Andrographolide promotes hippocampal neurogenesis and spatial memory in the APPswe/PS1ΔE9 mouse model of Alzheimer’s disease

In Alzheimer´s disease (AD) there is a reduction in hippocampal neurogenesis that has been associated to cognitive deficits. Previously we showed that Andrographolide (ANDRO), the main bioactive component of Andrographis paniculate, induces proliferation in the hippocampus of the APPswe/PSEN1ΔE9 (APP/PS1) mouse model of AD as assessed by staining with the mitotic marker Ki67. Here, we further characterized the effect of ANDRO on hippocampal neurogenesis in APP/PS1 mice and evaluated the contribution of this process to the cognitive effect of ANDRO. Treatment of 8-month-old APP/PS1 mice with ANDRO for 4 weeks increased proliferation in the dentate gyrus as evaluated by BrdU incorporation. Although ANDRO had no effect on neuronal differentiation of newborn cells, it strongly increased neural progenitors, neuroblasts and newborn immature neurons, cell populations that were decreased in APP/PS1 mice compared to age-matched wild-type mice. ANDRO had no effect on migration or in total dendritic length, arborization and orientation of immature neurons, suggesting no effects on early morphological development of newborn neurons. Finally, ANDRO treatment improved the performance of APP/PS1 mice in the object location memory task. This effect was not completely prevented by co-treatment with the anti-mitotic drug TMZ, suggesting that other effects of ANDRO in addition to the increase in neurogenesis might underlie the observed cognitive improvement. Altogether, our data indicate that in APP/PS1 mice ANDRO stimulates neurogenesis in the hippocampus by inducing proliferation of neural precursor cells and improves spatial memory performance.

Production Enhancement of Human Adipose-Derived Mesenchymal Stem Cells By Low-Intensity Ultrasound Stimulation

Background: Low-intensity ultrasound (LIUS) has been used to increase the proliferation rate of various stem cells including human adipose-derived mesenchymal stem cells (hAdMSCs). hAdMSCs is now commercially produced for various therapeutic applications. The purpose of this study was to show feasibility of enhancing the productivity of cell culture during 16-day cell culturing and increasing proliferation rate of hAdMSCs by LIUS stimulation with appropriate ultrasound parameters. Methods: Beam patterns of 5 and 10 MHz ultrasound transducers were measured to confirm the area of stimulation. The intensity of sound waves transmitted through a Petri-dish was measured in situ for quantitative evaluation. Bromodeoxyuridine (BrdU) incorporation assay was performed to search for appropriate parameters for LIUS stimulation of hAdMSCs. Cell culture medium supplemented with 8% fetal bovine serum (FBS) in a 35 mm Petri-dish was used for 16 days with subculture from 2 to 6 passage. Results: A frequency of 5 MHz, an intensity of 300 , a duration of 10 minutes per day, and continuous waves with 100% duty cycle were the best parameters according to the BrdU assay of proliferation rate of hAdMSCs. LIUS stimulation group had about 3.25-fold greater number of cells from passage 2 to 6 compared with the control group. Doubling time was decreased to 4.44 hours in average. Cell viability was the same between the control and LIUS stimulation groups.Conclusions: This study of enchanced proliferation rate and cell culture productivity of hAdMSCs by LIUS stimulation may lay the foundation for the application of LIUS stimulation in cell therapeutic industry by reducing the production cost and time required for cell therapy.

CC-92480 Enhances Cell-Autonomous Cytotoxicity through Blockade of G 2/M Transition When Combined with Bortezomib/Dexamethasone in Pre-Clinical Multiple Myeloma

