Glioblastomas are considered the most common and aggressive primary brain tumor in adults, with an average of 15 months’ survival rate. The treatment is surgery resection, followed by chemotherapy with temozolomide, and/or radiotherapy. Glioblastoma must have wild-type IDH gene and some characteristics, such as TERT promoter mutation, EGFR gene amplification, microvascular proliferation, among others. Glioblastomas have great heterogeneity at cellular and molecular levels, presenting distinct phenotypes and diversified molecular signatures in each tumor mass, making it difficult to define a specific therapeutic target. It is believed that the main responsibility for the emerge of these distinct patterns lies in subcellular populations of tumor stem cells, capable of tumor initiation and asymmetric division. Studies are now focused on understanding molecular mechanisms of chemoresistance, the tumor microenvironment, due to hypoxic and necrotic areas, cytoskeleton and extracellular matrix remodeling, and in controlling blood brain barrier permeabilization to improve drug delivery. Another promising therapeutic approach is the use of oncolytic viruses that are able to destroy specifically glioblastoma cells, preserving the neural tissue around the tumor. In this review, we summarize the main biological characteristics of glioblastoma and the cutting-edge therapeutic targets that are currently under study for promising new clinical trials.

The blood–brain barrier (BBB) is a highly intricate neurovascular structure that plays a crucial role in maintaining neural homeostasis by selectively allowing certain molecules to enter the central nervous system (CNS). However, in the context of Alzheimer’s Disease (AD), a progressive neurodegenerative disorder characterized by a gradual decline in cognitive function, the BBB’s functionality becomes impaired. This impairment leads to the breakdown of the barrier and disrupts its ability to regulate molecular transport effectively. Consequently, cellular infiltration into the CNS occurs, along with aberrant signaling and clearance of molecules, ultimately contributing to neurological deficits. One of the key factors implicated in the failure of amyloid-beta (Aβ) transport, a hallmark of AD, is the decreased expression of low-density lipoprotein receptor-related protein 1 (LRP1). LRP1 plays a crucial role in facilitating the transport of Aβ across the BBB. Additionally, the increased levels of the receptor for advanced glycation end products (RAGE) further contribute to the deregulation of the BBB in AD. These molecular imbalances significantly impact Aβ clearance and contribute to the development and progression of AD. In this review, we aimed to summarize the critical aspects of Aβ transporters in the BBB that become dysfunctional during the pathogenesis of AD.

Concerns over the replicability and reproducibility of published research have grown in many research fields, but empirical data to inform policies are still scarce. Biomedical research in Brazil expanded rapidly over the last three decades, with no systematic assessment of the replicability of its findings. With this in mind, we set up the Brazilian Reproducibility Initiative, a multicenter replication of published experiments from Brazilian science using three common experimental methods: the MTT assay, the reverse transcription polymerase chain reaction (RT-PCR) and the elevated plus maze (EPM). A total of 56 laboratories performed 143 replications of 56 experiments; of these, 90 replications of 45 experiments were considered valid by an independent committee. Replication rates for these experiments varied between 20 and 44% according to five predefined criteria. In median terms, ratios between group means were 58% lower in replications than in original experiments, while coefficients of variation were 82% higher. Effect size decrease was smaller for MTT experiments, original results with less variability and those considered more challenging to replicate, while t values for replications were positively correlated with researcher predictions about replicability, and negatively correlated with the rate of publications by the original article’s last author. Deviations from preregistered protocols were very common in replications, most frequently due to reasons inherent to the experimental model or related to infrastructure and logistics. Our results highlight factors that limit the replicability of results published by researchers in Brazil and suggest ways by which this scenario can be improved.

