New insights into the reverse of chromium-induced reprotoxicity of pregnant mice by melatonin.

Hexavalent chromium Cr(VI) is a well-known environmental toxic metal that causes reprotoxicity in pregnant females. There are currently no appropriate interventions or treatments for Cr(VI) exposure during pregnancy. Herein, the protective effect of melatonin (MLT) against Cr(VI)-induced reprotoxicity is investigated by administrating MLT to pregnant mice exposed to Cr(VI). The results indicate that MLT effectively alleviates Cr(VI)-induced adverse pregnancy outcomes, restoring the decreased fetal weight and increased fetal resorption and malformation caused by Cr(VI) exposure to normal levels. MLT reduces the negative effects of Cr(VI) on follicular atresia and the development of primordial follicle in the maternal ovarian, thereby mitigating the decline in the reserve of primordial follicles. MLT alleviates Cr(VI)-induced oxidative stress, hence reducing the excessive accumulation of malondialdehyde in the maternal ovary. MLT inhibits Cr(VI)-induced apoptosis of ovarian granulosa cells and the expression of cleaved caspase-3 in the ovary. MLT reduces the increase in serum follicle-stimulating hormone caused by Cr(VI) exposure, while elevating anti-Mullerian hormone levels. We demonstrate that MLT reverses Cr(VI)-induced reprotoxicity in pregnant mice, opening up a new avenue for treating reproductive defects caused by environmental stress.

Polyphenol Oxidase as a Promising Alternative Therapeutic Agent for Cancer Therapy.

Cancers have always been the most difficult to fight, the treatment of cancer is still not considered. Thus, exploring new anticancer drugs is still imminent. Traditional Chinese medicine has played an important role in the treatment of cancer. Polyphenol oxidase (PPO) extracted from Edible mushroom has many related reports on its characteristics, but its role in cancer treatment is still unclear. This study aims to investigate the effects of PPO extracted from Edible mushroom on the proliferation, migration, invasion, and apoptosis of cancer cells in vitro and explore the therapeutic effects of PPO on tumors in vivo. A cell counting kit-8 (CCK8) assay was used to detect the effect of PPO on the proliferation of cancer cells. The effect of PPO on cancer cell migration ability was detected by scratch test. The effect of PPO on the invasion ability of cancer cells was detected by a transwell assay. The effect of PPO on the apoptosis of cancer cells was detected by flow cytometry. Female BALB/c mice (18-25 g, 6-8 weeks) were used for in vivo experiments. The experiments were divided into control group, model group, low-dose group (25 mg/kg), and high-dose group (50 mg/kg). In vitro, PPO extracted from Edible mushroom significantly inhibited the proliferation, migration, and invasion capability of breast cancer cell 4T1, lung cancer cell A549, and prostate cancer cell C4-2, and significantly promoted the apoptosis of 4T1, A549, and C4-2. In vivo experiments showed PPO inhibitory effect on tumor growth. Collectively, the edible fungus extract PPO could play an effective role in treating various cancers, and it may potentially be a promising agent for treating cancers.

REGγ regulates hair cycle by activating Lgr5 positive hair follicle stem cells.

BACKGROUND: REGγ acts as a proteasome activating factor mediating proteasome degradation of substrate proteins in an ATP and ubiquitination independent manner and also as an important regulator of cell cycle, proliferation and apoptosis. Hair cycle involves dynamic, continuous morphological changes of three stages (anagen, catagen and telogen). OBJECTIVE: The function of REGγ in hair cycling is still unclear. METHODS: Here, we used REGγ knockout 293 T cells, inducible 293WT and 293N151Y cell, REGγ knockout mice to identify the novel molecular mechanism of REGγ in regulating hair follicle stem cells. RESULTS: In the present study, we found that REGγ deletion markedly delayed the transition of hair follicles from telogen to anagen and hair regeneration in mice. We also observed significant decrease of hair follicle stem cell number, stem-like property and proliferation ability. Interestingly, the results from real-time PCR, FACS, Western Blot and immunofluorescent analysis showed that REGγ deletion could greatly downregulate Lgr5 expression in the hair follicles. Meanwhile, REGγ was demonstrated to directly interact with LHX2 and promotes its degradation. Importantly, REGγ specific deletion in Lgr5+ stem cells induced the marked delay of hair regeneration after depilation. CONCLUSION: These data together indicate that REGγ was a new mediator of Lgr5 expression in hair follicle at least partly by promoting the degradation of its suppressive transcription factor LHX2. It seemed that REGγ regulated hair anagen entry and hair regrowth by activating Lgr5 positive hair follicle stem cells.

