Dihydrocelastrol induces antitumor activity and enhances the sensitivity of bortezomib in resistant multiple myeloma by inhibiting STAT3-dependent PSMB5 regulation.

Multiple myeloma (MM) is characterized by excessive aggregation of B-cell-derived malignant plasma cells in the hematopoietic system of bone marrow. Previously, we synthesized an innovative molecule named dihydrocelastrol (DHCE) from celastrol, a triterpene purified from medicinal plant Tripterygium wilfordii. Herein, we explore the therapeutic properties and latent signal transduction mechanism of DHCE action in bortezomib (BTZ)-resistant (BTZ-R) MM cells. In this study, we first report that DHCE shows antitumor activities in vitro and in vivo and exerts stronger inhibitory effects than celastrol on BTZ-R cells. We find that DHCE inhibits BTZ-R cell viability by promoting apoptosis via extrinsic and intrinsic pathways and suppresses BTZ-R MM cell proliferation by inducing G0/G1 phase cell cycle arrest. In addition, inactivation of JAK2/STAT3 and PI3K/Akt pathways are involved in the DHCE-mediated antitumor effect. Simultaneously, DHCE acts synergistically with BTZ on BTZ-R cells. PSMB5, a molecular target of BTZ, is overexpressed in BTZ-R MM cells compared with BTZ-S MM cells and is demonstrated to be a target of STAT3. Moreover, DHCE downregulates PSMB5 overexpression in BTZ-R MM cells, which illustrates that DHCE overcomes BTZ resistance through increasing the sensitivity of BTZ in resistant MM via inhibiting STAT3-dependent PSMB5 regulation. Overall, our findings imply that DHCE may become a potential therapeutic option that warrants clinical evaluation for BTZ-R MM.

Supplementation of EGF, IGF-1, and Connexin 37 in IVM Medium Significantly Improved the Maturation of Bovine Oocytes and Vitrification of Their IVF Blastocysts.

The quality and developmental capacity of oocytes derived from in vitro maturation (IVM) remain unsatisfactory, which greatly impairs the efficiency and application of embryo technologies. The present experiment was designed to investigate the effect of the supplementation of EGF, IGF-1, and Cx37 in an IVM medium on the maturation quality and development ability of bovine oocytes. The cytoplasmic maturation events of oocytes and the quality of in vitro fertilization (IVF) blastocysts were examined to investigate the relative mechanisms. Our results showed that the nuclear maturation and blastocyst development after the IVF of oocytes treated with 25 µg/mL Cx37 or the combination of 50 ng/mL EGF and 100 ng/mL IGF-1 were significantly increased compared to those of the control group (p < 0.05). Furthermore, the blastocyst rate, and blastocyst total cell number and survival rate after vitrification of the EGF+IGF-1+Cx37 group, were significantly higher than those of the control group (p < 0.05), but lower than those of the FSH+LH+EGF+IGF-1+Cx37 group (p < 0.05). The transzonal projection (TZP) intensity, glutathione (GSH) level, and mitochondrial function of the EGF+IGF-1+Cx37 group were significantly higher than that of the control group, and lower than those of the FSH+LH+EGF+IGF-1+Cx37 group, in contrast to the results of the reactive oxygen species (ROS) levels. In conclusion, our results showed that the supplementation of 50 ng/mL EGF, 100 ng/mL IGF-1, and 25 µg/mL Cx37 in the IVM of bovine oocytes significantly improved their quality and developmental ability by increasing the TZP, mitochondrial function, and GSH level.

HYAL4-V1/Chondroitinase (Chase) Drives Gemcitabine Resistance and Predicts Chemotherapy Failure in Patients with Bladder Cancer.

