Tisch Multiple Sclerosis Research Center of New York

Author Of 2 Presentations

Experimental Models Poster Presentation

P0963 - Filtration of primary progressive MS CSF removes factors causing delayed remyelination of lysolecithin lesions (ID 1799)

Speakers
Presentation Number
P0963
Presentation Topic
Experimental Models

Abstract

Background

Primary progressive MS (PPMS) is characterized by disease progression from clinical onset and failure of remyelination. In our prior work, we showed that intrathecal injection of cerebrospinal fluid (CSF) from PPMS patients, but not relapsing-remitting (RRMS) or secondary progressive (SPMS) patients, delayed spontaneous remyelination in lysolecithin-induced lesions. The PPMS CSF factors that impede remyelination have not yet been isolated or characterized. To better understand the size of these undetermined factor(s), we filtered PPMS CSF at 100 kDa and determined the effect of filtered CSF on remyelination in lysolecithin-induced lesions.

Objectives

To investigate whether filtration of PPMS CSF mitigates the delayed remyelination induced by PPMS CSF factors following lysolecithin-induced demyelination.

Methods

CSF obtained from PPMS patients was passed through a tangential flow filtration system for 3 filtration cycles to remove CSF components larger than 100 kDa. Mice underwent a laminectomy at cervical level 5 (C5). 1 μL of 1% lysolecithin was injected into the dorsal column. Five days post injection, 3 μL of PPMS CSF or filtered PPMS CSF were injected into the subarachnoid space at C5. Control mice were injected with saline. Mice were perfused at 12 days post lysolecithin injection and pathology was assessed in the cervical spinal cord.

Results

Intrathecal injection of PPMS CSF at the site of a lysolecithin-induced lesion resulted in significantly larger demyelinated lesions compared to saline controls, as determined by luxol fast blue staining. However, there was no significant difference in lesion volume between filtered PPMS CSF-injected mice and saline controls. This suggests that the 100 kDa filter removed pathological PPMS CSF factor(s) preventing spontaneous remyelination in lysolecithin-induced lesions. Preliminary data suggest that mice injected with filtered PPMS CSF display reduced reactive astrogliosis (GFAP) and microglial activation (Iba1) within the lesion compared to unfiltered PPMS CSF-injected mice. There was no significant difference in numbers of proliferating oligodendrocyte progenitor cells (NG2/Ki67) or mature oligodendrocytes (APC/Olig2).

Conclusions

Our results indicate that PPMS CSF factors responsible for impeding remyelination are larger than 100 kDa and can be removed by filtration. This suggests that CSF pheresis may be a therapeutic option.

Collapse
Experimental Models Poster Presentation

P0987 - Pathological effects of primary progressive MS cerebrospinal fluid are antibody-mediated (ID 1021)

Speakers
Presentation Number
P0987
Presentation Topic
Experimental Models

Abstract

Background

Primary progressive multiple sclerosis (PPMS) is characterized by unremitting disease progression from disease onset and afflicts 10-15% of MS patients. We previously reported that intrathecal delivery of PPMS cerebrospinal fluid (CSF) from PPMS, but not relapsing-remitting (RRMS) or secondary progressive (SPMS) patients, in mice can induce significant forelimb motor deficits along with demyelination, reactive astrogliosis, and axonal damage in the spinal cord. We also showed that CSF filtration with a 5 kDa molecular weight cutoff (MWCO) filter attenuated the pathology-inducing capacity of PPMS CSF. The PPMS CSF factor(s) responsible for inducing these pathological outcomes have yet to be identified.

Objectives

To identify the factor(s) present in PPMS CSF responsible for inducing motor deficits and spinal cord pathology in mice.

