A variant in IL6ST with a selective IL-11 signaling defect in human and mouse

The GP130 cytokine receptor subunit encoded by IL6ST is the shared receptor for ten cytokines of the IL-6 family. We describe a homozygous non-synonymous variant in IL6 ST(p.R281 Q) in a patient with craniosynostosis and retained deciduous teeth. We characterize the impact of the variant on cytokine signaling in vitro using transfected cell lines as well as primary patient-derived cells and support these findings using a mouse model with the corresponding genome-edited variant Il6 st p.R279 Q. We show that human GP130 p.R281 Q is associated with selective loss of IL-11 signaling without affecting IL-6, IL-27, OSM, LIF, CT1, CLC, and CNTF signaling. In mice Il6 st p.R279 Q lowers litter size and causes facial synostosis and teeth abnormalities. The effect on IL-11 signaling caused by the GP130 variant shows incomplete penetrance but phenocopies aspects of IL11 RA deficiency in humans and mice. Our data show that a genetic variant in a pleiotropic cytokine receptor can have remarkably selective defects.

Intraoperative perfusion magnetic resonance imaging: Cutting-edge improvement in neurosurgical procedures

The goal in brain tumor surgery is to remove the maxi-mum achievable amount of the tumor, preventing damage to "eloquent" brain regions as the amount of brain tumor resection is one of the prognostic factors for time to tumor progression and median survival. To achieve this goal, a variety of technical advances have been in-troduced, including an operating microscope in the late 1950 s, computer-assisted devices for surgical navigation and more recently, intraoperative imaging to incorporate and correct for brain shift during the resection of the lesion. However, surgically induced contrast enhancement along the rim of the resection cavity hampers interpretation of these intraoperatively acquired magnetic resonance images. To overcome this uncertainty, perfusion techniques [dynamic contrast enhanced magnetic resonance imaging(DCE-MRI), dynamic susceptibility contrast magnetic resonance imaging(DSC-MRI)] have been introduced that can differentiate residual tumor from surgically induced changes at the rim of the resec-tion cavity and thus overcome this remaining uncer-tainty of intraoperative MRI in high grade brain tumor resection.

Targeting UDP-α-D-glucose 6-dehydrogenase alters the CNS tumor immune microenvironment and inhibits glioblastoma growth

Glioblastoma(GBM,WHO grade IV glioma)is the most common and lethal malignant brain tumor in aduts with a dismal prognosis.The extracellular matrix(ECM)supports GBM progression by promoting tumor cell proliferation,migration,and immune escape.Uridine diphosphate(UDP)-glucose 6-dehydrogenase(UGDH)is the rate-limiting enzyme that catalyzes the biosynthesis of glycosaminoglycans that are the principal component of the CNS ECM.We investigated how targeting UGDH in GBM infuence$the GBM immune microenvironment,including tumor-associated microglia/macrophages(TAMs)and T cells.TAMs are the main im-mune effector cells in GBM and can directly target tumor cells if properly activated.In co-cultures of GBM cells and human primary macrophages,UGDH knockdown in GBM cells pro-moted macrophage phagocytosis and M-like polarization.In orthotropic human GBM xeno-grafts and syngeneic mouse glioma models,targeting UGDH decreased ECM deposition,increased TAM phagocytosis marker expression,reduced M2-like TAMS and inhibited tumor growth.UGDH knockdown in GBM cells also promoted cytotoxic T cell ifltration and activa-tion in orthotopic syngeneic mouse glioma models.The potent and in-human-use small mole-cule GAG synthesis inhibitor 4-methylumbelliferone(4-MU)was found to inhibit GBM cell proliferation and migration in vitro,mimic the macrophage and T-cell responses to UGDH knockdown in vitro and in vivo and inhibit growth of orthotopic murine GBM.Our study shows that UGDH supports GBM growth through multiple mechanisms and supports the development of ECM-based therapeutic strategies to simultaneously target tumor cells and their microenvi-ronment.