser473), and increased vulnerability to high glucose treatment. Furthermore, both INS1 control (CTRL) and WFS1 knockout (KO) cells showed increased NCS1 mRNA following high glucose treatment. However, only the CTRL cells showed increased NCS1 protein expression, whereas WFS1 KO cells showed decreased NCS1 expression. These results suggest that NCS1‐WFS1 interaction protects NCS1 from degradation, potentially by the calcium‐dependent protease calpain. Lastly, we showed that overexpression of NCS1, or treatment with a putative NCS1‐binding drug, rescued the deficits observed in WFS1 KO cells. Overall, we demonstrated a physiological function of the WFS1‐NCS1 interaction and that protecting NCS1 levels can ameliorate the deficits caused by loss of WFS1. These findings will facilitate the discovery of drugs that can prevent or reduce the symptoms of WS.

Read the entire research article here

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