Bortezomib elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 to inhibit multiple myeloma cells.

Iron contributes to tumor initiation and progression; however, excessive intracellular free Fe2+ can be toxic to cancer cells. Our findings confirmed that multiple myeloma (MM) cells exhibited elevated intracellular iron levels and increased ferritin, a key protein for iron storage, compared with normal cells. Interestingly, Bortezomib (BTZ) was found to trigger ferritin degradation, increase free intracellular Fe2+, and promote ferroptosis in MM cells. Subsequent mechanistic investigation revealed that BTZ effectively increased NCOA4 levels by preventing proteasomal degradation in MM cells. When we knocked down NCOA4 or blocked autophagy using chloroquine, BTZ-induced ferritin degradation and the increase in intracellular free Fe2+ were significantly reduced in MM cells, confirming the role of BTZ in enhancing ferritinophagy. Furthermore, the combination of BTZ with RSL-3, a specific inhibitor of GPX4 and inducer of ferroptosis, synergistically promoted ferroptosis in MM cell lines and increased cell death in both MM cell lines and primary MM cells. The induction of ferroptosis inhibitor liproxstatin-1 successfully counteracted the synergistic effect of BTZ and RSL-3 in MM cells. Altogether, our findings reveal that BTZ elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 by increasing ferroptosisin MM cells.

Rapid and Sensitive Detection of Streptococcus iniae in Trachinotus ovatus Based on Multienzyme Isothermal Rapid Amplification.

Infectious diseases caused by Streptococcus iniae lead to massive death of fish, compose a serious threat to the global aquaculture industry, and constitute a risk to humans who deal with raw fish. In order to realize the early diagnosis of S. iniae, and control the outbreak and spread of disease, it is of great significance to establish fast, sensitive, and convenient detection methods for S. iniae. In the present study, two methods of real-time MIRA (multienzyme isothermal rapid amplification, MIRA) and MIRA-LFD (combining MIRA with lateral flow dipsticks (LFD)) for the simA gene of S. iniae were established, which could complete amplification at a constant temperature of 42 °C within 20 min. Real-time MIRA and MIRA-LFD assays showed high sensitivity (97 fg/µL or 7.6 × 102 CFU/mL), which were consistent with the sensitivity of real-time PCR and 10 times higher than that of PCR with strong specificity, repeatability simplicity, and rapidity for S. iniae originating from Trachinotus ovatus. In summary, real-time MIRA and MIRA-LFD provide effective ways for early diagnosis of S. iniae in aquaculture, especially for units in poor conditions.

Pharmacologic targeting of the P-TEFb complex as a therapeutic strategy for chronic myeloid leukemia.

BACKGROUND: The positive transcription elongation factor b (P-TEFb) kinase activity is involved in the process of transcription. Cyclin-dependent kinase 9 (CDK9), a core component of P-TEFb, regulates the process of transcription elongation, which is associated with differentiation and apoptosis in many cancer types. Wogonin, a natural CDK9 inhibitor isolated from Scutellaria baicalensis. This study aimed to investigate the involved molecular mechanisms of wogonin on anti- chronic myeloid leukemia (CML) cells. MATERIALS AND METHODS: mRNA and protein levels were analysed by RT-qPCR and western blot. Flow cytometry was used to assess cell differentiation and apoptosis. Cell transfection, immunofluorescence analysis and co-immunoprecipitation (co-IP) assays were applied to address the potential regulatory mechanism of wogonin. KU-812 cells xenograft NOD/SCID mice model was used to assess and verify the mechanism in vivo. RESULTS: We reported that the anti-CML effects in K562, KU-812 and primary CML cells induced by wogonin were regulated by P-TEFb complex. We also confirmed the relationship between CDK9 and erythroid differentiation via knockdown the expression of CDK9. For further study the mechanism of erythroid differentiation induced by wogonin, co-IP experiments were used to demonstrate that wogonin increased the binding between GATA-1 and FOG-1 but decreased the binding between GATA-1 and RUNX1, which were depended on P-TEFb. Also, wogonin induced apoptosis and decreased the mRNA and protein levels of MCL-1 in KU-812 cells, which is the downstream of P-TEFb. In vivo studies showed wogonin had good anti-tumor effects in KU-812 xenografts NOD/ SCID mice model and decreased the proportion of human CD45+ cells in spleens of mice. We also verified that wogonin exhibited anti-CML effects through modulating P-TEFb activity in vivo. CONCLUSIONS: Our study indicated a special mechanism involving the regulation of P-TEFb kinase activity in CML cells, providing evidences for further application of wogonin in CML clinical treatment. Video Abstract.

