PRDX1 exerts a photoprotection effect by inhibiting oxidative stress and regulating MAPK signaling on retinal pigment epithelium.

BACKGROUND: The purpose of this study was to investigate the photoprotection effect of peroxiredoxin 1 (PRDX1) protein in ultraviolet B (UVB) irradiation-induced damage of retinal pigment epithelium (RPE) and its possible molecular mechanism. METHODS: ARPE-19 cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the PRDX1 expression. The corresponding kits were employed to measure the levels or activities of lactate dehydrogenase (LDH), 8-hydroxy-2-deoxyguanosine (8-OHdG), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD). Western blotting was applied to examine PRDX1 expression and mitogen-activated protein kinase (MAPK) signaling pathway-related proteins. RESULTS: After exposure to 20 mJ/cm2 intensity of UVB irradiation for 24 h, ARPE-19 cells viability was decreased, the leakage degree of LDH and 8-OHdG were increased, and cell apoptosis was elevated. The expression of PRDX1 was significantly down-regulated in UVB-induced ARPE-19 cells. The low expression of PRDX1 was involved in high irradiation intensity. Overexpression of PRDX1 increased cell activity, decreased cell apoptosis, and LDH as well as 8-OHdG leakage in UVB-induced ARPE-19 cells. In addition to alleviating UVB-induced cell damage, PRDX1 overexpression also inhibited UVB-induced oxidative stress (down-regulation of ROS and MDA levels, up-regulation of GSH-Px and SOD activities) and the activation of MAPK signaling pathway in ARPE-19 cells. CONCLUSION: PRDX1 exerts a photoprotection effect on RPE by attenuating UVB-induced cell damage and inhibiting oxidative stress, which can be attributed to the inhibition of MAPK signaling pathway activation.

Simultaneous screening of four epidermal growth factor receptor antagonists from Curcuma longa via cell membrane chromatography online coupled with HPLC-MS.

The epidermal growth factor receptors (EGFRs) are significant targets for screening active compounds. In this work, an analytical method was established for rapid screening, separation, and identification of EGFRs antagonists from Curcuma longa. Human embryonic kidney 293 cells with a steadily high expression of EGFRs were used to prepare the cell membrane stationary phase in a cell membrane chromatography model for screening active compounds. Separation and identification of the retention chromatographic peaks was achieved by HPLC-MS. The active sites, docking extents and inhibitory effects of the active compounds were also demonstrated. The screening result found that ar-turmerone, curcumin, demethoxycurcumin, and bisdemethoxycurcumin from Curcuma longa could be active components in a similar manner to gefitinib. Biological trials showed that all of four compounds can inhibit EGFRs protein secretion and cell growth in a dose-dependent manner, and downregulate the phosphorylation of EGFRs. This analytical method demonstrated fast and effective characteristics for screening, separation and identification of the active compounds from a complex system and should be useful for drug discovery with natural medicinal herbs.

[Corrigendum] ND­09 inhibits chronic myeloid leukemia K562 cell growth by regulating BCR­ABL signaling.

Subsequently to the publication of this paper, the authors have realized that an error was made during the compilation of Fig. 2A as it appeared on p. 4. Essentially, the partial Q2­3 images of the '1.56 µm' group were inadvertently copied across to the Q2­3 images of the '3.12 µm' group, leading to the cell number of the Q2­3 quadrant being the same for both the 1.56 µm and the 3.12 µm groups, and also leading the total cell number of the 3.12 µm group being calculated as 106.97%, which was clearly incorrect (the total percentage should have added up to 100%). The corrected version of Fig. 2, showing the correct data for the Q2­3 images in the '3.12 µm' group, is shown on the next page. Note that this error did not significantly affect the results or the conclusions reported in this paper, and all the authors agree with the publication of this Corrigendum. The authors are grateful to the Editor of Oncology Reports for allowing them this opportunity to publish a corrigendum, and apologize to the readership for any inconvenience caused. [Oncology Reports 46: 136, 2021; DOI: 10.3892/or.2021.8087].

ND­09 inhibits chronic myeloid leukemia K562 cell growth by regulating BCR­ABL signaling.

Chronic myeloid leukemia (CML) accounts for approximately 15% of new adult leukemia cases. The fusion gene BCR­ABL is an important biological basis and target for CML. In the present study, a novel compound, ND­09, was developed and its inhibitory effect and mechanism of action on CML growth were evaluated using RT­PCR and western blot analysis. The results showed that ND­09 demonstrated a high level of inhibitory action toward CML cells overexpressing BCR­ABL and induced K562 cell apoptosis through the mitochondrial pathway. Notably, combined ND­09 and BCR­ABL siRNA treatment could better inhibit cell proliferation and induce apoptosis in K562 cells. Furthermore, this growth effect of BCR­ABL siRNA could be fully rescued by transfection with BCR­ABL. ND­09 exhibited a good fit within BCR­ABL and occupied its ATP­binding pocket, thus altering BCR­ABL kinase activity. Therefore, ND­09 downregulated the phosphorylation of BCR­ABL and ABL, ultimately inhibiting the downstream signaling pathways in K562 cells. These findings suggest that ND­09 induces growth arrest in CML cells by targeting BCR­ABL.