REGγ ablation impedes dedifferentiation of anaplastic thyroid carcinoma and accentuates radio-therapeutic response by regulating the Smad7-TGF-ß pathway.

Anaplastic thyroid cancer (ATC) is the most aggressive human thyroid malignancy, characterized by dedifferentiation and resistance to radioiodine therapy. The underlying mechanisms regulating ATC dedifferentiation are largely unknown. Here, we show that REGγ, a noncanonical proteasome activator highly expressed in ATC, is an important regulator of differentiation in ATC cells. Ablation of REGγ significantly restored expression of thyroid-specific genes, enhanced iodine uptake, and improved the efficacy of 131I therapy in ATC xenograft models. Mechanistically, REGγ directly binds to the TGF-ß signaling antagonist Smad7 and promotes its degradation, leading to the activation of the TGF-ß signal pathway. With gain- and loss-of-function studies, we demonstrate that Smad7 is an important mediator for the REGγ function in ATC cell dedifferentiation, which is supported by expression profiles in human ATC tissues. It seems that REGγ impinges on repression of thyroid-specific genes and promotion of tumor malignancy in ATC cells by activating the TGF-ß signal pathway via degradation of Smad7. Thus, REGγ may serve as a novel therapeutic target for allowing radioiodine therapy in anaplastic thyroid cancer patients with poor prognosis.

Mycophenolic Acid Synergizing with Lipopolysaccharide to Induce Interleukin-1ß Release via Activation of Caspase-1.

BACKGROUND: The previous study showed that mycophenolic acid (MPA) synergizing with lipopolysaccharide (LPS) promoted interleukin (IL)-1ß release, but the mechanism is unclear. This study aimed to investigate the mechanism of MPA synergizing with LPS to induce IL-1ß release. METHODS: Undiluted human blood cells, THP-1 human myeloid leukemia mononuclear cells (THP-1) cells, or monocytes were stimulated with LPS and treated with or without MPA, and the supernatant IL-1ß was detected by enzyme-linked immunosorbent assay. The mRNA levels of IL-1ß were detected by real-time quantitative polymerase chain reaction. The intracellular protein levels of nuclear factor kappa B (NF-κB) phospho-p65 (p-p65), precursor interleukin-1ß (pro-IL-1ß), NOD-like receptor pyrin domain containing-3 (NLRP3), and cysteine aspartic acid-specific protease-1 (caspase-1) p20 in THP-1 cell were measured by Western blot. RESULTS: The MPA alone failed to induce IL-1ß, whereas MPA synergized with LPS to increase IL-1ß in a dose-dependent manner (685.00 ± 20.00 pg/ml in LPS + 5 µmol/L MPA group, P = 0.035; 742.00 ± 31.58 pg/ml in LPS + 25 µmol/L MPA group, P = 0.017; 1000.00 ± 65.59 pg/ml in LPS + 75 µmol/L MPA group, P = 0.024; versus 408.00 ± 35.50 pg/ml in LPS group). MPA alone has no effect on the IL-1ß mRNA expression, LPS induced the expression of IL-1ß mRNA 2761 fold, and LPS + MPA increased the IL-1ß expression 3018 fold, which had the same effect with LPS group (P = 0.834). MPA did not affect the intracellular NF-κB p-p65 and pro-IL-1ß protein levels but activated NLRP3 inflammasome. Ac-YVAD-cmk blocked the activation of caspase-1 and subsequently attenuated IL-1ß secretion (181.00 ± 45.24 pg/ml in LPS + MPA + YVAD group vs. 588.00 ± 41.99 pg/ml in LPS + MPA group, P = 0.014). CONCLUSIONS: Taken together, MPA synergized with LPS to induce IL-1ß release via the activation of caspase-1, rather than the enhanced production of pro-IL-1ß. These findings suggested that patients immunosuppressed with mycophenolate mofetil may have overly activated caspase-1 during infection, which might contribute to a more sensitive host defense response to invading germs.

