We have found that the tripotential glial-restricted precursor (GRP) cell of the embryonic rat spinal cord can give rise in vitro to bipotential cells that express defining characteristics of ...oligodendrocyte-type-2 astrocyte progenitor cells (O2A/OPCs). Generation of O2A/OPCs is regulated by environmental signals and is promoted by platelet-derived growth factor (PDGF), thyroid hormone (TH) and astrocyte-conditioned medium. In contrast to multiple observations indicating that oligodendrocyte precursor cells in the embryonic day 14 (E14) spinal cord are ventrally restricted, GRP cells are already present in both the dorsal and ventral spinal cord at E13.5. Ventral-derived GRP cells, however, were more likely to generate O2A/OPCs and/or oligodendrocytes than were their dorsal counterparts when exposed to TH, PDGF, or even bone morphogenetic protein-4. The simplest explanation of our results is that oligodendrocyte generation occurs as a result of generation of GRP cells from totipotent neuroepithelial stem cells, of O2A/OPCs from GRP cells and, finally, of oligodendrocytes from O2A/OPCs. In this respect, the responsiveness of GRP cells to modulators of this process may represent a central control point in the initiation of this critical developmental sequence. Our findings provide an integration between the earliest known glial precursors and the well-studied O2A/OPCs while opening up new questions concerning the intricate spatial and temporal regulation of precursor cell differentiation in the CNS.
Transplantation of glial restricted precursor (GRP) cells has been shown to reduce glial scarring after spinal cord injury (SCI) and, in combination with neuronal restricted precursor (NRP) cells or ...enhanced expression of neurotrophins, to improve recovery of function after SCI. We hypothesized that combining GRP transplants with rolipram and cAMP would improve functional recovery, similar to that seen after combining Schwann cell transplants with increasing cAMP. A short term study, (1) uninjured control, (2) SCI+vehicle, and (3) SCI+cAMP, showed that spinal cord cAMP was increased 14days after SCI. We used 51 male rats subjected to a thoracic SCI for a 12-week survival study: (1) SCI+vehicle, (2) SCI+GRP, (3) SCI+cAMP, (4) SCI+GRP+cAMP, and (5) uninjured endpoint age-matched control (AM). Rolipram was administered for 2weeks after SCI. At 9days after SCI, GRP transplantation and injection of dibutyryl-cAMP into the spinal cord were performed. GRP cells survived, differentiated, and formed extensive transplants that were well integrated with host tissue. Presence of GRP cells increased the amount of tissue in the lesion; however, cAMP reduced the graft size. White matter sparing at the lesion epicenter was not affected. Serotonergic input to the lumbosacral spinal cord was not affected by treatment, but the amount of serotonin immediately caudal to the lesion was reduced in the cAMP groups. Using telemetric monitoring of corpus spongiosum penis pressure we show that the cAMP groups regained the same number of micturitions per 24hours when compared to the AM group, however, the frequency of peak pressures was increased in these groups compared to the AM group. In contrast, the GRP groups had similar frequency of peak pressures compared to baseline and the AM group. Animals that received GRP cells regained the same number of erectile events per 24hours compared to baseline and the AM group. Since cAMP reduced the GRP transplant graft, and some modest positive effects were seen that could be attributable to both GRP or cAMP, future research is required to determine how cAMP affects survival, proliferation, and/or function of progenitor cells and how this is related to function. cAMP may not always be a desirable addition to a progenitor cell transplantation strategy after SCI.
► GRP cells survived, differentiated, and formed extensive transplants. ► GRP cells and cAMP had modest positive effects on micturitions and erections. ► cAMP reduced the graft size throughout the lesion region and at the lesion center. ► Serotonin immediately caudal to the lesion was reduced in the cAMP groups.
