Search

Oxidative stress-mediated excessive apoptosis and senescence of chondrocytes are the main pathological alterations in the osteoarthritis (OA) development. The protective effects of theaflavin (TF), a common group of polyphenols in black tea, against many degenerative diseases by attenuating oxidative stress are well reported. Nevertheless, its role in the OA treatment is still scantily understood. In the current research, by applying enzyme-linked immunosorbent assay (ELISA) kits and immunofluorescent staining, TF treatment was found to inhibit tert-Butyl hydroperoxide (TBHP)-induced imbalance of anabolism and catabolism in primary mouse chondrocytes. Then, according to western blot, live-dead staining, and SA-β-gal staining, the dramatically increased level of apoptosis and senescence of chondrocytes in response to TBHP was also found to be reduced by TF administration. With regard to upstream signaling investigation, the in vitro molecular binding analysis indicated that the beneficial effects of TF might be related to the regulation of the Keap1/Nrf2/HO-1 axis. Furthermore, the Silencing of Nrf2 resulted in the abolishment of the anti-apoptosis and anti-senescence effects of TF. In addition, the oral administration of TF was demonstrated to ameliorate osteoarthritis development in a surgically induced mouse OA model. Taken together, these results suggest that TF might be a promising therapeutic option for the treatment of OA.

Chronic myeloid leukemia (CML) is a malignant tumor caused by the abnormal proliferation of hematopoietic stem cells. Among a new series of acridone derivatives previously synthesized, it was found that the methoxybenzyl 5-nitroacridone derivative 8q has nanomolar cytotoxicity in vitro against human chronic myelogenous leukemia K562 cells. In order to further explore the possible anti-leukemia mechanism of action of 8q on K562 cells, a metabolomics and molecular biology study was introduced. It was thus found that most of the metabolic pathways of the G1 phase of K562 cells were affected after 8q treatment. In addition, a concentration-dependent accumulation of cells in the G1 phase was observed by cell cycle analysis. Western blot analysis showed that 8q significantly down-regulated the phosphorylation level of retinoblastoma-associated protein (Rb) in a concentration-dependent manner, upon 48 h treatment. In addition, 8q induced K562 cells apoptosis, through both mitochondria-mediated and exogenous apoptotic pathways. Taken together, these results indicate that 8q effectively triggers G1 cell cycle arrest and induces cell apoptosis in K562 cells, by inhibiting the CDK4/6-mediated phosphorylation of Rb. Furthermore, the possible binding interactions between 8q and CDK4/6 protein were clarified by homology modeling and molecular docking. In order to verify the inhibitory activity of 8q against other chronic myeloid leukemia cells, KCL-22 cells and K562 adriamycin-resistant cells (K562/ADR) were selected for the MTT assay. It is worth noting that 8q showed significant anti-proliferative activity against these cell lines after 48 h/72 h treatment. Therefore, this study provides new mechanistic information and guidance for the development of new acridones for application in the treatment of CML.

Background: Human skin or mucosa exposes cells to both an internal and exogeneous thermal environment and the cells survive within a certain range of temperature. Exogeneous hyperthermia has been applied for the treatment of various types of cancers, fungal disease, and warts., Objectives: To determine whether different cellular components in the skin adapt to hyperthermic conditions differentially and further elucidate the mechanisms involved., Materials & Methods: Cell lines derived from normal and tumour epithelial cells were treated with hyperthermic conditions and tested for viability (using an MTS assay), apoptosis (using a FITC-conjugated annexin V apoptosis detection kit), and changes in intracellular calcium (using a calcium-sensitive fluorescent single-wavelength dye, Fluo-4 AM)., Results: Thermo-resistance of different cell types was different when cells were subjected to heat at 45̊C for 30 minutes. Stronger effects of hyperthermia were noted on cell viability and apoptosis in epidermal cells relative to their malignant counterparts, except for cell lines harbouring human papillomavirus (HPV). Hyperthermia had a much greater effect on cell viability and apoptosis in a HPV-negative cell line compared to HPV-positive cell lines. We further found that hyperthermia treatment resulted in a strong calcium influx which led to apoptotic cells. However, no obvious increase in apoptosis was observed in cells treated with the CRAC channel selective inhibitor, BTP2, before application of hyperthermia in all cell types, except three cervical cell lines harbouring HPV., Conclusion: We propose that hyperthermia results in a CRAC-related strong calcium influx which induces apoptosis, with the exception of HPV-positive cells.

