Activation of leukocyte immunoglobulin-like receptor B2 signaling pathway in cortical lesions of pediatric patients with focal cortical dysplasia type IIb and tuberous sclerosis complex

Targeting leukocyte immunoglobulin‑like receptor B2 in the tumor microenvironment: A new treatment prospect for solid tumors (Review)

Leukocyte immunoglobulin-like receptor B2 (LILRB2) functions as an immunosuppressive receptor that has a prominent role in immune regulation. The expression of LILRB2 is higher in a variety of solid malignant tumors compared with that in corresponding normal tissues. LILRB2 can be expressed in tumor cells and tumor stromal cells within the tumor microenvironment. Upregulation of LILRB2 in tumors is significantly associated with a poorer tumor phenotype, increased tolerance to certain therapeutic drugs, tumor immune escape and shorter patient overall survival time. Therefore, LILRB2 can be utilized as a novel biomarker to predict the prognosis of patients with solid malignant tumors, and targeting LILRB2 may be an effective strategy for targeted cancer therapy. The present review provides a general overview of the role and mechanisms of LILRB2 in the microenvironment of solid tumors, and emphasizes the significance of targeting LILRB2 as a promising approach for tumor-specific therapy.

Focal cortical dysplasia type II: review of neuropathological manifestations and pathogenetic mechanisms

Focal cortical dysplasia (FCD) is an important cause of intractable epilepsy, with FCD type II (FCD II) being the most common subtype. FCD II is characterized by cortical dyslamination accompanied by dysmorphic neurons (DNs). Identifying the molecular alterations and targetable biomarkers is pivotal for developing therapies. Here, we provide a detailed description of the neuropathological manifestations of FCD II, including morphological alterations and immunophenotypic profiles, indicating that abnormal cells exhibit a diverse spectrum of mixed differentiation states. Furthermore, we summarize current research on the pathogenetic mechanisms, indicating that gene mutations, epigenetic alterations, cortical developmental protein disturbances, inflammatory processes, and extrinsic damages may lead to abnormal neuronal proliferation and migration, thereby contributing to the emergence and progression of FCD II. These findings not only enhance our understanding of the pathogenesis of FCD II but also offer new directions for clinical diagnosis and treatment. Future research should further explore the interactions among these factors and employ multidisciplinary approaches to advance our understanding of FCD II.

Iconography of abnormal non-neuronal cells in pediatric focal cortical dysplasia type IIb and tuberous sclerosis complex

Once believed to be the culprits of epileptogenic activity, the functional properties of balloon/giant cells (BC/GC), commonly found in some malformations of cortical development including focal cortical dysplasia type IIb (FCDIIb) and tuberous sclerosis complex (TSC), are beginning to be unraveled. These abnormal cells emerge during early brain development as a result of a hyperactive mTOR pathway and may express both neuronal and glial markers. A paradigm shift occurred when our group demonstrated that BC/GC in pediatric cases of FCDIIb and TSC are unable to generate action potentials and lack synaptic inputs. Hence, their role in epileptogenesis remained obscure. In this review, we provide a detailed characterization of abnormal non-neuronal cells including BC/GC, intermediate cells, and dysmorphic/reactive astrocytes found in FCDIIb and TSC cases, with special emphasis on electrophysiological and morphological assessments. Regardless of pathology, the electrophysiological properties of abnormal cells appear more glial-like, while others appear more neuronal-like. Their morphology also differs in terms of somatic size, shape, and dendritic elaboration. A common feature of these types of non-neuronal cells is their inability to generate action potentials. Thus, despite their distinct properties and etiologies, they share a common functional feature. We hypothesize that, although the exact role of abnormal non-neuronal cells in FCDIIb and TSC remains mysterious, it can be suggested that cells displaying more glial-like properties function in a similar way as astrocytes do, i.e., to buffer K+ ions and neurotransmitters, while those with more neuronal properties, may represent a metabolic burden due to high energy demands but inability to receive or transmit electric signals. In addition, due to the heterogeneity of these cells, a new classification scheme based on morphological, electrophysiological, and gene/protein expression in FCDIIb and TSC cases seems warranted.

Balloon cells in malformations of cortical development: friends or foes?

Balloon cells (BCs) are specific pathological marker of cortical malformations during brain development, often associated with epilepsy and development delay. Although a large number of studies have investigated the role of BCs in these diseases, the specific function of BCs as either epileptogenic or antiepileptic remains controversial. Therefore, we reviewed literatures on BCs, delved into the molecular mechanisms and signaling pathways, and updated their profile in several aspects. Firstly, BCs are heterogeneous and some of them show progenitor/stem cell characteristics. Secondly, BCs are relatively silent in electrophysiology but not completely isolated from their surroundings. Notably, abnormal mTOR signaling and aberrant immunogenic process have been observed within BCs-containing malformations of cortical development (MCDs). The question whether BCs function as the evildoer or the defender in BCs-containing MCDs is further discussed. Importantly, this review provides perspectives on future investigations of the potential role of BCs in epilepsy.

Progress of clinical research studies on tuberous sclerosis complex-related epilepsy in China

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous syndrome, with 75.6%-83.5% and 54.1% patients presenting with epilepsy and drug-resistant epilepsy (DRE), respectively. Clinical studies on TSC, particularly surgical interventions, have achieved rapid and substantial progress. The TSC-Task Force Committee of the China Association Against Epilepsy (CAAE-TFTSC) was founded in 2012, and annual academic conferences on the surgical treatment of TSC-related epilepsy have been held since 2013. 'China experts' consensus on surgical treatment of TSC-related epilepsy' was published in 2019. This review focuses on surgical treatment, including resective surgery, neuromodulations, corpus callosotomy and mini-invasive ablations, as well as studies on phenotype, genotype and anti-seizure therapies of mammalian target of rapamycin inhibitor, vigabatrin and ketogenic diet in patients with TSC-related DRE in China.