LW-213 induces cell apoptosis in human cutaneous T-cell lymphomas by activating PERK-eIF2α-ATF4-CHOP axis.

Cutaneous T-cell lymphoma (CTCL) is characterized by a heterogeneous group of extranodal non-Hodgkin lymphomas, in which monoclonal T lymphocytes infiltrate the skin. LW-213, a derivative of wogonin, was found to induce cell apoptosis in chronic myeloid leukemia (CML). In this study, we investigated the effects of LW-213 on CTCL cells and the underlying mechanisms. We showed that LW-213 (1-25 µM) dose-dependently inhibited human CTCL cell lines (Hut-102, Hut-78, MyLa, and HH) with IC50 values of around 10 µM, meanwhile it potently inhibited primary leukemia cells derived from peripheral blood of T-cell lymphoma patients. We revealed that LW-213-induced apoptosis was accompanied by ROS formation and the release of calcium from endoplasmic reticulum (ER) through IP3R-1channel. LW-213 selectively activated CHOP and induced apoptosis in Hut-102 cells via activating PERK-eIF2α-ATF4 pathway. Interestingly, the degree of apoptosis and expression of ER stress-related proteins were alleviated in the presence of either N-acetyl cysteine (NAC), an ROS scavenger, or 2-aminoethyl diphenylborinate (2-APB), an IP3R-1 inhibitor, implicating ROS/calcium-dependent ER stress in LW-213-induced apoptosis. In NOD/SCID mice bearing Hut-102 cell line xenografts, administration of LW-213 (10 mg/kg, ip, every other day for 4 weeks) markedly inhibited the growth of Hut-102 derived xenografts and prolonged survival. In conclusion, our study provides a new insight into the mechanism of LW-213-induced apoptosis, suggesting the potential of LW-213 as a promising agent against CTCL.

LW-213, a newly synthesized flavonoid, induces G2/M phase arrest and apoptosis in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell neoplasm characterized by an uncontrolled proliferation of moderately and well differentiated cells of the granulocytic lineage. LW-213, a newly synthesized flavonoid compound, was found to exert antitumor effects against breast cancer through inducing G2/M phase arrest. We investigated whether LW-213 exerted anti-CML effects and the underlying mechanisms. We showed that LW-213 inhibited the growth of human CML cell lines K562 and imatinid-resistant K562 (K562r) in dose- and time-dependent manners with IC50 values at the low µmol/L levels. LW-213 (5, 10, 15 µM) caused G2/M phase arrest of K562 and K562r cells via reducing the activity of G2/M phase transition-related proteins Cyclin B1/CDC2 complex. LW-213 treatment induced apoptosis of K562 and K562r cells via inhibiting the expression of CDK9 through lysosome degradation, thus leading to the suppression of RNAPII phosphorylation, down-regulation of a short-lived anti-apoptic protein MCL-1. The lysosome inhibitor, NH4Cl, could reverse the anti-CML effects of LW-213 including CDK9 degradation and apoptosis. LW-213 treatment also degraded the downstream proteins of BCR-ABL1, such as oncoproteins AKT, STAT3/5 in CML cells, which was blocked by NH4Cl. In primary CML cells and CD34+ stem cells, LW-213 maintained its pro-apoptotic activity. In a K562 cells-bearing mice model, administration of LW-213 (2.5, 5.0 mg/kg, ip, every other day for 4 weeks) dose-dependently prolonged the survival duration, and significantly suppressed huCD45+ cell infiltration and expression of MCL-1 in spleens. Taken together, our results demonstrate that LW-213 may be an efficient agent for CML treatment.

Mitotic catastrophe and p53-dependent senescence induction in T-cell malignancies exposed to nonlethal dosage of GL-V9.