REGγ Controls Hippo Signaling and Reciprocal NF-κB-YAP Regulation to Promote Colon Cancer.

Purpose: Colorectal cancer is one of the most commonly diagnosed cancers closely associated with inflammation and hyperactive growth. We previously demonstrated a regulatory circuit between the proteasome activator REGγ and NF-kappaB (NF-κB) during colon inflammation, known to be important in the development of colitis-associated cancer as well as sporadic colorectal cancer. How the inflammatory microenvironment affects the Hippo pathway during colorectal cancer development is largely unknown.Experimental Design: Here, we used REGγ-deficient colon cancer cell lines, REGγ knockout mice, and human colorectal cancer samples to identify the novel molecular mechanism by which REGγ functions as an oncoprotein in the development of colorectal cancer.Results: REGγ can directly interact with Lats1 and promote its degradation, which facilitates Yes-associated protein (YAP) activation in colon cancer cells. REGγ deficiency significantly attenuated colon cancer growth, associated with decreased YAP activity. Suppression of tumor growth due to REGγ depletion was overcome by constitutively active YAP. Surprisingly, reciprocal activation of the YAP and NF-κB pathways was observed in human colon cancer cells. REGγ overexpression was found in over 60% of 172 colorectal cancer specimens, highly correlating with the elevation of YAP and p65. Postoperative follow-up revealed a significantly lower survival rate in patients with concomitantly high expression of REGγ, YAP, and p-p65.Conclusions: REGγ could be a master regulator during colorectal cancer development to promote YAP signaling and reinforce cross-talks between inflammation and growth pathways, and REGγ might be a new marker for prognosis of colorectal cancer patients. Clin Cancer Res; 24(8); 2015-25. ©2018 AACR.

Mycophenolic Acid Synergizing with Lipopolysaccharide to Induce Interleukin-1β Release via Activation of Caspase-1 / 中华医学杂志(英文版)

<p><b>Background</b>The previous study showed that mycophenolic acid (MPA) synergizing with lipopolysaccharide (LPS) promoted interleukin (IL)-1β release, but the mechanism is unclear. This study aimed to investigate the mechanism of MPA synergizing with LPS to induce IL-1β release.</p><p><b>Methods</b>Undiluted human blood cells, THP-1 human myeloid leukemia mononuclear cells (THP-1) cells, or monocytes were stimulated with LPS and treated with or without MPA, and the supernatant IL-1β was detected by enzyme-linked immunosorbent assay. The mRNA levels of IL-1β were detected by real-time quantitative polymerase chain reaction. The intracellular protein levels of nuclear factor kappa B (NF-κB) phospho-p65 (p-p65), precursor interleukin-1β (pro-IL-1β), NOD-like receptor pyrin domain containing-3 (NLRP3), and cysteine aspartic acid-specific protease-1 (caspase-1) p20 in THP-1 cell were measured by Western blot.</p><p><b>Results</b>The MPA alone failed to induce IL-1β, whereas MPA synergized with LPS to increase IL-1β in a dose-dependent manner (685.00 ± 20.00 pg/ml in LPS + 5 μmol/L MPA group, P = 0.035; 742.00 ± 31.58 pg/ml in LPS + 25 μmol/L MPA group, P = 0.017; 1000.00 ± 65.59 pg/ml in LPS + 75 μmol/L MPA group, P = 0.024; versus 408.00 ± 35.50 pg/ml in LPS group). MPA alone has no effect on the IL-1β mRNA expression, LPS induced the expression of IL-1β mRNA 2761 fold, and LPS + MPA increased the IL-1β expression 3018 fold, which had the same effect with LPS group (P = 0.834). MPA did not affect the intracellular NF-κB p-p65 and pro-IL-1β protein levels but activated NLRP3 inflammasome. Ac-YVAD-cmk blocked the activation of caspase-1 and subsequently attenuated IL-1β secretion (181.00 ± 45.24 pg/ml in LPS + MPA + YVAD group vs. 588.00 ± 41.99 pg/ml in LPS + MPA group, P = 0.014).</p><p><b>Conclusions</b>Taken together, MPA synergized with LPS to induce IL-1β release via the activation of caspase-1, rather than the enhanced production of pro-IL-1β. These findings suggested that patients immunosuppressed with mycophenolate mofetil may have overly activated caspase-1 during infection, which might contribute to a more sensitive host defense response to invading germs.</p>

REGγ accelerates melanoma formation by regulating Wnt/ß-catenin signalling pathway.