In addition to dopaminergic neuron loss, it is clear that Parkinson disease includes other pathological changes, including loss of additional neuronal populations. As a means of addressing multiple ...pathological changes with a single therapeutically‐relevant approach, we employed delayed transplantation of a unique class of astrocytes, GDAsBMP, that are generated in vitro by directed differentiation of glial precursors. GDAsBMP produce multiple agents of interest as treatments for PD and other neurodegenerative disorders, including BDNF, GDNF, neurturin and IGF1. GDAsBMP also exhibit increased levels of antioxidant pathway components, including levels of NADPH and glutathione. Delayed GDABMP transplantation into the 6‐hydroxydopamine lesioned rat striatum restored tyrosine hydroxylase expression and promoted behavioral recovery. GDABMP transplantation also rescued pathological changes not prevented in other studies, such as the rescue of parvalbumin+ GABAergic interneurons. Consistent with expression of the synaptic modulatory proteins thrombospondin‐1 and 2 by GDAsBMP, increased expression of the synaptic protein synaptophysin was also observed. Thus, GDAsBMP offer a multimodal support cell therapy that provides multiple benefits without requiring prior genetic manipulation.
Synopsis
In vitro‐generated astrocytes GDAsBMP transplantation is the first example of a multimodal single therapeutic cell therapy approach with the potential to promote recovery of multiple neuron populations of relevance to Parkinson's Disease in a rat model.
Transplantation of GDAsBMP provides a successful astrocyte‐based multimodal treatment in a model of Parkinson's Disease without the need for prior genetic modification of cells or the use of neuron transplants to restore function.
Recovery of multiple neuronal populations, including tyrosine hydroxylase expressing, dopaminergic neurons and parvalbumin+ GABAergic interneurons, was caused by post‐symptomatic transplantation of GDAsBMP into a hemiparkinsonian model.
Consistent with high levels of expression of the synaptic modulatory proteins thrombospondin 1 and 2 in GDAsBMP, restored expression of the synaptic protein synaptophysin was also seen in the striatum of transplanted animals.
Multiple factors of interest for the treatment of neurodegenerative disease, including brain‐ and glia‐derived neurotrophic factor, neurturin and IGF1 and‐2, are intrinsically produced by GDAsBMP and are produced at levels far exceeding that seen in their parental precursor cells or in other astrocytes derived from these precursors.
Additional protection against oxidative stress, a process widely involved in CNS pathology, is also provided by increased glutathione production by GDAsBMP.
In vitro‐generated astrocytes GDAsBMP transplantation is the first example of a multimodal single therapeutic cell therapy approach with the potential to promote recovery of multiple neuron populations of relevance to Parkinson's Disease in a rat model.
Transplantation of stem cells and immature cells has been reported to ameliorate tissue damage, induce axonal regeneration, and improve locomotion following spinal cord injury. However, unless these ...cells are pushed down a neuronal lineage, the majority of cells become glia, suggesting that the alterations observed may be potentially glially mediated. Transplantation of glial-restricted precursor (GRP) cells—a precursor cell population restricted to oligodendrocyte and astrocyte lineages—offers a novel way to examine the effects of glial cells on injury processes and repair. This study examines the survival and differentiation of GRP cells, and their ability to modulate the development of the lesion when transplanted immediately after a moderate contusion injury of the rat spinal cord. GRP cells isolated from a transgenic rat that ubiquitously expresses heat-stable human placental alkaline phosphatase (PLAP) were used to unambiguously detect transplanted GRP cells. Following transplantation, some GRP cells differentiated into oligodendrocytes and astrocytes, retaining their differentiation potential after injury. Transplanted GRP cells altered the lesion environment, reducing astrocytic scarring and the expression of inhibitory proteoglycans. Transplanted GRP cells did not induce long-distance regeneration from corticospinal tract (CST) and raphe-spinal axons when compared to control animals. However, GRP cell transplants did alter the morphology of CST axons toward that of growth cones, and CST fibers were found within GRP cell transplants, suggesting that GRP cells may be able to support axonal growth in vivo after injury.
Abstract
In addition to dopaminergic neuron loss, it is clear that Parkinson disease includes other pathological changes, including loss of additional neuronal populations. As a means of addressing ...multiple pathological changes with a single therapeutically‐relevant approach, we employed delayed transplantation of a unique class of astrocytes,
GDA
s
BMP
, that are generated
in vitro
by directed differentiation of glial precursors.
GDA
s
BMP
produce multiple agents of interest as treatments for
PD
and other neurodegenerative disorders, including
BDNF
,
GDNF
, neurturin and
IGF
1.
GDA
s
BMP
also exhibit increased levels of antioxidant pathway components, including levels of
NADPH
and glutathione. Delayed
GDA
BMP
transplantation into the 6‐hydroxydopamine lesioned rat striatum restored tyrosine hydroxylase expression and promoted behavioral recovery.