PURPOSE: Gemcitabine-based chemotherapy regimens are first-line for several advanced cancers. Because of better tolerability, gemcitabine + cisplatin is a preferred neoadjuvant, adjuvant, and/or palliative chemotherapy regimen for advanced bladder cancer. Nevertheless, predicting treatment failure and overcoming resistance remain unmet clinical needs. We discovered that splice variant (V1) of HYAL-4 is a first-in-class eukaryotic chondroitinase (Chase), and CD44 is its major substrate. V1 is upregulated in bladder cancer and drives a malignant phenotype. In this study, we investigated whether V1 drives chemotherapy resistance. EXPERIMENTAL DESIGN: V1 expression was measured in muscle-invasive bladder cancer (MIBC) specimens by qRT-PCR and IHC. HYAL-4 wild-type (Wt) and V1 were stably expressed or silenced in normal urothelial and three bladder cancer cell lines. Transfectants were analyzed for chemoresistance and associated mechanism in preclinical models. RESULTS: V1 levels in MIBC specimens of patients who developed metastasis, predicted response to gemcitabine + cisplatin adjuvant/salvage treatment and disease-specific mortality. V1-expressing bladder cells were resistant to gemcitabine but not to cisplatin. V1 expression neither affected gemcitabine influx nor the drug-efflux transporters. Instead, V1 increased gemcitabine metabolism and subsequent efflux of difluorodeoxyuridine, by upregulating cytidine deaminase (CDA) expression through increased CD44-JAK2/STAT3 signaling. CDA inhibitor tetrahydrouridine resensitized V1-expressing cells to gemcitabine. While gemcitabine (25-50 mg/kg) inhibited bladder cancer xenograft growth, V1-expressing tumors were resistant. Low-dose combination of gemcitabine and tetrahydrouridine abrogated the growth of V1 tumors with minimal toxicity. CONCLUSIONS: V1/Chase drives gemcitabine resistance and potentially predicts gemcitabine + cisplatin failure. CDA inhibition resensitizes V1-expressing tumors to gemcitabine. Because several chemotherapy regimens include gemcitabine, our study could have broad significance.

Protective effect of vitamin C and lycopene on the in vitro fertilization capacity of sex-sorted bull sperm by inhibiting the oxidative stress.

The fertilization capacity of sex-sorted sperms is seriously decreased, which inhibits its wide application. However, little information is still available about the effect of vitamin C (VC) and lycopene (Lyc) on the fertilization capacity of sex-sorted bull sperm. In this study, the washing medium and fertilization medium of sex-sorted sperm from three bull individuals were supplemented with different concentrations of VC (0, 1 × 10-3 , 1 × 10-4 , 1 × 10-5 , 1 × 10-6  M) or Lyc (0, 1 × 10-4 , 1 × 10-5 , 1 × 10-6 , 1 × 10-7 ). After washing twice and incubation for 1.5 hr, the malondialdehyde (MDA) level, phosphatidylserine (PS) translocation, membrane potential (Δψm) and IVF (in vitro fertilization) ability of sex-sorted sperm were investigated. For the sex-sorted sperm of bulls A, B and C, 1 × 10-3  M VC or 1 × 10-4  M Lyc treatment significantly decreased their MDA levels and PS translocation and increased their Δψm levels and cleavage rates after IVF. When blastocysts were concerned, 1 × 10-4  M Lyc significantly improved the blastocyst rates and their IFN-tau expression of bulls A and C. In conclusion, supplementation of 1 × 10-3  M VC or 1 × 10-4  M Lyc in washing and fertilization medium contributed greatly to improving the fertilization capacity of sex-sorted bull sperm during IVF procedure.

Melatonin Improves the Fertilization Capacity of Sex-Sorted Bull Sperm by Inhibiting Apoptosis and Increasing Fertilization Capacitation via MT1.

Little information is available regarding the effect of melatonin on the quality and fertilization capability of sex-sorted bull sperm, and even less about the associated mechanism. Sex-sorted sperm from three individual bulls were washed twice in wash medium and incubated in a fertilization medium for 1.5 h, and each was supplemented with melatonin (0, 10-3 M, 10-5 M, 10-7 M, and 10-9 M). The reactive oxygen species (ROS) and endogenous antioxidant activity (glutathione peroxidase (GPx); superoxide dismutase (SOD); catalase (CAT)), apoptosis (phosphatidylserine [PS] externalization; mitochondrial membrane potential (Δψm)), acrosomal integrity events (malondialdehyde (MDA) level; acrosomal integrity), capacitation (calcium ion [Ca2+]i level; cyclic adenosine monophosphate (cAMP); capacitation level), and fertilization ability of the sperm were assessed. Melatonin receptor 1 (MT1) and 2 (MT2) expression were examined to investigate the involvement of melatonin receptors on sex-sorted bull sperm capacitation. Our results show that treatment with 10-5 M melatonin significantly decreased the ROS level and increased the GPx, SOD, and CAT activities of sex-sorted bull sperm, which inhibited PS externalization and MDA levels, and improved Δψm, acrosomal integrity, and fertilization ability. Further experiments showed that melatonin regulates sperm capacitation via MT1. These findings contribute to improving the fertilization capacity of sex-sorted bull sperm and exploring the associated mechanism.

Resveratrol significantly improves the fertilisation capacity of bovine sex-sorted semen by inhibiting apoptosis and lipid peroxidation.

