Atpif1 gene regulates heme synthesis in red blood cell formation

Scientists at the University of Georgia, Harvard Medical School and the University of Utah have discovered a new gene that regulates heme synthesis in red blood cell formation. Heme is the deep-red, iron-containing component of hemoglobin, the protein in red blood cells responsible for transporting oxygen in the blood.
The study was published online Nov. 7 and will be in the Nov. 22 print edition of the journal Nature. The findings promise to advance the biomedical community's understanding and treatment of human anemias and mitochondrial diseases, both known and unknown.
The gene-known as mitochondrial ATPase inhibitory factor-1 gene or Atpif1-was uncovered from a chemical mutagenesis screen of zebrafish, an organism which shares many of the same genes that regulate blood development in humans.
"With zebrafish, we are able to accelerate natural disease processes and screen for many more mutations in blood than we could ever see in random circumstance of human patients," said study senior co-author Dr. Barry Paw, a hematologist and associate professor of medicine at Harvard Medical School.
"In our case, we were looking for mutants that were bloodless, presumably because whatever gene that was inactivated by the random mutation must be critical for blood development, if one of these embryos were bloodless."
That is what Paw and his team found when they stumbled upon the particular "bloodless" mutant zebrafish called pinotage. The loss of the Atpif1 gene was the cause of the fish's severe anemia.
The next step for the team was to determine if the anemia was a defect of iron metabolism or heme homeostasis. Collaborating with molecular biologist Jerry Kaplan at the University of Utah, the researchers discovered a possible link between Atpif1 and ferrochelatase, the terminal enzyme in heme synthesis.
UGA microbiologist Harry Dailey, a leading authority in the structure and function of ferrochelatase, was brought on board. Collaborative work between the Paw and Dailey laboratories uncovered a broader mechanistic role for Atpif1 in regulating the enzymatic activity of ferrochelatase.

"We believe that the two iron-two sulfur (2Fe- 2S) cluster of ferrochelatase allows it to sense certain metabolic fluxes in the cell and respond to those fluxes in an appropriate way," said Dailey, who is a professor of microbiology and director of the UGA Biomedical and Health Sciences Institute. "When Atpf1 is deficient, there is a change in the mitochondrial pH/redox potential. This change is sensed by the cluster, and ferrochelatase activity is turned down, which results in diminished heme synthesis."
The researchers also were able to produce data on the human version of Atpif1, noting its functional importance for normal red blood cell differentiation as well as how a deficiency may contribute to human diseases-such as congenital anemias and disorders related to dysfunctional mitochondria, the organelles that power the cell.
Overall, Dailey believes the study's results will impact the field of red blood cell development significantly with the establishment of the ferrochelatase [2Fe-2S] cluster as a new regulatory component in heme synthesis. New areas of investigation will open, he said, and the molecular basis of currently undefined red blood cell-based syndromes and diseases may be revealed.
Source: University of Georgia

Atpif1 gene regulates hemoglobin synthesis during red blood cell formation

Researchers at Brigham and Women's Hospital (BWH) have discovered a new gene that regulates hemoglobin synthesis during red blood cell formation. The findings advance the biomedical community's understanding and treatment of human anemias and mitochondrial disorders.
The study will be published online on November 7, 2012 in Nature.
The researchers used an unbiased zebrafish genetic screen to clone mitochondrial ATPase inhibitory factor-1 gene, or Atpif1. The gene allows animals-zebrafish, mice and humans for instance-to efficiently make hemoglobin. Hemoglobin is the protein in red blood cells responsible for transporting oxygen in the blood.
The researchers found that loss of Atpif1 causes severe anemia. Moreover, the researchers uncovered a broader mechanistic role for Atpif1-regulating the enzymatic activity of ferrochelatase, or Fech. Fech is the terminal enzyme in heme (a component of hemoglobin) synthesis.
"Our study has established a unique functional link between Atpif1-regulated mitochondrial pH, redox potential, and [2Fe-2S] cluster binding to Fech in modulating its heme synthesis," said Dhvanit Shah, PhD, BWH Division of Hematology, Department of Medicine, first study author.
The researchers were also able to produce data on the human version of Atpif1, noting its functional importance for normal red blood cell differentiation, and noting that a deficiency may contribute to human diseases, such as congenital sideroblastic anemias and other diseases related to dysfunctional mitochondria (the energy powerhouses of cells).

