Dr. Cherqui and the Amazing Lysosome-Swapping Macrophage!

Dr. Stephanie Cherqui has previously shown that if you transplant hematopoietic stem cells (HSCs) into cystinosis mice, you get stem cell engraftment with reduction in cystine in the tissues and preservation of organ function.  She is currently working on safety studies so that we can move forward with human trials with autologous HSC transplant for patients with cystinosis. 

But how do the stem cells actually fix the cystinosis cells?  Dr. Cherqui and her lab recently published a paper in Stem Cells revealing the mechanism.  Several hypotheses had been suggested.  Do the stem cells turn into new kidney cells, or do they fuse with the diseased cells to create a functioning hybrid?  It turns out it’s neither.


First you have to remember that cystinosis is a disease of the lysosome.  The lysosome is like the recycling plant of the cell.  It takes up old proteins, digests them into amino acid building blocks, and spits them out through transporter pumps to be reused.  

Cystinosin is the transporter that pumps out cystine, and if it is broken, like it is in cystinosis, then the cystine can’t get out of the lysosome. Cystine builds up, damaging the lysosome and the cell. Cystinosin is probably involved in a lot of other cellular functions too, which explains why giving people cysteamine doesn’t cure cystinosis.  You can’t just get rid of cystine; you have to replace the Cystinosin transporter somehow.

Dr. Cherqui showed that most of the stem cells turn into macrophages after transplantation.  Macrophages are a type of immune cell, and their name literally means “big eater.” Macrophages like to munch on bacteria, and they also clean up the big mess made by the other immune cells that are fighting viruses and bacteria.  Since the macrophage is designed to clean up, it has lots of LYSOSOMES!   

MACROPHAGE!

Dr. Cherqui’s latest research shows that these helpful macrophages respond to a distress call from the sick cystinosis cells by creating little tubes, called tunneling nanotubules (TNTs), through which they share lysosomes with the sick cells.  Healthy lysosomes with the Cystinosin transporter move into the cystinosis cells, and the sick lysosomes move out of the cystinosis cells and into the macrophages.  It’s almost like a lysosome transplant!

In the movie below, posted with Dr. Cherqui's paper in Stem Cells, you can actually see the lysosomes (the little green dots) leaving the macrophage through the tunneling nanotubules to the cystinosis cells, which are red.  So cool! 

This research could have big implications for other diseases.  Cystinosis is just one of fifty lysosome disorders.  Other lysosome disorders include Tay-Sachs disease, Fabry disease, Niemann-Pick disease, Gaucher disease and metachromatic leukodystrophy.  What if HSC transplantation could swap out the broken lysosomes in these diseases?  It's also interesting to note that lysosomes aren't the only organelles that move across the tunneling nanotubules.  Dr. Cherqui and other researchers have also noted mitochondria making the trek.  Mitochondria are the "powerhouse" of the cell, where most of the energy required for cellular function is generated.  There are many mitochondrial disorders, and it is possible that HSC transplantation could be used to treat these as well.  The cure for cystinosis could be the cure for a whole host of genetic diseases!   

Vitamin D and Muscle Wasting

Dr. Robert Mak, a pediatric nephrologist, gave a talk at the 2014 CRF family conference about the effects of Vitamin D on muscle wasting in cystinosis.  His talk generated a lot of excitement and interest, so I thought it would be worthwhile to break it down here.

Muscle wasting is one of the major complications of cystinosis, and it is typically seen later in life, in the second and third decade.  Cystine accumulation damages muscle cells.  The muscles predominantly affected are swallowing and limb muscles.  Many patients with cystinosis have trouble swallowing, especially as they get older, and the deterioration of these muscles can lead to aspiration of food and saliva into the lungs, which can cause serious complications, even death.  Wasting of the limb muscles can cause weakness in grip strength and affect dexterity, as well as exercise endurance.

