Neural Placode Tissue Derived From Myelomeningocele Repair Serves as a Viable Source of Oligodendrocyte Progenitor Cells

The loss of microglia activities facilitates glaucoma progression in association with CYP1B1 gene mutation (p.Gly61Glu)

Background

Glaucoma represents the second main cause of irreversible loss of eyesight worldwide. Progression of the disease is due to changes around the optic nerve, eye structure and optic nerve environment. Focusing on primary congenital glaucoma, which is not completely understood, we report an evaluation of an untested mutation (c.182G>A, p.Gly61Glu) within the CYP1B1 gene in the context of microglia, astrocytes and mesenchymal stem cells. We investigated the behaviours of these cells, which are needed to maintain eye homeostasis, in response to the CYP1B1 mutation.

Methods and results

CRISPR technology was used to edit normal CYP1B1 genes within normal astrocytes, microglia and stem cells in vitro. Increased metabolic activities were found in microglia and astrocytes 24 hours after CYP1B1 manipulation. However, these activities dropped by 40% after 72 hrs. In addition, the nicotinamide adenine dinucleotide phosphate (NADP)/NADPH reducing equivalent process decreased by 50% on average after 72 hrs of manipulation. The cytokines measured in mutated microglia showed progressive activation leading to apoptosis, which was confirmed with annexin-V. The cytokines evaluated in mutant astrocytes were abnormal in comparison to those in the control.

Conclusions

The results suggest a progressive inflammation that was induced by mutations (p.Gly61Glu) on CYP1B1. Furthermore, the mutations enhanced the microglia’s loss of activity. We are the first to show the direct impact of the mutation on microglia. This progressive inflammation might be responsible for primary congenital glaucoma complications, which could be avoided via an anti-inflammatory regimen. This finding also reveals that progressive inflammation affects recovery failure after surgeries to relieve glaucoma. Moreover, microglia are important for the survival of ganglion cells, along with the clearing of pathogens and inflammation. The reduction of their activities may jeopardise homeostasis within the optic nerve environment and complicate the protection of optic nerve components (such as retinal ganglion and glial cells).

Direct Stimulation of Neural Placode and Nerve Roots in Open Myelomeningocele: The Efficacy of Neural Tube Reconstruction

INTRODUCTION

Intraoperative electrophysiological studies are increasingly used in spinal surgery. However, its use in myelomeningocele (MMC) surgery is still not widespread. The aim of this study was to present our experience in neural placode (NP) and nerve root stimulations in newborns with open MMC.

METHODS

Eight newborns underwent surgical treatment for thoracolumbar and lumbosacral MMCs. Intraoperative neuromonitoring including free-running electromyography and stimulation of NP, nerve roots, and spinal cord were performed in all cases. Stimulation sites and intensities and distal response's amplitudes and latencies were recorded.

RESULTS

Five patients had thoracolumbar and 3 patients had lumbosacral MMC. Two patients had no movements at the lower extremities while the other had some movements. No response on the lower extremities was obtained in only 1 patient. Responses from the nerve root stimulations were more robust and significant than the placode stimulations.

CONCLUSIONS

It is clear that the NP and nerve roots originating from the placode are mostly functional and should be preserved during the surgery. Intraoperative neuromonitoring and direct stimulation should be performed during the MMC repair in order to obtain a better neurological outcome.

Cardiac Fibrosis: The Fibroblast Awakens

Myocardial fibrosis is a significant global health problem associated with nearly all forms of heart disease. Cardiac fibroblasts comprise an essential cell type in the heart that is responsible for the homeostasis of the extracellular matrix; however, upon injury, these cells transform to a myofibroblast phenotype and contribute to cardiac fibrosis. This remodeling involves pathological changes that include chamber dilation, cardiomyocyte hypertrophy and apoptosis, and ultimately leads to the progression to heart failure. Despite the critical importance of fibrosis in cardiovascular disease, our limited understanding of the cardiac fibroblast impedes the development of potential therapies that effectively target this cell type and its pathological contribution to disease progression. This review summarizes current knowledge regarding the origins and roles of fibroblasts, mediators and signaling pathways known to influence fibroblast function after myocardial injury, as well as novel therapeutic strategies under investigation to attenuate cardiac fibrosis.