"Discovering the novel mechanism of Atpif1 as a regulator of heme synthesis advances the understanding of mitochondrial heme homeostasis and red blood cell development," said Barry Paw, MD, PhD, BWH Division of Hematology, Department of Medicine, senior study author.
Shah and Paw continue to identify new genes responsible for hematopoietic stem cell development and red cell differentiation. Their identification of new genes will elucidate the new mechanisms regulating hematopoiesis-the formation of blood cell components. Their work not only provides greater insight into human congenital anemias, but also new opportunities for improved therapies.
Anemia, a condition in which your blood has a lower than normal number of red blood cells or hemoglobin levels, can affect people of all ages. Women of childbearing age and older adults are at higher risk. Babies and children are also at risk for anemia due to nutritional iron deficiency or lead poisoning.
Source: Brigham and Women's Hospital

Patient Profile: Khai - Healing, Halfway Around the World

When Heather and Aaron Ayris decided to welcome a nine-year old boy with thalassemia into their home for six weeks, they hoped their hospitality would help improve his health. They wanted to show their guest a good time and lift his spirit.
But it’s the Ayris family whose lives were changed – and it all began in May 2009, as soon as they met nine-year old Khai at the airport in Charlotte, North Carolina.    

“I am quite certain that, at that moment in the airport, as I hugged him, he became a part of our family - no words needed,” Heather said.

Khai came to the United States from war-torn Afghanistan through a non-profit organization that organizes medical and dental care for impoverished Afghan children. He was placed with the Ayris family, who had volunteered to host him.  Khai had struggled with thalassemia for his entire life, receiving transfusions but no medications. So, within just a few days of his arrival, Heather took him to the doctor – and, right away, discovered the challenges they had to confront together.

   

“When we were told he had beta thalassemia major, I calmly asked, ‘What is that?’ The doctor told us is was a severe form of anemia,” Heather explained. “While we knew he was anemic, we were about to learn a lot more about a genetic disease that I’d never heard of before.”

 And so the Ayris family began racing against time to find out – and do – as much as they could for Khai within the six weeks they had with him. Through numerous doctor visits and dozens of tests, they found out that Khai had severe iron overload – the result of years of transfusions without iron chelation medication. 

“The ferritin count in his blood tests was above 13,000, and there was no telling how high the iron concentration was in his organs,” Heather said. “We knew they were at risk for failure. We contacted Khai’s family in Afghanistan and found out that three of his siblings had died from the illness, including his 13-year-old sister who’d recently died of heart failure.”

With that, a race against time became a struggle to save Khai’s life. When she wasn’t visiting physicians with Khai, working or taking care of her two children – A.J. and Cade – Heather was busy researching ways to quickly get Khai’s iron levels under control. But his six-week stay was fast coming to an end.

Just three days before he was scheduled to depart, Khai’s family in Afghanistan agreed that he should stay longer for treatment. The nonprofit organization that had brought him to the United States arranged for a visa extension. A pharmaceutical company approved Khai for participation in an assistance program that gave him access to critical iron chelation medication. And a local hospital pledged to help cover the costs of Khai’s monthly blood  transfusions.

.

Everything seemed to be going right in pursuit of better health for Khai – but Heather Ayris kept on researching, looking for better possibilities for the little boy who had become part of their family.

