Sox2 Regulates Astrocytic and Vascular Development in the Retina

We have a new publication out in the journal glia that examines the role of the gene Sox2 on the development of astrocytes and the vasculature in the retina.  Read the full article here.

Authors: Amanda Kautzman, Patrick Keeley, Michael Nahmou, myself, Steven Fisher, Benjamin Reese

Abstract:  Sox2 is a transcriptional regulator that is highly expressed in retinal astrocytes, yet its function in these cells has not previously been examined. To understand its role, we conditionally deleted Sox2 from the population of astrocytes and examined the consequences on retinal development. We found that Sox2 deletion does not alter the migration of astrocytes, but it impairs their maturation, evidenced by the delayed upregulation of glial fibrillary acidic protein (GFAP) across the retina. The centro-peripheral gradient of angiogenesis is also delayed in Sox2-CKO retinas. In the mature retina, we observed lasting abnormalities in the astrocytic population evidenced by the sporadic loss of GFAP immunoreactivity in the peripheral retina as well as by the aberrant extension of processes into the inner retina. Blood vessels in the adult retina are also under-developed and show a decrease in the frequency of branch points and in total vessel length. The developmental relationship between maturing astrocytes and angiogenesis suggests a causal relationship between the astrocytic loss of Sox2 and the vascular architecture in maturity. We suggest that the delay in astrocytic maturation and vascular invasion may render the retina hypoxic, thereby causing the abnormalities we observe in adulthood. These studies uncover a novel role for Sox2 in the development of retinal astrocytes and indicate that its removal can lead to lasting changes to retinal homeostasis.

Volcanic 50

Northern slope of Mt. St. Helens.

Volcanic 50 is a 50km ultra trail race, organized by Go Beyond Racing that circumnavigates beautiful Mt. St. Helens.  I choose this event to enjoy a race outside of California, and experience a unique course leading up to Mountain Lakes 100 in late September. Heading into the event I felt fit and healthy, I was thoroughly enjoying spending time on the trails with friends and my training had been progressing injury-free.  After spending a few recreational days exploring Echo Lake I took a short Thursday evening flight from San Francisco to Portland where I picked up my rental car and drove an hour to my hotel for the night.  On Friday, the day before Volcanic 50, I arrived at the event site located at Marble Mountain with plenty of time to relax and take in the scenery before Saturday’s race.

Race day started out well, after checking in at 530am I ate a small breakfast and finished preparing for the event, eventually walking over with the masses to the starting coral at 645am for the race directors pre-race instructions and well-wishes.  The race started out on a relatively short 2,000 ft climb that covered miles 0 to 4, after-which the course leveled out and traversed a boulder field that at first was an amusing novelty, however, later became a complete nightmare.  During this initial climb up to Loowit trail we were afforded brief views of the volcano through trees as we arrived at mile 4 and the first aid station.  Here, I quickly ate PB&J sandwiches and S-caps to help blunt what was forecasted to be a toasty day.  After leaving the aid station in good spirits I made my way towards aid station 2, positioned 8 miles away.

Southern slope of Mt. St. Helens.

The course between aid station 1 and 2 was deceptively smooth and tranquil, by this time the traffic jam at the start had thinned out, and the elevation profile was relatively flat or downhill.  In retrospect, I wish I had slowed down, but thought, its 32 miles, that’s just a sizable training run, I can floor it (relatively speaking) while its still cool, and so I did.  We wound our way through miles of forested terrain until arriving at aid station 2, 12 miles into the race.   Here, I ate more of the usual aid station foods, thanked the wonderful volunteers and headed out towards aid station 3, 8.2 miles away.  Little did I know that immediately after leaving aid station 2 the true difficulty of course would begin to reveal itself.  Less than 100 yards away from aid station 2, we headed down a rather large, gravel filled ravine that required both a water crossing and the use of anchored ropes to descend and ascend.  I dreaded getting my shoes soaked and then having to continue to run across rugged volcanic terrain.  Once we emerged from the ravine we climbed over the next 2 miles on loose, sandy terrain that was only about a foot and a quarter wide alongside a rather steep embankment.  This was probably the most memorable part of the race as we became up close and personal with the beginnings of the northern slope of Mt. St. Helens (the side reorganized in the massive 1980 eruption).  After reaching the northern slope of the volcano temperatures noticeably began to rise as the course guided us across the barren side Mt. St. Helens.

