Decline In Cell Viability Research Articles

5-(3′,4′-dihydroxyphenyl)-γ-valerolactone, a microbiota metabolite of flavan-3-ols, activates SIRT1-mediated autophagy to attenuate H₂O₂-induced inhibition of osteoblast differentiation in MC3T3-E1 cells

Phenolic compounds are promising agents for the prevention of osteoporosis. 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (DHPV) is the major microbiota metabolite of the flavan-3-ols phenolic compound. Herein, we aimed to investigate the potential mechanisms underlying the effects of DHPV on an osteoblast cell model with H2O2-induced oxidative injury. The MC3T3-E1 cell cultured with H2O2 was used as an oxidative injury model after pretreating with DHPV. Pretreatment with DHPV significantly attenuated cell viability decline, enhanced the activity of alkaline phosphatase and mineralization capacity in MC3T3-E1 cells. Reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels as well as increased in mitochondrial membrane potential and superoxide dismutase (SOD) activities indicated that DHPV affected both the oxidative and antioxidative processes in the cells. DHPV administration increased the LC3-II/I ratio and Beclin-1 protein levels, thereby promoting autophagy, which perhaps contributes to ROS elimination. However, the inhibition of Sirtuin 1 (SIRT1) by SIRT1 small interfering RNA reduced the protective effect of DHPV or SRT1720, as revealed by the increased ROS and MDA levels and decreased SOD, LC3-II/I ratio and Beclin-1 levels. DHPV may promote autophagy and reduce oxidative stress through the SIRT1-mediated pathway, thereby protecting MC3T3-E1 cells from H2O2-induced oxidative damage.

METTL14 Suppresses Tumor Stemness and Metastasis of Colon Cancer Cells by Modulating m6A-Modified SCD1.

Colon cancer (CC) is a malignant disease of the digestive tract, and its rising prevalence poses a grave threat to people's health. N6-methyladenosine (m6A) modification is essential for various crucial life processes through modulating gene expression. Methyltransferase-like 14 (METTL14), the m6A methylation transferase core protein, and its aberrant expression is intimately correlated to tumor development. This study was conducted to probe the impacts and specific mechanisms of METTL14 on the biological process of CC. Bioinformatics data disclosed that METTL14 was significantly attenuated in CC. Functional assays were executed to ascertain how METTL14 affected CC tumorigenicity, and METTL14 overexpression caused a notable decline in viability, migration, invasion, and stemness phenotype of CC cells. Then, in-depth mechanistic studies displayed that stearoyl-CoA desaturase 1 (SCD1) was a downstream target gene of METTL14-mediated m6A modification. METTL14 overexpression substantially augmented the m6A modification of SCD1 mRNA and diminished the SCD1 mRNA level. In addition, we revealed that YTHDF2 was the m6A reader to recognize METTL14 m6A-modified SCD1 mRNA and abolish its stability. Finally, we also validated that METTL14 might impede the tumorigenic process of CC through SCD1 mediated Wnt/β-catenin signaling. Taken together, this study presented that METTL14 performed as a potential therapeutic target in CC with important implications for the prognosis amelioration of CC patients.

Comparative toxicity assessment of individual, binary and ternary mixtures of SiO2, Fe3O4, and ZnO nanoparticles in freshwater microalgae, Scenedesmus obliquus: Exploring the role of dissolved ions

Metal oxide nanoparticles (NPs) are considered among the most prevalent engineered nanomaterials. To have a deeper understanding of the mode of action of multiple metal oxide nanoparticles in mixtures, we have used a unicellular freshwater microalga Scenedesmus obliquus as a model organism. The toxicity of silicon dioxide (SiO2), iron oxide (Fe3O4), and zinc oxide (ZnO) NPs was studied individually as well as in their binary (SiO2 + Fe3O4, Fe3O4 + ZnO, and ZnO + SiO2) and ternary (SiO2 + Fe3O4 + ZnO) combinations. The effects of metal ions from ZnO and Fe3O4 were investigated as well. The results observed from the study, showed that a significant amount of toxicity was contributed by the dissolved ions in the mixtures of the nanoparticles. Decreases in the cell viability, ROS generation, lipid peroxidation, antioxidant enzyme activity, and photosynthetic efficiency were analyzed. Among all the individual particles, ZnO NPs showed the maximum effects and increased the toxicities of the binary mixtures. The binary and ternary mixtures of the NPs clearly showed increased toxic effects in comparison with the individual entities. However, the ternary combination had lesser toxic effects than the binary combination of Fe3O4 + ZnO. The decline in cell viability and photosynthetic efficiency were strongly correlated with various oxidative stress biomarkers emphasizing the crucial role of reactive oxygen species in inducing the toxic effects. The findings from this study highlight the importance of evaluating the combinatorial effects of various metal oxide NPs as part of a comprehensive ecotoxicity assessment in freshwater microalgae.