Methods

CSF derived from PPMS patients was pumped through a tangential flow filtration system with 100 kDa MWCO filters for 3 filtration cycles. 8-10 week old female mice underwent laminectomies at cervical levels 4 and 5, then received 3µl injections into the subarachnoid space of either PPMS CSF, filtered PPMS CSF, or filtered PPMS CSF spiked with recombinant IgG antibodies (rAbs) produced from B-cells in PPMS CSF. Control mice were injected with saline. Functional deficits were evaluated by measuring forelimb grip strength, reaching accuracy and tail rigidity at 1 day post injection (DPI), then mice were immediately perfused for histological analyses of the cervical spinal cord.

Results

At 1 DPI, PPMS CSF-injected mice exhibited significantly impaired forelimb function and grip strength compared to saline controls and mice injected with filtered PPMS CSF. Luxol fast blue staining, GFAP and SMI-32 immunostaining showed demyelination, reactive astrogliosis and axonal damage in the dorsal column of PPMS CSF-injected mice, respectively. These pathological changes were not observed in controls or mice injected with filtered PPMS CSF. Mice injected with filtered PPMS CSF spiked with a PPMS rAb developed significant motor deficits at 1 DPI.

Conclusions

Attenuation of the pathology-inducing capacity of PPMS CSF using 100 kDa MWCO filters indicates that the target CSF component is larger than 100 kDa. The addition of PPMS rAbs (150 kDa) into filtered PPMS CSF was able to restore the pathological effects in vivo, suggesting that the induction of motor deficits and pathology by PPMS CSF is antibody-mediated.

Collapse

Presenter Of 1 Presentation

Experimental Models Poster Presentation

P0987 - Pathological effects of primary progressive MS cerebrospinal fluid are antibody-mediated (ID 1021)

Speakers
Presentation Number
P0987
Presentation Topic
Experimental Models

Abstract

Background

Primary progressive multiple sclerosis (PPMS) is characterized by unremitting disease progression from disease onset and afflicts 10-15% of MS patients. We previously reported that intrathecal delivery of PPMS cerebrospinal fluid (CSF) from PPMS, but not relapsing-remitting (RRMS) or secondary progressive (SPMS) patients, in mice can induce significant forelimb motor deficits along with demyelination, reactive astrogliosis, and axonal damage in the spinal cord. We also showed that CSF filtration with a 5 kDa molecular weight cutoff (MWCO) filter attenuated the pathology-inducing capacity of PPMS CSF. The PPMS CSF factor(s) responsible for inducing these pathological outcomes have yet to be identified.

Objectives

To identify the factor(s) present in PPMS CSF responsible for inducing motor deficits and spinal cord pathology in mice.

Methods

CSF derived from PPMS patients was pumped through a tangential flow filtration system with 100 kDa MWCO filters for 3 filtration cycles. 8-10 week old female mice underwent laminectomies at cervical levels 4 and 5, then received 3µl injections into the subarachnoid space of either PPMS CSF, filtered PPMS CSF, or filtered PPMS CSF spiked with recombinant IgG antibodies (rAbs) produced from B-cells in PPMS CSF. Control mice were injected with saline. Functional deficits were evaluated by measuring forelimb grip strength, reaching accuracy and tail rigidity at 1 day post injection (DPI), then mice were immediately perfused for histological analyses of the cervical spinal cord.

Results

At 1 DPI, PPMS CSF-injected mice exhibited significantly impaired forelimb function and grip strength compared to saline controls and mice injected with filtered PPMS CSF. Luxol fast blue staining, GFAP and SMI-32 immunostaining showed demyelination, reactive astrogliosis and axonal damage in the dorsal column of PPMS CSF-injected mice, respectively. These pathological changes were not observed in controls or mice injected with filtered PPMS CSF. Mice injected with filtered PPMS CSF spiked with a PPMS rAb developed significant motor deficits at 1 DPI.

Conclusions

Attenuation of the pathology-inducing capacity of PPMS CSF using 100 kDa MWCO filters indicates that the target CSF component is larger than 100 kDa. The addition of PPMS rAbs (150 kDa) into filtered PPMS CSF was able to restore the pathological effects in vivo, suggesting that the induction of motor deficits and pathology by PPMS CSF is antibody-mediated.

Collapse