Mitotic catastrophe of cancer cells induced by drugs is characterized by low dosage and low toxicity, representing a significant advantage in the cancer treatment. Effective therapeutic options are limited for T-cell malignancies patients who are still treated by high-dose multiagent chemotherapy, potentially followed by hematopoietic stem cell transplantation, highlighting the urgency for identification of more effective anti-T-cell malignancies drugs. The use of antineoplastic drugs which induced tumor cell mitotic catastrophe would be a new strategy for cancer therapy. Nevertheless, there is still no effective mitotic catastrophe agent in T-cell malignancies. Our study showed that nonlethal dosage (ND) of GL-V9 (5-hydroxy-8-methoxy-2-phenyl-7-(4-(pyrrolidin-1-yl) butoxy) 4 H-chromen-4-one) (2 µM), a potential anticancer drug, not only attenuated cell growth and survival, but also arrested the cell cycle in G2/M phase and induced multipolar spindles, nuclear alterations (micronucleation and multinucleation), which are the most prominent morphological characteristics of mitotic catastrophe, in T-cell malignancies cell lines including Jurkat, HuT-102, and HuT-78. Moreover, ND GL-V9 could trigger DNA damage, and significantly influence several mitosis-associated proteins. Besides, results showed that ND GL-V9 increased the activity of senescence-associated ß-galactosidase (SA-ß-Gal) following the induction of mitotic catastrophe in Jurkat and HuT-102 cells with intact p53, while causing apoptosis in p53-deficient HuT-78 cells. We concluded that the anti-T-cell malignancies effects of ND GL-V9 and clarified the precise regulation in the process of mitosis under the action of GL-V9 in T-cell malignancies. Our data provided new evidence for the study of T-cell malignancies treatment associated with mitotic catastrophe and cellular senescence induction.

The DNA damage checkpoint protein RAD9A is essential for male meiosis in the mouse.

In mitotic cells, RAD9A functions in repairing DNA double-strand breaks (DSBs) by homologous recombination and facilitates the process by cell cycle checkpoint control in response to DNA damage. DSBs occur naturally in the germline during meiosis but whether RAD9A participates in repairing such breaks is not known. In this study, we determined that RAD9A is indeed expressed in the male germ line with a peak of expression in late pachytene and diplotene stages, and the protein was found associated with the XY body. As complete loss of RAD9A is embryonic lethal, we constructed and characterized a mouse strain with Stra8-Cre driven germ cell-specific ablation of Rad9a beginning in undifferentiated spermatogonia in order to assess its role in spermatogenesis. Adult mutant male mice were infertile or sub-fertile due to massive loss of spermatogenic cells. The onset of this loss occurs during meiotic prophase, and there was an increase in the numbers of apoptotic spermatocytes as determined by TUNEL. Spermatocytes lacking RAD9A usually arrested in meiotic prophase, specifically in pachytene. The incidence of unrepaired DNA breaks increased, as detected by accumulation of γH2AX and DMC1 foci on the axes of autosomal chromosomes in pachytene spermatocytes. The DNA topoisomerase IIß-binding protein 1 (TOPBP1) was still localized to the sex body, albeit with lower intensity, suggesting that RAD9A may be dispensable for sex body formation. We therefore show for the first time that RAD9A is essential for male fertility and for repair of DNA DSBs during meiotic prophase I.

Study on Predicting Clinical Stage of Patients with Bronchial Asthma Based on CT Radiomics.

Objective: To explore the value of a new model based on CT radiomics in predicting the staging of patients with bronchial asthma (BA). Methods: Patients with BA from 2018 to 2021 were retrospectively analyzed and underwent plain chest CT before treatment. According to the guidelines for the prevention and treatment of BA (2016 edition), they were divided into two groups: acute attack and non-acute attack. The images were processed as follows: using Lung Kit software for image standardization and segmentation, using AK software for image feature extraction, and using R language for data analysis and model construction (training set: test set = 7: 3). The efficacy and clinical effects of the constructed model were evaluated with ROC curve, sensitivity, specificity, calibration curve and decision curve. Results: A total of 112 patients with BA were enrolled, including 80 patients with acute attack (range: 2-86 years old, mean: 53.89±17.306 years old, males of 33) and 32 patients with non-acute attack (range: 4-79 years old, mean: 57.38±19.223 years old, males of 18). A total of 10 imaging features are finally retained and used to construct model using multi-factor logical regression method. In the training group, the AUC, sensitivity and specificity of the model was 0.881 (95% CI:0.808-0.955), 0.804 and 0.818, separately; while in the test group, it was 0.792 (95% CI:0.608-0.976), 0.792 and 0.80, respectively. Conclusion: The model constructed based on radiomics has a good effect on predicting the staging of patients with BA, which provides a new method for clinical diagnosis of staging in BA patients.

