Biology subjects

Mather, M. L.

Publications and source records attributed to Mather, M. L..

3 recordsLinked to original sources

bioRxiv2020

Oligodendrocyte progenitor proliferation is disinhibited following traumatic brain injury in LIF heterozygous mice

Traumatic brain injury (TBI) is a significant problem that affects [~]500,000 children each year. As cell proliferation is disturbed by injury and is required for normal brain development, we investigated how a pediatric closed head injury (CHI) would affect the progenitors of the subventricular zone (SVZ). Additionally, we evaluated the contribution of Leukemia Inhibitory Factor (LIF) using LIF-heterozygous mice (LIF Het), as LIF is an injury-induced cytokine, known to influence neurogenesis and gliogenesis. CHIs were performed on P20 LIF Het and WT mice. Ki-67 staining and stereology revealed that cell proliferation increased [~]250% in injured LIF Het mice compared to the 30% increase observed in injured WT mice at 48 h post CHI. Furthermore, Olig2+ cell proliferation increased in the SVZ and white matter of LIF Het injured mice at 48 h recovery. Using an 8-color flow cytometry panel, the proliferation of three distinct multipotential progenitors were greater in LIF Het injured mice compared to WT injured mice. Early oligodendrocyte progenitor cell (OPC) proliferation was 6-fold higher in LIF Het injured mice compared to WT injured mice. In vitro, addition of LIF decreased overall cell proliferation and OPC proliferation compared to controls. Addition of LIF to OPC cultures induced an increase of phospho-Akt after 20 minutes and an increase of phospho-S6RP at 20 and 40 minutes of exposure, suggesting that LIF stimulates the mammalian target of Rapamycin pathway. Altogether, our data provide new insights into the regulatory role of LIF in suppressing neural progenitor cell proliferation after a mild TBI. Main PointsO_LIOPC proliferation is dis-inhibited in LIF haplodeficient mice. C_LIO_LILIF directly inhibits glial progenitor cell proliferation. C_LIO_LILIF stimulates the mTOR pathway. C_LI

neuroscience↗

bioRxiv2020

Single-cell Sequencing Reveals Brain/Spinal Cord Oligodendrocyte Precursor Heterogeneity and Requirement for mTOR in Cholesterol Biosynthesis and Myelin Maintenance

Brain and spinal cord oligodendroglia have distinct functional characteristics, and cell autonomous loss of individual genes can result in different regional phenotypes. However, sequencing studies to date have not revealed distinctions between brain and spinal cord oligodendroglia. Using single-cell analysis of oligodendroglia during myelination, we demonstrate that brain and spinal cord precursors are transcriptionally distinct, defined predominantly by cholesterol biosynthesis. We further identify mechanistic target of rapamycin (mTOR) as a major regulator promoting cholesterol biosynthesis in oligodendroglia. Oligodendroglial-specific loss of mTOR compromises cholesterol biosynthesis in both the brain and spinal cord. Importantly, mTOR loss has a greater impact on cholesterol biosynthesis in spinal cord oligodendroglia that corresponds with more pronounced developmental deficits. However, loss of mTOR in brain oligodendroglia ultimately results in oligodendrocyte death, spontaneous demyelination, and impaired axonal function, demonstrating that mTOR is required for myelin maintenance in the adult brain.

neuroscience↗

bioRxiv2020

Self-activated photoblinking of nitrogen vacancy centers in nanodiamonds (sandSTORM): A method for rapid single molecule localization microscopy with unlimited observation time

Stochastic optical reconstruction microscopy (STORM) is one of the most commonly used super-resolution microscopy techniques. Popular implementations of STORM utilize aromatic fluorophores and consist of a number of intrinsic limitations such the finite photostability of the dyes, the reliance upon non-physiological redox buffers and speed which is ultimately limited by the off-rates of the photoblinking. Self-activated nanodiamond-based STORM (sandSTORM) has been developed as an accelerated STORM protocol which harvests the rapid, high quantum-yield and sustained photoblinking of nanodiamonds (ND). Photoluminescence emanating from the stochastic charge-state interconversion of Nitrogen Vacancy (NV) centers between NV0and NV- is localized using conventional STORM-optimized hardware and image processing protocols over an unlimited duration of imaging. This produces super-resolution images of matching resolution at [~] 3-times the speed and [~] 100 times less light exposure to the sample compared to traditional STORM. The enabling NDs have been used to map arrays of ryanodine receptor in skeletal muscle tissues via immunolabelling and directly visualize the internal spaces of living neurons via endocytosis of NDs. This paper details the physical basis of sandSTORM, factors which optimize its performance, and key characteristics which make it a powerful STORM protocol suitable for imaging nanoscale sub-cellular structures.

biophysics↗