GDA
BMP
transplantation also rescued pathological changes not prevented in other studies, such as the rescue of parvalbumin
+
GABA
ergic interneurons. Consistent with expression of the synaptic modulatory proteins thrombospondin‐1 and 2 by
GDA
s
BMP
, increased expression of the synaptic protein synaptophysin was also observed. Thus,
GDA
s
BMP
offer a multimodal support cell therapy that provides multiple benefits without requiring prior genetic manipulation.
Synopsis
image
In vitro
‐generated astrocytes
GDA
s
BMP
transplantation is the first example of a multimodal single therapeutic cell therapy approach with the potential to promote recovery of multiple neuron populations of relevance to Parkinson's Disease in a rat model.
Transplantation of
GDA
s
BMP
provides a successful astrocyte‐based multimodal treatment in a model of Parkinson's Disease without the need for prior genetic modification of cells or the use of neuron transplants to restore function.
Recovery of multiple neuronal populations, including tyrosine hydroxylase expressing, dopaminergic neurons and parvalbumin+
GABA
ergic interneurons, was caused by post‐symptomatic transplantation of
GDA
s
BMP
into a hemiparkinsonian model.
Consistent with high levels of expression of the synaptic modulatory proteins thrombospondin 1 and 2 in
GDA
s
BMP
, restored expression of the synaptic protein synaptophysin was also seen in the striatum of transplanted animals.
Multiple factors of interest for the treatment of neurodegenerative disease, including brain‐ and glia‐derived neurotrophic factor, neurturin and
IGF
1 and‐2, are intrinsically produced by
GDA
s
BMP
and are produced at levels far exceeding that seen in their parental precursor cells or in other astrocytes derived from these precursors.
Additional protection against oxidative stress, a process widely involved in
CNS
pathology, is also provided by increased glutathione production by
GDA
s
BMP
.
To identify genes important for human cognitive development, we studied Williams syndrome (WS), a developmental disorder that includes poor visuospatial constructive cognition. Here we describe two ...families with a partial WS phenotype; affected members have the specific WS cognitive profile and vascular disease, but lack other WS features. Submicroscopic chromosome 7q11.23 deletions cosegregate with this phenotype in both families. DNA sequence analyses of the region affected by the smallest deletion (83.6 kb) revealed two genes,
elastin (
ELN ) and
LIM-kinase1 (
LIMK1). The latter encodes a novel protein kinase with LIM domains and is strongly expressed in the brain. Because
ELN mutations cause vascular disease but not cognitive abnormalities, these data implicate
LIMK1 hemizygosity in impaired visuospatial constructive cognition.
INTS11 and CPSF73 are metal-dependent endonucleases for Integrator and pre-mRNA 3′-end processing, respectively. Here, we show that the INTS11 binding partner BRAT1/CG7044, a factor important for ...neuronal fitness, stabilizes INTS11 in the cytoplasm and is required for Integrator function in the nucleus. Loss of BRAT1 in neural organoids leads to transcriptomic disruption and precocious expression of neurogenesis-driving transcription factors. The structures of the human INTS9-INTS11-BRAT1 and Drosophila dIntS11-CG7044 complexes reveal that the conserved C terminus of BRAT1/CG7044 is captured in the active site of INTS11, with a cysteine residue directly coordinating the metal ions. Inspired by these observations, we find that UBE3D is a binding partner for CPSF73, and UBE3D likely also uses a conserved cysteine residue to directly coordinate the active site metal ions. Our studies have revealed binding partners for INTS11 and CPSF73 that behave like cytoplasmic chaperones with a conserved impact on the nuclear functions of these enzymes.
Display omitted
•BRAT1/CG7044 is a binding partner that stabilizes INTS11 in the cytoplasm•BRAT1/CG7044 is required for Integrator function in the nucleus•The conserved C terminus of BRAT1-CG7044 is captured in the INTS11 active site•UBE3D is a binding partner of CPSF73 with a similar mechanism of action
Lin et al. reveal BRAT1/CG7044 as a binding partner for the INTS11 endonuclease that behaves like a cytoplasmic chaperone and is required for Integrator function in the nucleus. UBE3D is also identified as a binding partner for the CPSF73 endonuclease in pre-mRNA 3′-end processing, with a similar mechanism of action.
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