NETs contribute to psoriasiform skin inflammation: A novel therapeutic approach targeting IL-36 cytokines by a small molecule tetrahydroxystilbene glucoside.

BACKGROUND: Psoriasis, a chronic immune-mediated skin disease with pathological features such as aberrant differentiation of keratinocytes, dermal-epidermal inflammation, and angiogenesis. 2,3,5,4'-Tetrahydroxy stilbene 2-Ο-ß-d-glucoside (2354Glu) is a natural small molecule polyhydrostilbenes isolated from Polygonum multiglorum Thunb. The regulation of IL-36 subfamily has led to new pharmacologic strategies to reverse psoriasiform dermatitis. PURPOSE: Here we investigated the therapeutic potential of 2354Glu and elucidated the underlying mechanism in psoriasis. METHODS: The effects of 2354Glu on IL-36 signaling were assessed by psoriasiform in vivo, in vitro and ex vivo model. The in vivo mice model of psoriasis-like skin inflammation was established by applying imiquimod (IMQ), and the in vitro and ex vitro models were established by stimulating mouse primary keratinocyte, human keratinocytes cells (HaCaT) and ex vivo skin tissue isolated from the mice back with Polyinosine-polycytidylic acid (Poly(I:C)), IMQ, IL-36γ and Lipopolysaccharide (LPS) respectively. Moreover, NETs formation was inhibited by Cl-amidine to evaluate the effect of NETs in psoriatic mouse model. The effects of 2354Glu on skin inflammation were assessed by western blot, H&E, immunohistochemistry, immunofluorescence, enzyme-linked immunosorbent assay and real-time quantitative PCR. RESULTS: In Poly(I:C)-stimulated keratinocytes, the secretion of IL-36 was inhibited after treatment with 2354Glu, similar to the effects of TLR3, P2X7R and caspase-1 inhibitors. In aldara (imiquimod)-induced mice, 2354Glu (100 and 25 mg/kg) improved immune cell infiltration and hyperkeratosis in psoriasis by directly targeting IL-36 in keratinocytes through P2X7R-caspase-1. When treatment with 2354Glu (25 mg/kg) was insufficient to inhibit IL-36γ, NETs reduced pathological features and IL-36 signaling by interacting with keratinocytes to combat psoriasis like inflammation. CONCLUSION: These results indicated that NETs had a beneficial effect on psoriasiform dermatitis. 2354Glu alleviates psoriasis by directly targeting IL-36/P2X7R axis and NET formation, providing a potential candidate for the treatment of psoriasis.

Efficacy and safety of naotaifang capsules for hypertensive cerebral small vessel disease: Study protocol for a multicenter, randomized, double-blind, placebo-controlled clinical trial.