[Measures for Maintaining the Vitality of Peripheral Blood Hematopoietic Stem Cells in vitro].

OBJECTIVE: To explore the maintaining measures for the vitality of hematopoietic stem cells (HSC) in vitro, so as provide technical support for ultra long distance transport of HSC collected from unrelated donors. METHODS: Peripheral blood hematopoietic stem cells (PBHSC) were treated by different methods according to various groups, then stored at 4 ℃ in the refrigerator. The percentage of CD34+ cells, relative cell activity, relative cell proliferation rate, relative colony-forming rate, oxygen fraction and intracellular reactive oxygen species (ROS) were detected at 0, 24, 48 and 72 h after storage of PBHSC respectively. RESULTS: The percentage of CD34+ cells during 72 h storage did not altered. Along with the prolonging of storage time, the relative cell activity, relative cell proliferation rate and relative colony-forming rate gradually decreased in untreated PBHSC(control group), the related coefficients were -0.796, -0.883 and -0.815 respectively. Plasma dilution, antioxidants and oxygenation could improve the relative cell activity and relative cell proliferation rate, but oxygenation could decrease the relative colony-forming rate of PBHSC. The combination of 2 or 3 factors showed stronger protection effects on PBHSC. The intracellular level of ROS decreased gradually with the prolonging of storage time. Oxygenation of PBHSC could increase oxygen fraction, and also increase the intracellular level of ROS at the same time. The addition of antioxidants could reduce the level of ROS. CONCLUSION: The percentage of CD34+ cells can not serve as the indicator of PBHSC vitality. Plasma dilution, oxygenation and antioxidants can increase the survival and viability of PBHSC, but oxygenation can increase the intracellular ROS level and impair colony-forming ability of PBHSC. The combination of multiple factors can maintain the vitality of PBHSC better.

[Expression of c-erbB2 protein and its relation to prognosis in 284 primary breast cancer patients].

OBJECTIVE: To investigate the expression of oncoprotein c-erbB2 in primary breast cancer and to analyze its relation to its prognosis. METHODS: Immunohistochemical staining for c-erbB2 was performed on paraffin-embedded specimens of primary breast cancer from 284 patients, and the relation to its prognosis was statistically analyzed. RESULTS: Positive expression rate of c-erbB2 was 26.8% (76/284) in 284 primary breast cancer patients. Expression of c-erbB2 was positively correlated with the status of lymph node metastasis (P = 0.003). Univariate analysis indicated that c-erbB2 expression is a significant prognostic factor for the disease-free survival (DFS) (P = 0.024) and overall survival (OS) (P = 0.002), while multivariate analysis demonstrated that c-erbB2 is an independent prognostic factor for OS (P = 0.023). Moreover, tumors with c-erbB2 positive expression are more tend to metastasis to other viscera than those with c-erbB2 negative. c-erbB2 expression has different prognostic values for patients with different status of estrogen receptor (ER) and lymph node metastasis. CONCLUSION: c-erbB2 expression is an independent prognostic factor for total survival time in primary breast cancer patients, and its prognostic values are different according to the different ER status and lymph node metastasis.

[Biological characteristics of wharton's jelly derived mesenchymal stem cells after cryopreservation].