Currently, there are no great therapies for muscle wasting.  Cysteamine depletes the cystine in the muscle tissue, but even patients taking cysteamine eventually develop muscle wasting.  Many cystinosis patients take carnitine supplements since this compound is wasted in the urine.  Carnitine is required for muscles to break down fat into energy, and carnitine deficiency leads to accumulation of fat in muscle tissue.  Giving patients carnitine supplements will normalize blood and muscle levels of carnitine, and it reduces accumulation of fat in muscle tissue, but no studies have been done to assess whether carnitine replacement results in higher muscle mass or better growth in the long term.   Dr. Doris Trauner, a neurologist, mentioned in her remarks at the CRF conference that other proposed treatments for muscle wasting include coenzyme Q and the different B vitamins. 

Dr. Mak has been studying the effect of vitamin D on muscle wasting using a mouse model for cystinosis.  In the mouse model, the gene that codes for the cystinosin protein has been "knocked out," so the mouse no longer makes the protein.  This effectively creates a mouse with cystinosis, and it is a good surrogate for testing different therapies, like vitamin D. 

Normally we make vitamin D in our skin, with exposure to sunlight.  We can also get vitamin D from fortified foods, or from supplements.  If the supplement is from a plant, it's called ergocalciferol, or D2.  If it's from animals or our skin, it is called cholecalciferol, or D3.  Whether we make it in our skin or eat a supplement, the vitamin D is modified by the liver to make 25-Vitamin D.  This form of vitamin D is then modified again by the kidneys, to 1,25-Vitamin D, which is the active form.  This form is also called calcitriol, and it is required to maintain calcium and phosphate levels in the blood and promote bone growth and remodeling.  1,25-Vitamin D increases absorption of calcium and phosphate in the intestines, both of which are needed for bone mineralization.  Patients with renal failure often have to take calcitriol because their kidneys can't make the active form anymore.

Dr. Mak pointed out three reasons cystinosis patients have low vitamin D: they lose it in their urine, they spend less time outside in the sun because of photophobia, and they develop chronic kidney disease. Doctors have always known that it is important to treat vitamin D deficiency in cystinosis patients, since vitamin D deficiency leads to rickets (in addition to the phosphorous wasting seen in Fanconi syndrome).  Low vitamin D levels may also be bad for the muscles.

Dr. Mak has shown that cystinosis mice with vitamin D deficiency have smaller muscle fibers, weaker grip strength, poor balance, and energy wasting.  He has also shown that vitamin D deficiency leads to genes being turned on that break down protein, which leads to muscle wasting.  He treated cystinosis mice with 25-Vitamin D (the kind your liver makes) and 1,25-Vitamin D (the active form that your kidneys make).  He found that in the mice treated with 25-Vitamin D, there was restoration of muscle mass, muscle fiber size, grip strength and balance, more than in the mice treated with 1,25-Vitamin D.

Remember that 25-Vitamin D is just the regular over-the-counter supplement after it is modified by the liver.  This is the form that the muscle uses, because the muscle has its own enzyme to activate it.  So while 1,25 Vitamin D (calcitriol) is crucial for bone health, it does not appear to be as important for muscle health. 

So what is the take home message?  Vitamin D deficiency is bad for muscles, so taking a vitamin D supplement is a good idea if you have low levels, and it may even help prevent muscle wasting.  This doesn't mean you should just start taking big doses of vitamin D, however, because you can theoretically get vitamin D toxicity.  Dr. Mak and Dr. Grimm said that if your doctor hasn't done it already, get your vitamin D levels checked, and if you are deficient, then take a supplement.

We built Sam and Lars a rock climbing wall in their bedroom to help them with limb muscle strengthening, especially arms and hands.  We have absolutely no evidence that it will make a difference in the long run, but it seems like a good idea, and they have a lot of fun with it! 





 

how to give procysbi with a g-tube

Here is a quick movie we made to show how we give Sam Procysbi, the new form of cysteamine.
Sam takes four large pills (75mg) and one small pill (25mg)

Cystaran: The New and FDA Approved Eye Drop

   The day has come... dun dun dun.  Sam has finally started taking hourly eye drops.  If untreated, crystals accumulate in the eyes causing photophobia and can eventually lead to blindness.  From what I've heard, the crystals feel like you have sand in your eyes.  We're starting Sam off small just so he can get used to the idea.  I prepared him for about one month before by talking about the new drops that were coming in the mail.  He seemed excited the day the package came.  I explained to him that it might feel "funny".  The drops can burn but I didn't want to tell him that and scare him.  He takes the drops six to seven times a day and doesn't seem to mind.  I don't set an alarm.  We just do them when we can... easiest medication yet.  Sam says the eye drops are his favorite.  I agree with that.  Eventually he will take them every hour he is awake.   It's a work up.