Mt. St. Helens from Lahar lookout point.

The northern side of Mt. St. Helens still bears geological scars that continue to dominate the landscape, the scene was so spectacular that I stopped several times to appreciate the magnitude of what happened on May 18th, 1980.  The scope of damaged landscape from the powerful pyroclastic flow  were clearly evident as the entire northern slope of the mountain was ripped open by the blast.  On this day, large waterfalls rushed millions of gallons of snowmelt off the north face and venting volcanic gases filled the distant air from a very active and growing lava dome.  Back to the race, as I trekked across the north side of the mountain the course traversed what looked like the surface of the moon, gentle rolling hills became increasingly challenging under the brutal 93 degree sun.

Nearing the spring of life aid station.

A swath of green in a landscape of brown as a result of rushing spring water.

At this juncture, I was a hair under halfway through the course, yet I began to accept that I was in for a long and difficult day.  The last two miles to aid station 3 were especially quite miserable as a result of dehydration and caloric depletion.  Indeed, three miles after leaving aid station 2, I had ran out of water, making the remaining 5.2 miles to the aid station 3 an eternity, however,  through tough love and encouraging words from fellow runners I arrived at aid station 3, “the spring of life.”  The supplies here were minimal as we were advised during the pre-race instructions, but still very much appreciated.  This aid station was staffed by NASA suited volunteers equipped with water pitchers that collected the most glorious natural spring water on the planet.  After was seemed liked never ending miles in the heat the feeling of being doused with refreshing, ice-cold water slowly began to revitalize me as I uncomfortably swallowed more S-caps and trail butter.

Aid station 3, “the spring of life” and NASA-certified bros.

Psychologically, seeing runners arrive at this oasis was comforting, it served as a critical reminder that I was not alone, this was a difficult course on a difficult day.  I watched runners arrive for several minutes as I continued to sit quietly on a volcanic rock (there are millions on this course) waiting to recoup enough energy to begin the trek to the next and final aid station.  I also took a few extra minutes before leaving and untied my shoes to examine my feet, shaking out the sand and rocks that had accumulated. Lastly, before leaving the spring of life, I topped off my water supply and slowly began to shuffle my way towards aid station 4, located 3.4 miles away.  It wasn’t far before I hit the proverbial wall a second time.  Luckily, I came across two wonderful race photographers who were kind enough to offer words of encouragement at a difficult time mentally.  As I hunched over seeking a moment of reprieve I recall uttering fragments of incoherent sentences as they continued to photograph the scenery and other runners. I distinctly recall one of the photographers saying, “we’ve so been there! are you questioning your life decisions right about now?” I thought, how can she hear my thoughts?  While I was trying to catch my breath, I had a direct line of sight to the next climb that needed to be negotiated in order get to the last aid station, the sight alone elicited a strong urge to let out a loud profanity-laced scream, but there were other individuals on the course struggling as I was, thus I opted against adding to what felt like humiliation.  As I unwillingly shuffled my feet on the trail heading towards the climb I said to the photographers, “I don’t know how I’m going to get over that ridge” and one replied, “you don’t know how, but you will.”

Heading towards the final aid station.

Slowly but surely I made my way up through the switchbacks eventually summiting the ridge, gasping for oxygen in the suffocating heat.  When I reached the summit, I looked back down towards the photographers who had turned into small dots on the landscape with a sense of elation, although I had no idea how I was going to get over that ridge under the circumstances I somehow managed to, and I thank them for it.  Heading down the ridge offered more rocky unstable terrain, endless ups and downs came and went, but my confidence began turn around on an emotional rollercoaster of a day. Finally, after hours of desert-like heat and negative thinking that, “this is going to be my first DNF,” I made it to the last aid station and only cutoff, well ahead of the 4pm deadline.  Here, I spent extra time in the shaded tent savoring several delicious pickles, PB&J sandwiches, oranges, Pringles, and more S-caps.  Finally, after eating and waiting for my heart rate to slow down, I decided it was time to tackle the last 8.5 miles and left aid station 4 on my way towards a difficult finish.

