Folia Biologica-Krakow最新文献

Drug resistance is a serious problem in cancer therapy. Growing evidence has shown that docosahexaenoic acid has anti-inflammatory and chemopreventive abilities. Studies have shown that autophagy inhibition and ferroptosis are promising therapeutic strategies for overcoming multidrug resistance. This study was aimed to examine whether docosahexaenoic acid (DHA) could reverse docetaxel resistance in prostate cancer cells. Cell survival was examined by MTT and colony formation. Protein expression was determined by Western blot. Reactive oxygen species (ROS) production was measured by flow cytometry. DHA displayed anti-cancer effects on proliferation, colony formation, migration, apoptosis, autophagy and epithelial mesenchymal transition. Glutathione-S-transferase π is an enzyme that plays an important role in drug resistance. DHA inhibited GSTπ protein expression and induced cytoprotective autophagy by regulating the PI3K/AKT signalling pathway in PC3R cells. DHA combined with PI3K inhibitor (LY294002) enhanced apoptosis by alleviating the expression of LC3B, (pro-) caspase- 3 and (uncleaved) PARP. DHA induced ferroptosis by attenuating the expression of glutathione peroxidase 4 (GPX4) and nuclear erythroid 2-related factor 2 (Nrf2). DHA-treated PC3R cells produced ROS. The ROS and cytotoxicity were reversed by treatment with ferrostatin-1. DHA combined with docetaxel inhibited EMT by regulating the expression of E-cadhein and N-cadherin. In summary, DHA reversed drug resistance and induced cytoprotective autophagy and ferroptosis by regulating the PI3K/AKT/Nrf2/GPX4 signalling pathway in PC3R cells. We propose that DHA could be developed as a chemosensitizer and that the PI3K/AKT /Nrf2/GPX4 signalling pathway might be a promising therapeutic target for overcoming cancer drug resistance.

Macranthoside B (MB) is a triterpenoid saponin extracted from Lonicera macranthoides, a traditional Chinese medicine. In the current study, we investigated the anticancer potential of MB in various cancer cells and elucidated its underlying mechanisms. MB exposure inhibited cell proliferation, induced mitochondrial membrane potential (MMP) loss, increased sub-G1 accumulation, and resulted in cleavage of caspase-3 and PARP, which are reflective of apoptosis. In HeLa cells, MB induced down-regulation of SOD2 and GPx1, phosphorylation of Akt and PDK1, and thus promoted ROS-mediated apoptosis. This was further supported by the protection of sub-G1 accumulation, MMP loss, cleavage of caspase-3 and PARP in the presence of N-acetylcysteine (NAC). Additionally, MB induced cell death via down-regulation of ubiquitin-like with PHD and ringfinger domains 1 (UHRF1) and Bcl-xL. Taken together, this study provides a new insight into the apoptosis- inducing potential of MB, and its molecular mechanisms are associated with an increase in oxidative stress and inhibition of the PDK1/Akt pathway.

Nucleolar RNA optical density (concentration) measurements at the single cell level indicated that differentiation of lymphocytes is accompanied by a slightly decreased nucleolar RNA concentration in contrast to the cytoplasmic rim around the nucleus. On the other hand, the nucleolar size was markedly reduced and the cytoplasmic rim surrounding the nucleus was reduced only weakly. Concerning the calculated rough estimate of the RNA content, the differentiation induced its larger decrease in the nucleoli than in the cytoplasmic rim. These observations indicated that the nucleolar RNA concentration and RNA content together with the nucleolar morphology are more sensitive markers of the differentiation process than the RNA concentration and content in the cytoplasm. Thus, the nucleolar RNA transfer to the cytoplasm in advanced differentiation steps might still be going on regardless of the decreasing or inhibited nucleolar biosynthetic activity. In addition, the presence of ring-shaped nucleoli and micronucleoli characteristic of mature and terminal lymphocytes in some lymphocytic less differentiated steps, i.e., lymphoblasts and prolymphocytes, might indicate the premature differentiation state of such cells.

