The gut–brain axis refers to the bidirectional communication network linking the gut microbiota and the central nervous system (CNS). Recent research has highlighted the critical role of gut microbiota in influencing brain health, neurogenesis, and neuroinflammation. In the context of brain tumors, especially gliomas, the gut–brain axis plays a significant role in tumor development, progression, and response to therapy. Gut dysbiosis, characterized by an imbalance in microbiota composition, has been linked to chronic inflammation, immune suppression, and altered blood–brain barrier (BBB) permeability, key factors in glioma pathogenesis. Gut-derived metabolites such as short-chain fatty acids (SCFAs) and neurotransmitters can either promote or inhibit tumor growth, impacting the tumor microenvironment (TME) and immune responses. Emerging evidence suggests that microbiome modulation, through strategies such as probiotics, prebiotics, and dietary interventions, may enhance anti-tumor immunity and improve the efficacy of conventional treatments like chemotherapy, radiotherapy, and immunotherapy. This review examines the interactions between gut microbiota and brain tumors, focusing on how microbiota alterations may influence tumor biology and therapeutic outcomes. Understanding the mechanisms of the gut–brain axis could lead to novel adjunctive therapies in neuro-oncology, offering new prospects for personalized treatment strategies in brain tumor management.

Neurodegenerative diseases (NDDs) are currently the most widespread neuronal pathologies in the world. Among these, the most widespread are Alzheimer’s disease (AD), dementia, Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD)—all characterized by a progressive loss of neurons in specific regions of the brain leading to varied clinical symptoms. At the basis of neurodegenerative diseases, an emerging role is played by genetic mutations in the leucine-rich repeat kinase 2 (LRRK2) gene that cause increased LRRK2 activity with consequent alteration of neuronal autophagy pathways. LRRK2 kinase activity requires GTPase activity which functions independently of kinase activity and is required for neurotoxicity and to potentiate neuronal death. Important in the neurodegeneration process is the upregulation of casein kinase (CK), which causes the alteration of the AMPK pathway by enhancing the phosphorylation of α-synuclein and huntingtin proteins, known to be involved in PD and HD, and increasing the accumulation of the amyloid-β protein (Aβ) for AD. Recent research has identified CK of the kinases upstream of LRRK2 as a regulator of the stability of the LRRK2 protein. Based on this evidence, this review aims to understand the direct involvement of individual kinases in NDDs and how their crosstalk may impact the pathogenesis and early onset of neurodegenerative diseases.

Myocardial ischemia–reperfusion injury (MI/R) is a negative and adverse cardiovascular outcome following myocardial ischemia, cardiac surgery, or circulatory arrest. Prolyl endopeptidase (PREP) appears to be involved in inflammatory responses, so it could be a possible therapeutic target for counteracting ischemia injury. This study aimed to investigate the role of PREP inhibitor, KYP-2047 (4-phenylbutanoyl-l-prolyl-2(S)-cyanopyrolidine), in the modulation of molecular and biochemical processes involved in MI/R. MI/R was induced through coronary artery occlusion (15 min), followed by reperfusion (2 h). KYP-2047 was intraperitoneally administrated at doses of 2.5 mg/kg and 5 mg/kg 24 h before the surgical procedures. The hearts were removed and processed for analysis. KYP-2047 treatment limited ischemic myocardial-induced histological damage and neutrophil accumulation, limiting inflammation, fibrosis, and apoptosis processes. Additionally, KYP-2047 was able to modulate p-38 and p-ERK expression, suggesting an improving role in recovering cardiac function. These findings highlighted the protective effects of KYP-2047 pretreatment in MI/R injury, suggesting PREP as a potential target therapy for the pathogenesis of MI/R. Although the molecular mechanisms underlying the action of KYP-2047 are still to be explored, these results suggested that the regulation of NF-κB, apoptosis, and MAPK pathways by KYP-2047 treatment could preventatively limit the damage caused by MI/R.