The last 8 miles of the race were nothing short of a mental slugfest.  The last section of Volcanic 50 offered up two very challenging features, one was the seemingly excessive amounts of lahars that had to be traversed, these constant ups and downs appeared to keep runners from finding any sort of rhythm.  Under different circumstances these lahars wouldn’t have caused concern, however, on this day, at this juncture they proved to be problematic.  Rocky, unstable sections became increasingly difficult to navigate.  I remember constantly looking towards Mt. St. Helens for feedback, noting familiar features that let me know I was nearing the finish line.  The second challenging feature was an almost mile long ankle-snapping boulder field that we were warned about during the pre-race instructions.  However, after the boulder field it was simply a left turn and downhill for 1.5 miles to the finish line on a smooth trail under the cover of shade.  Unfortunately, about 300 yards away from the infamous, “left-turn” I lost my hearing and began to experience blurred vision.  I was aware that my body was physiologically shutting down, so I sat down on a very uncomfortable volcanic rock that was close enough to see the turn downhill and began to dry heave.  Two women, who were out hiking were kind enough to talk sense into me about taking my time finishing.  I slowly drank more water and electrolytes, forcefully ate small salted potatoes (thank you runner kind enough to share) and waited in the shadows of the rock until my muscles somewhat stopped cramping before I proceeded to cross the remaining boulder field to the left turn.  I ended up crossing the finish line 12 hours after I begun, in a race that packed over 7,000 of elevation gain in 32 miles on a course that simultaneously humbled and inspired me.

Volcanic 50 turned out to be a unique experience on a historical site that offered spectacular views of other stratovolcanoes on the Cascade Range, namely Mt. Rainier, Mt. Adams, Mt. Jefferson, and Mt. Hood.   Symbolically, on land that was obliterated decades ago, new signs of life were emerging, small tree shrubs and wildflowers now dot a landscape that was once strangulated by volcanic debris, much like individuals who struggled through the 2017 edition of Volcanic 50.

Lastly, a very heartfelt thank you to all the volunteers who were gracious enough be out in the elements for hours on end in order to support all the runners.  The photographers for helping to capturing the journey and of course the race directors who organized and executed a one of a kind race.

Renee Seker, race director.

Echo Lake

Echo Lake via picture point.

Leading up to my Volcanic 50 race on Mt. St. Helens I spent a few days at Echo Lake relaxing, exploring, and getting training runs in before heading out to Washington.  The oxygen in the atmosphere was noticeably reduced compared to the levels I’m used to in Santa Barbara, it took me a day or so to get accustomed to moving under these conditions.   Echo Lake is a glacial lake located near south Lake Tahoe at 7,400 ft of elevation, and is divided into upper Echo Lake (lake nearest in the image above) and lower Echo Lake (lake furthest in the image above).  This slice of paradise is one of the last stops before heading into Desolation Wilderness.  During my stay here I was lucky enough to experience rugged, yet beautiful terrain on the Pacific Crest Trail (PCT).

Ralston peak; elevation 9,300ft.

Several lakes surround Echo Lake which make  detours off the PCT a most welcome adventure. The first venture was to Triangle Lake, on the way to this small lake there were plenty of snow mounds left over from a relatively intense winter season.  Indeed, I later discovered water was overflowing the Echo Lake dam as a result of the large amount of snow melt.  On this very warm summer day the trek to Triangle Lake was filled with mosquito’s and towering pine trees.

Heading towards Triangle Lake.

Triangle lake.

After Triangle Lake, the adventure continued onward and upward towards Lake Aloha (image below) about 5 miles away from Echo Lake.  Lake Aloha is a large body of water that was a highlight of my time in the area, here I enjoyed peaceful stillness of the water, the sun was perfect and a gentle breeze made for ideal napping conditions on a rock near the water.

Crystal range towering above Lake Aloha.

Sign posts guiding hikers and backpackers on the PCT.

Weather around Echo Lake changed frequently and rapidly, there were a couple of hours of sporadic thunder and lightening, one minute there wasn’t a cloud in the sky, the next minute a series of storm clouds rolled through the area on there way towards Lake Tahoe.

Lower Echo Lake.

Verga seen over lower Echo Lake during a thunder storm.

