Our next talk will be on the effects of combined neural stem cell therapy and treadmill training on functional recovery, cyst formation, and astrogliosis after cervical spinal cord injury with Alexander Yudin. Thank you. Ladies and gentlemen, thank you very much for the opportunity to present some data of our Neurodermatology Lab in Heidelberg, Germany. I'm a neurosurgical resident there. I'll talk about the effects of combined neural stem cell therapy and treadmill training on functional recovery after cervical SCI. These are my disclosures. I think that the idea behind the experiment I'll be talking about is pretty straightforward. We know that transportation of NPCs, neuroprecursor cells, after spinal cord injury, SCI has shown and does show beneficial effects on neural regeneration. We also know that, unfortunately, especially functional recovery is still very limited due to different post-traumatic changes, all basically preventing NPCs to survive and to differentiate. On the other hand, we know that treadmill training is an example for physical therapy in animal models, rodent models, but also in our patients in the clinical setting is sought and does improve such detrimental effects. So we sought to combine those two treatment approaches to add treadmill training to NPC transplantation in order to hopefully increase NPC survival, NPC differentiation to reduce post-traumatic negative effects and ultimately to improve functional recovery. We designed an experiment. We had 40 female VISTARETs at the end for analysis. 30 of those had received cervical compression, contusion, SCI at the C6 level. We chose this trauma model because we believe that it's as close as it gets to SCI in the clinical setting, and we chose the cervical spine because both the upper and the lower extremities are affected and because injury burden is just so much higher. It comes with a price. Unfortunately, morbidity and also mortality in this trauma model are high. We had four treatment groups, group one with SCI, NPC transplantation and treadmill training, group two with SCI NPC only, group three with vehicle transplantation, SCI, and group four as a sham group. It was a pretty long experiment. We planned to assess long-term effects of treadmill training on NPC transplantation. We had to generate NPCs out of the subventricular zone of GFP-expressing red embryos. We characterized them, cultivated them, and then when the cells were ready, the fun part of the experiment started. We performed a spinal cord injury. You can see the clip that is used. It's pretty similar to an aneurysm clip. The lamina at C6 is already removed here. The clip is placed, let it snap, and it rests for exactly a minute. This is done by the same surgeon all the time, and when you remove the clip, you can already see some continual changes in the spinal cord. We waited for 10 days, and after the acute injury phase was over, we transplanted NPCs into four sites, two in the rostral and caudal of the lesion, so technically, as you can see here, and we also performed a skip laminectomy to place a little superior catheter over the lesion in order to deliver growth factors from a little osmotic pump for seven days in all animals. We then started treatment training 48 hours after transplantation. This is the treatment we used. This is how rats run when they're uninjured, and this is how they run after injury. They need body weight support at the beginning, and it's kind of hard for them. We did training every day for seven weeks, two times a day for 20 minutes with increased intensity. To assess frontal recovery, we had to perform new behavioral tests as well. We did this every week. We chose catwalk gait analysis, which gives you a lot of computerized, objective, quantifiable measurements for gait, for the function of front limbs and hind limbs. Front limbs are especially important for a cervical trauma model. We performed a gridlock test, a classic rug ladder test, where you count stepping errors, and we performed the... We continuously used BUB score and 21-point open-put motor score to assess hind limb function. We performed some other tests as well. We did MRI. We did fiber labeling, and yet, at the end of the day, after eight weeks post-injury, we sacrificed the animals and did the whole histological assessment. This talk is focusing on functional recovery. Nevertheless, I want to start with one slide that shows MPC survival, probably the most important histological finding here. You can see in this graph that MPCs survived significantly more often in MPC plus training animals, and this is just a glimpse on the differentiation analysis we performed here with screen for mature neurons in oligodendrocytes, and it was interesting to see that MPCs significantly more often differentiated into oligodendrocytes. This is just an example for a typical spine cross-section under 10-time magnification confocal laser scanning microscope that was used for colonization analysis. Now, how did this affect functional recovery? This is a BUB score for all animals over the time of the experiment, and after injury, you can see that a BUB score drops in all treatment groups, and then recovery starts, and the green line are the MPC plus training animals, and you can see that they recover faster and significantly better after three and five weeks, respectively, compared to MPC in the little animals. You can also see that recovery overall is still very limited, even in the combined treatment group, and that a plateau is reached pretty soon, after a couple of weeks. Now, in the BUB score, reaching 11 or more scores is fairly important because it means that animals have frequent to consistent rate-supported plantar steps. So we had a look at how many animals in each treatment group reached this level, and in the MPC plus training group, all animals had reached this level, which means significantly more than in both other treatment groups. Accordingly, in the gridwalk test, animals in the MPC plus training group had significantly less stepping errors than animals in the MPC only and vehicle group. And finally, the catwalk analysis, which really gives you a lot of information, we picked out these two pretty relevant measurements for cervical spinal cord injury. Print area of the front limbs is a static measurement, and swing speed of the hind limbs is a dynamic measurement. And you can see in the graphs that MPC plus training animals had significantly bigger print area of front limbs, which is good, and also significantly faster swing speed of the hind limbs, which is also good, compared to the other groups eight weeks after SCI. With this, I would want to conclude that the addition of treadmill training to MPC transplantation in our experiment of cervical spinal cord injury in rats leads to a significantly higher MPC survival and significantly faster and better functional recovery. We think that it might therefore be useful as an enhancement to current and future stem cell therapy approaches. Thank you. Very nice work.

Alexander Yudin

neural stem cell therapy

treadmill training

functional recovery

cervical spinal cord injury