Challenges and Improvements of Developing an Ischemia Mouse Model Through Bilateral Common Carotid Artery Occlusion.

Brain ischemia is one of the principal causes of death and disability worldwide in which prevention or an effective treatment does not exist. In order to develop successful treatments, an adequate and useful ischemia model is essential. Transient global cerebral ischemia is one of the most interesting pathological conditions in stroke studies because of the observed degeneration of forebrain and delayed neuronal cell death in selective vulnerable regions such as hippocampus. Transient occlusion of both common carotid arteries is the most convenient model to induce tGCI. Although there are effective rat and gerbil models using this method, the induction of a reproducible and reliable injury after global ischemia in mouse has presented higher variations, mainly because of its size and the necessary monitoring skills in order to accomplish homogeneous and reproducible results. Further, great variability among cerebral vasculature and susceptibility of the different strains and sub-strains is observed. In recent years, some modifications have been made to the model in order to normalize the heterogenic effects. Analysis of posterior communicating artery patency has been proposed as an exclusion parameter due to the direct relationship reported with the reduction of cerebral blood flow. Another method used to significantly reduce blood flow is the induction of hypotension with isoflurane. Each protocol produces distinct injury outcomes. Further improvements are needed to attain a general, simpler, reproducible and globally accepted model that allows comparisons between research groups, progress in understanding ischemia and the consequent development of therapeutic alternatives for ischemic injury.

Walk Locomotion Kinematic Changes in a Model of Penetrating Hippocampal Injury in Male/Female Mice and Rats.

Traumatic brain injury has been the leading cause of mortality and morbidity in human beings. One of the most susceptible structures to this damage is the hippocampus due to cellular and synaptic loss and impaired hippocampal connectivity to the brain, brain stem, and spinal cord. Thus, hippocampal damage in rodents using a stereotaxic device could be an adequate method to study a precise lesion from CA1 to the dentate gyrus structures. We studied male and female rats and mice, analyzing hindlimb locomotion kinematics changes to compare the locomotion kinematics using the same methodology in rodents. We measure (1) the vertical hindlimb metatarsus, ankle, and knee joint vertical displacements (VD) and (2) the factor of dissimilarity (DF). The VD in intact rats in metatarsus, ankle, and knee joints differs from that in intact mice in similar joints. In rats, the vertical displacement through the step cycle changed in the left and right metatarsus, ankle, and knee joints compared to the intact group versus the lesioned group. More subtle changes were also observed in mice. DF demonstrates contrasting results when studying locomotion kinematics of mice or rats and sex-dependent differences. Thus, a precise lesion in a rodent's hippocampal structure discloses some hindlimb locomotion changes related to species and sex. Thus, we only have a qualitative comparison between murine species. In order to make a comparison with other species, we should standardize the model.

Mesenchymal Stem Cell-Based Therapies in the Post-Acute Neurological COVID Syndrome: Current Landscape and Opportunities.

One of the main concerns related to SARS-CoV-2 infection is the symptoms that could be developed by survivors, known as long COVID, a syndrome characterized by persistent symptoms beyond the acute phase of the infection. This syndrome has emerged as a complex and debilitating condition with a diverse range of manifestations affecting multiple organ systems. It is increasingly recognized for affecting the Central Nervous System, in which one of the most prevalent manifestations is cognitive impairment. The search for effective therapeutic interventions has led to growing interest in Mesenchymal Stem Cell (MSC)-based therapies due to their immunomodulatory, anti-inflammatory, and tissue regenerative properties. This review provides a comprehensive analysis of the current understanding and potential applications of MSC-based interventions in the context of post-acute neurological COVID-19 syndrome, exploring the underlying mechanisms by which MSCs exert their effects on neuroinflammation, neuroprotection, and neural tissue repair. Moreover, we discuss the challenges and considerations specific to employing MSC-based therapies, including optimal delivery methods, and functional treatment enhancements.

Assessment of the levels of polybrominated diphenyl ethers in blood samples from Guadalajara, Jalisco, Mexico.

The purpose of this study was to measure levels of polybrominated diphenyl ethers (PBDEs) in the blood of children (50 individuals) living in Guadalajara, Jalisco, Mexico. We analyzed six PBDE congeners by gas chromatography-mass spectrometry. Total PBDE levels ranged from not detectable (nd) to 15.2 µg/L on a whole-weight basis and from nd to 6,435 ng/g lipid on a lipid-weight basis. The dominant congener in our study was BDE-153, followed by BDE-154, BDE-99, BDE-100, and BDE-47. Levels of BDE-209 were below the detection limit. Our data indicate that children living in the areas studied in this work are exposed to high levels of PBDEs.