Some trees in the area are well over 1,000 years old.

One phenomenon I continually noticed on runs were trees that had branches point in only one direction.  The locals explained that the wind can be a brutal element and creates these wind swept trees (image below).

Wind swept pine.

Lastly, one of my favorite experiences about my time at Echo Lake was sleeping outside under the stars.  The last time I slept outside was a couple of years ago on a rock in the ‘foothills’ of Santa Barbara.  On this particular evening there was a waxing gibbous moon in the night sky, even so, the Milky Way was quite visible, I don’t recall ever seeing so many stars under a moonlit sky.  I can only imagine what the Milky Way looks like here under a new moon. Perhaps life will be kind enough to allow me a return trip with a more appropriate lens for the environment and on a moonless night.

Milky Way from lower Echo Lake.

Santa Barbara Fireworks Show

Who doesn’t love a well-choreographed fireworks show?  Last night, downtown Santa Barbara put on a wonderful show, here are a few images from the festivities.  This year I opted away from the massive crowds that gather along the beach, so I grabbed my camera, hopped in my car and drove around the riviera until I found a suitable viewing location.  I hope everyone had a delightful holiday and is enjoying the shortened work week.

Le retine

The retina is the light-sensitive layer of the eye, responsible for initiating the cascade of events that ultimately leads to visual perception. Vision relies on two types of photoreceptors; rods, used in low-light conditions, and cones (green colored structures in the image above) used for high acuity vision as well as the detection of different wavelengths of radiation (color).  Both are highly specialized cell types that posses the ability to convert photons of light into electrochemical signals that are relayed to the lateral geniculate nucleus and then onto higher centers in the visual cortex where humans experience visual perception.   Under certain conditions (i.e., inherited genetics or physical trauma) photoreceptor degeneration can lead to a gradual decline in visual acuity, and in extreme cases blindness.

To treat certain types sight-threatening conditions, we have begun testing the efficacy of intraocular injections of stem cells (blue and green ovoid structure in the image below) as a means of ameliorating the effects of photoreceptor degeneration, thus preserving vision.

As part of this particular project, I investigated whether intraocular injections of stem cells elicited a response from the immune cells in the retina.  Here, I used a laser scanning confocal microscope to capture many high-resolution images to generate a composite image the entire neural retina (image below).

Composite image.

Magnified 400 times.

Magnified 600 times.

In these sample images the larger green ‘blobs’ reveal immune cells as they infiltrate the retina in response to neural degeneration.   The blue color in these images shows the layer of photoreceptor nuclei.  While much remains to be seen about whether these cell-based therapies have a positive impact on the preservation of vision, an increasing number of these therapeutic approaches are making their way into clinical trails.

Born To Run Ultra-marathons Extravaganza 2017

In 2009, Christopher McDougall authored the national best-selling book, “Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World has Never Seen” a story about arguably the most gifted natural runners on the planet, the Tarahumara Indians of the Copper Canyons in Northern Mexico.  Eight years later, on an 8,000 acre working cattle ranch in Los Olivos, California I was introduced to the Born to Run Ultra-marathons Extravaganza (BTR), an event that embodies many aspects of the running community, and to a larger extent humanity.

Every May, BTR is coordinated and directed by Luis Escobar (AKA, the Sheriff; pictured above), who also organizes the Santa Barbara Nine Trails Endurance Run, Santa Barbara Red Rock Trail Run, and La Cuesta the Ranch Trail Race in Santa Barbara County.  Mr. Escobar has been fortunate enough to visit the Copper Canyons and meet members of the elusive Tarahumara Indians, he has also raised funds to bring these incredible, largely unrecognized super athletes to the United States to participate in local running events.  Of these events, BTR is by far the ‘most dynamic,’ this 4-day event that is loaded with race options ranging from 0 to 200 miles in distance.  Here, participants can race as competitively or as casually as they please, evidenced by the genesis of the 0.0km event.  In addition to formal running events there are also other activities around “the ranch,” that registered participants may enjoy such as, wrestlemania, prom, cartwheel contests, the beer mile, or the no-talent show to name a few.  Course-record holders and first-time runners alike gathered for a fun-filled extravaganza of trail racing and shenanigans on a very warm and dusty weekend.