The aim of this study was to test the effects of five different concentrations (0, 10-3, 10-4, 10-5, and 10-6 M) of resveratrol (Res) supplementation in bull sperm washing and fertilisation medium on levels of reactive oxygen species (ROS), phosphatidylserine (PS) externalisation, mitochondrial membrane potential (Δψm), ATP and malondialdehyde (MDA), acrosomal integrity, blastocyst rate, and blastocyst quality after in vitro fertilisation (IVF). The results for sex-sorted sperm from three bulls showed: (1) ROS and MDA levels in 10-3 M and 10-4 M Res groups were significantly lower than those of controls (P < 0.05); (2) the percentage of viable sperm, percentage of sperm with high Δψm, and the ATP content in 10-3 M and 10-4 M Res groups were significantly higher than those of controls (P < 0.05); (3) the percentage of viable sperm with acrosomal integrity, and the blastocyst percentage and quality of the 10-4 M Res group were significantly higher than those of controls (P < 0.05). In conclusion, 10-4 M Res supplementation in washing and fertilisation medium of sex-sorted bull sperm significantly decreased ROS, PS externalisation, and MDA, and protected mitochondrial function and acrosomal integrity, thereby increasing blastocyst percentage and quality following IVF.

Protective effects of melatonin on the in vitro developmental competence of bovine oocytes.

The present study investigated the effects of melatonin on bovine oocyte maturation and subsequent embryonic development in vitro. Results showed that the nuclear and cytoplasmic maturation, characterized by first polar body extrusion, normal distribution of cortical granules and mitochondria, as well as increased mitochondrial membrane potential, were significantly improved in 10-9  mol/L melatonin-treated oocytes. Melatonin supplementation reduced intracellular reactive oxygen species level and enhanced glutathione production. Meanwhile, the presence of melatonin (10-9  mol/L) during oocyte maturation resulted in a decreased early apoptotic rate in oocytes. After in vitro fertilization, oocytes receiving melatonin supplementation exhibited a significantly higher blastocyst formation rate and yielded a markedly lower number of apoptotic cells. Mechanistic explorations showed that addition of 10-9  mol/L melatonin to in vitro maturation media significantly attenuated the transcript level of caspase-3, while the expressions of BCL-2, XIAP, CAT and HSP70 were significantly reinforced in the resultant embryos. Taken together, melatonin ameliorates bovine oocyte maturation potential, and the beneficial effects can affect subsequent embryonic development. The protective role of melatonin may be due to its anti-apoptotic and anti-oxidative activities.

Melatonin improves the fertilization capacity and developmental ability of bovine oocytes by regulating cytoplasmic maturation events.

Melatonin is a well-characterized antioxidant that has been successfully used to protect oocytes from reactive oxygen species during in vitro maturation (IVM), resulting in improved fertilization capacity and development ability. However, the mechanism via which melatonin improves oocyte fertilization capacity and development ability remains to be determined. Here, we studied the effects of melatonin on cytoplasmic maturation of bovine oocytes. In the present study, bovine oocytes were cultured in IVM medium supplemented with 0, 10-7 , 10-9 , and 10-11  mol/L melatonin, and the cytoplasmic maturation parameters of MII oocytes after IVM were investigated, including redistribution of organelles (mitochondria, cortical granules [CGs], and endoplasmic reticulum [ER]), intracellular glutathione (GSH) and ATP levels, expression of endogenous antioxidant genes (Cat, Sod1, and GPx), and fertilization-related events (IP3R1 distribution and expression of CD9 and Juno). Our results showed that melatonin significantly improved the cytoplasmic maturation of bovine oocytes by improving the normal distribution of organelles, increasing intracellular GSH and ATP levels, enhancing antioxidant gene expression levels, and modulating fertilization-related events, all of which resulted in increased fertilization capacity and developmental ability. Meanwhile, melatonin also increased the mRNA and protein expression levels of the Tet1 gene and decreased the Dnmt1 gene mRNA and protein levels in bovine oocytes, indicating that melatonin regulates the expression of the detected genes via demethylation. These findings shed insights into the potential mechanisms by which melatonin improves oocyte quality during IVM.

Calcium ion regulation by BAPTA-AM and ruthenium red improved the fertilisation capacity and developmental ability of vitrified bovine oocytes.