Allogeneic Mesenchymal Stem Cell-Based Treatment Legislation in Latin America: The Need for Standardization in a Medical Tourism Context.

Medicinal signaling cells (MSCs) secrete bioactive molecules with paracrine effects. These cells are widely used in basic and clinical research to treat several human diseases and medically relevant conditions. Although there are promising results, only a few treatments are approved of its administration, and clinicians should not underestimate the potential risks of its application without proper authorization. However, some treatments advertised mainly through the internet are not supported by solid or rigorous scientific evidence, legal consent, or the assurance of safety and efficacy, especially in the cell therapy tourism space. This practice allows patients to travel from stringently regulated countries to less restricted ones and increase the flourishing of nonendorsed therapies in these regions. Clinical applications of MSC-based treatments are subject to health legislation, and regulatory agencies are responsible for supervising their manufacture, quality control, and marketing approval. Consensus is needed to homologize and strengthen health legislation regarding those therapies, particularly in regions where medical tourism is frequent. Latin America and the Caribbean, an overlooked region with very heterogeneous legislation regarding cell therapy, is a popular medical tourism destination. Brazil and Argentina created regulations to supervise cell-based treatment manufacture, quality, and marketing, while Mexico, considered the second-largest drug market in Latin America, does not recognize nor authorize any cell as therapy. Also, some regulatory bodies miss the importance of several critical good manufacture practice processes to ensure reproducible, reliable, safe, and potentially more favorable results and do not consider them in their legislation. These inconsistencies make the region vulnerable to unproven or unethical treatments, potentially becoming a public health problem involving people from countries worldwide. This review attempts to generate awareness for the legal status of cell therapies in Latin America and the need for standardization as this region is a significant medical tourism destination.

Proliferation and apoptosis regulation by G protein-coupled estrogen receptor in glioblastoma C6 cells.

Glioblastoma is the most frequent primary tumor in the human brain. Glioblastoma cells express aromatase and the classic estrogen receptors ERα and ERß and can produce estrogens that promote tumor growth. The membrane G protein-coupled estrogen receptor (GPER) also plays a significant role in numerous types of cancer; its participation in glioblastoma tumor development is not entirely known. The present study investigated the effect of the agonists [17ß-estradiol (E2) and G1] and antagonist (G15) of GPER on proliferation and apoptosis of C6 glioblastoma cells. GPER expression was evaluated by immunofluorescence, western blotting and reverse transcription-quantitative PCR. Cell proliferation was determined using Ki67 immunopositivity. Cell viability was examined using the MTT assay and apoptosis using caspase-3 immunostaining and ELISA. C6 cells express GPER, and the immunopositivity increased after exposure to E2, G1, or their combination. GPER protein expression increased after treatment with E2 combined with G1. However, GPER mRNA expression decreased in treated cells compared with control. The percentage of Ki67 immunopositive C6 cells increased under the effect of E2 in combination with G1 or G1 alone. G15 significantly reduced Ki67 immunopositivity. Pearson's correlation analysis revealed a positive relationship between GPER and Ki67 immunopositivity across the study conditions. Additionally, the MTT assay showed a significant reduction in C6 cell viability after G15 treatment, alone or in combination with G1. The exposure to G15 increased the percentage of caspase-3 immunopositivity cells and caspase-3 levels. Pearson's correlation analysis demonstrated a negative correlation between GPER and caspase-3 immunopositivity across the study conditions. Glioblastoma C6 cells express GPER, and this receptor modulates cell proliferation and apoptosis. The GPER agonists E2 and G1 favored cell proliferation; meanwhile, the antagonist G15 reduced cell proliferation, viability and favored apoptosis. Therefore, GPER may be used as a biomarker of glioblastoma and as a target to develop new therapeutic strategies for glioblastoma treatment.

Kinematic Changes in a Mouse Model of Penetrating Hippocampal Injury and Their Recovery After Intranasal Administration of Endometrial Mesenchymal Stem Cell-Derived Extracellular Vesicles.