This is the first histological and molecular analysis of two chondrosarcomas with target-like chondrocytes that were compared with a group of conventional chondrosarcomas and enchondromas. The unique histological feature of target-like chondrocytes is the presence of unusual hypertrophic eosinophilic APAS-positive perichondrocytic rings (baskets). In the sections stained with Safranin O/Fast green, the outer part of the ring was blue and the material in the lacunar space stained orange, similarly to intercellular regions. Immunohistochemical examination showed strong positivity for vimentin, factor XIIIa, cyclin D1, osteonectin, B-cell lymphoma 2 apoptosis regulator (Bcl-2), p53 and p16. The S-100 protein was positive in 25 % of neoplastic cells. Antibodies against GFAP, D2-40 (podoplanin), CD99, CKAE1.3 and CD10 exhibited weak focal positivity. Pericellular rings/baskets contained type VI collagen in their peripheral part, in contrast to the type II collagen in intercellular interterritorial spaces. Ultrastructural examination revealed that pericellular rings contained an intralacunar component composed of microfibrils with abundant admixture of aggregates of dense amorphous non-fibrillar material. The outer extralacunar zone was made up of a layer of condensed thin collagen fibrils with admixture of non-fibrillar dense material. NGS sequencing identified a fusion transcript involving fibronectin 1 (FN1) and fibroblast growth factor receptor 2 (FGFR2) at the RNA level. At the DNA level, no significant variant was revealed except for the presumably germline variant in the SPTA1 gene.

The original article was published in Folia Biologica (Praha) Volume 68, No. 3 (2022), 112-124.

Autologous serum eye drops (ASEDs) are used as a treatment for severe dry eye disease. The concentration and stability of various growth factors in ASEDs is determinative for their efficiency. We therefore assessed the concentrations of transforming growth factor beta 1 (TGF-β1), epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) in ASEDs following storage at 4-8, -20, -80 and -156 °C. Twenty % and 100% sera from eight healthy volunteers were analysed by the sandwich enzyme immunoassay at different time intervals up to seven months. The mean levels of TGF-β1 and EGF in undiluted and 20% serum did not differ significantly from the baseline levels in fresh serum for any storage conditions after 7 days at 4-8 °C, as well as after 4- and 7-month preservation at sub-zero temperatures. In 20% serum, no IGF-1 concentration decrease was found following 7 days of preservation at 4-8 °C. However, a decrease to 78 % and 81 % (P < 0.01) of baseline values was found in 20% serum after 4-month storage at -20 °C and 7-month storage at -156 °C, respectively. A more pronounced decrease in IGF-1 was observed in undiluted serum. All assessed growth factors present in 20% frozen serum remained stable for up to 7 months. The highest stability was achieved at -80 °C. At -20 and -156 °C, some decrease in IGF-1 occurred. Our results indicate that 20% ASEDs can be stored frozen up to 7 months under proper conditions.

Transient receptor potential cation channel subfamily V member 1 (TRPV1) has been found over-expressed in low back pain (LBP) patients with neuropathic pain (NP), but the underlying mechanism is still unclear. In the present study, the up-regulation of the TRPV1 protein level in sinuvertebral nerve biopsies from patients with NP was verified by immunoblotting, but the TRPV1 mRNA level was not significantly changed. MiRNAs targeting TRPV1 mRNA were predicted by a bioinformatic tool, and the interactions between the miRNAs and TRPV1 were confirmed by dual luciferase assay. The correlation between NFKB1 signalling and TRPV1 expression was analysed and confirmed by using sNF96.2 cells after lipopolysaccharide stimulation. We found that five out of 18 miRNAs repressed TRPV1 expression, and the levels of miR-375 and miR-455 were negatively correlated with the protein level of TRPV1 in patients with NP. MiR-375 and miR-455 were identified to repress TRPV1 expression via targeting the 3'UTR of TRPV1 mRNA. NFKB1 signalling activation down-regulated the expression of miR-375 and miR-455, and thus up-regulated the TRPV1 protein level. In conclusion, we partially unveiled the mechanism of how TRPV1 is over-expressed in chronic LBP patients with NP and provided two potential candidate miRNAs for NP treatment.

