Search Results (1,961)

Serial block-face scanning electron microscopy (SBEM) is a powerful technique for three-dimensional ultrastructural analysis of biological samples, though its application to in vitro cultured human cells remains underutilized. In this study, we present an optimized SBEM sample preparation protocol using human dermal fibroblasts and induced pluripotent stem cells (iPSCs). The method includes key modifications to the original protocol, such as using only glutaraldehyde for fixation and substituting the toxic cacodylate buffer with a less hazardous phosphate buffer. These adaptations result in excellent preservation of cellular ultrastructure, with high contrast and clarity, as validated by transmission electron microscopy (TEM). The loss of natural cell morphology resulted from fixation during passage, when cells formed a precipitate, rather than from fixation directly within the culture medium. The protocol is time-efficient, safe, and broadly applicable to both stem cells and differentiated cells cultured under 2D conditions, providing a valuable tool for ultrastructural analysis in diverse biomedical research settings. Full article

A dietary supplement, trans-resveratrol and hesperetin (tRES+HESP)—also known as GlucoRegulate—induces increased expression of glyoxalase 1 (Glo1) by activation of transcription factor Nrf2, countering accumulation of the reactive dicarbonyl glycating agent, methylglyoxal. tRES+HESP corrected insulin resistance and decreased fasting and postprandial plasma glucose and low-grade inflammation in overweight and obese subjects in a clinical trial. The aim of this study was to explore, for the first time, health-beneficial gene expression other than Glo1 induced by tRES+HESP in human endothelial cells and fibroblasts in primary culture and HepG2 hepatoma cell line and activity of cis-resveratrol (cRES) as a Glo1 inducer. We measured antioxidant response element-linked gene expression in these cells in response to 5 µM tRES+HESP by the NanoString method. tRES+HESP increases gene expression linked to the prevention of dicarbonyl stress, lipid peroxidation, oxidative stress, proteotoxicity and hyperglycemia-linked glycolytic overload. Downstream benefits were improved regulation of glucose and lipid metabolism and decreased inflammation, extracellular matrix remodeling and senescence markers. The median effective concentration of tRES was ninefold lower than cRES in the Glo1 inducer luciferase reporter assay. The GlucoRegulate supplement provides a new treatment option for the prevention of type 2 diabetes and metabolic dysfunction–associated steatotic liver disease and supports healthy aging. Full article

Cell culture models are of central importance for the investigation of cellular metabolism, proliferation and stress responses. In this study, the effects of different concentrations of glucose (1 g/L vs. 4.5 g/L) and fetal bovine serum (FBS; 5%, 10%, 15%) on viability, mitochondrial function and autophagy are investigated in four human cell lines: MRC-5, HeLa, Caco-2 and SW-620. Cells were cultured in defined media for 72 h, and viability was assessed by LDH release, mitochondrial membrane potential using Rhodamine 123, ATP content by luminescence and autophagy activity by dual fluorescence staining. The results showed that HeLa and SW-620 cancer cells exhibited increased proliferation and mitochondrial activity under high glucose conditions, while low glucose media resulted in decreased ATP content and increased membrane permeability in HeLa cells. MRC-5 fibroblasts and Caco-2 cells showed greater resilience to nutrient stress, with minimal changes in LDH release and consistent proliferation. Autophagy was activated under all conditions, with a significant increase only in selected cell-medium combinations. These results highlight the importance of medium composition in influencing cellular bioenergetics and stress responses, which has implications for cancer research, metabolic disease modelling and the development of serum-free culture systems for regenerative medicine. Full article

