CNS-wide repopulation by hematopoietic-derived microglia-like cells corrects progranulin deficiency in mice.

Hematopoietic stem cell transplantation can deliver therapeutic proteins to the central nervous system (CNS) through transplant-derived microglia-like cells. However, current conditioning approaches result in low and slow engraftment of transplanted cells in the CNS. Here we optimized a brain conditioning regimen that leads to rapid, robust, and persistent microglia replacement without adverse effects on neurobehavior or hematopoiesis. This regimen combines busulfan myeloablation and six days of Colony-stimulating factor 1 receptor inhibitor PLX3397. Single-cell analyses revealed unappreciated heterogeneity of microglia-like cells with most cells expressing genes characteristic of homeostatic microglia, brain-border-associated macrophages, and unique markers. Cytokine analysis in the CNS showed transient inductions of myeloproliferative and chemoattractant cytokines that help repopulate the microglia niche. Bone marrow transplant of progranulin-deficient mice conditioned with busulfan and PLX3397 restored progranulin in the brain and eyes and normalized brain lipofuscin storage, proteostasis, and lipid metabolism. This study advances our understanding of CNS repopulation by hematopoietic-derived cells and demonstrates its therapeutic potential for treating progranulin-dependent neurodegeneration.

Comparison of different DNA preservation solutions for oral cytological samples.

OBJECTIVE: The objective of this study was to compare the DNA preservation capacity of buccal mucosa exfoliated cells when stored in different solutions under varying time and temperature conditions. DESIGN: DNA preservation solutions, including Dimethyl sulphoxide disodium-EDTA-saturated NaCl (DESS), Tris-EDTA-NaCl-Tween20 buffer (TENT), Nucleic Acid Preservation Buffer (NAP), and phosphate-buffered saline (PBS), were prepared. Buccal mucosa cells from a single patient were collected, dispensed into these solutions, and stored at room temperature (RT) and 4 °C for 24 h, 72 h, 30 days, 90 days, and 180 days. DNA was extracted using the salting-out method and the QIAamp DNA Mini Kit. DNA concentration and purity were determined using the QuBit device and NanoDrop, while DNA integrity was assessed using the Agilent 4200 TapeStation system. The ability to amplify the IFNA primer was also evaluated by PCR. RESULTS: The salting-out method yielded better concentration and purity results, with PBS, TENT, and DESS buffers demonstrating superior concentration values when stored at 4 °C, resulting in mean values exceeding 10 ng/µL for up to 30 days. DESS consistently exhibited the best integrity values over time for both temperature conditions. Amplification capacity was enhanced when samples were stored at 4 °C. When stored at RT, PBS achieved 100% amplification within 24 h. NAP yielded the poorest results. CONCLUSION: In the context of long-term preservation, the DESS buffer emerges as the most effective solution, maintaining requisite DNA quality and quantity standards for up to 30 days at RT and up to 3 months at 4 °C.

Genome editing in lysosomal disorders.

Lysosomal disorders are a group of heterogenous diseases caused by mutations in genes that encode for lysosomal proteins. With exception of some cases, these disorders still lack both knowledge of disease pathogenesis and specific therapies. In this sense, genome editing arises as a technique that allows both the creation of specific cell lines, animal models and gene therapy protocols for these disorders. Here we explain the main applications of genome editing for lysosomal diseases, with examples based on the literature. The ability to rewrite the genome will be of extreme importance to study and potentially treat these rare disorders.

Identification of Ezetimibe and Pranlukast as Pharmacological Chaperones for the Treatment of the Rare Disease Mucopolysaccharidosis Type IVA.

Mucopolysaccharidosis type IVA (MPS IVA) is a rare disease caused by mutations in the gene encoding the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS). We report here two GALNS pharmacological chaperones, ezetimibe and pranlukast, identified by molecular docking-based virtual screening. These compounds bound to the active cavity of GALNS and increased its thermal stability as well as the production of recombinant GALNS in bacteria, yeast, and HEK293 cells. MPS IVA fibroblasts treated with these chaperones exhibited increases in GALNS protein and enzyme activity and reduced the size of enlarged lysosomes. Abnormalities in autophagy markers p62 and LC3B-II were alleviated by ezetimibe and pranlukast. Combined treatment of recombinant GALNS with ezetimibe or pranlukast produced an additive effect. Altogether, the results demonstrate that ezetimibe and pranlukast can increase the yield of recombinant GALNS and be used as a monotherapy or combination therapy to improve the therapeutic efficacy of MPS IVA enzyme replacement therapy.