“Over the next few months, I made countless phone calls and sent email, trying to understand more about beta thalassemia major and the concerns with chronic iron overload. Most of the e-mails I sent went unanswered, but one very important e-mail received a reply – from the Cooley’s Anemia Foundation,” Heather explained. “I'm thankful every day for the response from Eileen Scott, Patient Services Manager at Cooley's Anemia Foundation. Every time I called with a tearful question on how to make the treatments less painful for Khai or to celebrate the lowering of his iron counts, she was there!”

With a group effort led by the Ayris family’s love and persistence, Khai’s health is much improved. His ferritin levels are less than half of what they were upon his arrival, and he was recently accepted into a clinical trial for more advanced forms of combined chelation treatment. And equally important for both Khai and his American family, he’s really enjoying his life in North Carolina.

"Khai is in Boy Scouts; he started this past year and really enjoys it.  He’s an ‘outside boy’ and enjoys hiking, nature and working in the yard,” Heather said. “He came to us knowing no English at all and previously was not able to attend school in Afghanistan, so he’s had to get used to formal education here.  He’s now able to read and write and, while he has some catching up to do, he’s definitely on the right track. And we’re all very proud of how resilient all three of our boys – Khai, A.J. and Cade – have been.”

But, even though he’s getting more accustomed to life in the United States – and is benefiting from the level of health care available to him here – Heather Ayris is determined to keep Khai connected to his family in Afghanistan and his roots.

“We try to Skype with Khai's Afghan family every two weeks or so.  We purchased a laptop for them, and Skyping has made a big difference for Khai, being able to see them in person,” Heather explained. “However, because he’s not using his native language (Pashto) frequently, he’s losing his ability to speak and understand it.  That really has made me sad because I don’t want him to lose his heritage.” 

“It’s important for him to remember where he comes from,” she continued. “We shared that concern with Khai’s family, but his father has told us that it doesn’t matter to them.  It’s more important to them to see their child healthy and thriving, and they are just so thankful that he has another family here that loves and cares for him.”

And that’s exactly what Khai has.

"Meeting, Overcoming and Understanding Life’s Challenges" - Patient Profile of Rucha Shah

For 25-year-old Rucha Shah, the hardest part of living with thalassemia is the impact it has on her family.  

“The most difficult thing for my family is making sure that I am healthy and will remain healthy in the near future,” Rucha explained. “Most parents of young adults do not have to worry about that.”

It’s hard to overstate the strain on families from a lifelong blood disorder like thalassemia. Rucha and her family have worked hard to maintain good health ever since she was diagnosed at just seven months old.

The Shah family was living in Mumbai, India at the time. Under the care of a local hematologist, Rucha underwent regular blood transfusions and took a chelation medication called L1 (also known as deferiprone)  to keep her iron levels under control. Iron buildup in vital organs, particularly the heart, is one of the main causes of early fatality for patients like Rucha.

Rucha’s family kept up-to-date about the latest research, medications and other information through newsletters from the Cooley ’s Anemia Foundation (CAF), which they learned about through one of their relatives. Especially early on, these newsletters were helpful in guiding family decisions about their daughter’s well being.

"Thalassemia, although a huge part of my life, does not dictate it.”

When she was 16, her hematologist placed her on a more aggressive regimen of iron-chelating medications, adding Desferal injections to Rucha’s routine. That meant enduring almost-daily needle jabs and between eight and 12 hours of being attached to a subcutaneous injection pump. And that’s one of the hardest things for parents of children with thalassemia: the treatments require long stretches of time and are often painful.

Rucha’s treatment regimen became even more complicated at age 18, when her family immigrated from Mumbai to the Philadelphia, Pennsylvania area in 2005. The L1 medication that she’d taken all her life hadn’t yet been approved in the United States (it received FDA approval in 2011 and is now available), and so she had to depend solely on Desferal injections. In 2006, she began using a newly approved oral chelation medication called Exjade, and has been taking it ever since.

In addition to the difficulty of switching medications, Rucha had to contend with the challenges of life in a new country.