Locomotion speed changes appear following hippocampal injury. We used a hippocampal penetrating brain injury mouse model to analyze other kinematic changes. We found a significant decrease in locomotion speed in both open-field and tunnel walk tests. We described a new quantitative method that allows us to analyze and compare the displacement curves between mice steps. In the tunnel walk, we marked mice with indelible ink on the knee, ankle, and metatarsus of the left and right hindlimbs to evaluate both in every step. Animals with hippocampal damage exhibit slower locomotion speed in both hindlimbs. In contrast, in the cortical injured group, we observed significant speed decrease only in the right hindlimb. We found changes in the displacement patterns after hippocampal injury. Mesenchymal stem cell-derived extracellular vesicles had been used for the treatment of several diseases in animal models. Here, we evaluated the effects of intranasal administration of endometrial mesenchymal stem cell-derived extracellular vesicles on the outcome after the hippocampal injury. We report the presence of vascular endothelial growth factor, granulocyte-macrophage colony-stimulating factor, and interleukin 6 in these vesicles. We observed locomotion speed and displacement pattern preservation in mice after vesicle treatment. These mice had lower pyknotic cells percentage and a smaller damaged area in comparison with the nontreated group, probably due to angiogenesis, wound repair, and inflammation decrease. Our results build up on the evidence of the hippocampal role in walk control and suggest that the extracellular vesicles could confer neuroprotection to the damaged hippocampus.

Establishment of Murine Model of Kidney Failure Induced by Severe Ischemia-Reperfusion Injury Useful to Evaluate Transplantation and Regenerative Therapies.

BACKGROUND: Severe ischemia-reperfusion injury (SIRI) seems to be the key factor that can significantly affect the function of both native kidneys and renal allografts. Therefore, the development of a successful strategy is of a paramount importance in both basic and clinical research. METHODS: To determine the effects of SIRI on the native kidney function, a murine model was planned as follows: group 1 (n = 6) mice underwent to nephrectomy plus ischemia-reperfusion injury for 30 minutes; group 2 (n = 6) mice underwent to nephrectomy without ischemia-reperfusion injury and thus served as sham controls for SIRI. The results of serum creatinine (SCr) were analyzed using Mann-Whitney U tests to calculate the significance between mean values. Survival between groups was measured by Kaplan-Meier test. RESULTS: To reliably achieve an elevation of SCr levels animals were exposed to a SIRI. The values of SCr increased from 0.35 (SD, 0.09) mg/dL to about 2-fold within 2 days and 3-fold within the following 5 days. Under these given conditions the mice displayed signs and histologic findings of severe kidney damage. The survival rate was about 83% of the animals within a week, and they showed no capacity of complete spontaneous self-regeneration. CONCLUSIONS: In this study, we aim to establish a murine model with extensive structural kidney damage and significant elevation of SCr levels, which could be used in basic and translational research of transplantation and regenerative therapies.

CYP2C9 and CYP2C19 Allele and Haplotype Distributions in Four Mestizo Populations from Western Mexico: An Interethnic Comparative Study.

AIMS: Polymorphisms in the CYP2C9 and CYP2C19 genes confer potential risk for specific adverse drug reactions and therapeutic effect failure. Their frequencies differ among ethnic groups. This study was aimed to describe the distribution of CYP2C9 and CYP2C19 alleles and haplotypes in four Mestizo populations from Western Mexico and their comparison with the reported data from other ethnic groups. METHODS: The CYP2C alleles (CYP2C9*2, CYP2C9*3, CYP2C19*2, and CYP2C19*3) were genotyped using polymerase chain reaction-restriction fragment length polymorphisms analyses using DNA samples from 477 healthy Mestizo individuals of Colima (n = 100), Jalisco (n = 147), Michoacán (n = 117), and Nayarit (n = 113). RESULTS: Frequencies ranged from 2.2-3.0% and 4.8-8.9% for CYP2C9*3 and CYP2C9*2 alleles, respectively, and 5.4-12.0% for CYP2C19*2, whereas the CYP2C19*3 allele was not found. Haplotype GACA, which harbors the loss-of-function allele CYP2C19*2, was the second most frequent (8.7%). Genetic heterogeneity between the Western Mexican populations studied here and the global population was evident (p < 0.05), except for most American populations and other Mexican Mestizo populations. CONCLUSION: Our findings increase the evidence for genetic variability at relevant pharmacogenetic loci and could be useful in association studies involving drugs that are substrates for CYP2C enzymes in the Western Mexican population.