Background: Oxidative stress is a critical factor contributing to male infertility, impairing spermatogonial stem cells (SSCs) and disrupting normal spermatogenesis. This study aimed to isolate and characterize human SSCs and to investigate oxidative stress-related gene expression, protein interaction networks, and developmental trajectories involved in SSC function. Methods: SSCs were enriched from human orchiectomy samples using CD49f-based magnetic-activated cell sorting (MACS) and laminin-binding matrix selection. Enriched cultures were assessed through morphological criteria and immunocytochemistry using VASA and SSEA4. Transcriptomic profiling was performed using microarray and single-cell RNA sequencing (scRNA-seq) to identify oxidative stress-related genes. Bioinformatic analyses included STRING-based protein–protein interaction (PPI) networks, FunRich enrichment, weighted gene co-expression network analysis (WGCNA), and predictive modeling using machine learning algorithms. Results: The enriched SSC populations displayed characteristic morphology, positive germline marker expression, and minimal fibroblast contamination. Microarray analysis revealed six significantly upregulated oxidative stress-related genes in SSCs—including CYB5R3 and NDUFA10—and three downregulated genes, such as TXN and SQLE, compared to fibroblasts. PPI and functional enrichment analyses highlighted tightly clustered gene networks involved in mitochondrial function, redox balance, and spermatogenesis. scRNA-seq data further confirmed stage-specific expression of antioxidant genes during spermatogenic differentiation, particularly in late germ cell stages. Among the machine learning models tested, logistic regression demonstrated the highest predictive accuracy for antioxidant gene expression, with an area under the curve (AUC) of 0.741. Protein oxidation was implicated as a major mechanism of oxidative damage, affecting sperm motility, metabolism, and acrosome integrity. Conclusion: This study identifies key oxidative stress-related genes and pathways in human SSCs that may regulate spermatogenesis and impact sperm function. These findings offer potential targets for future functional validation and therapeutic interventions, including antioxidant-based strategies to improve male fertility outcomes. Full article

Although cold atmospheric plasma (CAP) has shown promise in facilitating wound repair due to its non-thermal and non-invasive properties, its dynamic effects on cellular response and metabolic regulation remain poorly characterized, and the mechanism is still unclear. In this study, we developed a microfluidic experimental system that integrates a CAP treatment module with multiparametric in situ sensing capabilities, along with precise environmental control of temperature, humidity, and CO₂ concentration. A stratified microfluidic chip was engineered to co-culture HaCaT keratinocytes and HSF fibroblasts. CAP treatment was applied within this platform, and the dynamic processes of cell migration, proliferation, and multiple metabolic markers were simultaneously monitored. The experimental results show that the system can not only achieve real-time observation in the healing process under plasma intervention, but also find that the healing process is closely related to the concentration of NO₂⁻. In addition, the study also found that keratin KRT14, which is thought to be closely related to wound healing, decreased significantly in the process of plasma-induced healing. The platform provides high-resolution experimental tools to elucidate the biological effects of CAP and has the potential for parameter optimization, material evaluation, and personalized therapeutic development to advance plasma research and clinical translational applications. Full article

In the context of critical challenges in curcumin-modified polyurethane synthesis—including limited curcumin bioavailability and suboptimal biodegradability/biocompatibility—a novel polyurethane material (Cur-PU) with good mechanical, shape memory, pH-responsive, and biocompatibility was synthesized via a one-pot, two-step synthetic protocol in which HO-PCL-OH served as the soft segment and curcumin was employed as the chain extender. The experimental results demonstrate that with the increase in Cur units, the crystallinity of the Cur-PU material decreases from 32.6% to 5.3% and that the intensities of the diffraction peaks at 2θ = 21.36°, 21.97°, and 23.72° in the XRD pattern gradually diminish. Concomitantly, tensile strength decreased from 35.5 MPa to 19.3 MPa, and Shore A hardness declined from 88 HA to 65 HA. These observations indicate that the sterically hindered benzene ring structure of Cur imposes restrictions on HO-PCL-OH crystallization, leading to lower crystallinity and retarded crystallization kinetics in Cur-PU. As a consequence, the material’s tensile strength and hardness are diminished. Except for the Cur-PU-3 sample, all other variants exhibited exceptional shape-memory functionality, with R_f and R_r exceeding 95%, as determined by three-point bending method. Analogous to pure curcumin solutions, Cur-PU solutions demonstrated pH-responsive chromatic transitions: upon addition of hydroxide ion (OH⁻) solutions at increasing concentrations, the solutions shifted from yellow-green to dark green and finally to orange-yellow, enabling sensitive pH detection across alkaline gradients. Hydrolytic degradation studies conducted over 15 weeks in air, UPW, and pH 6.0/8.0 phosphate buffer solutions revealed mass loss <2% for Cur-PU films. Surface morphological analysis showed progressive etching with the formation of micro-to-nano-scale pores, indicative of a surface-erosion degradation mechanism consistent with pure PCL. Biocompatibility assessments via L929 mouse fibroblast co-culture experiments demonstrated ≥90% cell viability after 72 h, while relative red blood cell hemolysis rates remained below 5%. Collectively, these findings establish Cur-PU as a biocompatible material with tunable mechanical properties, and pH responsiveness, underscoring its translational potential for biomedical applications such as drug delivery systems and tissue engineering scaffolds. Full article

