Katherine Athayde Teixeira de Carvalho

Background/Objectives: Pereskia grandifolia Haw. is a plant native to Central and South America and belongs to the Cactaceae family, and it is valued in the human diet for its nutritional value. Recently, this species was reported to contain a variety of saponins, but structural details remain limited because of their number and complexity. Saponins exhibit pharmacological properties, making their characterization useful. Methods: Comprehensive mass spectrometry analysis, combined with chemical methylation of the entire saponins, provided critical information on the distribution of sugar moieties associated with the monosaccharides and the aglycone. We also assessed cellular antioxidant capacity, cytotoxicity, and antiproliferative effects against breast tumor cell lines by staining for Ki-67, Annexin V, and 7AAD. Results: Fifteen saponins were identified with oleanolic and ursolic acids. Oligosaccharides were formed by glucuronic acid, with additional glucose units attached to the glucuronic acid or the aglycone, which had not been reported previously. This fraction showed cytotoxic and antiproliferative effects against various tumor cell lines, with the best IC50 at 90 µg·mL⁻¹, and reduced chemotherapy-induced reactive oxygen species (ROS) levels. Whereas cytotoxic effects in most cell lines involved necrosis, MCF-7 exhibited antiproliferative and cytostatic effects, with apoptosis as the main death pathway. Conclusions: The methods used here enabled a comprehensive evaluation of saponins, eliminating the need for extensive purification. Even in a mixture, methylation provided critical structural details that enabled the characterization of different structures, including several isomers. The anti-ROS activity observed in this extract may be associated with modulating cytotoxic responses by preventing oxidative cell damage.

Background: Exosomes are nanoscale extracellular vesicles capable of crossing the blood–brain barrier and delivering functional microRNAs (miRNAs), positioning them as promising vectors for cell-free therapies in neurodegenerative diseases. Mesenchymal stem cell (MSC)-derived exosomal miRNAs have emerged as key regulators of interconnected pathogenic pathways, including neuroinflammation, oxidative stress, apoptosis, and protein aggregation. Objectives: This systematic review aimed to critically evaluate the therapeutic potential and mechanistic roles of MSC-derived exosomal miRNAs in neurodegeneration. Methods: A comprehensive search over 12 years (2014–2026) across PubMed, Scopus, Web of Science, and ScienceDirect identified 157 studies, of which 10 met the inclusion criteria. Results: Across the included experimental models, exosomal miRNAs, including miR-23b-3p, miR-23a-3p, members of the miR-29 family, miR-214-3p, and miR-223, consistently promoted neuroprotection and functional recovery. These effects were associated with modulation of key molecular pathways, including Wnt/β-catenin signaling, PI3K/Akt activation, and BACE1-mediated amyloid processing. Although methodological variability was observed among studies, particularly regarding exosome characterization and validation of miRNA cargo, the reported findings consistently demonstrated therapeutic benefits.Across experimental models, exosomal miRNAs such as miR-23b-3p, miR-23a-3p, members of the miR-29 family, miR-214-3p, and miR-223 consistently promoted neuroprotection and functional recovery by modulating key pathways, including Wnt/β-catenin signaling, PI3K/Akt activation, and BACE1-mediated amyloid processing. However, despite these promising findings, some methodological variability was observed across studies, particularly regarding exosome characterization and validation of miRNA cargo, which may influence reproducibility. Nevertheless, the overall body of evidence consistently supports the therapeutic potential of MSC-derived exosomal miRNAs in neurodegenerative disorders. Conclusions: This systematic review demonstrates that MSC-derived exosomal miRNAs act as key regulators of interconnected pathways involved in neurodegeneration, including neuroinflammation, apoptosis, oxidative stress, and protein aggregation. Notably, miR-23b-3p, miR-29 family members, miR-22, miR-34b, and miR-214-3p emerged as consistent neuroprotective candidates across different models.These findings support the concept that MSC-derived extracellular vesicles function as multi-target delivery systems capable of modulating disease-relevant pathways at a systems level.

Background/Objectives: Methylmercury (MeHg) is a well-known environmental neurotoxic agent with significant detrimental effects on human health, particularly targeting the central nervous system. This study aimed to evaluate the impact of physiologically relevant species of MeHg, specifically MeHg–cysteine and MeHg–glutathione, on mesenchymal stem cells (MSCs) and neural precursor cells (NPCs). Methods: The NPCs were differentiated from the MSCs after being seeded on a natural functional biopolymer matrix. The cells were exposed to 0, 0.01, 0.5, 1.5, and 2.0 µM MeHgCl or its physiologically relevant species. Biochemical markers, including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and reduced glutathione (GSH), were analyzed. Results: MeHgCl and its physiological species did not affect MSC viability. However, 1.5 and 2.0 µM MeHgCl caused a significant reduction (~25%) in NPC viability. SOD activity and GSH levels were not significantly altered in either MSCs or NPCs. In contrast, MeHg–glutathione (2.0 µM) significantly decreased GPx activity in both MSCs (~62%) and NPCs (~78%). GST activity remained unchanged in MSCs, but NPCs showed a significant decrease (~50%) after exposure to 1.5 and 2.0 µM MeHg–glutathione. Conclusions: The results indicate that MSCs are more resistant to MeHg toxicity, whereas NPCs display markedly susceptibility. These findings highlight the distinct cellular responses to MeHg exposure. The disruption of antioxidant defenses, particularly in NPCs, may promote oxidative stress and ultimately lead to cell death.