Cinnamaldehyde alleviates zearalenone-induced LS174T cell apoptosis, barrier dysfunction and mucin reduction through JNK/NF-κB signaling pathway

As a natural aldehyde organic compound, cinnamaldehyde (CA) is one of the main components of cinnamon essential oil with multiple bioactivities. In this study, we investigated the protective effects of CA on zearalenone (ZEA)-induced apoptosis, barrier dysfunction and mucin reduction, as well as underlying mechanisms in LS174T cells. In the present study, cells pre-treated with or without CA for 24 h were left untreated or subjected to ZEA for indicated time points Our results showed that 10 μM CA significantly prevented ZEA-induced cell viability decline, reversed ZEA-induced increase of the LDH level, cell cycle disruption and apoptosis in LS174T cells. Periodic acid-schiff (PAS) staining analysis showed that CA significantly alleviated the reduction of mucin secretion in LS174T cells caused by ZEA exposure. Western blot analysis showed that CA significantly reversed ZEA-induced reduction of the expression of mucin 2 (MUC2) and tight junction (TJ) proteins (claudin-1, claudin-3, ZO-1 and ZO-2) in LS174T cells. Notably, CA can significantly reduce the upregulation of the main effector of MAPK and NF-κB signaling pathways in LS174T cells. Further study showed that CA protects cells against ZEA-induced cellular damage through JNK/NF-κB signaling pathway in LS174T cells. Supplementation with CA might be an potential strategy to alleviate the damaging effect of ZEA on epithelial cells.

Nesfatin-1 alleviates hyperoxia-induced lung injury in newborn mice by inhibiting oxidative stress through regulating SIRT1/PGC-1α pathway

Bronchopulmonary dysplasia (BPD) is a pulmonary disease commonly observed in premature infants and it is reported that oxidative stress is a critical induction factor in BPD and is considered as a promising target for treating BPD. Nesfatin-1 is a brain-gut peptide with inhibitory effects on food intake, which is recently evidenced to show suppressive effect on oxidative stress. The present study aims to explore the therapeutic effect and mechanism of Nesfatin-1 in BPD mice. AECIIs were extracted from newborn rats and exposed to hyperoxia for 24 h, followed by treatment with 5 and 10 nM Nesfatin-1. Declined cell viability, increased apoptotic rate, upregulated Bax, downregulated Bcl-2, increased release of ROS and MDA, and suppressed SOD activity were observed in hyperoxia-treated AECIIs, which were extremely reversed by Nesfatin-1. Newborn rats were exposed to hyperoxia, followed by treated with 10 μg/kg Nesfatin-1 and 20 μg/kg Nesfatin-1. Severe pathological changes, elevated MDA level, and declined SOD activity were observed in lung tissues of BPD mice, which were rescued by Nesfatin-1. Furthermore, the protective effect of Nesfatin-1 on hyperoxia-challenged AECIIs was abolished by silencing SIRT1. Collectively, Nesfatin-1 alleviated hyperoxia-induced lung injury in newborn mice by inhibiting oxidative stress through regulating SIRT1/PGC-1α pathway.