Sam gets a sticker every time he takes his eye drops.  He gets to watch a show every time he reaches the ten sticker mark.  I have been very impressed with his mad-eye-drop-taking-skillz.  

 

just some pics from the Stack's fundraiser

 

noice.

good things are happening: a long post

 Sam has started potty training himself.  He reminds me to set the timer for 30 minutes.  When the timer goes off, he tells me he's running to the potty.  He does it all by himself.  The drawback is that he won't wear clothes.  Only underwear.  My good friend, Allie, gave him an undershirt that he likes to wear every single day.  An undershirt is better than no shirt at all so I'm going to track down some more goatmilk undies.  Thank you, Alpha.

Sam has been eating food since early December.  Tasting. Chewing. Swallowing.  Eating.  I'd guess he's getting around 200 calories via mouth each day.   Just thinking about it makes me cry (happy tears of course).  He has been very brave.  He'll try something new almost every day with his usual side of cheese, cheese crackers, and pine nuts.  There are 222 calories in 3 tablespoons of pine nuts. Those are some expensive calories.   He has chosen some good foods to like as far as calories go.  I hope he'll like milk one day.  

On the opposite side of the spectrum.... Lars is eating six jars of baby food in a day, plus he's still nursing.  There is not a food he won't eat.  I think cystagon prepared him for that ;)

Lars has been sitting up since early December.  Life is much easier now that he can entertain himself on the floor for awhile.  Despite all our efforts, he refuses to roll over.  Not even my cell phone will entice him to move two inches.  He's a cute little/big sloth.  If he gains one more pound he's legally too large for his car seat.  He's probably already too long for it.  I suppose we'll be buying a new one very soon. 

Sam fell and skinned his knee the other day.  After I put a band-aid on him he stopped crying but sadly told me that he wished Macey would kiss it better.  From five feet away Macey stood up, walked over to Sam, and started licking his knee.  Our dog speaks English. 

  

Thank you California

Who can guess what show Sam is watching?

 Our last trip to Stanford was by far the most stressful yet.  I'll spare everyone the details.  I'm sick of talking about it.  The one part that did go well though was supposed to have been the hardest... so that's good news. We arrived at Lucile Packard Medical Center at 7am for Sam to get a hep-lock IV and have his first blood draw.  We were at the hospital from 7am to 8pm so Sam could give a blood sample almost every hour.  Sam didn't even complain.  After he had his EKG he sat up and said, "I like EKG's!  EKG's are my favorite!"

Sam is fascinated with the color of his blood.  I tried to distract him from looking at it because that stuff makes me woozy but apparently he likes it. 

Sam was showing me how they take his blood.  He kept saying, "I can't even feel it!" during the process.  He was pretty happy he didn't have to be poked more than once.

Classic Lars face.

Stanford has the coolest headphones.

I looked at that clock about a million gazillion times.

The nurses at Lucile Packard Dialysis center/short stay unit were absolutely amazing.  They were kind and patient with Sam.  They took time to talk with him and ask him questions.  He was given a few different toys when he left, which made him happy.  We're very grateful to be a part of this study and Sam really looks forward to flying on airplanes but we'll be so happy when we no longer have to travel.

happy new year!

some great clips of the boys, with the shins. 

Goodbye 2012

some stuff from 2012

  

- we had a baby.  his name is lars.

-sam started swallowing food, in small amounts.  he really likes shredded cheese.

- stephen is more than half way done with medical school.

- we got a dog named macey.

- i lost track of how many times we flew to stanford for rp103.

 i love their faces in this picture. bwah-ahaha.

lars is... sitting up, eating solid food and LOVING it, very chatty, drooling, and weighting over 17 lbs these days. 