Background: Hypertensive cerebral small vessel disease (HT-CSVD) is a cerebrovascular clinical, imaging and pathological syndrome caused by hypertension (HT). The condition manifests with lesions in various vessels including intracranial small/arterioles, capillaries, and small/venules. Hypertensive cerebral small vessel disease has complex and diverse clinical manifestations. For instance, it can present as an acute stroke which progresses to cause cognitive decline, affective disorder, unstable gait, dysphagia, or abnormal urination. Moreover, hypertensive cerebral small vessel disease causes 25-30% of all cases of ischemic strokes and more than 50% of all cases of single or mixed dementias. The 1-year recurrence rate of stroke in cerebral small vessel disease patients with hypertension is 14%. In the early stage of development, the symptoms of hypertensive cerebral small vessel disease are concealed and often ignored by patients and even clinicians. Patients with an advanced hypertensive cerebral small vessel disease manifest with severe physical and mental dysfunction. Therefore, this condition has a substantial economic burden on affected families and society. Naotaifang (NTF) is potentially effective in improving microcirculation and neurofunction in patients with ischemic stroke. In this regard, this multicenter randomized controlled trial (RCT) aims to furtherly evaluate the efficacy and safety of naotaifang capsules on hypertensive cerebral small vessel disease. Methods: This study is a multicenter, randomized, double-blind, placebo-controlled clinical trial. A total of 388 eligible subjects were recruited from the First Hospital of Hunan University of Chinese Medicine, Hunan Academy of Chinese Medicine Affiliated Hospital, the First Hospital of Shaoyang University, the First Traditional Chinese Medicine Hospital of Changde, and Jiangmen Wuyi Hospital of Traditional Chinese Medicine from July 2020 to April 2022. After a 4-week run-in period, all participants were divided into the intervention group (represented by Y-T, N-T) and control group (represented by Y-C, N-C); using a stratified block randomized method based on the presence or absence of brain damage symptoms in hypertensive cerebral small vessel disease (represented by Y and N). The Y-T and N-T groups were administered different doses of naotaifang capsules, whereas Y-C and N-C groups received placebo treatment. These four groups received the treatments for 6 months. The primary outcome included Fazekas scores and dilated Virchow-robin spaces (dVRS) grades on magnetic resonance imaging (MRI). The secondary outcomes included the number of lacunar infarctions (LI) and cerebral microbleeds (CMB) on magnetic resonance imaging, clinical blood pressure (BP) level, traditional Chinese medicine (TCM) syndrome scores, mini-mental state examination (MMSE) scale, and safety outcomes. Fazekas scores, dilated Virchow-robin spaces grades, and the number of lacunar infarctions and cerebral microbleeds on magnetic resonance imaging were tested before enrollment and after 6 months of treatment. The clinical blood pressure level, traditional Chinese medicine syndrome scores, mini-mental state examination scale and safety outcomes were tested before enrollment, after 3-month, 6-month treatment and 12th-month follow-up respectively. Conclusion: The protocol will comfirm whether naotaifang capsules reduce Fazekas scores, dilated Virchow-robin spaces grades, and the number of lacunar infarctions and cerebral microbleeds, clinical blood pressure, increase mini-mental state examination scores, traditional Chinese medicine syndrome scores of Qi deficiency and blood stasis (QDBS), and improve the quality of life of subjects. The consolidated evidence from this study will shed light on the benefits of Chinese herbs for hypertensive cerebral small vessel disease, such as nourishing qi, promoting blood circulation and removing blood stasis, and dredging collaterals. However, additional clinical trials with large samples and long intervention periods will be required for in-depth research. Clinical Trial registration: www.chictr.org.cn, identifier ChiCTR1900024524.

The bromodomain-containing gene BRD2 is regulated at transcription, splicing, and translation levels.

The human BRD2 gene has been linked and associated with a form of common epilepsy and electroencephalographic abnormalities. Disruption of Brd2 in the mouse revealed that it is essential for embryonic neural development and that viable Brd2(+/-) heterozygotes show both decreased GABAergic neuron counts and increased susceptibility to seizures. To understand the molecular mechanisms by which mis-expression of BRD2 might contribute to epilepsy, we examined its regulation at multiple levels. We discovered that BRD2 expresses distinct tissue-specific transcripts that originate from different promoters and have strikingly different lengths of 5' untranslated regions (5'UTR). We also experimentally confirmed the presence of a highly conserved, alternatively spliced exon, inclusion of which would result in a premature termination of translation. Downstream of this alternative exon is a polymorphic microsatellite (GT-repeats). Manipulation of the number of the GT-repeats revealed that the length of the GT-repeats affects the ratio of the two alternative splicing products. In vitro translation and expression in cultured cells revealed that among the four different mRNAs (long and short 5'UTR combined with regular and alternative splicing), only the regularly spliced mRNA with the short 5'UTR yields full-length protein. In situ hybridization and immunohistochemical studies showed that although Brd2 mRNA is expressed in both the hippocampus and cerebellum, Brd2 protein only can be detected in the cerebellar Purkinje cells and not in hippocampal cells. These multiple levels of regulation would likely affect the production of functional BRD2 protein during neural development and hence, its role in the etiology of seizure susceptibility.

Overexpression of HOXB5, cyclin D1 and PCNA in congenital cystic adenomatoid malformation.