My BTR experience began with an impulsive entry into the infamous beer mile.  The rules were simple, chug a beer and run a quarter mile, 4 times.  After the second lap, my head began to grow heavy and eye sight became distorted only half-way through my first beer mile.  I was lucky enough to have an experienced and supportive crew to hand me my beers as I made my way back to the start line.  Friendly advice from strangers regarding pacing as well as taking extra precaution when belching on the run so as not to lose the alcohol, which was penalized by having to do an extra lap, was critical as I finished my first beer mile smiling ear to ear, albeit stumbling and heavily intoxicated.

After the beer mile I spent time hydrating, enjoying a delicious burrito, and spending time with friends.  But perhaps my most rewarding event began that evening at 8pm with an graveyard shift at the 4-day/200miler Oasis aid station directed by Mara and Manley Klassen.  This was the first time I’ve volunteered at a racing event, motivated by my desire to obtain a new and different perspective.

In prior races I’ve found myself in dire conditions and it was only through the kindness of wonderful strangers at aid stations that I have been able to achieve my goals.  Experiencing those moments of misery reminded me about the importance of aid stations and their volunteers, indeed, on this night I witnessed exhausted souls make there way to our oasis after completing their 5th or 6th 20-mile loop.  Many times I’ve arrived at an aid station during the course of an endurance race with an attitude,”what do you know” as volunteers asked me what I needed or how I felt.  Importantly, this weekend taught me that those “strangers,” most likely have much more experience than I do, as I later toured the course, I came across a,’whose, who’ of the local running community that showcased many 100-mile finishers and even a few of those mythical individuals who have conquered a 200-mile endurance race.  Throughout the night, athletes stumbled into our tent, at times bordering on delirium seeking momentary shelter and nourishment.  Whether it was a warm cup of soup, vasoline, a few minutes next to a heater as temperatures dropped to the 30s, or serving as an alarm while they enjoyed much needed sleep I felt privileged to provide support to people that were pushing their own limits.  Volunteering at this years BTR has perhaps been one of my most proudest contributions.  The experience was nothing short of inspirational as I witnessed both men and women fight through despair and push through the physical pain of blistered feet, severe dehydration, and extreme mental fatigue.

The following morning, after my volunteering shift ended I joined several friends for a portion of their 50K adventure.  It’s always a treat to spend time on the trails with friends and this was no different.  Saturday provided an incredible heat wave that effected everyone on the course, temperatures reached near 100 degrees on a course that was almost entirely exposed to the elements.  I rationalized the difficult times on the course as practice time being physically uncomfortable, entertaining a torrent of thoughts including the all too common, “why am I doing this?”  In the end, BTR was an entirely new experience that afforded me a new perspective on running and its my understanding that I missed out on several key events this year, which means I will have to return to BTR in 2018 as a seasoned veteran.

 

Santa Barbara Nine Trails

At 6:05 AM on Saturday morning, 11 year-old Sebastian Salsbury of Santa Barbara, California walked out onto the dark San Roque Rd. pavement in front of over a hundred trail runners, myself included, and led participants in the formal swearing in of the 2017 edition of the Santa Barbara Nine Trails Endurance Race.   As we raised our right hand, we repeated after Sebastian, “If I get hurt, lost, or die, its my own damn fault.”  Impressively, Sebastian is the youngest finisher in the history of Nine Trails, completing the course in 2016 at the age of 10, and again in 2017.  As runners made their way toward the Jesusita trailhead equipped with firefly-like headlamps lit one of the most rewarding days began on a course created 27 years ago in December 1990 by local icon Patsy Dorsey.  Patsy and friends sought to engineer a course that was challenging yet displayed the beauty of Santa Barbara’s front country via the local trail system.  In my brief ultra running experience Nine Trails has been the most physically daunting and exhilarating event.  Although 35-miles, Nine Trails veterans will tell you that it feels like running a tough 50-miler as a result of the over 11,000 feet of elevation gain.  This course is also notoriously known for providing Nine Trails virgins with a cathartic experience of the highest order.

Approaching Inspiration Point. Photo: Howie Stern.