Depleted uranium induces thyroid damage through activation of ER stress via the thrombospondin 1-PERK pathway

Depleted uranium (DU) can cause damage to the body, but its effects on the thyroid are unclear. The purpose of this study was to investigate the DU-induced thyroid damage and its potential mechanism in order to find new targets for detoxification after DU poisoning. A model of acute exposure to DU was constructed in rats. It was observed that DU accumulated in the thyroid, induced thyroid structure disorder and cell apoptosis, and decreased the serum T4 and FT4 levels. Gene screening showed that thrombospondin 1 (TSP-1) was a sensitive gene of DU, and the expression of TSP-1 decreased with the increase of DU exposure dose and time. TSP-1 knockout mice exposed to DU had more severe thyroid damage and lower serum FT4 and T4 levels than wild-type mice. Inhibiting the expression of TSP-1 in FRTL-5 cells aggravated DU-induced apoptosis, while exogenous TSP-1 protein alleviated the decreased viability in FRTL-5 cells caused by DU. It was suggested that DU may caused thyroid damage by down-regulating TSP-1. It was also found that DU increased the expressions of PERK, CHOP, and Caspase-3, and 4-Phenylbutyric (4-PBA) alleviated the DU-induced FRTL-5 cell viability decline and the decrease levels of rat serum FT4 and T4 caused by DU. After DU exposure, the PERK expression was further up-regulated in TSP-1 knockout mice, and the increased expression of PERK was alleviated in TSP-1 over-expressed cells, as well as the increased expression of CHOP and Caspase-3. Further verification showed that inhibition of PERK expression could reduce the DU-induced increased expression of CHOP and Caspase-3. These findings shed light on the mechanism that DU may activate ER stress via the TSP 1-PERK pathway, thereby leading to thyroid damage, and suggest that TSP-1 may be a potential therapeutic target for DU-induced thyroid damage.

Physiological and biochemical responses to caffeine and microplastics in Mytilus galloprovincialis

Caffeine (Caff) is one of the most widely used substances in the human diet and a well-recognized drug. Its input into surface waters is remarkable, but biological effects on aquatic organisms are unclear, particularly in combination with pollutants of suspected modulatory activity, like microplastics (MP). The aim of this study was to reveal the impact on the marine mussel Mytilus galloprovincialis (Lamark, 1819) of Caff (20.0 μg L−1) in the environmentally relevant combination (Mix) with MP 1 mg L−1 (size 35–50 μm) after the exposure for 14 days. Untreated and exposed to Caff and MP separately groups were also examined. Cell viability and cell volume regulation in hemocytes and digestive cells, as well as the indexes of oxidative stress, glutathione (GSH/GSSG) and metallothioneins levels, and caspase-3 activity in digestive gland were assessed. MP and Mix reduced Mn-superoxide dismutase, catalase, and glutathione S-transferase activities and level of lipid peroxidation, but increased the digestive gland cell viability, GSH/GSSG ratio (by 1.4–1.5-fold), metallothioneins level and their Zn content, while Caff did not affect oxidative stress indexes and metallothionein-related Zn chelation. Protein carbonyls were not targeted in all exposures. The distinguishing feature of the Caff group was the decline (2-fold) in caspase-3 activity and low cell viability. The multi-stress effect of Mix was shown by the worsening of the volume regulation of digestive cells and confirmed by discriminant analysis of biochemical indexes. The special capabilities of M. galloprovincialis as a sentinel organism make it an excellent bio-indicator reflecting the multi-stress effects in sub-chronic exposures to potentially harmful substances. The identification of the modulation of individual effects in combined exposure increases the need to base monitoring programs on studies of multi-stress effects in sub-chronic exposures.

Chondrocyte Viability of Particulated Porcine Articular Cartilage Is Maintained in Tissue Storage After Cryoprotectant Exposure, Vitrification, and Tissue Warming.

Vitrification of articular cartilage (AC) is a promising technique which may enable long-term tissue banking of AC allografts. We previously developed a 2-step, dual-temperature, multi-cryoprotectant agent (CPA) loading protocol to cryopreserve particulated AC (1 mm3 cubes). Furthermore, we also determined that the inclusion of ascorbic acid (AA) effectively mitigates CPA toxicity in cryopreserved AC. Prior to clinical translation, chondrocytes must remain viable after tissue re-warming and before transplantation. However, the effects of short-term hypothermic storage of particulated AC after vitrification and re-warming are not documented. This study evaluated the chondrocyte viability of post-vitrified particulated AC during a 7-day tissue storage period at 4 °C. We hypothesized that porcine particulated AC could be stored for up to 7 days after successful vitrification without significant loss of cell viability, and these results would be enhanced when cartilage is incubated in storage medium supplemented with clinical grade AA. Three experimental groups were examined at 5 time points: a fresh control (only incubated in medium), a vitrified - AA group, and a vitrified + AA group (N = 7). There was a mild decline in cell viability but both treatment groups maintained a viability of greater than 80% viable cells which is acceptable for clinical translation. We determined that particulated AC can be stored for up to 7 days after successful vitrification without a clinically significant decline in chondrocyte viability. This information can be used to guide tissue banks regarding the implementation of AC vitrification to increase cartilage allograft availability.