Globins are a class of globular proteins that function in the transportation or storage of oxygen. They are critical for cellular metabolism. Notable examples include hemoglobin, which is found in red blood cells, and myoglobin, which is present in muscle cells. Approximately two decades ago, a third globin, designated as neuroglobin, was identified, expressed predominantly in neuronal cells. This was followed two years later by the fourth, cytoglobin, found in cells of the fibroblast lineage, as well as in neuronal cell populations of the central and nervous systems. Both neuroglobin and cytoglobin have been found in the sensory and endocrine systems, albeit inconsistently, and it is thought that they are engaged in functions such as oxygen transport and storage, scavenging of free radicals, NO metabolism, peroxidase activity, and signaling functions. Neuroglobin is also expressed in astrocytes under challenging conditions. Common neuroscience methods were utilized to study the distribution and regulation of globin tissues and of single brain cells. Despite considerable overlap in the findings of various studies, some results deviate significantly from other studies. The potential causes of these discrepancies may include variations in detection methods, animal age and sex, time of day and year, and differing cell culture conditions. This review will explore factors that may influence functional aspects of globins and their detection in the mammalian brain. Full article

Tissue-resident macrophages are essential for skin homeostasis. This study investigated whether lipopolysaccharide (LPS)-activated macrophages affect senescence and rejuvenation in human dermal fibroblasts. Human monocytic THP-1 cells were stimulated with Pantoea agglomerans–derived LPS (1–1000 ng/mL), and culture supernatants were collected. These were applied to two NB1RGB fibroblast populations: young, actively dividing cells (Young cells) and senescent cells with high population doubling levels and reduced proliferation (Old cells). Senescence markers P16, P21, and Ki-67 were analyzed at gene and protein levels. Conditioned medium from Old cells induced senescence in Young cells, increasing P16 and P21 expression levels. This effect was suppressed by cotreatment with LPS-activated THP-1 supernatant. Old cells treated with the LPS-activated supernatant exhibited decreased P16 and P21 levels as well as increased Ki-67 expression, indicating partial rejuvenation. These effects were not observed following treatment with unstimulated THP-1 supernatants or LPS alone. Overall, these findings suggest that secretory factors from LPS-activated macrophages can suppress cellular senescence and promote human dermal fibroblast rejuvenation, highlighting the potential role of macrophage activation in regulating cellular aging and offering a promising strategy for skin aging intervention. Full article

Tissue engineering enables autologous reconstruction of human tissues, addressing limitations in tissue availability and immune compatibility. Several tissue engineering techniques, such as self-assembly, rely on or benefit from extracellular matrix (ECM) secretion by fibroblasts to produce biomimetic scaffolds. Models have been developed for use in humans, such as skin and corneas. Ascorbic acid (vitamin C, AA) is essential for collagen biosynthesis. However, AA is chemically unstable in culture, with a half-life of 24 h, requiring freshly prepared AA with each change of medium. This study aims to demonstrate the functional equivalence of 2-phospho-L-ascorbate (2PAA), a stable form of AA, for tissue reconstruction. Dermal, vaginal, and bladder stroma were reconstructed by self-assembly using tissue-specific protocols. The tissues were cultured in a medium supplemented with either freshly prepared or frozen AA, or with 2PAA. Biochemical analyses were performed on the tissues to evaluate cell density and tissue composition, including collagen secretion and deposition. Histology and quantitative polarized light microscopy were used to evaluate tissue architecture, and mechanical evaluation was performed both by tensiometry and atomic force microscopy (AFM) to evaluate its macroscopic and cell-scale mechanical properties. The tissues produced by the three ascorbate conditions had similar collagen deposition, architecture, and mechanical properties in each organ-specific stroma. Mechanical characterization revealed tissue-specific differences, with tensile modulus values ranging from 1–5 MPa and AFM-derived apparent stiffness in the 1–2 kPa range, reflecting the nonlinear and scale-dependent behavior of the engineered stroma. The results demonstrate the possibility of substituting AA with 2PAA for tissue engineering. This protocol could significantly reduce the costs associated with tissue production by reducing preparation time and use of materials. This is a crucial factor for any scale-up activity. Full article

