Transforming growth factor-β1 induces fibrosis in rat meningeal mesothelial cells via the p38 signaling pathway

Genetic and molecular mechanisms of hydrocephalus

Hydrocephalus is a neurological condition caused by aberrant circulation and/or obstructed cerebrospinal fluid (CSF) flow after cerebral ventricle abnormal dilatation. In the past 50 years, the diagnosis and treatment of hydrocephalus have remained understudied and underreported, and little progress has been made with respect to prevention or treatment. Further research on the pathogenesis of hydrocephalus is essential for developing new diagnostic, preventive, and therapeutic strategies. Various genetic and molecular abnormalities contribute to the mechanisms of hydrocephalus, including gene deletions or mutations, the activation of cellular inflammatory signaling pathways, alterations in water channel proteins, and disruptions in iron metabolism. Several studies have demonstrated that modulating the expression of key proteins, including TGF-β, VEGF, Wnt, AQP, NF-κB, and NKCC, can significantly influence the onset and progression of hydrocephalus. This review summarizes and discusses key mechanisms that may be involved in the pathogenesis of hydrocephalus at both the genetic and molecular levels. While obstructive hydrocephalus can often be addressed by removing the obstruction, most cases require treatment strategies that involve merely slowing disease progression by correcting CSF circulation patterns. There have been few new research breakthroughs in the prevention and treatment of hydrocephalus.

Progressive histological and behavioral deterioration of a novel mouse model of secondary hydrocephalus after subarachnoid hemorrhage

Hydrocephalus commonly occurs after subarachnoid hemorrhage (SAH) and is associated with increased morbidity and disability in patients with SAH. Choroid plexus cerebrospinal fluid (CSF) hypersecretion, obliterative arachnoiditis occluding the arachnoid villi, lymphatic obstruction, subarachnoid fibrosis, and glymphatic system injury are considered the main pathological mechanisms of hydrocephalus after SAH. Although the mechanisms of hydrocephalus after SAH are increasingly being revealed, the clinical prognosis of SAH still has not improved significantly. Further research on SAH is needed to reveal the underlying mechanisms of hydrocephalus and develop translatable therapies. A model that can stably mimic the histopathological and neuroethological features of hydrocephalus is critical for animal experiments. There have been fewer animal studies on hydrocephalus after SAH than on other stroke subtypes. The development of a reproducible and effective model of hydrocephalus after SAH is essential. In this study, we establish a mouse model of SAH that stably mimics brain injury and hydrocephalus after SAH through injections of autologous blood into the cisterna magna via different methods and characterize the model in terms of neurological behavior, histology, imaging, neuronal damage, and white matter damage.

Modulation of Cerebrospinal Fluid Dysregulation via a SPAK and OSR1 Targeted Framework Nucleic Acid in Hydrocephalus

Hydrocephalus is one of the most common brain disorders and a life-long incurable condition. An empirical "one-size-fits-all" approach of cerebrospinal fluid (CSF) shunting remains the mainstay of hydrocephalus treatment and effective pharmacotherapy options are currently lacking. Macrophage-mediated ChP inflammation and CSF hypersecretion have recently been identified as a significant discovery in the pathogenesis of hydrocephalus. In this study, a pioneering DNA nano-drug (TSOs) is developed by modifying S2 ssDNA and S4 ssDNA with SPAK ASO and OSR1 ASO in tetrahedral framework nucleic acids (tFNAs) and synthesis via a one-pot annealing procedure. This construct can significantly knockdown the expression of SPAK and OSR1, along with their downstream ion channel proteins in ChP epithelial cells, thereby leading to a decrease in CSF secretion. Moreover, these findings indicate that TSOs effectively inhibit the M0 to M1 phenotypic switch of ChP macrophages via the MAPK pathways, thus mitigating the cytokine storm. In in vivo post-hemorrhagic hydrocephalus (PHH) models, TSOs significantly reduce CSF secretion rates, alleviate ChP inflammation, and prevent the onset of hydrocephalus. These compelling results highlight the potential of TSOs as a promising therapeutic option for managing hydrocephalus, with significant applications in the future.