Our previous study showed that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) and glucocorticoid elevation in the fetus. Researchers suggested that IUGR is a risk factor for T helper cell (Th)1/Th2 deviation. However, whether PCE can induce these immune disorders and the underlying mechanisms of that induction remain unknown. This study aimed to observe the effects of PCE on the Th1/Th2 balance in offspring and further explore the developmental origin mechanisms from the perspective of glucocorticoid overexposure-induced thymocyte apoptosis. An IUGR model was established by caffeine administration from gestational day (GD) 9 to GD 18, and the offspring were immunized on postnatal day (PND) 42. The results show that maternal glucocorticoid overexposure increased fetal thymocyte apoptosis by activating both the Fas-mediated and the Bim-regulated apoptotic pathways. After birth, accelerated thymocyte apoptosis and Th1 suppression were also found in the PCE offspring at PND 14 and PND 49. Moreover, the PCE offspring showed immune disorders after immunization, manifesting as increased IgG1/IgG2a ratio and IL-4 production in the serum. In conclusion, PCE could induce fetal overexposure to maternal glucocorticoids and increase thymocyte apoptosis, which could persist into postnatal life and be implicated in Th1 inhibition and further immune disorders.

Apoptosis has been regarded to mediate intervertebral disc degeneration (IDD); however, the basic question of how the apoptotic bodies are cleared in the avascular intervertebral disc without phagocytes, which are essential to apoptosis, remains to be elucidated. Our goals were to investigate the ultrastructure of nucleus pulposus (NP) cells undergoing chondroptosis, a variant of apoptotic cell death, in a rabbit annular needle-puncture model of IDD. Experimental IDD was induced by puncturing discs with a 16-G needle in New Zealand rabbits. At 4 and 12 weeks after puncture, progressive degeneration was demonstrated by X-ray, magnetic resonance imaging and histological staining. TUNEL staining suggested a significant increase in the apoptosis index in the degenerated NP. However, the percentage of apoptotic cells with the classic ultrastructure morphology was much less than that with chondroptotic ultrastructure morphology under transmission electron microscopy (TEM). The chondroptotic cells from the early to late stage were visualized under TEM. In addition, the percentage of chondroptotic cells was significantly enhanced in the degenerated NP. Furthermore, 'paralyzed' cells were found in the herniated tissue. Western blotting revealed an increase in caspase3 expression in the degenerated NP. The expression of the Golgi protein (58K) was increased by the fourth week after puncture but decreased later. These findings indicate that chondroptosis is a major type of programmed cell death in the degenerated rabbit NP that may be related to the progressive development of IDD., (© 2017 Anatomical Society.)

Nicotine, a definite risk factor during pregnancy, is an immunomodulator. This study was designed to investigate the effects of prenatal nicotine exposure (PNE) on the balance of Th1/Th2 in offspring, and further explore the developmental origin mechanisms from the perspective of fetal thymocytes apoptosis. Pregnant Balb/c mice were administered 1.5 mg/kg nicotine subcutaneously twice per day from gestational day (GD) 9 to GD18. Results showed that PNE could cause a Th2 shift in male offspring, manifested as increased ratio of IgG1/IgG2a, IL-4 production in serum, and IL-4/IFN-γ expression ratio in spleen. Increased apoptosis of total thymocytes and CD4SP and reduced cell proportion of CD4SP were found in PNE male offspring on postnatal day (PND) 14 and PND 49. In the fetuses, decreased body weight and organ index of fetal thymus, histological changes in fetal thymus, reduced CD4SP proportion and increased fetal thymocyte apoptosis were observed in nicotine group. The increased mRNA expression of genes involved in Fas-mediated apoptotic pathway and protein expression of Fas were also detected. In conclusion, PNE could cause a Th2 shift in male offspring mediated by reduced CD4 + T cells output, which may result from the increasing apoptosis of total thymocytes and CD4SP.

Hyperthermia has shown clinical potency as a single agent or as adjuvant to other therapies in cancer treatment. However, thermotolerance induced by thermosensitive genes such as the heat shock proteins can limit the efficacy of hyperthermic treatment. In the present study, we identified HSPB1 (HSP27) is hyperthermically inducible or endogenously highly expressed in both murine and human melanoma cell lines. We used a siRNA strategy to reduce HSPB1 levels and showed increased intolerance to hyperthermia via reduced cell viability and/or proliferation of cells. In the investigation of underlying mechanisms, we found knock down of HSPB1 further increased the proportion of apoptotic cells in hyperthermic treated melanoma cells when compared with either single agent alone, and both agents leaded to cell cycle arrest at G0/G1 or G2/M phases. We concluded that hyperthermia combined with silencing of HSPB1 enhanced cell death and resulted in failure to thrive in melanoma cell lines, implying the potential clinical utility of hyperthermia in combination with HSPB1 inhibition in cancer treatment.