Diosgenin Inhibits ROS Generation by Modulating NOX4 and Mitochondrial Respiratory Chain and Suppresses Apoptosis in Diabetic Nephropathy.

Diosgenin (DIO) is a dietary steroid sapogenin possessing multiple biological functions, such as the amelioration of diabetes. However, the remission effect of DIO on diabetic nephropathy (DN) underlying oxidative stress and cell apoptosis remains unclear. Here, the effect of DIO on ROS generation and its induced cell apoptosis was studied in vitro and in vivo. Renal proximal tubular epithelial (HK-2) cells were treated with DIO (1, 2, 4 µM) under high glucose (HG, 30 mM) conditions. DN rats were induced by a high-fat diet combined with streptozotocin, followed by administration of DIO for 8 weeks. Our data suggested that DIO relieved the decline of HK-2 cell viability and renal pathological damage in DN rats. DIO also relieved ROS (O2- and H2O2) production. Mechanistically, DIO inhibited the expression of NOX4 and restored mitochondrial respiratory chain (MRC) complex I-V expressions. Further, DIO inhibited mitochondrial apoptosis by ameliorating mitochondrial membrane potential (MtMP) and down-regulating the expressions of CytC, Apaf-1, caspase 3, and caspase 9, while up-regulating Bcl2 expression. Moreover, the ER stress and its associated cell apoptosis were inhibited through decreasing PERK, p-PERK, ATF4, IRE1, p-CHOP, and caspase 12 expressions. Collectively, DIO inhibited ROS production by modulating NOX4 and MRC complexes, which then suppressed apoptosis regulated by mitochondria and ER stress, thereby attenuating DN.

Autograft Cellular Contribution to Spinal Fusion and Effects of Intraoperative Storage Conditions.

Controlled animal study. To assess the cellular contribution of autograft to spinal fusion and determine the effects of intraoperative storage conditions on fusion. Autograft is considered the gold standard graft material in spinal fusion, purportedly due to its osteogenic properties. Autograft consists of adherent and non-adherent cellular components within a cancellous bone scaffold. However, neither the contribution of each component to bone healing is well understood nor are the effects of intraoperative storage of autograft. Posterolateral spinal fusion was performed in 48 rabbits. Autograft groups evaluated included: (1) Viable, (2) partially devitalized, (3) devitalized, (4) dried, and (5) hydrated iliac crest. Partially devitalized and devitalized grafts were rinsed with saline, removing nonadherent cells. Devitalized graft was, in addition, freeze/thawed, lysing adherent cells. For 90 minutes before implantation, air dried iliac crest was left on the back table whereas the hydrated iliac crest was immersed in saline. At 8 weeks, fusion was assessed through manual palpation, radiography, and microcomputed tomography. In addition, the cellular viability of cancellous bone was assayed over 4 hours. Spinal fusion rates by manual palpation were not statistically different between viable (58%) and partially devitalized (86%) autografts ( P = 0.19). Both rates were significantly higher than devitalized and dried autograft (both 0%, P < 0.001). In vitro bone cell viability was reduced by 37% after 1 hour and by 63% after 4 hours when the bone was left dry ( P < 0.001). Bone cell viability and fusion performance (88%, P < 0.001 vs . dried autograft) were maintained when the graft was stored in saline. The cellular component of autograft is important for spinal fusion. Adherent graft cells seem to be the more important cellular component in the rabbit model. Autograft left dry on the back table showed a rapid decline in cell viability and fusion but was maintained with storage in saline.

