Cortical AAV-CNTF Gene Therapy Combined with Intraspinal Mesenchymal Precursor Cell Transplantation Promotes Functional and Morphological Outcomes after Spinal Cord Injury in Adult Rats

Abstract

Ciliary neurotrophic factor (CNTF) promotes survival and enhances long-distance regeneration of injured axons in parts of the adult CNS. Here we tested whether CNTF gene therapy targeting corticospinal neurons (CSN) in motor-related regions of the cerebral cortex promotes plasticity and regrowth of axons projecting into the female adult F344 rat spinal cord after moderate thoracic (T10) contusion injury (SCI). Cortical neurons were transduced with a bicistronic adeno-associated viral vector (AAV1) expressing a secretory form of CNTF coupled to mCHERRY (AAV-CNTFmCherry) or with control AAV only (AAV-GFP) two weeks prior to SCI. In some animals, viable or nonviable F344 rat mesenchymal precursor cells (rMPCs) were injected into the lesion site two weeks after SCI to modulate the inhibitory environment. Treatment with AAV-CNTFmCherry, as well as with AAV-CNTFmCherry combined with rMPCs, yielded functional improvements over AAV-GFP alone, as assessed by open-field and Ladderwalk analyses. Cyst size was significantly reduced in the AAV-CNTFmCherry plus viable rMPC treatment group. Cortical injections of biotinylated dextran amine (BDA) revealed more BDA-stained axons rostral and alongside cysts in the AAV-CNTFmCherry versus AAV-GFP groups. After AAV-CNTFmCherry treatments, many sprouting mCherry-immunopositive axons were seen rostral to the SCI, and axons were also occasionally found caudal to the injury site. These data suggest that CNTF has the potential to enhance corticospinal repair by transducing parent CNS populations.

Optimization of adeno-associated viral vector-mediated transduction of the corticospinal tract: comparison of four promoters

“…The AAV1 serotype is commonly used to transduce the CST via intracortical injections [31][32][33][34][35][36][37][38]. An earlier study that compared seven AAV serotypes (AAV1-AAV6, and AAV8) identified AAV1 and AAV5 as the best and secondbest serotypes to transduce the CST in rats [20].…”

Promoting functions of microRNA-29a/199B in neurological recovery in rats with spinal cord injury through inhibition of the RGMA/STAT3 axis

“…Under a sterile condition, the T9-T11 laminae were removed by laminectomy, and then the T10 segment was compressed using a modified aneurysm clip at 20 g for 60 s. Pain was alleviated by analgesics, while the infection was prevented with antibiotics. Successful model establishment in rats was confirmed by a < 1 score 1 h after surgery according to a Basso, Beattie, and Bresnahan (BBB) locomotor rating scale [ 18 , 19 ]. The remaining 8 rats were subjected to sham operation with only the skin and muscle cut open and sutured.…”

MSC based gene delivery methods and strategies improve the therapeutic efficacy of neurological diseases

“…Other potential treatment strategies using implanted MSCs include promoting neural differentiation (EGF, Shh and miR-124) [ 159 , 176 , 247 , 248 ]; enhancing proliferation (bFGF, PTEN, IGF-1, and Nice4, Fig. 6 ) [ 203 , [249] , [250] , [251] ]; increasing migration ability (ChABC, Snail, miR-31 and SDF-1α) [ 250 , [252] , [253] , [254] ]; inhibiting apoptosis (GIT1 and miR-21) [ 255 , 256 ]; reducing antioxidative stress (miR-200a) [ 256 ]; proangiogensis (miR-17-5p) [ 257 ]; and neurotrophic effect (CNTF, BDNF, miR-146a-5p and miR-383) [ [258] , [259] , [260] , [261] , [262] ]. The details of these transgenic MSCs for SCI treatment are summarized in Table 2 .…”