Background/Objectives: Prostate cancer (PCa) is diagnosed at an earlier median age, more advanced stage, and has worse clinical outcomes in African American (AA) men compared to European Americans (EA). Methods: To investigate the role of aberrant DNA methylation in tumor-adjacent stroma (TAS), methyl binding domain sequencing (MBD-seq) was performed on AA (n = 17) and EA (n = 15) PCa patients. This was independently confirmed using the long interspersed nuclear element-1 (LINE-1) assay. Pathway analysis was performed on statistically significantly differentially methylated genes for AA and EA TAS. DNA methylation profiles of primary cultured AA and EA carcinoma-associated fibroblasts (CAFs) were compared with AA and EA TAS. AA and EA CAFs were treated with demethylating agent 5-Azacytidine (5-AzaC). Results: AA TAS exhibited higher global DNA methylation than EA TAS (p-value < 0.001). Of the 3268 differentially methylated regions identified (DMRs, p-value < 0.05), 85% (2787 DMRs) showed increased DNA methylation in AA TAS, comprising 1648 genes, of which 1379 were protein-coding genes. Based on DNA methylation levels, two AA subgroups were identified. Notably, AA patients with higher DNA methylation were predominantly those with higher Gleason scores. Pathway analysis linked methylated genes in AA TAS to several key signaling pathways (p-value < 0.05), including immune response (e.g., IL-1, IL-15, IL-7, IL-8, IL-3, and chemokine), Wnt/β-catenin, androgen, PTEN, p53, TGF-β, and circadian clock regulation. A total of 168 concordantly methylated genes were identified, with 109 genes (65%) showing increased methylation in AA CAFs and TAS (p-value < 0.05). Treatment with 5-AzaC significantly reduced DNA methylation of concordant genes in AA CAFs (p-value < 0.001). Conclusions: These findings suggest a distinct stromal methylome in AA, providing a foundation for integrating demethylating agents into standard therapies. This approach targets the tumor microenvironment, potentially addressing PCa disparities in AA men. Full article

Exosomes, small extracellular vesicles secreted by various cell types, have gained significant attention in cancer investigations. Isolation and characterization of exosomes derived from DOK (dysplastic oral keratinocyte), SCC (squamous cell carcinoma) and HaCaT (normal skin keratinocyte) cell lines and microRNA profiling were conducted. Magnetic sorting was applied to obtain pure exosomes. Morphology and size were characterized by transmission electron microscopy and nanoparticle tracking analysis. Validation of membrane exosomal markers (CD9, CD63) was performed via Western blotting. MiR-21, miR-31, and miR-133 levels were analyzed in exosomes and parent cells by qPCR. Biological effects of the exosomes were tested by adding them to fibroblast cultures and determining the expression of relevant carcinogenesis markers by qPCR. Exosomes appeared as cup-shaped nano-sized particles, and there was no difference regarding particle diameter and concentration between the three types of exosomes. The oncogenic miR-21 was significantly upregulated both in SCC and SCC-derived exosomes compared to DOK and HaCaT cells and their respective exosomes. However, miR-31 unexpectedly showed the highest expression in normal cells and the lowest in HaCaT exosomes. MiR-133, the tumor suppressor miRNA, was downregulated in both SCC and DOK cells compared to normal (HaCaT) cells, while the opposite situation was observed in exosomes, with HaCaT cells showing the lowest levels of miR-133. The differences in exosome content were reflected in signaling pathway activation in exosome-treated fibroblasts, with SCC exosomes exerting the most potent effect on several cancer-related pathways, notably PIK3/AKT, PTEN, and NOTCH signaling cascades. Full article

The therapeutic target of COVID-19 is focused on controlling inflammation and preventing fibrosis. Collagen–polyvinylpyrrolidone (collagen-PVP) and pirfenidone both have the ability to control the cytokine storm observed in rheumatic and fibrotic disorders. In this work, our aim was to understand the benefits of treatment with each of these drugs in patients with severe COVID-19. In total, 36 patients were treated with dexamethasone and enoxaparin, but 26 were allocated collagen-PVP or pirfenidone (n = 15 and 11, respectively); the clinical and metabolic effects were compared among them. Since pirfenidone works via transcriptional mechanisms, we performed a human genome microarray assay using RNA isolated from fibroblast and monocyte cultures treated with the biodrug, with the aim of hypothesising a possible mechanism of action for collagen-PVP. Our results showed that hospital stay duration, quick COVID-19 severity index (qCSI), and admission to the intensive care unit were statistically significantly lower (p < 0.02) in patients treated with collagen-PVP or pirfenidone when compared with the control group, and that only collagen-PVP normalised serum glucose at discharge. Ingenuity Pathway Analysis showed that the cell cycle, inflammation, and cell surface–extracellular matrix interactions could be regulated with collagen-PVP via the downmodulation of proinflammatory cytokines, while Th2 anti-inflammatory response signalling could be upregulated. Furthermore, the downregulation of some of the genes involved in nitric oxide production showed a possible control for JAK in the IFN-γ pathway, allowing for the possibility of controlling inflammation through the JAK/STAT pathway, as has been observed for pirfenidone and other immunomodulators, such as ruxolitinib. Full article