“The hardest thing was settling down, making new friends and understanding new culture,” Rucha said. “And there’s the added difficulty of explaining to friends that I have thalassemia.”

“And there are also physical difficulties,” she continued. “At the end of the day, I just want to go home and crash in my bed, especially few days before my next transfusion. I see my friends go out and have a good time after work or school is over. That is hard for me.”

Difficulties aside, Rucha was determined to meet all of these challenges, and more. With resolve and support from her family, she went to college to study the very things that had both complicated her life and helped keep her healthy.

	“I am as optimistic and capable of achieving my dreams as anybody else.”

   

“I received my Bachelor of Science degree in biochemistry. And right now, I’m considering post-graduate studies in biomedical sciences, clinical or basic research,” she explained. “I have always been fascinated by how our body works and how genes, proteins and biochemical messengers send signals to various parts of our body.”

It’s always difficult for a family – and especially a child – to understand illnesses and why their bodies don’t always work the way other peoples’ bodies do. Rucha Shah, whose life has involved all kinds of medications and treatments, is trying to develop a deeper understanding of those things, in the hope of helping others like herself and her family. She’s still receiving helpful information and social support from CAF to help her along the way.

“I am as optimistic and capable of achieving my dreams as anybody else,” Rucha said. “Thalassemia, although a huge part of my life, does not dictate it.”

Help CAF Keep Helping Patients Like Rucha. Click Here to Make an Online Donation.

Story: Roger Burks ____ Photos: Thatcher Hullerman Cook

Mechanical treatment shows promise in thalassemia

By Laura Cowen
Vibration therapy may be an effective nonpharmacologic intervention to increase bone mass in patients with thalassemia, US researchers report.
The pilot study, conducted among nine adults (age >18 years) and nine adolescents (age 10-18 years), showed that standing on a vibrating platform (30 Hz, 0.3g) for 20 minutes per day for 6 months increased whole-body bone mineral content (BMC) by a significant 2.6% compared with baseline.
Areal bone mineral density (aBMD) and BMC/height, both measured by dual-energy X-ray absorptiometry, increased by a significant 1.3% and 2.6%, respectively, during the intervention period, and remained elevated at 12 months.
Furthermore, the rate of change in hip BMD during the 6-month intervention in adults was significantly greater than the change observed in the year before study entry (2.2 vs -2.7%).
"Though these data are preliminary, they suggest promise of a non-invasive intervention in a group of patients who have a significant risk of osteoporosis morbidity," remark Ellen Fung (Children's Hospital and Research Center, Oakland, California) and co-authors in the American Journal of Hematology.
Fung and team explain that patients with thalassemia have low bone mass, which can lead to fracture and decreased quality of life.
Patients are commonly treated for hypogondism through hormonal supplementation and encouraged to take calcium and vitamin D, but the majority continue to lose bone, as much as 1% to 2% per year, as they age.
Mechanical stimulation through whole-body vibration has been shown to promote bone formation in previous studies, the researchers therefore tested its efficacy in thalassemia.
The increases in aBMD and BMC were accompanied by significant increases in levels of the bone formation marker osteocalcin and decreases in the bone resorption marker serum collagen type 1 cross-linked C-telopeptide.
Of note, although aBMD and BMC increased during the intervention period among adolescents, the increase was no greater than that recorded in the 6 months prior to the intervention. This was possibly because adolescents were captured during a period of rapid growth and pubertal development, limiting the ability to observe change, Fung et al remark.
They conclude: "Future research is needed to confirm these findings in a larger sample for longer duration."

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.

Haploidentical bone marrow transplants for sickle cell disease: an interview with Dr. Javier Bolaños Meade

 Interview conducted by April Cashin-Garbutt, BA Hons (Cantab)

Please could you give a brief introduction to bone marrow transplants?