OBJECTIVE: We investigated the patterns of expression of HOXB5, cyclin D1 and proliferating cell nuclear antigen (PCNA) proteins in human congenital cystic adenomatoid malformation (CCAM) to establish the molecular basis of its etiology. METHODS: Immunohistochemistry was performed on frozen archival specimens of CCAM and normal lung tissue as controls using antibodies against HOXB5, cyclin D1 and PCNA proteins. RESULTS: Immunohistochemistry revealed a higher level of expression of HOXB5, cyclin D1 and PCNA predominantly in mesenchymal cells of the CCAM tissues as compared to normal adjacent control lung tissues. CONCLUSION: Elevated levels of immunohistochemical detection of HOXB5, cyclin D1 and PCNA were characteristic properties of lung tissue cells in CCAM. This elevated HOXB5 expression may correlate with the aberrant cellular differentiation observed in the CCAM disorder. Elevated expression of cyclin D1 and PCNA further suggests that increased cellular proliferation contributes to the overgrowth of lung tissue in CCAM.

Mouse Rad9b is essential for embryonic development and promotes resistance to DNA damage.

RAD9 participates in promoting resistance to DNA damage, cell cycle checkpoint control, DNA repair, apoptosis, embryogenesis, and regulation of transcription. A paralogue of RAD9 (named RAD9B) has been identified. To define the function of mouse Rad9b (Mrad9b), embryonic stem (ES) cells with a targeted gene deletion were constructed and used to generate Mrad9b mutant mice. Mrad9b(-/-) embryos are resorbed after E7.5 while some of the heterozygotes die between E12.5 and a few days after birth. Mrad9b is expressed in embryonic brain and Mrad9b(+/-) embryos exhibit abnormal neural tube closure. Mrad9b(-/-) mouse embryonic fibroblasts are not viable. Mrad9b(-/-) ES cells are more sensitive to gamma rays and mitomycin C than Mrad9b(+/+) controls, but show normal gamma-ray-induced G2/M checkpoint control. There is no evidence of spontaneous genomic instability in Mrad9b(-/-) cells. Our findings thus indicate that Mrad9b is essential for embryonic development and mediates resistance to certain DNA damaging agents.

One-Two Punch Therapy for the Treatment of T-Cell Malignancies Involving p53-Dependent Cellular Senescence.

T-cell malignancies are still difficult to treat due to a paucity of plans that target critical dependencies. Drug-induced cellular senescence provides a permanent cell cycle arrest during tumorigenesis and cancer development, particularly when combined with senolytics to promote apoptosis of senescent cells, which is an innovation for cancer therapy. Here, our research found that wogonin, a well-known natural flavonoid compound, not only had a potential to inhibit cell growth and proliferation but also induced cellular senescence in T-cell malignancies with nonlethal concentration. Transcription activity of senescence-suppression human telomerase reverse transcriptase (hTERT) and oncogenic C-MYC was suppressed in wogonin-induced senescent cells, resulting in the inhibition of telomerase activity. We also substantiated the occurrence of DNA damage during the wogonin-induced aging process. Results showed that wogonin increased the activity of senescence-associated ß-galactosidase (SA-ß-Gal) and activated the DNA damage response pathway mediated by p53. In addition, we found the upregulated expression of BCL-2 in senescent T-cell malignancies because of the antiapoptotic properties of senescent cells. Following up this result, we identified a BCL-2 inhibitor Navitoclax (ABT-263), which was highly effective in decreasing cell viability and inducing apoptotic cell death in wogonin-induced senescent cells. Thus, the "one-two punch" approach increased the sensibility of T-cell malignancies with low expression of BCL-2 to Navitoclax. In conclusion, our research revealed that wogonin possesses potential antitumor effects based on senescence induction, offering a better insight into the development of novel therapeutic methods for T-cell malignancies.

Mouse Rad1 deletion enhances susceptibility for skin tumor development.