Low-level laser therapy (LLLT) is gaining attention as an effective adjunct to non-surgical periodontal treatment. This study evaluates the potential of LLLT to reduce bacterial load in a clinically relevant in vitro subgingival biofilm model and its impact on the inflammatory response. A subgingival biofilm model consisting of seven bacterial species was established. Primary human gingival fibroblasts (GFs) and periodontal ligament cells (PDLs) were cultured. Both biofilms and host cells were treated with the DenLase Diode Laser (980 nm) under various clinically relevant settings. The composition and structure of the seven-species biofilms were evaluated using quantitative PCR and fluorescence microscopy, respectively. The inflammatory response in host cells was analyzed by measuring the gene and protein expression levels of various inflammatory mediators. Laser treatment at power outputs ranging from 0.3 to 2 W had no significant effect on biofilm composition or architecture. LLLT, particularly at higher power settings, reduced the viability in both GFs and PDLs up to 70%. Gene expression levels of inflammatory mediators were only minimally influenced by laser treatment. However, LLLT significantly decreased the secretion of all examined cytokines. These findings suggest that LLLT with a 980 nm diode laser, under clinically relevant conditions, exerts anti-inflammatory rather than antimicrobial effects. Full article

Background: The natural compounds caracasine acid (1) and its methyl ester, caracasine (2), isolated from the flowers of Croton micans, are effective against several tumor cell lines. Five semi-synthetic derivatives (3–7) were synthesized based on these structures. The study aimed to evaluate the cytotoxic activity of these compounds in 2D and spheroid cultures. Methods: The assays were performed in a panel of 12 human cell lines, 8 cancer and 4 normal cell lines. The compounds were evaluated on spheroids derived from the HCT116, HCT116 p53 knockout (p53KO), A549, and U2OS cell lines, as well as mixed spheroids comprising tumor cells and normal fibroblasts. Results: The parent compound (1), the natural ester (2), and two novel derivatives, the anhydride (7) and the cyclohexanol ester (3), demonstrated cytotoxicity against different leukemic cells and HCT116, HCT116 p53 knockout (p53KO), A549, and U2OS cell lines in conventional two-dimensional cultures. Peroxide formation, however, was significantly higher in leukemic cell lines (p < 0.01) in 2D culture as compared with the other tumor cell lines. The compounds did not induce cell death in spheroid cultures; caspases 8, 9, and 3 were not activated upon treatment. Conclusions: These findings indicate potential applications in leukemia treatment, albeit with limited efficacy against solid tumors. Full article

The mechanical properties of the extracellular matrix critically influence cell behavior in both physiological and pathophysiological states, including cardiac fibrosis. In vitro models have played a critical role in assessing biological mechanisms. In this study, we characterized mechanically tunable enzymatically crosslinked gelatin-microbial transglutaminase (mTG) hydrogels for modeling cardiovascular diseases. Gelatin hydrogels were fabricated via direct mixing or immersion crosslinking methods. Hydrogel formulations were assessed using the Piuma nanoindenter and Instron systems. This study investigates the effects of fabrication methods, UV ozone (UVO) sterilization, crosslinking methods, and incubation media on hydrogel stiffness. Further, this study examined the response of murine cardiac fibroblasts to hydrogel stiffness. The hydrogels exhibited modulus ranges relevant to both healthy and fibrotic cardiac tissues. UVO exposure led to slight decreases in hydrogel modulus, while the fabrication method had a significant impact on the modulus. Hydrogels incubated in phosphate buffered saline (PBS) were stiffer than those incubated in Medium 199 (M199), which correlated with lower pH in PBS. Fibroblasts cultured on stiffer hydrogels display enhanced smooth muscle actin (SMA) expression, suggesting sensitivity to material stiffness. These findings highlight how fabrication parameters influence the modulus of gelatin-mTG hydrogels for cardiac tissue models. Full article