Bone marrow transplant (also called stem cell transplant) is a medical intervention that allows a physician to deliver very high doses of chemotherapy (if needed) but more importantly, deliver a new immune system to the patient to fight a disease (such as cancer).
For instance, if a patient has leukaemia, and I give that patient a transplant from a donor, he will get a new immune system that will fight the leukaemia, and will also get a new marrow to produce blood (the marrow is the part of the body in charge of making new blood).
In the case of patients with sickle cell disease (and related disorders) the important point is to replace the marrow that is producing defective red cells, for a new marrow that produces healthy red cells.

What exactly is a haploidentical bone marrow transplant?

Historically, in order to perform a bone marrow transplant, donor and recipient have to be 100% matched at the HLA genes level (human lymphocyte antigen). Many patients cannot get a transplant because they lack this matched donor.
But we have shown already in patients with cancer that they can receive a bone marrow transplant from a 50% match (or haploidentical). Over 90% of patients will have a sibling, child or parent that may be used as a donor and in the large majority (almost 100% but not quite) these first degree relatives will be at least 50% match. Therefore, if the patient’s sibling is not a perfect match but at last 50% may be still a good donor.

How did your work on haploidentical transplants for sickle cell disease originate?

Originally we start working on haploidentical transplants on patients with cancer (leukaemia, lymphoma, etc) at the end of the XX century – late 1990’s. Once we established that it was a safe procedure we wanted to test it in patients with non-malignant (non-cancer) conditions like sickle cell for which it is very difficult to find fully matched donors, either because their siblings are also affected, or they cannot find unrelated donors through registries like the National Marrow Donor Program. So, in these cases, a haploidentical transplant may be a good option.

How does a haploidentical bone marrow transplant eliminate sickle cell disease?

When we give new bone marrow to a patient, the donor’s immune system will allow the new marrow and immune system to establish its dominance in the recipient. Then, the donor’s marrow will start making new red cells that are healthy as opposed to those made by the sickle cell marrow.
The abnormal red cells in sickle cell cause many health problems. Once the new and healthy red cells are produced, one can expect that no new complications will develop. However, the damage already done by the sickle cell will not be reversed.

Does a haploidentical transplant always eliminate sickle cell disease or do some patients need a fully matched transplant?

We only performed a haploidentical transplant if the patient does not have a fully matched donor. But transplants do not always eliminate sickle cell. Approximately 50% of the haploidentical transplants done for sickle cell have been successful.

What are the benefits of a haploidentical bone marrow transplant?

Haploidentical transplant offers the possibility of finding donors for patients who otherwise would not be able to receive a transplant. Haploidentical donors (close relatives) are usually willing to donate and are usually readily available. It increases the pool of potential donors. In our study, a large majority of patients would not have received transplants without a haploidentical donor since they lacked a fully matched donor.

Are there any dangers of a haploidentical bone marrow transplant?

Yes, bone marrow transplant is a dangerous procedure that can be life threatening. Infections, graft-versus-host disease, organ toxicities are commonly seen after transplant and these can be very dangerous.

Are there any plans to use haploidentical bone marrow transplants for other conditions?

Currently at Johns Hopkins we have clinical trials with haploidentical transplants available for patients with blood cancers such as leukaemia, lymphoma, etc. We also have it available to patients with sickle cell disease and other haemoglobinopathies such as thalassemia. There are plans to expand to other diseases but that will be in the future.

How do you think the future of bone marrow transplants will develop?

The transplant community is actively researching ways to perform transplants with less toxic approaches, decreasing the rates of complications such as graft versus host disease. I think the areas receiving more attention now are:

1. Alternative donors (such as haploidentical or cord cell grafts)
2. Reduction of graft versus host disease

What plans do you have for further research in this field?

We are currently studying if increasing the number of cells infused in the graft will increase the success in patients undergoing transplants for sickle cell disease.

Would you like to make any further comments?