Lars's Diagnosis

The math was simple.  We knew if we tried for another child, we had a 25% chance that the baby would have cystinosis.  But there was a 75% chance the child wouldn’t have cystinosis!  We wanted our three-year-old, Sam, who has cystinosis, to have a brother or a sister.   Seeing how strong and happy Sam is, we rolled the dice.

Lars Andrew Jenkins was born on July 30, 2012, 6 days after Sam’s birthday and just a day shy of our fourth anniversary.  He was a hefty 8 pounds 1 oz and 20 inches long.  He was beautiful, with a nice round head and a slightly smooshed nose.  But that blond hair – that was a little concerning.  Sam had that same head of blond hair. 

We were ready though.  We coughed up the 350 bucks to do the genetic test for the 57kb mutation, the most common cystinosis mutation.   Sure, it wasn’t a definitive test since we didn’t know Sam’s mutation, and it’s not even incredibly accurate.  But our nephrologist wanted to wait till Lars was about 4 weeks old to draw blood for the WBC cystine test, and we thought we’d burst if we had to wait that long for some kind of answer.  We just wanted to buy ourselves some time.

We got the results back when Lars was about a week old.  He tested negative for the 57kb mutation.  We were pretty relieved.  We didn’t start broadcasting the good news, however, because we knew there was still a small but significant chance Lars had cystinosis.  But we breathed a little easier.

Lars was a good baby and a healthy eater from the start.  From all appearances he was a normal newborn.  He was gaining weight.  He took decent naps.  But by the second and third weeks that all started to change.  He started wanting to eat more often.  He was colicky and hard to console.  He started sleeping less.  He was acting a whole lot like Sam as a baby.

At 3 weeks we couldn’t wait any longer and we got the blood drawn for the WBC cystine test.  We waited an agonizing 8 days for the definitive answer.  The results came on a Tuesday, 4 weeks and 1 day after Lars was born.  He tested positive for cystinosis.

            
We hoped and prayed for Lars to be healthy.   We also prayed that we would have energy and optimism if God had a different plan for our family.   We’d never have imagined 4 years ago when we got married that we would one day have two children with a rare disease.  Although it’s not the future we had planned on, we feel incredibly grateful to be the parents of two special boys who mean the world to us.

            
We were able to start Lars on Cystagon immediately.  He tolerates it surprisingly well, and despite the grimaces he makes when we squirt the malodorous mixture in his mouth, sometimes he gives us a smile, as if to say, “Thanks, Mom!”  As soon as we started the drug he started nursing at more normal intervals and sleeping a little longer.  We don’t know if the drug is just killing his appetite or sedating him, but it has been a welcome change!  We’re hopeful that the FDA will approve RP103 early next year, when Lars will be moving on to solid foods.  Hopefully he’ll like applesauce!  He’s also on the mandatory proton-pump inhibitor, as well as some vitamin D supplement.  We’re hoping that since he was diagnosed so early we will be able to avoid the kidney damage that Sam had already sustained at diagnosis.   Our nephrologist told us to feed Lars whenever he wants, and he is certainly putting on the pounds.  At 8 weeks old he was nearly 14 pounds.  Sam was still 14 pounds at one year.  We don’t plan on losing any ground.

            
Sam loves having a baby brother.  He is so sweet with Lars and constantly tells us how “koot” Lars is.  He refers to him as “Baby Larziroo,” and wants to be at his side all the time.   After Lars’s first dose of Cystagon, Sam hugged him and said, “Good job, Baby Lars!  You took your medicine!”  Lars doesn’t even mind when Sam pokes and prods him or plays a little rough.  Lars even smiles during such behavior.  You can tell these two are going to be best friends.

            
Sam is doing very well on RP103.  He throws up much less often and has boundless energy.  He can come across as timid and serious when you first meet him, but he doesn’t have to be around other children for long before he becomes the loudest and most mischievous.  He is a truly happy kid.  He loves to make up jokes and laughs hysterically after telling each one.  He likes to imagine there are trolls under every bridge, or that he is Simba from Lion King, and there are always “bad guys to fight off” wherever we play.  We love to go on family hikes and Sam won’t let us take resting breaks because he’s too excited to get to the top.   He has become adept at building with duplos, assembling train tracks and racing Hot Wheels.  He’s learning his alphabet and numbers, too.   He loves flying on airplanes and going to Stanford every 3 months for the RP103 trial. 