Adjuvant therapy and radiotherapy improves the survival of patients with metastatic and locally advanced gastric cancer (GC). However, the resistance to radiotherapy limits its clinical usage. Rhotekin 2 (RTKN2) functions as an oncogene and confers resistance to ultraviolet B-radiation and apoptosis- inducing agents. Here, the role of RTKN2 in radiosensitivity of GC cell lines was investigated. RTKN2 was found to be elevated in GC tissues and cells. A series of functional assays revealed that overexpression of RTKN2 induced GC cell proliferation, promoted GC cell migration and invasion, while inhibiting GC cell apoptosis. However, silence of RTKN2 promoted GC cell apoptosis, while repressing GC cell proliferation, invasion and migration. GC cells were exposed to irradiation, and data from cell survival and apoptotic assays showed that knock-down of RTKN2 enhanced radiosensitivity of GC through up-regulation of apoptosis and down-regulation of proliferation in irradiation-exposed GC cells. Moreover, the protein expression of β-catenin and c-Myc in GC cells was enhanced by RTKN2 over-expression, but reduced by RTKN2 silence. Interference of RTKN2 down-regulated nuclear β-catenin expression, while up-regulating cytoplasmic β-catenin in GC. In conclusion, RTKN2 contributed to cell growth and radioresistance in GC through activation of Wnt/β-catenin signalling.

Proliferation and migration of retinal endothelial cells (RECs) contribute to the development of diabetic retinopathy. PLAG1 (pleomorphic adenoma gene 1) functions as a zinc-finger transcription factor to participate in the development of lipoblastomas or pleomorphic adenomas of the salivary glands through regulation of cell proliferation and migration. The role of PLAG1 in diabetic retinopathy was investigated in this study. Firstly, RECs were induced under high glucose conditions, which caused reduction in viability and induction of apoptosis in the RECs. Indeed, PLAG1 was elevated in high glucosetreated RECs. Functional assays showed that silence of PLAG1 increased viability and suppressed apoptosis in high glucose-induced RECs, accompanied with up-regulation of Bcl-2 and down-regulation of Bax and cleaved caspase-3. Moreover, migration of RECs was promoted by high glucose conditions, while repressed by knockdown of PLAG1. High glucose also triggered angiogenesis of RECs through up-regulation of vascular endothelial growth factor (VEGF). However, interference of PLAG1 reduced VEGF expression to retard the angiogenesis. Silence of PLAG1 also attenuated high glucose-induced up-regulation of Wnt3a, β-catenin and c-Myc in RECs. Moreover, silence of PLAG1 ameliorated histopathological changes in the retina of STZ-induced diabetic rats through down-regulation of β-catenin. In conclusion, knockdown of PLAG1 suppressed high glucose-induced angiogenesis and migration of RECs, and attenuated diabetic retinopathy by inactivation of Wnt/ β-catenin signalling.

Osteogenesis is an important process of bone metabolism, and abnormal osteogenesis leads to various skeletal system diseases. Osteoblasts, the main cells involved in bone formation, are central elements in the study of bone metabolic diseases. Single-cell RNA sequencing is an important tool for studying the transcriptome of cells and can help to elucidate various cellular and molecular functions at the single-cell level, providing new avenues for life science research. Here we explore the heterogeneity of osteoblasts and try to reveal the developmental trajectory of osteoblasts, thereby contributing to efforts to describe the mechanism of osteogenesis. In this study, single-cell sequencing data of murine bone marrow cells were used to identify osteoblasts. Finally, osteoblasts were divided into four groups, each differing in characteristic genes and signal pathways. We also identify clues of the changes of some genes in the process of osteoclast formation, providing directions for further study. Collectively, our findings suggest that bone marrow osteoblasts can be divided into several subgroups, which represent different stages of cells, and that the specific genes of each subgroup respond to the molecular mechanisms of cell development. This data will likely be of great help in resolving diseases of the skeletal system.