Despite the fact that transplantation is the only curative therapy for patients with sickle cell disease, it is not the only available option. Not all patients are candidates (either because they do not have severe enough disease or because their overall health is poor).

Where can readers find more information?

http://www.cancer.gov/clinicaltrials/search/view?cdrid=675373&version=HealthProfessional&protocolsearchid=10925161
http://www.hopkinsmedicine.org/news/media/releases/half_match_bone_marrow_transplants_wipe_out_sickle_cell_disease_in_selected_patients

About Dr. Javier Bolaños Meade

Dr. Javier Bolaños Meade is the Associate Professor of Oncology at the Johns Hopkins Sidney Kimmel Comprehensive Cancer Center.
His expertise includes:

• Bone Marrow Transplant
• General Internal Medicine
• Graft-versus-Host Disease
• Hematologic Malignancies

His group is researching into finding novel therapies for the treatment of both acute and chronic graft versus host disease (GVHD).

"We're driven to do big things." - Patient Profile of Robert Mannino

Source: http://www.thalassemia.org


Robert Mannino knows more about blood transfusions than most people.  Diagnosed with thalassemia when he was just six months old, he’s spent much of his life in clinics, hooked up to transfusion machines for treatment of the disorder – at least once every three weeks for six hours at a time. 
   

Now 20 years old and a junior at the Georgia Institute of Technology (Georgia Tech), Robert is turning that life experience into motivation for studying his chosen field: biomedical engineering.

“I’ve always been interested in science and math.  And being in a hospital all the time growing up, and getting to know a lot of people with blood-related illnesses, I wanted to use my talents to help others,” he says.

One of the people he most wants to help is his 15-year-old brother, Kevin, who also has thalassemia.  Robert says that theCooley’s Anemia Foundation (CAF) has been there for his family throughout his life, pioneering research and improving treatment centers to make transfusion days more bearable.  And, more recently, CAF helped Robert in another very significant way: providing a scholarship for him to study ways to help his fellow patients.

Robert wants to help his 15-year-old brother who also has thalassemia.

 This semester, Robert is enrolled in 17 hours of classes at Georgia Tech.  Each weekday, he typically spends three hours in the classroom, three hours in the lab and at least three hours on homework.  Part of his work in the laboratory involves hands-on work with the kinds of machines he encounters each time he goes for a blood transfusion.

“I’m working on a project where I choose a medical device, figure out its flaws and strengths, tear it apart and put it back together again,” he explains.  “There are a lot of engineering components, as well as mechanical and biological considerations.”

 As Robert works in the lab, answering questions for this story, his fellow researchers stop to ask him what the interview is about.

“I don’t know if you know this, but I have a medical condition called thalassemia, and these are guys from the Foundation that supports me,” he tells them.  This happens on several occasions and, each time, Robert is brave and patient in his explanation.

He says that research work in the lab is one of his favorite parts of the day; in fact, he enjoys it so much that he wants to go to graduate school to study hematology. Eventually, he’d like to work for a medical device company, building better products to improve the lives of those with blood disorders. It’s something that he knows, and feels, from a lifetime of experience.

	"We're driven to do big things."

 “There’s something different about people confronted with hardships like this,” Robert says.  “We’re driven to do big things.” 

"Thalassemia was emotionally taxing on my family, but we adapted" - Patient profile of Aaron Cheng,

My name is Aaron Cheng, and I’ve just completed my first semester of college at Harvard

University.

I don’t remember when I was diagnosed with beta thalassemia major, which is also known as Cooley’s Anemia, but my parents tell me it was when I was around one year old.  We were visiting Taiwan, and my mother and father noticed specks of blood in my diaper.  Soon afterward, doctors told my parents that I had Cooley’s anemia. 