The deficiency of N6-methyladenosine demethylase ALKBH5 enhances the neurodegenerative damage induced by cobalt

Cobalt exposure, even at low concentrations, induces neurodegenerative damage, such as Alzheimer's disease (AD). The specific underlying mechanisms remain unclear. Our previous study demonstrated that m6A methylation alteration is involved in cobalt-induced neurodegenerative damage, such as in AD. However, the role of m6A RNA methylation and its underlying mechanisms are poorly understood. In this study, both epidemiological and laboratory studies showed that cobalt exposure could downregulate the expression of the m6A demethylase ALKBH5, suggesting a key role for ALKBH5. Moreover, Methylated RNA immunoprecipitation and sequencing (MeRIP-seq) analysis revealed that ALKBH5 deficiency is associated with neurodegenerative diseases. KEGG pathway and Gene ontology analyses further revealed that the differentially m6A-modified genes resulting from ALKBH5 downregulation and cobalt exposure were aggregated in the pathways of proliferation, apoptosis, and autophagy. Subsequently, ALKBH5 deficiency was shown to exacerbate cell viability decline, motivate cell apoptosis and attenuate cell autophagy induced by cobalt with experimental techniques of gene overexpression/inhibition. In addition, morphological changes in neurons and the expression of AD-related proteins, such as APP, P-Tau, and Tau, in the cerebral hippocampus of wild-type and ALKBH5 knockout mice after chronic cobalt exposure were also investigated. Both in vitro and in vivo results showed that lower expression of ALKBH5 aggravated cobalt-induced neurodegenerative damage. These results suggest that ALKBH5, as an epigenetic regulator, could be a potential target for alleviating cobalt-induced neurodegenerative damage. In addition, we propose a novel strategy for the prevention and treatment of environmental toxicant-related neurodegeneration from an epigenetic perspective.

Long term culture promotes changes to growth, gene expression, and metabolism in CHO cells that are independent of production stability.

Phenotypic stability of Chinese hamster ovary (CHO) cells over long term culture (LTC) presents one of the most pressing challenges in the development of therapeutic protein manufacturing processess. However, our current understanding of the consequences of LTC on recombinant (r-) CHO cell lines is still limited, particularly as clonally-derived cell lines present distinct production stability phenotypes. This study evaluated changes of culture performance, global gene expression, and cell metabolism of two clonally-derived CHO cell lines with a stable or unstable phenotype during the LTC (early [EP] vs. late [LP] culture passages). Our findings indicated that LTC altered the behavior of CHO cells in culture, in terms of growth, overall gene expression, and cell metabolism. Regardless whether cells were categorized as stable or unstable in terms of r-protein production, CHO cells at LP presented an earlier decline in cell viability and loss of any observable stationary phase. These changes were parallelled by the upregulation of genes involved in cell proliferation and survival pathways (i.e., MAPK/ERK, PI3K-Akt). Stable and unstable CHO cell lines both showed increased consumption of glucose and amino acids at LP, with a parallel accumulation of greater amounts of lactate and TCA cycle intermediates. In terms of production stability, we found that decreased r-protein production in the unstable cell line directly correlated to the loss in r-gene copy number and r-mRNA expression. Our data revealed that LTC produced ubiquitious effects on CHO cell phenotypes, changes that were rooted in alterations in cell transcriptome and metabolome. Overall, we found that CHO cells adapted their cellular function to proliferation and survival during the LTC, some of these changes may well have limited effects on overall yield or specific productivity of the desired r-product, but they may be critical towardthe capacity of cells to handle r-proteins with specific molecular features.

Tectorigenin alleviates the apoptosis and inflammation in spinal cord injury cell model through inhibiting insulin-like growth factor-binding protein 6.