Background: The therapeutic effect of stem cells is attributed to their direct maturation into somatic cells and their paracrine effects, which influence the extracellular environment. One such component released is extracellular vesicles containing proteins and genetic materials with immunomodulatory functions and facilitating cell-to-cell communication. Purpose: The study’s main objective was to characterize extracellular vesicles (EVs) from Human Neural Precursor Cells (hNPCs). Methods: Wharton’s Jelly mesenchymal stem cells (WJ-MSCs) were isolated by explant technique and characterized by flow cytometry and trilineage differentiation. The hNPCs obtained from neurospheres were produced by seeding WJ-MSCs on a natural functional biopolymer matrix. EVs derived from WJ-MSCs and hNPCs were isolated by precipitation methodology and characterized by flow cytometry, nanoparticle tracking analysis (NTA), scanning electron microscopy (TEM), and proteomic. Results: hNPCs expressed proteins and genes characteristic of neural precursor cells. The EVs were characterized by flow cytometry and showed varied expression for the markers CD63, CD9, and CD81, indicating different subpopulations based on their origin of formation. NTA and TEM of the EVs exhibited characteristic size, shape, and structural integrity consistent with the criteria established by the International Society for Extracellular Vesicles (ISEV). EV-hNPCs function enrichment analysis of the proteomic results showed that these vesicles presented abundant proteins directly involved in neuronal biological processes such as plasticity, transduction, postsynaptic density, and overall brain development. Discussion: The results indicate that EVs derived from hNPCs maintain key neural precursor characteristics and exhibit marker variability, suggesting distinct subpopulations. Their structural integrity aligns with ISEV standards, supporting their potential as reliable biological entities. The proteomic analysis highlights their role in neuronal functions, reinforcing their applicability in neurodegenerative research and therapeutic strategies. Conclusion: The EVs were successfully isolated from hNPCs with abundant proteins involved in neuronal processes, making them attractive for acellular therapies to treat neurodegenerative diseases.

Background: This systematic review describes the most common methodologies for immortalizing human and animal mesenchymal stem cells (MSCs). This study follows the rules of PRISMA and is registered in the Institutional Review Board of PROSPERO International of systematic reviews, numbered protocol code: CRD42020202465. Method: The data search systematization was based on the words “mesenchymal stem cell” AND “immortalization.” The search period for publications was between 2000 and 2022, and the databases used were SCOPUS, PUBMED, and SCIENCE DIRECT. The search strategies identified 384 articles: 229 in the SCOPUS database, 84 in PUBMED, and 71 in SCIENCE DIRECT. After screening by titles and abstracts, 285 articles remained. This review included thirty-nine articles according to the inclusion and exclusion criteria. Result: In 28 articles, MSCs were immortalized from humans and 11 animals. The most used immortalization methodology was viral transfection. The most common immortalized cell type was the MSC from bone marrow, and the most used gene for immortalizing human and animal MSCs was hTERT (39.3%) and SV40T (54.5%), respectively. Conclusion: Also, it was observed that although less than half of the studies performed tumorigenicity assays to validate the immortalized MSCs, other assays, such as qRT-PCR, colony formation in soft agar, karyotype, FISH, and cell proliferation, were performed in most studies on distinct MSC cell passages.

This study aims to evaluate and compare cellular therapy with human Wharton’s jelly (WJ) mesenchymal stem cells (MSCs) and neural precursors (NPs) in experimental autoimmune encephalomyelitis (EAE), a preclinical model of Multiple Sclerosis. MSCs were isolated from WJ by an explant technique, differentiated to NPs, and characterized by cytometry and immunocytochemistry analysis after ethical approval. Forty-eight rats were EAE-induced by myelin basic protein and Freund’s complete adjuvant. Forty-eight hours later, the animals received intraperitoneal injections of 250 ng/dose of Bordetella pertussis toxin. Fourteen days later, the animals were divided into the following groups: a. non-induced, induced: b. Sham, c. WJ-MSCs, d. NPs, and e. WJ-MSCs plus NPs. 1 × 10⁵. Moreover, the cells were placed in a 10 µL solution and injected via a stereotaxic intracerebral ventricular injection. After ten days, the histopathological analysis for H&E, Luxol, interleukins, and CD4/CD8 was carried out. Statistical analyses demonstrated a higher frequency of clinical manifestation in the Sham group (15.66%) than in the other groups; less demyelination was seen in the treated groups than the Sham group (WJ-MSCs, p = 0.016; NPs, p = 0.010; WJ-MSCs + NPs, p = 0.000), and a lower cellular death rate was seen in the treated groups compared with the Sham group. A CD4/CD8 ratio of p = 0.366), astrocytes (p = 0.247), and cell death (p = 0.577) in WJ-MSCs. WJ-MSCs and NPs were immunomodulatory and neuroprotective in cellular therapy, which would be translated as an adjunct in demyelinating diseases.

Recent studies have suggested that therapies with stem cells and amniotic membrane can modulate the inflammation following an ischemic injury in the heart. This study evaluated the effects of bone-marrow mononuclear cells (BMMC) and acellular human amniotic membrane (AHAM) on cardiac function and NLRP3 complex in a rat model of heart failure.On the 30th day,the echocardiographic showed improvements on ejection fraction and decreased pathological ventricular remodeling on BMMC and AHAM groups.Oxidative stress analysis was similar between the three groups,and the NLRP3 inflammasome activity were not decreased with the therapeutic use of both BMMC and AHAM,in comparison to the control group.

Recently, various molecular bases of heart protection have been discovered and used in many experimental and clinical investigations

Editorial: Examining genetic and epigenetic regulation in cardiovascular development, regeneration and disease