I’ve been under treatment for as long as I can remember. From when I was an infant to when I became a middle-schooler, I took Desferal infusions four times a week.  The Desferal treatment would last for about eight hours every night, from when I went to sleep to when I woke up. Treatment now is definitely a lot more convenient: instead of having injections every night, I use the oral chelator Exjade every night, so my schedule is a lot more flexible now.  I am so thankful that treatment is becoming a lot more convenient for Cooley’s anemia patients; as a college student, I find taking a pill a lot easier than injecting a drug for eight hours every night. 

I remember that as a child thalassemia was a lot more painful for my family and me than it is now.  The most difficult aspect for me was feeling different from my friends, since I would be noticeably absent from school when I visited the doctor.  I think the hardest part for my parents was trying to deal with the disease and make sure I had a balanced life.  Thalassemia was emotionally taxing on my family in the early part of my life, but we quickly adapted to the new lifestyle, and now it feels like thalassemia is nothing more than an easily managed inconvenience. 

Besides keeping up with my medicine every day, I don’t think thalassemia greatly impacts my life.  I am still able to lead a perfectly normal college life and try new things every day.  Perhaps thalassemia might make me more tired than the average person when it gets close to a transfusion day, but I find college exciting enough that any physical effect that thalassemia has on me is usually barely noticeable. 

My family first found out about the Cooley’s Anemia Foundation when my doctor introduced my father to the association.  From then on, my family has been very involved, and I attend conferences as often as I can.  It has offered a great community through which I can share my experiences and learn from others who have thalassemia as well.  I find the Foundation to be an extremely helpful forum for patients and family; my family and I have met many friends and gotten a lot of help coping with thalassemia through the CAF.  

I decided to attend Harvard primarily because it had always been my dream school; I love the Boston area and thought it would be a great experience to live on the East Coast and learn in such an academically-driven community.  Furthermore, the Boston area is very convenient, and I am able to go to the Boston Children’s Hospital quickly every three weeks for my transfusions. 

It was such a surprise for me when I was accepted to Harvard and I knew right when I found out that I couldn’t turn this opportunity down.  It has been a great experience for me so far; I am involved in the Harvard Crimson (Cambridge’s daily newspaper), and the Harvard Square Homeless Shelter where I volunteer.  I’ve enjoyed all of my classes so far and learned so much.  Right now I am unsure what I will study for a major, but I am strongly considering molecular/cellular biology, neurobiology, or applied math with a focus on biology.  I am keeping my career options open until I find out in the coming years what I enjoy most.  

Adjusting to a new climate away from my family was easier than I imagined, partly because Harvard keeps me so busy and also because the people there are so friendly that it took a very short time for me to make a lot of new friends.  The weather is noticeably colder than sunny Southern California, but I’ve been having a lot of fun experiencing the new climate. 

The adjustment to Boston Children’s Hospital has been exceptionally smooth; every three weeks I go to the nearby clinic to get my blood drawn, then on the Saturday after I take a 20-minute bus ride to Boston for my transfusion. 

The future looks bright, and I’m looking forward to learning so much more and having the opportunity to give back to the community!

 