The kinin receptors are classically involved in inflammation, pain and sepsis. The effects of the kinin B1 receptor agonist des-Arg9-bradykinin (DBK) and lipopolysaccharide (LPS) were investigated by comparing the membrane potential responses of aortic rings from transgenic rats overexpressing the kinin B1 receptor (B1R) in the endothelium (TGR(Tie2B1)) and Sprague Dawley (SD) rats. No difference in the resting membrane potential in the aorta’s smooth muscle from the transgenic and SD rats was observed. The aorta rings from SD rats hyperpolarized only to LPS but not to DBK, whereas the aorta rings from TGR(Tie2B1) responded by the administration of both drugs. DBK and LPS responses were inhibited by the B1 receptor antagonist R715 and by iberiotoxin in both cases. Thapsigargin induced a hyperpolarization in the smooth muscle of SD rats that was not reversed by R715, but was reversed by iberiotoxin and this hyperpolarization was further augmented by DBK administration. These results show that the model of overexpression of vascular B1 receptors in the TGR(Tie2B1) rats represent a good model to study the role of functional B1 receptors in the absence of any pathological stimulus. The data also show that KCa channels are the final mediators of the hyperpolarizing responses to DBK and LPS. In addition, we suggest an interaction between the B1R and TLR4, since the hyperpolarization induced by LPS could be abolished in the presence of R715.

Background/Objectives: The low permeability of the blood-brain barrier (BBB) represents a significant challenge to effective systemic chemotherapy for primary and metastatic brain cancers. Kinin receptors play a crucial role in modulating BBB permeability, and their agonist analogs have been explored in preclinical animal models to enhance drug delivery to the brain. In this study, we investigated whether des-Arg⁹-bradykinin (DBK), a physiological agonist of kinin B₁ receptor (B1R), acts as a brain drug delivery adjuvant by promoting the transient opening of the BBB. Methods: Human brain microvascular endothelial cells (HBMECs) were treated with DBK in the culture medium and in conditioned media from glioblastoma cell lines, namely T98G (CMT98G) and U87MG (CMU87). Immunofluorescence, RT-qPCR, in-cell Western assay, and proximity ligation assay (PLA) were performed to analyze BBB components, kinin receptors and TLR4, a receptor associated with the kinin pathway and inflammation. The effect of DBK on enhancing paracellular molecule transport was evaluated using Evans blue dye (EB) quantification in a cell culture insert assay and in an in vivo model, where mice with and without brain tumors were treated with DBK. To assess the functional impact of the transient BBB opening induced by DBK, the chemotherapeutic drug doxorubicin (DOX) was administered. Results: Treatment with DBK facilitates the presence of EB in the brain parenchyma by transiently disrupting the BBB, as further evidenced by the increased paracellular passage of the dye in an in vitro assay. B1R activation by DBK induces transient BBB opening lasting less than 48 h, enhancing the bioavailability of the DOX within the brain parenchyma and glioma tumor mass. The interaction between B1R and TLR4 is disrupted by the secreted factors released by glioblastoma cells, as conditioned media from T98G and U87 reduce TLR4 staining in endothelial cells without affecting B1R expression. Conclusions: These results further support the potential of B1R activation as a strategy to enhance targeted drug delivery to the brain.

The Zika virus received significant attention in 2016, following a declaration by the World Health Organization of an epidemic in the Americas, in which infections were associated with microcephaly. Indeed, prenatal Zika virus infection is detrimental to fetal neural stem cells and can cause premature cell loss and neurodevelopmental abnormalities in newborn infants, collectively described as congenital Zika syndrome. Contrastingly, much less is known about how neonatal infection affects the development of the newborn nervous system. Here, we investigated the development of the dentate gyrus of wild-type mice following intracranial injection of the virus at birth (postnatal day 0). Through this approach, we found that Zika virus infection affected the development of neurogenic regions within the dentate gyrus and caused reactive gliosis, cell death and a decrease in cell proliferation. Such infection also altered volumetric features of the postnatal dentate gyrus. Thus, we found that Zika virus exposure to newborn mice is detrimental to the subgranular zone of the dentate gyrus. These observations offer insight into the cellular mechanisms that underlie the neurological features of congenital Zika syndrome in children.