Aim of this study was to explore the effects of cryopreservation on biological characteristics of wharton's jelly derived mesenchymal stem cells (WJ-MSC), and to provide experimental evidence for clinical applications and the establishment of WJ-MSC bank. Primary WJ-MSC were produced by umbilical cord tissue culture in vitro. Fifth passage of WJ-MSC acquired by continuous cell culture were mixed with cryoprotectants, frozen in -80°C refrigerator and stored in liquid nitrogen. After the cryopreserved WJ-MSC were thawed, the first passage of WJ-MSC was obtained through cell culture and was taken as the 1st preserved passage (PP1). Thus, PP2-PP15 WJ-MSC were obtained by continuous cell subculture. The 1st control passage (CP1) to 15th passage (CP15) represented the 6th passage to 21st passage WJ-MSC acquired by subculturing in non-cryopreserved group. The biological characteristics of WJ-MSC from cryopreserved and control group, including the recovery rate of nucleated cells, trypan blue exclusion, CCK-8 activity, cell apoptosis, cell adherence, proliferation index, cell surface antigen, cell cycle and the capacities of induced differentiation into adipocyte, osteoblast and neuron, were detected and compared. The results indicated that the recovery rate of nucleated cells of cryopreserved WJ-MSC was 98.2%, trypan blue exclusion rate was 94.3%, CCK-8 activity was 91.4%, apoptotic rate was 3.9%, and the adherence rate was 92.6%. There was a statistically significant difference in proliferation index between PP1 and CP1 (P < 0.05), but there were no statistically significant differences between PP2-PP15 and their corresponding controls. The subculture cells highly expressed CD29, CD44, CD71, CD73, CD90, CD105, CD166 and HLA-ABC, and lowly expressed CD34, CD45 and HLA-DR. The expressions of above-mentioned surface antigens were not different statistically between two groups. The proliferation latency and logarithm proliferation of the subculture cells between two groups were also not different. After induced differentiation into adipocyte, osteoblast and neuron, the staining with oil red O, alkaline phosphatase and neuron-specific enolase was performed respectively, and the positive degrees were not clearly different macroscopically between two groups. Relatively high levels of triglyceride, alkaline phosphatase, and neuron-specific enolase in relevant cells could be detected, but had no significant differences between two groups. It is concluded that some WJ-MSC (< 10%) are damaged after cryopreservation, and the biological characteristics of WJ-MSC in cryopreservation group keep constant, as compared with that in non-cryopreservation group.

[Morphologic diagnosis and onset characteristics of acute leukemia: a retrospective analysis of 233 cases in 10 years].

The objective of this study was to evaluate the value of morphologic diagnosis for acute leukemia (AL), to explore the relation of morphologic diagnosis with immunology, cytogenetics and molecular biology diagnosis of AL and to analyze the onset characteristics of AL in 10 years. The samples of bone marrow and peripheral blood from 233 newly diagnosed cases of AL were collected during 2001-2011 years; the morphologic examination and immunologic, cytogenetic and molecular biologic examination (ICM) were carried out, the consistency of morphologic diagnosis with ICM diagnosis was compared, the onset characteristics of AL was analyzed. The results showed that: (1) the consistent rate of immunology, cytogenetics, molecular biology diagnosis with morphologic diagnosis was 84.3%. The order of consistent rat was AUL, M0 < M1 < HAL < M4 < M2 < M3 < M5 < ALL < M6, M7, AP; (2) Misdiagnosis always occurred among AUL, M0, M1, ALL and HAL or among M2a, M3v, M4 and M5. (3) In 233 cases, the highest ratio of blast was observed in M1 (92.5%), while the lowest ratio of blast was observed in M2 (49.5%). (4) AL occurred more frequently in males than that in female (147:86). (5) AL occurred in patients aged from 1 to 88 years. The median age was 41.5 for AUL, 40.8 for M0, 43.4 for M1, 46.3 for M2, 33.8 for M3, 42.6 for M4, 48.8 for M5, 77.3 for M6, 2.5 for M7, 65.0 for AP, 29.1 for ALL and 40.3 for HAL. (6) The number of patients in the later five years (139 cases) was significantly greater than that in the first five years (94 cases), especially the patients with M1, M2, M3, M4, and M5. It is concluded that morphologic diagnosis has important clinical value in the MICM diagnosis of AL. Attaching importance to the confusing cell morphology and onset characteristics of AL can improve the diagnostic accuracy.

Role of phospholipase D1 in glucose-induced insulin secretion in pancreatic Beta cells.

As glucose is known to induce insulin secretion in pancreatic Beta cells, this study investigated the role of a phospholipase D (PLD)-related signaling pathway in insulin secretion caused by high glucose in the pancreatic Beta-cell line MIN6N8. It was found that the PLD activity and PLD1 expression were both increased by high glucose (33.3 mM) treatment. The dominant negative PLD1 inhibited glucose-induced Beta2 expression, and glucose-induced insulin secretion was blocked by treatment with 1-butanol or PLD1-siRNA. These results suggest that high glucose increased insulin secretion through a PLD1-related pathway. High glucose induced the binding of Arf6 to PLD1. Pretreatment with brefeldin A (BFA), an Arf inhibitor, decreased the PLD activity as well as the insulin secretion. Furthermore, BFA blocked the glucose-induced mTOR and p70S6K activation, while mTOR inhibition with rapamycin attenuated the glucose induced Beta2 expression and insulin secretion. Thus, when taken together, PLD1 would appear to be an important regulator of glucose-induced insulin secretion through an Arf6/PLD1/mTOR/p70S6K/ Beta2 pathway in MIN6N8 cells.