New gene transfer technique can treat beta-thalassemia, sickle cell anemia

A team of researchers led by scientists at Weill Cornell Medical College has designed what appears to be a powerful gene therapy strategy that can treat both beta-thalassemia disease and sickle cell anemia. They have also developed a test to predict patient response before treatment.
This study's findings, published in PLoS ONE, represents a new approach to treating these related, and serious, red blood cells disorders, say the investigators.
"This gene therapy technique has the potential to cure many patients, especially if we prescreen them to predict their response using just a few of their cells in a test tube," says the study's lead investigator, Dr. Stefano Rivella, Ph.D., an associate professor of genetic medicine at Weill Cornell Medical College. He led a team of 17 researchers in three countries.
Dr. Rivella says this is the first time investigators have been able to correlate the outcome of transferring a healthy beta-globin gene into diseased cells with increased production of normal hemoglobin -- which has long been a barrier to effective treatment of these disease.
So far, only one patient in France has been treated with gene therapy for beta thalassemia, and Dr. Rivella and his colleagues believe the new treatment they developed will be a significant improvement. No known patient has received gene therapy yet to treat sickle cell anemia.
A Fresh Approach to Gene Therapy
Beta-thalassemia is an inherited disease caused by defects in the beta-globin gene. This gene produces an essential part of the hemoglobin protein, which, in the form of red blood cells, carries life-sustaining oxygen throughout the body.
The new gene transfer technique developed by Dr. Rivella and his colleagues ensures that the beta-globin gene that is delivered will be active, and that it will also provide more curative beta-globin protein. "Since the defect in thalassemia is lack of production of beta-globin protein in red blood cells, this is very important," Dr. Rivella says.
The researchers achieved this advance by hooking an "ankyrin insulator" to the beta-globin gene that is carried by a lentivirus vector. During the gene transfer, this vector would be inserted into bone marrow stem cells taken from patients, and then delivered back via a bone marrow transplant. The stem cells would then produce healthy beta-globin protein and hemoglobin.

This ankyrin insulator achieves two goals. First, it protects delivery of the normal beta-globin gene. "In many gene therapy applications, a curative gene is introduced into the cells of patients in an indiscriminate fashion," Dr. Rivella explains. "The gene lands randomly in the genome of the patient, but where it lands is very important because not all regions of the genome are the same." For example, some therapeutic genes may land in an area of the genome that is normally silenced -- meaning the genes in this area are not expressed. "The role of ankyrin insulator is to create an active area in the genome where the new gene can work efficiently no matter where it lands," Dr. Rivella says. He adds that the small insulator used in his vector should eliminate the kind of side effects seen in the French patient treated with beta-thalassemia gene therapy.
The research team also discovered that the insulator increases the efficiency by which the beta-globin gene is transcribed during the process of making the red blood cells. "We found the gene is integrated into cells which have not yet begun to make red blood cells, and when they do, the beta-globin gene is activated," Dr. Rivella says. "We showed that if the insulator is present, activation of the curative gene is more efficient. This provides more curative protein to red blood cells."

The study further provides evidence that the vector had different rates of efficiency depending on the beta-thalassemia mutation it was used in -- thus providing the basis for a predictive test in patients. The investigators tested 19 different beta-thalassemia samples comprising the two types commonly found in patients -- "beta-zero" cells that do not produce any beta-globin (forcing patients to receive blood transfusions throughout life), and "beta-plus" cells that produce suboptimal levels of hemoglobin. On average, they found that one copy of the vector in beta-zero cells produced 55 percent of the adult hemoglobin seen in normal individuals. Beta-plus cells, after treatment, produced hemoglobin comparable to a healthy individual, and were thus cured.
"The variable nature of the beta-thalassemia mutations suggests that some patients would be better candidates for gene therapy than others, and that success of gene therapy depends on the ability of a specific vector to make hemoglobin," Dr. Rivella says. "This is something we can test in advance using a little bit of a patient's blood -- which is quite extraordinary."
The issue in sickle cell anemia is very different, Dr. Rivella says. The hemoglobin protein is made in the right quantities, but it is not normal -- the red cell is shaped like a sickle and is abnormal in function. "One of the problem in gene therapy of sickle cell anemia is to add a new gene without increasing too much the total amount of protein, both normal and sickle. This would cause other problems," he says.
By treating eight cell specimens taken from sickle cell anemia patients, the investigators discovered that attaching the ankyrin insulator to a normal beta-globin gene increases the amount of normal beta globin protein while reducing the quantity of sickled protein. "The total amount of protein stays the same, which is very important," says first author Dr. Laura Breda, pediatric research associate at Weill Cornell Medical College.
The researchers say that their advances will likely make a substantial impact on a number of fields, including gene regulation and transfer and the design of gene therapy trials. "This study represents a fresh departure from previously published work in the field of gene therapy," Dr. Rivella says.

Source: Weill Cornell Medical College