            
The future for our children is bright!  We have so much hope for a cure.  Our two sons will lead wonderful lives and have such a positive influence on those around them.  Their sweet young spirits have already added so much joy to our family.

Check out our first fundraiser for Sam’s Hope For a Cure.  We have been overwhelmed by the generosity, kindness and support of our friends and family.   We have raised almost $8,000 so far.  We will be giving all the donations to the Cystinosis Research Foundation to further the research and development of new and improved treatments and eventually a cure for cystinosis.   

Cure Cystinosis International Registry

Sam and Lars have excellent doctors here in Utah but even they can't answer all of our questions.  The disease is so rare that sometimes it's hard to find a doctor who has ever seen a patient with the disease.  Our nephrologist is currently treating four kids with cystinosis... basically every kid in Utah with the disease.  If I'm wrong, call me.  We feel incredibly blessed to have the doctors we have. 

Cure Cystinosis International Research (click here)

     This a greatGreatGREATgreat place to find information about cystinosis.  Their goal is to register 400 people with cystinosis by the end of 2012!  That said, go register now! The information is used to help researchers find out more about cystinosis and how they can help.  I have had many questions answered from this site.  For instance...

At what age do most patients start cysteamine treatment?

Is it okay to make up cystagon in advance and store it in your fridge?

Are males with cystinosis sterile? 

What else should I take into consideration before starting Sam on growth hormone shots?

Do most kids with cystinosis really have blond hair and blue eyes?

What current drug trials are out there?

I just updated the info. for both boys and it took less than 30 min.  Yippee!!

    

Lars Overload & Test Results

Lars's cystine test results are back from UCSD.  Anything under 1.0 is good so we were happy to hear that his cystine level is 0.55.  We were thinking his cystagon dosage would need to be increased due to his rapid growth but it looks like it's working just fine.  He tolerates the drug much better than Sam ever did.  Although a couple of days ago, I did have to give it to him three times within thirty minutes because he kept spitting it up.  This was a reoccurring pattern with Sam when he was on cystagon.  I'm so grateful Sam can be on RP103.

Lars slept from 9 pm to 7 am last night.  He slept right through the 3 am cystagon dosage.  Tioooonkk! 

chunky monkey; behemoth baby

We had a checkup with Dr. Nelson on Thursday for Lars.  His kidney function is still perfectly intact.  His electrolytes looked totally normal, and his growth charts were stellar.  He was 14 pounds 3 oz at 9 weeks of age, putting him at about the 90-95% for weight.  Sam was only 14 pounds at 12 months, so we're pretty happy with this level of chubbiness.  Lars's length was just over 24 inches, also in the 90% percentile.  He definitely likes to eat, and we hope he keeps it up indefinitely.  He's tolerating the full dose of cystagon now, at 100 mg every 6 hours.  He sleeps through the night for the most part, too, except for when we have to give him his meds at 3:00 a.m. 

 

We figured out where Lars gets his infantile behavior from.

Sam LOVES LOVES LOVES his baby brother.

Ask the wise Buddha for advice.

Back to Stanford for RP103

blood pressure, weight check, height check, temperature, blood draw = no big deal.  urine sample = armageddon.  Sam refuses to pee in a cup so he has to wear a bag in his diaper to catch the urine.  He absolutely hates when we have to do this test.

The nurses at Stanford are great with Sam.

We're thrilled he's still on the growth charts for height.  He grew almost an inch in the last 3 months.  We're lucky we won't have to start growth hormone shots anytime soon.  Yippee.  Good growing, Sam!!

While we waited for Sam to fill his pee bag he watched The Lion King on the i-Pod. 

 

Lars was amazing the whole day.  I carried him in the baby bjorn almost all morning with no fuss.  He will not be able to take RP103 like Sam until it is FDA approved.  We're praying it's approved in January.