Vitrification reduces the fertilisation capacity and developmental ability of mammalian oocytes; this effect is closely associated with an abnormal increase of cytoplasmic free calcium ions ([Ca2+]i). However, little information about the mechanism by which vitrification increases [Ca2+]i levels or a procedure to regulate [Ca2+]i levels in these oocytes is available. Vitrified bovine oocytes were used to analyse the effect of vitrification on [Ca2+]i, endoplasmic reticulum Ca2+ (ER Ca2+), and mitochondrial Ca2+ (mCa2+) levels. Our results showed that vitrification, especially with dimethyl sulfoxide (DMSO), can induce ER Ca2+ release into the cytoplasm, consequently increasing the [Ca2+]i and mCa2+ levels. Supplementing the cells with 10 µM 1,2-bis (o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM or BAPTA) significantly decreased the [Ca2+]i level and maintained the normal distribution of cortical granules in the vitrified bovine oocytes, increasing their fertilisation ability and cleavage rate after in vitro fertilisation (IVF). Treating vitrified bovine oocytes with 1 µM ruthenium red (RR) significantly inhibited the Ca2+ flux from the cytoplasm into mitochondria; maintained normal mCa2+ levels, mitochondrial membrane potential, and ATP content; and inhibited apoptosis. Treating vitrified oocytes with a combination of BAPTA and RR significantly improved embryo development and quality after IVF.

Melatonin inhibits apoptosis and improves the developmental potential of vitrified bovine oocytes.

Vitrification of oocytes has been shown to be closely associated with increased levels of reactive oxygen species (ROS) and apoptotic events. However, little information is available the effect of melatonin on the ROS levels and apoptotic events in vitrified oocytes. Therefore, we studied the effect of melatonin on ROS and apoptotic events in vitrified bovine oocytes by supplementing vitrification solution or in vitro maturation (IVM) and vitrification solution with 10(-9) m melatonin. We analyzed the ROS, mitochondrial Ca(2+) (mCa(2+) ) and membrane potential (ΔΨm), externalization of phosphatidylserine (PS), caspase-3 activation, DNA fragmentation, mRNA expression levels of Bax and Bcl2 l1, and developmental potential of vitrified bovine oocytes. Vitrified bovine oocytes exhibited increased levels of ROS, mCa(2+) , Bax mRNA, and caspase-3 protein and higher rates of PS externalization and DNA fragmentation, and decreased ΔΨm and Bcl2 l1 mRNA expression level. However, melatonin supplementation in vitrification solution or IVM and vitrification solution significantly decreased the levels of ROS, mCa(2+) , Bax mRNA expression, and caspase-3 protein, and PS externalization and DNA fragmentation rates, and increased the ΔΨm and Bcl2 l1 mRNA expression level in vitrified oocytes, resulting in an increased developmental ability of vitrified bovine oocytes after parthenogenetic activation. The developmental ability of vitrified oocytes with melatonin supplementation in IVM and vitrification solution was similar to that of fresh ones. This study showed that supplementing the IVM and vitrification medium or vitrification medium with 10(-9) m melatonin significantly decreased the ROS level and inhibited apoptotic events of vitrified bovine oocytes, consequently increasing their developmental potential.

Effect of 5-aza-2'-deoxycytidine on methylation of the putative imprinted control region of H19 during the in vitro development of vitrified bovine two-cell embryos.

OBJECTIVE: To determine the effect of vitrification and 5-aza-2'-deoxycytidine (5-aza-dC) on the methylation levels of the putative imprinted control region (ICR) of H19 and H19 expression in bovine two-cell embryos and their derived blastocysts. DESIGN: Experimental animal study. SETTING: Academic institution. ANIMAL(S): Abattoir-derived bovine ovaries. INTERVENTION(S): Vitrified two-cell embryos were cultured in vitro to blastocysts with 0.01 µM 5-aza-dC (5-aza-dC group) or without 5-aza-dC (vitrification group). Fresh embryos and their derived blastocysts were used as control. MAIN OUTCOME MEASURE(S): Putative ICR methylation of H19 was measured by bisulfate mutagenesis and sequencing, blastocyst development rate; total cell number were determined; and H19 expression was measured by real-time reverse transcriptase-polymerase chain reaction (PCR). RESULT(S): Vitrification significantly increased putative ICR methylation of H19 in two-cell embryos and their derived blastocysts; 5-aza-dC significantly reduced putative ICR methylation of H19 in vitrified two-cell embryos and their derived blastocysts. The H19 expression level was significantly higher in blastocysts from the 5-aza-dC group than the vitrification group. The blastocyst development rate and total cell number in the 5-aza-dC and vitrification groups were similar. CONCLUSION(S): Putative ICR methylation levels of H19 significantly increased in vitrified two-cell embryos and their derived blastocysts; 5-aza-dC significantly reduced putative ICR methylation of H19 and increased H19 expression in blastocysts derived from vitrified two-cell embryos.