Since tectorigenin has been reported to possess anti-inflammation, redox balance restoration, and anti-apoptosis properties, we determine to unravel whether tectorigenin has potential in alleviating spinal cord injury (SCI). Herein, PC12 cells were induced by lipopolysaccharide (LPS) to establish in vitro SCI models. The cell viability and apoptosis were detected through cell counting kit-8 and flow cytometry assays. The caspase-3/8/9 content was measured by colorimetric method. Western blot was conducted to quantify the expressions of cleaved caspse-3/8/9, IGFBP6, TLR4, IκBα, p-IκBα, RELA proto-oncogene, p65, and p-p65. Enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction were carried out to quantitate expressions of IGFBP6, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). SwissTargetPrediction and GSE21497 database were utilized to predict the potential therapeutic targets of tectorigenin. Comparison of IGFBP6 expression in SCI tissues and normal tissues was analyzed by GEO2R. Our study found that LPS induced the declined cell viability, elevated cell apoptosis, upregulation of caspase-3/8/9, cleaved caspase-3/8/9, IL-1β, IL-6, TNF-α, IGFBP6, and TLR4, and the activation of IκBα and p65 in PC12 cells. Tectorigenin reversed the above effects of LPS. IGFBP6 was predicted to be the potential therapeutic target of tectorigenin and was overexpressed in SCI tissues. Notably, IGFBP6 overexpression offset the effects of tectorigenin on PC12 cells. In conclusion, tectorigenin could alleviate the LPS-induced apoptosis, inflammation, and activation of NF-κB signaling in SCI cell models via inhibiting IGFBP6.

CK2 inhibitor DMAT ameliorates spinal cord injury by increasing autophagy and inducing anti-inflammatory microglial polarization

Spinal cord injury (SCI) is a destructive and disabling nerve injury from which complete recovery has not yet been achieved due to complex pathology. Casein kinase II (CK2) is a pleiotropic serine/threonine protein kinase that plays an essential role in the nervous system. This study aimed to investigate the role of CK2 in SCI to understand the pathogenesis of SCI and explore new therapeutic methods. The SCI rat model of C5 unilateral clamp was established by modified clamp method in male adult SD rats. Then, CK2 inhibitor DMAT was used to treat SCI rats, and the behaviour, pathological changes in the spinal cord and microglial polarization were analysed. Additionally, the effects of DMAT on the polarization and autophagy of microglial BV-2 cells were investigated in vitro, and the effects of BV-2 polarization on spinal cord neuronal cells were analysed by Transwell coculture. Results showed that DMAT significantly increased the BBB score, improved histopathological injury, decreased the expression of inflammatory cytokines, and promoted M2 polarization of microglia in SCI rats. In vitro experiments further confirmed that DMAT could promote the polarization of BV-2 to the M2 type, promote autophagy, and reverse the LPS-induced decline in cell viability and increase in apoptosis of neuronal cells. The use of 3-MA confirmed that autophagy plays an important role in DMAT promoting M2 polarization of BV-2 to improve neuronal cell viability. In conclusion, CK2 inhibitor DMAT improved SCI by inducing anti-inflammatory polarization of microglia through autophagy and is a potential therapeutic target for SCI.

Exposure to nanoplastics induces mitochondrial impairment and cytomembrane destruction in Leydig cells

Plastic particle pollution poses an emerging threat to ecological and human health. Laboratory animal studies have illustrated that nano-sized plastics can accumulate in the testis and cause testosterone deficiency and spermatogenic impairment. In this study, TM3 mouse Leydig cells were in vitro exposed to polystyrene nanoparticles (PS-NPs, size 20 nm) at dosages of 50, 100 and 150 μg/mL to investigate their cytotoxicity. Our results demonstrated that PS-NPs can be internalized into TM3 Leydig cells and led to a concentration-dependent decline in cell viability. Furthermore, PS-NPs stimulation amplified ROS generation and initiated cellular oxidative stress and apoptosis. Moreover, PS-NPs treatment affected the mitochondrial DNA copy number and collapsed the mitochondrial membrane potential, accompanied by a disrupted energy metabolism. The cells exposed to PS-NPs also displayed a down-regulated expression of steroidogenesis-related genes StAR, P450scc and 17β-HSD, along with a decrease in testosterone secretion. In addition, treatment with PS-NPs destructed plasma membrane integrity, as presented by increase in lactate dehydrogenase release and depolarization of cell membrane potential. In summary, these data indicated that exposure to PS-NPs in vitro produced cytotoxic effect on Leydig cells by inducing oxidative injury, mitochondrial impairment, apoptosis, and cytomembrane destruction. Our results provide new insights into male reproductive toxicity caused by NPs.