It has been reported that the proteasome activator REGγ is associated with multiple oncogenic pathways in human cancers. However, the role of REGγ in the development of melanoma and the underlying mechanisms remain unclear. In this study, we attempted to investigate the effects of REGγ on human melanoma cell proliferation in vitro and in vivo. We demonstrated that knockdown of REGγ inhibited melanoma cell growth and arrested melanoma cell at G1 phase. Furthermore, depletion of REGγ also inhibited the xenograft growth of human melanoma. Mechanistically, REGγ activates Wnt/ß-catenin signal pathway by degrading GSK-3ß in melanoma cell lines and mouse models. Transient knockdown of ß-catenin effectively blocked cell proliferation in REGγ wild-type melanoma cells. In human melanoma samples, REGγ was overexpressed and positively correlated with ß-catenin levels. This study demonstrates that REGγ is a central molecule in the development of melanoma by regulating Wnt/ß-catenin pathway. This suggests that targeting REGγ could be an alternative therapeutic approach for melanoma.

Hydrogen sulfide alleviates chlorobenzene toxicity in soybean seedlings / Sulfeto de hidrogênio e clorobenzeno na toxicidade da soja

ABSTRACT: As a gas signaling molecule, endogenous hydrogen sulfide (H2S) plays a crucial role in the plant stress response. However, the role of H2S in the response to organic pollutants specifically has not been studied. Here, the effects of H2S addition on soybean (Glycine max) seedlings tolerance of 1,4-dichlorobenzene (1,4-DCB) were investigated. Under 1,4-DCB stress, the growth of soybean seedlings roots and stems was inhibited, while L-/D-cysteine desulfhydrase (LCD/DCD) activity was induced and endogenous H2S increased. When applied jointly with sodium hydrosulfide (NaHS), a H2S donor, root growth inhibition was effectively alleviated. Pre-treatment of seedlings with 0.4mmol L-1 NaHS reduced the malondialdehyde (MDA) and reactived oxygen species (ROS) content, mitigating root cell toxicity significantly. Further experiments confirmed that NaHS enhanced soybean seedlings peroxidase (POD) and superoxide dismutase (SOD) enzyme activities. In contrast, these effects were reversed by hypotaurine (HT), a H2S scavenger. Therefore, H2S alleviated 1,4-DCB toxicity in soybean seedlings by regulating antioxidant enzyme activity to reduce cell oxidative damage.

RESUMO: Tal como uma molécula de sinal de gás, sulfureto de hidrogenio endógena (H2S) desempenha um papel crucial na resposta ao stress das plantas. Mas não foi relatado o papel de H2S em plantas poluentes orgânicos stress. Este estudo sobre a variação de H2S envolvido em plântulas de soja tolerância 1,4-Diclorobenzeno foi investigada. Os resultados mostraram sob o 1,4-diclorobenzeno stress, que o crescimento da soja (Glycine max) de raiz de mudas e caule foram inibidas, L- / D-cisteína desulfhydrase (LCD / DCD) atividades enzimáticas foram empossados, em seguida, H2S endógeno aumentado. Quando aplicado com hidrossulfureto de sódio (NaSH), um doador de H2S, raiz de plântulas de soja, a inibição do crescimento pode ser melhorada. Tratamentos prévios com 0,4mmol L-1 NaHS, malondialdeído (MDA) e espécies de oxigênio reactivas conteúdo (ROS) foi reduzida, em seguida, a toxicidade celular da raiz foi reduzida significativamente. Outros experimentos confirmaram que NaSH melhorou a peroxidase de plântulas de soja (POD), superóxido dismutase (SOD) atividades enzimáticas. Em contraste, estes efeitos foram revertidos por hypotaurine (HT), um eliminador de H2S. Então H2S pode aliviar toxicidade 1,4-diclorobenzeno em plântulas de soja por meio da regulamentação das atividades de enzimas antioxidantes para manter a integridade da estrutura celular.