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Rolo, A.

Publications and source records attributed to Rolo, A..

3 recordsLinked to original sources
bioRxiv2025

NDR2 Kinase Regulate Microglial Metabolic Adaptation and Inflammatory Response: Critical Role in Glucose-Dependent Functional Plasticity

Diabetes and its retinal complication, diabetic retinopathy (DR), are a rapidly increasing health, societal and economic burden. Diabetic retinopathy is a complex disease with a chronic inflammatory component mediated by retinal microglial cells. Recent studies have demonstrated the importance of the Hippo pathway kinases, Ndr1/Stk38 and Ndr2/Stk38l, in the regulation of macrophages, immune cells that share similarities with microglial cells. However, the role of NDR2 kinases in microglial inflammatory response and in the pathophysiology of diabetic retinopathy has not yet been uncovered. This study investigates the role of NDR2 kinase in microglial cells, particularly in response to high glucose (HG) conditions. Using CRISPR-Cas9, we downregulated Ndr2 kinase in BV-2 microglial cells and analyzed the impact on cellular metabolism, phagocytosis and migratory capabilities. We demonstrate that microglial cells expressed NDR2 kinase protein, especially in HG conditions, suggesting its importance in regulating microglial functions during hyperglycemia. Ndr2 downregulated cells present a decreased basal respiration, indicating an impaired mitochondrial function. They also showed decreased metabolic flexibility to stress conditions, such as adaptation to HG conditions. Functionally, Ndr2 downregulation led to decreased phagocytic capacity and migration of microglial cells, both cytoskeleton-based functions. Furthermore, Ndr2 downregulation resulted in altered cytokine and chemokine secretion profiles. Notably, increased levels of pro-inflammatory cytokines such as IL-6, TNF, IL-17 and IL-12p70 were observed in Ndr2 downregulated cells, even under normal glucose conditions. In conclusion, our findings indicate that NDR2 kinase is crucial for microglial metabolic adaptation to stress, such as high glucose exposure and for influencing microglial inflammatory responses. Therefore, NDR2 kinase plays a vital role in maintaining microglial functional plasticity in response to glucose variations, suggesting potential implications for neuroinflammatory processes in conditions like diabetic retinopathy. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/659313v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1380275org.highwire.dtl.DTLVardef@2950f9org.highwire.dtl.DTLVardef@833593org.highwire.dtl.DTLVardef@325171_HPS_FORMAT_FIGEXP M_FIG C_FIG Research in Context What is already known about this subject?O_LIThe pathogenesis of diabetic retinopathy (DR) involves chronic inflammation mediated by retinal microglial cells, which contribute to vascular damage and neurodegeneration. C_LIO_LIMicroglial dysfunction under high glucose (HG) conditions exacerbates cytokine release and oxidative stress, driving DR progression. C_LIO_LINDR kinases regulate inflammatory pathways in macrophages, but their role in microglia during DR was previously unexplored. C_LI What is the key question?O_LIHow do NDR2 kinase regulate microglial inflammatory responses and functional adaptability in diabetic retinopathy? C_LI What are the new findings?O_LINDR2 expression is upregulated in microglia exposed to HG. C_LIO_LINdr2 downregulation in microglia impairs metabolic flexibility, phagocytosis, and migration. C_LIO_LINdr2 downregulation disrupts cytoskeleton-dependent microglial functions, limiting their ability to adapt to metabolic stress. C_LIO_LINdr2 downregulation in microglia increases pro-inflammatory cytokines (IL-17, TNF) and reduces anti-inflammatory factors (sTNFRI, VEGF), exacerbating inflammation. C_LI How might this impact clinical practice?O_LITargeting Ndr2 signaling could emerge as a therapeutic strategy to modulate microglial-driven inflammation, potentially slowing DR progression and complementing existing glycemic control approaches. C_LI

immunology↗
bioRxiv2019

Novel mouse model of encephalocele: post-neurulation origin and relationship to open neural tube defects

Encephalocele is a clinically important birth defect that can lead to severe disability in childhood and beyond. The embryonic pathogenesis of encephalocele is poorly understood and, while usually classified as a neural tube defect, there is conflicting evidence on whether encephalocele results from defective neural tube closure, or is a post-neurulation defect. It is also unclear whether encephalocele can result from the same causative factors as anencephaly and open spina bifida, or whether it is aetiologically distinct. This lack of information results largely from the scarce availability of animal models of encephalocele, particularly ones that resemble the commonest, non-syndromic human defects. Here we report a novel mouse model of occipito-parietal encephalocele, in which the small GTPase Rac1 is conditionally ablated in the (non-neural) surface ectoderm. Most mutant fetuses have open spina bifida, and some also exhibit exencephaly/anencephaly. However, a large proportion of mutant fetuses exhibit encephalocele affecting the occipito-parietal region. The encephalocele phenotype does not result from a defect in neural tube closure, but rather from a later disruption of the surface ectoderm covering the already closed neural tube, allowing the brain to herniate. The neuroepithelium itself shows no down-regulation of Rac1 and appears morphologically normal until late gestation. A large skull defect develops overlying the region of brain herniation. Our work provides a new genetic model of occipito-parietal encephalocele, particularly resembling non-syndromic human cases. While encephalocele has a different, later-arising pathogenesis than open neural tube defects, both can share the same genetic causation.\n\nSUMMARY STATEMENTEncephalocele - a severe brain defect - arises after neural tube closure, but can share a common genetic cause with anencephaly, a defect of neural tube closure.

developmental biology↗
bioRxiv2018

Characterization of convergent thickening, a major convergence force producing morphogenic movement in amphibians

We characterize the morphogenic process of convergent thickening (CT), which occurs in the involuting marginal zone (IMZ) during gastrulation of Xenopus, the African clawed frog. CT was described previously as the tendency of explants of the ventral IMZ of Xenopus to converge their circumblastoporal dimension and thicken their radial dimension (Keller and Danilchik 1988). Here we show that CT occurs from the onset of gastrulation, initially throughout the pre-involution IMZ. We suggest that CT is driven by an increase in the interfacial tension between the deep IMZ and its epithelium, resulting in cells of the deep IMZ tending to minimize their surface area. In explants, this results in a progressive shortening (convergence) of the IMZ along its longer mediolateral axis and thickening in the orthogonal planes, and can generate tensile force (Shook et al. 2018). In vivo, convergence of the annular IMZ generates circumferential tension, closing the blastopore. These results provide the first clear example of a tensile morphogenic force from a Holtfreterian/Steinbergian change in tissue affinity.

developmental biology↗