Synthesis and characterization of dual light/temperature-responsive supramolecular injectable hydrogel based on host-guest interaction between azobenzene and starch-grafted β-cyclodextrin: Melanoma therapy with paclitaxel

Injectable stimuli-responsive hydrogels could offer an opportunity for local administration at the tumor site and a sustained drug release. In this paper, a copolymer of azobenzene derivative and N-isopropyl acrylamide (NIPAM) was synthesized, which are performed as light- and thermo-sensitive parts, respectively. The DAS@SCD/NIPAZO hydrogel was prepared upon the establishment of host-guest interactions between the hydrophobic core of CD and azobenzene moiety. The LCST of the synthesized copolymer was modified from 31.3 °C to 36.5 °C by the incorporation of the hydrophilic host moieties of the modified starch into the NIPAM copolymer structure. The LCST-based property of the hydrogel made it syringable in low temperatures and switch to a gel state after local injection. The drug release profile of the hydrogel was explored in four different conditions involving two distinct temperatures combined with two different light wavelengths to examine the light- and thermo-sensitivity of the hydrogel. Moreover, a Paclitaxel-loaded hydrogel was prepared to study the in vitro efficiency of the sample and was investigated by MTT assay against the cancerous fibroblastic cells (A-431), which revealed a sharp decline in cell viability under 365 nm light irradiation; furthermore, to evaluate the in vivo effects of the PTX-loaded hydrogel, histological studies based on staining techniques were carried out.

Hybrid Nanomat: Copolymer Template CdSe Quantum Dots In Situ Stabilized and Immobilized within Nanofiber Matrix

Fabrication and characterization of hybrid nanomats containing quantum dots can play a prominent role in the development of advanced biosensors and bio-based semiconductors. Owing to their size-dependent properties and controlled nanostructures, quantum dots (QDs) exhibit distinct optical and electronic characteristics. However, QDs include heavy metals and often require stabilizing agents which are toxic for biological applications. Here, to mitigate the use of toxic ligands, cadmium selenide quantum dots (CdSe QDs) were synthesized in situ with polyvinylpyrrolidone (PVP) at room temperature. The addition of PVP polymer provided size regulation, stability, and control over size distribution of CdSe QDs. The characterization of the optical properties of the CdSe QDs was performed using fluorescence and ultraviolet-visible (UV-Vis) spectroscopy. CdSe QDs exhibited a typical absorbance peak at 280 nm and a photoluminescence emission peak at 580 nm. Transmission electron microscopy (TEM) micrographs demonstrated that CdSe QDs having an average size of 6 ± 4 nm were obtained via wet chemistry method. CdSe QDs were immobilized in a blend of PVP and poly(L-lactide-co-ε-caprolactone) (PL-b-CL) copolymer that was electrospun to produce nanofibers. Scanning electron microscopy (SEM), thermal analyses and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) were used to characterize properties of fabricated nanofibers. Both pristine and hybrid nanofibers possessed cylindrical geometry and rough surface features, facilitating increased surface area. Infrared absorption spectra showed a slight shift in absorbance peaks due to interaction of PVP-coated CdSe QDs and nanofiber matrix. The presence of CdSe QDs influenced the fiber diameter and their thermal stability. Further, in vitro biological analyses of hybrid nanofibers showed promising antibacterial effect and decline in cancer cell viability. This study offers a simple approach to obtain hybrid nanomats immobilized with size-controlled PVP-coated CdSe QDs, which have potential applications as biosensors and antibacterial and anticancer cell agents.

Echinacoside hampers malignant progression of breast cancer MCF-7 cells by modulating AKR1B10/ERK signal transduction