BACKGROUND: Cells are constantly exposed to stresses from cellular metabolites as well as environmental genotoxins. DNA damage caused by these genotoxins can be efficiently fixed by DNA repair in cooperation with cell cycle checkpoints. Unrepaired DNA lesions can lead to cell death, gene mutation and cancer. The Rad1 protein, evolutionarily conserved from yeast to humans, exists in cells as monomer as well as a component in the 9-1-1 protein complex. Rad1 plays crucial roles in DNA repair and cell cycle checkpoint control, but its contribution to carcinogenesis is unknown. RESULTS: To address this question, we constructed mice with a deletion of Mrad1. Matings between heterozygous Mrad1 mutant mice produced Mrad1+/+ and Mrad1+/- but no Mrad1-/- progeny, suggesting the Mrad1 null is embryonic lethal. Mrad1+/- mice demonstrated no overt abnormalities up to one and half years of age. DMBA-TPA combinational treatment was used to induce tumors on mouse skin. Tumors were larger, more numerous, and appeared earlier on the skin of Mrad1+/- mice compared to Mrad1+/+ animals. Keratinocytes isolated from Mrad1+/- mice had significantly more spontaneous DNA double strand breaks, proliferated slower and had slightly enhanced spontaneous apoptosis than Mrad1+/+ control cells. CONCLUSION: These data suggest that Mrad1 is important for preventing tumor development, probably through maintaining genomic integrity. The effects of heterozygous deletion of Mrad1 on proliferation and apoptosis of keratinocytes is different from those resulted from Mrad9 heterozygous deletion (from our previous study), suggesting that Mrad1 also functions independent of Mrad9 besides its role in the Mrad9-Mrad1-Mhus1 complex in mouse cells.

Cyclin A2 is essential for mouse gonocyte maturation.

In mammals, male gonocytes are derived from primordial germ cells during embryogenesis, enter a period of mitotic proliferation, and then become quiescent until birth. After birth, the gonocytes proliferate and migrate from the center of testicular cord toward the basement membrane to form the pool of spermatogonial stem cells (SSCs) and establish the SSC niche architecture. However, the molecular mechanisms underlying gonocyte proliferation, migration and differentiation are largely unknown. Cyclin A2 is a key component of the cell cycle and required for cell proliferation. Here, we show that cyclin A2 is required in mouse male gonocyte development and the establishment of spermatogenesis in the neonatal testis. Loss of cyclin A2 function in embryonic gonocytes by targeted gene disruption affected the regulation of the male gonocytes to SSC transition, resulting in the disruption of SSC pool formation, imbalance between SSC self-renewal and differentiation, and severely abnormal spermatogenesis in the adult testis.

Influence of Electrostatic Field on the Quality Attributes and Volatile Flavor Compounds of Dry-Cured Beef during Chill Storage.

The purpose was to investigate the quality characteristics of dry-cured beef with different storage times under a high-voltage electrostatic field (HVEF) condition. The pH, moisture content, meat color, and volatile compounds of dry-cured beef samples treated with HVEF (3 kV) were compared with those of a common refrigerator (CON) at days 0, 3, 7, 10, and 14. The results showed that, compared with CON group, the decline rates of the pH and moisture content of beef and ∆E values were lower under HVEF storage condition. From the fingerprints, the 42 volatile compounds identified were mainly aldehydes, alcohols, ketones, and esters. The benzaldehyde, trimethyl pyrazine, and maltol contents in the HVEF group exhibited a dramatic increase after 10 days of storage. Principal component analysis revealed clustering of compound classes, distributed in a separate time. Based on the above findings, we concluded that HVEF treatment could promote color stability and enhance characteristic flavor during the storage of dry-cured beef. These results suggested that HVEF might be applicable for dry-cured meat storage techniques.

Natural HDAC-1/8 inhibitor baicalein exerts therapeutic effect in CBF-AML.