In general, this vaunted course is teeming with steep, technical climbs and descents, from start to finish.  Chronologically, the course follows Jesusita trail over three miles culminating at the Inspiration Point connector trail, from there the course heads downhill towards the very steep and rocky Tunnel trail where it joins with the ensuing Tunnel trail connector.   After a very short stent on the connector this trail intersects with the Rattlesnake connector for approximately half a mile, although this segment on the return leg seems a lot longer and much less enjoyable.

Tunnel trail.

Return leg at West-fork Cold Spring/Gibraltar junction.  Photo: Howie Stern.

The Rattlesnake connector then leads runners through upper Rattlesnake Canyon ultimately meeting up with the only asphalt section, Gibraltar road.  After one and a half miles on the road, participants speed down West-Fork Cold Springs and onto Cold Spring trail itself.  Next, the course traverses the Hot Springs connector en route to Hot Springs trail and briefly onto Saddle rock.  From here, the Edison catwalk guides runners to Buena Vista trail and finally heads down Romero Canyon for some much needed nutritional aid, only to turn around and run all the way back to the start line.

Tunnel trail connector, looking towards Inspiration Point.  Almost home.

The out-and-back format of Nine Trails provides a nice way of allowing all participants, fast or slow, to cross paths.  Indeed, in my experience sometimes seeing a familiar face for a sweaty high-five, a few words of encouragement, or a simple smile can be as critical and uplifting as nutrition itself.  However, this also means each section of Nine Trails presents a difficult challenge either on the outbound or return leg.  Downhill sections of the course on the outbound leg naturally become seemingly never ending uphill sections on tired legs, making this a course that truly gives runners no breaks.

After eight and a half hours of trails I completed historic and iconic Santa Barbara Nine Trails Endurance Race, thus completing an event to remember.  Following the race I decided to wait at the finish line to watch as fellow runners completed their own journey through Nine Trails.  Surprisingly, I felt as much excitement witnessing participants survive/conquer Nine Trails as I felt running the race itself.  Throughout my experience, trail running has taught me many things, not only about the art of ultra-running, but about life, especially through both the successes and perceived failures.  The community of athletes I share the trails on a weekly basis exist happily without ego, a valuable trait for anyone to learn.  Its hard to maintain any sort of ego when you’re throwing up a chocolate Ensure shake on the side of the trail.

Whether its laughing, sharing stories, or simply gasping for oxygen while climbing, “the wall” or “the wall 2.0”, trail running has opened up a new avenue, one that has allowed me to smile comfortably.  In part due to the welcoming and supportive environment, chalked full with people as crazy as me.

There are many folks to thank, first, the Santa Barbara trail runners for their constant encouragement and willingness to share their wealth of knowledge and experience, without it, I doubt I would undertake these challenges.  I would also like to thank Luis Escobar for organizing and executing another exceptional event.  This is my second ‘Luis’ event, the first being Red Rock 2016, a memorable race in its own right, a race loaded with torrential downpours and freezing temperatures.

Race Director: Luis Escobar.  Pre-race remarks, “This course is hard as shit, it’s over 11,000 ft of this, and this.”

I can’t thank Patsy Dorsey enough for greeting everyone at the finish line with a genuinely enthusiastic hug (I’d take a Patsy Dorsey hug over a medal any day).  After speaking with Patsy, I was fortunate enough to gain a better sense of appreciation by learning about the history and challenges that went into creating this magnificent annual event.  Additionally, I want to thank my friends, colleagues, and trainers for their support, it was especially wonderful to receive so many encouraging emails, texts, phone calls etc., from across the globe prior to race day.  Lastly, but most certainly not least, a special thank you to all of the volunteers who marked the course, as well as provided support to all the participants on race day.

In the end, Nine Trails left me with two thoughts, first, “what the hell just happened?”, and secondly I hope to see more of my amazing friends at 6:00AM March 24th, 2018 for the next edition of SB9T.

Creator and founder of Santa Barbara Nine Trails: Patsy Dorsey.

Retinal Pericytes

Retinal pericytes (green) are a component of blood vessels (red) that contact endothelial cells (blue).  Pericytes also interact with glial cells such as astrocytes (white), receiving signals that modulate contraction, dilation, and permeability of the vascular wall.  In diseases such as diabetic retinopathy, or retinopathy of prematurity (ROP) the blood vessels of the retina can be severely effected, leading to various degrees of retinal degeneration that may ultimately result in visual impairment.  Understanding how these contractile cells breakdown may be a step towards developing improved therapeutic approaches for diseases and conditions involving the vascular system.