This study analyzes the impact of echinacoside(ECH) in the proliferation, metastasis and adriamycin(ADR) resistance of breast cancer(BC) MCF-7 cells via the modulation of aldo-keto reductase family 1 member 10(AKR1B10)/extracellular signal-regulated kinase(ERK) pathway. The chemical structure of ECH was firstly confirmed. MCF-7 cells were treated with different concentration(0, 10, 20, 40 μg·mL~(-1)) of ECH for 48 h. Western blot was used to analyze expression of AKR1B10/ERK pathway-associated proteins and cell counting kit-8(CCK-8) assay to determine cell viability. MCF-7 cells were collected and classified into control group, ECH group, ECH + Ov-NC group, and ECH + Ov-AKR1B10 group. Then Western blot was employed to analyze the expression of AKR1B10/ERK pathway-associated proteins. CCK-8 and 5-ethynyl-2'-deoxyuridine(EdU) assay were used to examine cell proliferation. Cell migration was appraised with scratch assay, Transwell assay, and Western blot. Eventually, MCF-7 cells were treated with ADR for 48 h to induce ADR resistance. Cell viability was tested by CCK-8 assay and cell apoptosis was estimated based on terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) assay and Western blot. Based on Protein Data Bank(PDB) and molecular docking, the binding affinity of ECH to AKR1B10 was assessed. Various doses of ECH decreased the expression of AKR1B10/ERK pathway-associated proteins in a dose-dependent manner and declined cell viability compared with the control group. Compared with the control group, 40 μg·mL~(-1) ECH blocked the AKR1B10/ERK pathway in MCF-7 cells and inhibited the proliferation, metastasis and ADR resistance of the cells. Compared with the ECH + Ov-NC group, ECH + Ov-AKR1B10 group showed the recovery of some biological behaviors of MCF-7 cells. ECH also targeted AKR1B10. ECH can inhibit the proliferation, metastasis, and ADR resistance of BC cells by blocking AKR1B10/ERK pathway.

A lef5-deficient baculovirus expression system with no virion contamination and promoting secretion

The baculovirus expression system (BEVS) is widely used in biomanufacturing. However, massive late and very late genes are expressed during baculovirus infection of the host cell, and the protein aggregation has a significant negative impact on the intercellular environment of cells and organelle function. Baculovirus particle contamination also hinders the purification of particulate products. In this study, a novel baculovirus vector of deficient-lef5 (Ac-Δlef5) was established to prevent the production of baculovirus particles. It could transduce cells and replicate viral DNA but the expression of the late and very late genes was reduced so that no virus was packed and budded. The Ac-Δlef5 expression system was successfully used to express a secreted protein, thyroid peroxidase (TPO). Compared to wild-type baculovirus (Ac-wt), Ac-Δlef5 delayed the decline in cell viability and prolonged the harvest period from 4 to 6 days after infection. When expressed in the Ac-Δlef5 system, 98% of TPO was secreted extracellularly, which was about 1.8 times that of the Ac-wt system. Meanwhile, the transcription levels of protein folding-related genes were significantly increased. The results show that the Ac-Δlef5 system is a potential novel viral-free baculovirus expression system, which omits the virion removal operation in biomanufacturing.

The adverse and beneficial effects of polyphenols in green and black teas in vitro and in vivo.

Although numerous studies highlight the health benefits of tea, excessive consumption has been linked to toxic conditions. Thus, understanding the optimal consumption of tea is essential to minimize toxicity while maximizing its benefits. In this study, we investigated the effects of eight green tea samples (G1-G8) and eight black tea samples (R1-R8) from Camellia sinensis, the most popular teas in Asian culture, on RSC96 Schwann neural cells and embryonic cardiomyocyte H9c2 cells. The results showed that the IC50 (mg/ml, weight/volume) of both tea types were inversely proportional to their polyphenol content, suggesting a relationship between toxicity and polyphenol levels in both green and black tea. Interestingly, green teas generally have higher polyphenol content than black teas. We also assessed the protective effects of tea in vitro by pretreating cells with the teas at indicated doses of polyphenol and subsequently exposing them to H2O2. Both tea types significantly reduced the decline in cell viability for both cell lines, and there was no significant difference in protective polyphenol concentrations for green (G3 & G7) and black (R3 & R8) teas at effective concentrations (EC20 and EC40). To evaluate the preventative effects of tea in vivo, we examined the impact of two green (G3 & G7) and two black (R3 & R8) teas with varying polyphenol content on dextran sulfate sodium (DSS)-induced inflammatory colitis in mice. Tea-treated groups exhibited significantly lower inflammatory scores (DAI) than the control group. DSS treatment in the control group led to shortened colorectal lengths in mice, while tea co-treatment partially prevented this loss. Histological analysis revealed that G7 and R3 (with a moderate polyphenol content) treatment improved colorectal crypt structure, decreased the severity of inflammatory ulcerative colitis, and significantly reduced histological scores compared to the control group. However, G3 and R8 (with high and low doses of polyphenol content, respectively) did not show these effects, suggesting that a moderate polyphenol level in both tea types is optimal for preventative benefits.