This study was aimed to investigate the effect of baicalin on proliferation and apoptosis of HL-60 cells and its mechanism. Cell proliferation was assayed by using Cell Counting Kit-8. The morphological changes of HL-60 cells were examined by light microscopy and nucleolus morphological changes were observed by fluorescent microscopy after Hoechst 33342 staining. The early cell apoptosis was detected by using flow cytometry with Annexin V-FITC/PI double staining. The expression of caspase-3, caspase-9, Bcl-2 and Bax mRNA was detected by RT-PCR and Western blot assay was carried out to examine Bax, Bcl-2, caspase-8 and cleaved caspase-3 expression. The results showed that Baicalin inhibited the proliferation of HL-60 cells in a time- and concentration-dependent manner. HL-60 cells exhibited typical morphological features (for example, cell shrinkage, membrane blebbing and formation of apoptotic bodies). Cell apoptosis in early stage could be detected, the expression of caspase-3, caspase-9 and Bax mRNA was obviously up-regulated, while the Bcl-2 expression down-regulated, and accordingly Bcl-2/Bax ratio decreased. Such results were consistent with the expression of these proteins. In addition, the expression of cleaved caspase-8 protein was induced significantly after treated with baicalin. It is concluded that baicalin can significantly inhibit the proliferation of HL-60 cells and induce the apoptosis of HL-60 cells, which may occur through decreasing Bcl-2/Bax ratio by intrinsic pathway and through extrinsic pathway. It suggests that baicalin may be a promising drug for the therapy of acute myeloid leukemia.

Objective: To observe the effect and mechanism of Pingtang Recipe containing drug-serum (DS-PTR) in improving INS-1 beta pancreatic cells lipoapoptosis., Methods: Experimental INS-1 beta cells were divided into 5 groups (6 pools for each group), namely, the blank control group treated with rat's serum (C), the other 4 model groups induced into lipoapoptosis by palmitic acid and treated respectively by rat's serum (M), high, middle and low dose DS-PTR (DSh, DSm and DSI). Cell apoptosis was detected by TUNEL staining; Caspase-3 activity of cells was measured by chemiluminescence method; intracellular production of reactive oxygen species (ROS) was detected by DCHF-DA incorporation, and expressions of uncoupling protein-2 (UCP-2) was determined by RT-PCR., Results: INS-1 beta cell apoptosis in Group M was significantly higher than that in Group C (P < 0.01), while that showed a decreased trend in the three DS-PTR treated groups. Caspase-3 activity was enhanced in Group M, it decreased significantly in Group DSm (P < 0.05). The over-produced ROS in cells after modeling was inhibited in Groups DSm and DSI (P < 0.05), meantime, expression of UCP-2 excited by PA (2.244 +/- 0.421) was reduced significantly in Group DSI and Group DSm to 1.286 +/- 0.373 (P < 0.01) and 1.627 +/- 0.348 (P < 0.05) respectively., Conclusion: DS-PTR shows a protective effect on INS-1 beta pancrentic cells against lipoapoptosis, which is possibly play its mechanism through regulating ROS and UCP-2.

Objective: To investigate systematically Schwann cell apoptosis in Wallerian-degenerated sciatic nerve of the rat, and evaluate its time-related feature., Methods: Ninety-five SD rats were divided randomly into one normal group (8 rats) and 11 experimental groups (66 rats, 6 in each). Both hind legs of each rat in experimental groups were randomly divided into test leg (sciatic nerve transected) and control one (nerve uninjured). All test legs constituted a test group and all control legs constituted a control one. After operation, all rats were respectively sacrificed at 1 h, 6 h, 12 h, 24 h, 2 d, 3 d, 4 d, 8 d, 14 d, 21 d, and 30 d. We analyzed the specimens of mid-distal sciatic nerve, especially the morphological changes of the nerve, the different expression levels of S-100 protein and apoptosis-related proteins such as Bcl-2, Bax, and Fas in Schwann cells. The TUNEL method was used to detect the apoptotic rate of Schwann cells., Results: (1) The test group showed Wallerian degeneration. The number of Schwann cells began to decrease at 24 h, obviously decreased on day 3 and 4, then began to increase from day 8 and formed Bungner belt after 14 days. (2) Schwann cells generally expressed S-100 at a low level in all groups. The control group was not significantly different from the normal group. The test group had statistical significance at 1 h and day 21. (3) As an inhibitory gene protein of Schwann cell apoptosis, Bcl-2 positive rates in the control and test groups apparently elevated and were statistically different from the normal group. (4) As a promotive gene protein of Schwann cell apoptosis, the control and test groups expressed Bax at a high level and were statistically different from the normal group. (5) As a promotive gene protein of Schwann cell apoptosis, Fas positive rate in control group was slightly elevated, but had no statistical significance compared with the normal group. Fas positive rate in test group continuously elevated in a fluctuant way, with highly statistical significance compared with the normal group. (6) TUNEL detection further proved that Schwann cell apoptosis rarely existed in the normal group, and the left sciatic nerve had no statistical significance compared with the right sciatic nerve. While the test group showed lots of apoptotic nuclei at 6 h, 2 d, 4 d, and 21 d. It had highly statistical significance compared with the normal group., Conclusions: Schwann cell apoptosis does exist in Wallerian-degenerated sciatic nerve of the rat after transection. Schwann cell apoptosis and its apoptotic genes expression have a time-related feature.