Cerebrovascular Anomalies: Perspectives From Immunology and Cerebrospinal Fluid Flow

Appropriate vascular function is essential for the maintenance of central nervous system homeostasis and is achieved through virtue of the blood-brain barrier; a specialized structure consisting of endothelial, mural, and astrocytic interactions. While appropriate blood-brain barrier function is typically achieved, the central nervous system vasculature is not infallible and cerebrovascular anomalies, a collective terminology for diverse vascular lesions, are present in meningeal and cerebral vasculature supplying and draining the brain. These conditions, including aneurysmal formation and rupture, arteriovenous malformations, dural arteriovenous fistulas, and cerebral cavernous malformations, and their associated neurological sequelae, are typically managed with neurosurgical or pharmacological approaches. However, increasing evidence implicates interacting roles for inflammatory responses and disrupted central nervous system fluid flow with respect to vascular perturbations. Here, we discuss cerebrovascular anomalies from an immunologic angle and fluid flow perspective. We describe immune contributions, both common and distinct, to the formation and progression of diverse cerebrovascular anomalies. Next, we summarize how cerebrovascular anomalies precipitate diverse neurological sequelae, including seizures, hydrocephalus, and cognitive effects and possible contributions through the recently identified lymphatic and glymphatic systems. Finally, we speculate on and provide testable hypotheses for novel nonsurgical therapeutic approaches for alleviating neurological impairments arising from cerebrovascular anomalies, with a particular emphasis on the normalization of fluid flow and alleviation of inflammation through manipulations of the lymphatic and glymphatic central nervous system clearance pathways.

Meningeal immunity: Structure, function and a potential therapeutic target of neurodegenerative diseases

Meningeal immunity refers to immune surveillance and immune defense in the meningeal immune compartment, which depends on the unique position, structural composition of the meninges and functional characteristics of the meningeal immune cells. Recent research advances in meningeal immunity have demonstrated many new ways in which a sophisticated immune landscape affects central nervous system (CNS) function under physiological or pathological conditions. The proper function of the meningeal compartment might protect the CNS from pathogens or contribute to neurological disorders. Since the concept of meningeal immunity, especially the meningeal lymphatic system and the glymphatic system, is relatively new, we will provide a general review of the meninges' basic structural elements, organization, regulation, and functions with regards to meningeal immunity. At the same time, we will emphasize recent evidence for the role of meningeal immunity in neurodegenerative diseases. More importantly, we will speculate about the feasibility of the meningeal immune region as a drug target to provide some insights for future research of meningeal immunity.

The Effect of Dry Eye Disease on Scar Formation in Rabbit Glaucoma Filtration Surgery

The success rate of glaucoma filtration surgery is closely related to conjunctival inflammation, and the main mechanism of dry eye disease (DED) is inflammation. The aim of this study was to evaluate the effect of DED on bleb scar formation after rabbit glaucoma filtration surgery. Sixteen New Zealand white rabbits were randomly divided into control and DED groups. A DED model was induced by twice-daily topical administration of 0.1% benzalkonium chloride (BAC) drops for three weeks. Ocular examinations were performed to verify the DED model. Surgical effects were assessed, and histologic assessments were performed on the 28th postoperative day. Higher fluorescein staining scores, lower basal tear secretion levels and goblet cell counts, and increased interleukin 1β (IL-1β) levels were observed in the DED group. The DED eyes displayed significantly higher intraocular pressure (IOP)% on the 14th postoperative day; a smaller bleb area on days 14, 21 and 28; and a shorter bleb survival time. Moreover, proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin (α-SMA) levels were significantly increased in the DED group. These results demonstrate that DED promotes filtering bleb scar formation and shortens bleb survival time; these effects may be mediated via IL-1β.