2017 Wellcome Image Award Winner

A couple of years ago I was working on a project that sought to develop semi-automated computational approaches for the analysis of complex large scale bio-imaging datasets, this year one image I generated for that project was selected as one of the 2017 Wellcome Image Award winners.  The Wellcome organization is based out of the United Kingdom and celebrates science, medicine, and life.   This work was made possible in part by working in the Retinal Cell Biology Lab in the Neuroscience Research Institute at the University of California, Santa Barbara. The image above is shows the neural retina, and was created with a laser scanning confocal microscope using fluorescently conjugated antibodies to identify different cellular structures within the tissue.  Here, hundreds of high-resolution images were optically captured and then seamlessly assembled into one complete image to provide both a global overview of the sample while maintaining sufficient spatial resolution to examine local regions. The blue color reveals the extensive vascular network of the retina, the green colored structures reveal a type of cell called astrocytes (due to their star-like appearance), while the red color identifies their bodies through genetic manipulation.

The image above is a smaller region of the whole retina to provide a sense of spatial resolution.  Many thanks to the Wellcome organization for the award, as well as for their outreach efforts regarding biomedical science.

Media coverage of the 2017 Wellcome Image Awards:

Wired

The Washington Post

Popular Science

MSN

Mirror

Telegraph

Quartz

Business Insider

The Sun

 

Cell-mediated remodeling of hydrogels triggered by adipogenic differentiation.

Adipose stem cells (immature fat cells) are among the most abundant cell-type in the human body, developing methodologies that take advantage of these cells for reconstructive procedures may one day provide a source for wound healing as a result of traumatic injury or to ameliorate congenital defects using autologous transplantation, thus obviating the potential of tissue rejection.  In a collaboration with Drs. Tracy Clevenger, Steve Fisher, Dennis Clegg we examined the ability of adipose stem cells to breakdown a hydrogel that was engineered to foster their growth and survival as these stem cells differentiated into a more mature state with the long-term rationale of increasing the chance of successful tissue grafting as well as accelerating the process of wound healing.  That research was published today in the Journal of Tissue Engineering.  This project involved a blend of computer science, molecular and cellular biology, as well as bio-imaging techniques to investigate these complex biological systems.

b-vnrgd-exp14-24hr-undiffmmp-slide-13_ipd-h244-1_mosaic

A 20-micron thick slice of a hydrogel immunostained (green; for reference the width of a human hair is about 180-microns) with embedded stem cells (blue) under “normal” conditions visualized using fluorescent microscopy.

ipd-14-slide-42-undiff-h_e-stain-20x-3

Using a stain that labels eosinophilic structures we are able to visualize the fine processes of hydrogel that uniformly interweave among the adipose stem cells using a light microscope.

b-vnrgd-exp13-4wk-diff-slide-32_ipd-h15-3_mosaic

A section of a hydrogel whose embedded stem cells were placed under conditions that induced them to differentiate into more mature state (blue).  Notice the increase in the number of cavities after 4 weeks as a result of the adipogenic differentiation.

ipd-16-slide-70-diff-h_e-stain-20x-1

We can also documented the changes in the filamentous appearance of the hydrogel to a increasingly smoother appearance under differentiated conditions, shown in pink.

ipd-13-4wk-diff-mmp-slide-77-hoescht-b-map2-r-b-vnrgd-g-40x-p2-sb-20um

A high-resolution immunofluorescent image of a group of adipose stem cells lining the edges of a subset of cavities within the hydrogel.  Here, the gel is visible in green, while the cell nucleus is blue, and the cytoplasm of the cell is red.

b-vnrgd-exp11-4wk-diff-slide-30_ipd-h11-3_mosaic_cellcounting

An example of a density map shows the relative distribution of cells across a section of hydrogel, here red areas show more densely populated regions. Data such as this illustrates the importance of undergraduate volunteers who contribute countless hours quantifying various parameters, those efforts help move research along at a faster pace than would otherwise happen.

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Dr. Tracy Clevenger, lead author.