BACKGROUND: Although targeting histone deacetylases (HDACs) may be an effective strategy for core binding factor-acute myeloid leukemia (CBF-AML) harboring t(8;21) or inv(16), HDAC inhibitors are reported to be limited by drug-resistant characteristic. Our purpose is to evaluate the anti-leukemia effects of Baicalein on CBF-AML and clarify its underlying mechanism. METHODS: Enzyme activity assay was used to measure the activity inhibition of HDACs. Rhodamine123 and RT-qPCR were employed to evaluate the distribution of drugs and the change of ATP-binding cassette (ABC) transporter genes. CCK8, Annexin V/PI, and FACS staining certified the effects of Baicalein on cell growth, apoptosis, and differentiation. Duolink and IP assay assessed the interaction between HDAC-1 and ubiquitin, HSP90 and AML1-ETO, and Ac-p53 and CBFß-MYH11. AML cell lines and primary AML cells-bearing NOD/SCID mice models were used to evaluate the anti-leukemic efficiency and potential mechanism of Baicalein in vivo. RESULTS: Baicalein showed HDAC-1/8 inhibition to trigger growth suppression and differentiation induction of AML cell lines and primary AML cells. Although the inhibitory action on HDAC-1 was mild, Baicalein could induce the degradation of HDAC-1 via ubiquitin proteasome pathway, thereby upregulating the acetylation of Histone H3 without promoting ABC transporter genes expression. Meanwhile, Baicalein increased the acetylation of HSP90 and lessened its connection to AML1/ETO, consequently leading to degradation of AML1-ETO in t(8;21)q(22;22) AML cells. In inv(16) AML cells, Baicalein possessed the capacity of apoptosis induction accompanied with p53-mediated apoptosis genes expression. Moreover, CBFß-MYH11-bound p53 acetylation was restored via HDAC-8 inhibition induced by Baicalein contributing the diminishing of survival of CD34+  inv(16) AML cells. CONCLUSIONS: These findings improved the understanding of the epigenetic regulation of Baicalein, and warrant therapeutic potential of Baicalein for CBF-AML.

Involvement of p53 Acetylation in Growth Suppression of Cutaneous T-Cell Lymphomas Induced by HDAC Inhibition.

Cutaneous T-cell lymphomas (CTCLs) represent a rare form of non-Hodgkin lymphomas characterized by an accumulation of malignant CD4+ T cells in the skin. TP53 genetic alteration is one of the most prevalent genetic abnormalities in CTCLs. Therefore, it is a promising target for innovative therapeutic approaches. We found that p53 could physically interact with histone deacetylase (HDAC) 1 and HDAC8, and was subsequently deacetylated to lose its function in CTCL cells, and the p53 downstream apoptosis-associated genes were repressed. Thus, the anti-CTCL activity displayed by HDAC inhibitors depends on p53 status. However, recent studies have reported that HDAC inhibitors could induce a wide variety of drug-resistant characteristics in cancer cells by regulating ATP-binding cassette transporters. Moreover, we discovered that Baicalein, a natural product, exhibited an inhibitory effect on HDAC1 and HDAC8. Though the inhibition of HDAC1 was mild, Baicalein could induce the degradation of HDAC1 through the ubiquitin proteasome pathway, thereby markedly upregulating the acetylation of histone H3 without promoting ATP-binding cassette transporter gene expression. In terms of the mechanism, Baicalein showed better growth inhibition than traditional HDAC inhibitors in CTCLs. This study indicates a special mechanism of HDAC1 and HDAC8 and p53 in T-cell lymphoma cells and identifies a potential and safe natural HDAC inhibitor for the treatment of CTCLs.

Evidence of stress imprinting with population-level differences in two moss species.

Plants are often repeatedly exposed to stresses during their lives and have a mechanism called stress imprinting that provides "memories" of stresses they experience and increases their ability to cope with later stresses. To test hypotheses that primed bryophytes can preserve their stress imprinting after 6 days of recovery and induce higher levels of osmolytes and ROS-scavenging activities upon later stress exposure, and there exist population-level differentiation in their desiccation defenses, we transplanted samples of two populations of each of two moss species, Hypnum plumaeforme and Pogonatum cirratum, in a nature reserve in southern China. After 16 months of acclimation, sets of each population were subjected to control, one-time desiccation stress, duplicated desiccation stress and cross-stress (low temperature stress followed by desiccation stress) treatments. Levels of oxidant enzymes, osmolytes, and phytohormones in the samples were then determined. The desiccation stress generally led to increases in activities or contents of superoxide dismutase, guaiacol peroxidase, catalase, proline, soluble sugars, soluble proteins, and stress hormones including abscisic acid (ABA), jasmonates (JA), and salicylic acid (SA), with differences between both species and populations. After a 6-day recovery period, contents of phytohormones (including ABA, JA, SA, and cytokinins) in stressed H. plumaeforme had substantially fallen toward control levels. The duplicated and cross-stress treatments generally led to further accumulation of proline, soluble sugars, and soluble proteins, with further increases in activities of antioxidant enzymes in some cases. Furthermore, significant differences between allochthonous and native populations were found in contents of malondialdehyde and osmolytes, as well as antioxidant enzyme activities. Our results confirm the hypotheses and highlight the importance of osmolytes in mosses' stress responses.