Background: Pomalidomide (POM) is an established agent in relapsed/refractory (R/R) multiple myeloma (MM). CC-92480, a novel cereblon E3 ligase modulator (CELMoD ®) agent, is being investigated in R/R MM patients in combination with the proteasome inhibitor (PI) bortezomib (BTZ) and steroid dexamethasone (DEX) (NCT03374085/NCT03989414). Previously, we showed mechanistic synergy of POM/BTZ/DEX in MM cell line models (Bjorklund et al). Here we analyzed the cell autonomous cytotoxic activities of CC-92480 or POM alone and in combination with BTZ/DEX to compare and differentiate their mechanisms of action (MOA). Results: Comparative analysis of the anti-proliferative activity against H929 and MM1.S cell lines revealed that CC-92480 demonstrated a more potent inhibition of proliferation by 100-fold lower dose compared to POM. Combination experiments utilizing a titration of POM or CC-92480 in combination with a 1 hr BTZ pulse, to mimic the clinical pharmacokinetics (+/- DEX co-treatment) showed an enhancement of antiproliferative capacity in both doublet and triplet combinations compared to single agents. Combination indices for POM/BTZ/DEX or CC-92480/BTZ/DEX resulted in values <1 for most combinations indicating a synergistic effect. Additionally, POM or CC-92480 in combination with BTZ or DEX, or in triplet combinations increased induction of apoptosis (>90% for each triplet compared to POM (20%) and CC-92480 (40%). Flow cytometric analysis of Aiolos and Ikaros protein level in MM cells treated with POM/BTZ/DEX or CC-92480/BTZ/DEX resulted in a slight kinetic delay in substrate depletion at early time points (1-4 hr), where the effect is less apparent with CC-92480, and indistinguishable at 24 hr compared to single agent POM or CC-92480 in the clinically relevant concentrations. We performed transcriptomic analyses of H929 cells treated with POM/BTZ/DEX or CC-92480/BTZ/DEX for 24 hrs to identify key pathways responsible for the observed synergistic combination effect. Common pathways dysregulated by POM or CC-92480 included previously identified interferon, protein homeostasis and proliferation gene sets. Gene set enrichment analysis (GSEA) showed many significant pathway differences when comparing the triplets, including general cell cycle progression, cell division and chromatin segregation. Interestingly, genes involved in negative regulation of G 2/M transition were identified as one of the most significant differences between POM/BTZ/DEX and CC-92480/BTZ/DEX. To understand how these pathways contributed to cell cycle effects and apoptosis, we assessed DNA fragmentation by TUNEL in conjunction with cell cycle flow cytometry to examine cell cycle specific apoptotic induction. Temporal assessment (6, 12, 18, 24, and 48 hr treatments) demonstrated accumulation of BrdU incorporation in all cell cycle phases when treated with POM/BTZ/DEX or CC-92480/BTZ/DEX indicating cell death was occurring within all phases. However, there was a marked enhancement of G 2/M BrdU incorporation (80% vs. 40% of G 2/M population) at 18-24 hr when treated with CC-92480/BTZ/DEX compared to POM/BTZ/DEX, or other single agent treatments. Additionally, G 2/M transition-dependent cyclins A and B were shown to be dysregulated by CC-92480. These data indicate that CC-92480 potentiates a G 2/M arrest in combination with BTZ in MM cells. Conclusions: These results demonstrate that CC-92480 alone or in combination with BTZ/DEX elicits a more potent cytotoxic effect on MM cells compared to POM. Importantly, the combination of either POM or CC-92480 with a PI, like BTZ, does not appreciatively affect single agent MOA. We have also identified a key differentiating mechanism of cell autonomous activity for CC-92480 in combination with BTZ/DEX where MM cells enhance apoptotic induction at the G 2/M stage compared to POM. Clinically, this added mechanistic difference suggests a more cytotoxic response in patients treated with CC-92480/BTZ/DEX compared to POM/BTZ/DEX. Disclosures Bjorklund: BMS: Current Employment, Current equity holder in publicly-traded company. Amatangelo: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Kang: BMS: Current equity holder in publicly-traded company. Chiu: Bristol Myers Squibb: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Pourdehnad: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: No royalty. Hagner: BMS: Current Employment, Current equity holder in publicly-traded company. Thakurta: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company.

H3K36 Trimethylation Mediated By SETD2 Regulates Cell Proliferation and Cell Cycle By Modulating BCMA-JNK and c-Myc Pathways in Multiple Myeloma

In addition to genetic aberrations, accumulating evidence indicates that deregulation of histone methyltransferases, such as MMSET, EZH2 and KDM6A, plays crucial roles in the oncogenic transformation and development of multiple myeloma (MM). For example, overexpression of MMSET leading to a global increase in H3K36me2, is believed to be the driving force in the pathogenesis of t (4;14) MM. However, as the histone methyltransferase is responsible for H3K36me3, the role of SETD2 is not been known in myeloma. To explore the possible clinical value of SETD2 in MM, we first examined the gene expression profile from GEO database, which indicated that the SETD2 expression was significantly decreased in MM patients when compared with monoclonal gammopathy of undetermined significance and smoldering multiple myeloma patients (GSE6477). Moreover, the expression of SETD2 decreased with the advanced international staging system stage of MM patients (GSE19784). The Kaplan-Meier analysis showed that low expression of SETD2 was significantly associated with a poor overall survival in MM patients (GSE2658, P<0.05; GSE9782, P<0.001). Thus, our analysis suggests that SETD2 might participate in cancer progression and could become a biomarker for the prognosis of patients with MM. We then investigated the biological role and the underlying mechanism of SETD2 in MM. Firstly, we used lentiviral-mediated RNA interference to knockdown SETD2 (SETD2 KD) in MM cell lines (RPMI8226 and MM.1S). CCK8 and colony-forming assays showed that reduced expression of SETD2 significantly promoted MM cell proliferation and colony growth. BrdU incorporation assay revealed increased DNA synthesis in SETD2 KD MM cells. Then, treatment with JIB-04, a small molecule inhibitor targeting H3K36me3 loss in SETD2 KD MM cells showed that H3K36me3 recovery was capable of reversing the tumor-promoting effect due to SETD2 down-regulation of MM cells in vitro. Moreover, the xenograft growth assay revealed that SETD2 down-regulation facilitated tumor growth and JIB-04 treatment exhibited anti-myeloma activity in vivo. Therefore, we conclude that SETD2 plays an important role in MM maintenance, and inhibition of H3K36me3 shows therapeutic efficacy for MM. To further explore the underlying mechanisms, we performed the RNA-Seq analysis and discovered that low H3K36me3 level was associated with reduced expression of CDKN1A and increased expression of TNFRSF17 (BCMA) and c-Myc in MM cells. The Gene Set Enrichment Analysis (GSEA) revealed that MAPK signaling pathway was enriched in SETD2 knockdown and JIB-04 treated MM cells. Subsequent Western blotting analysis further confirmed that SETD2 KD cells had increased JNK activation, while JIB-04 treated group showed decreased level of p-JNK. To investigate whether BCMA was the directly transcriptional target for H3K36me3, we carried out a dual-luciferase reporter assay in both SETD2 KD and JIB-04 treated MM cells, and confirmed that H3K36me3 inhibited the expression of BCMA through physically interacting with motifs in its promoter. Furthermore, down-regulation of BCMA in SETD2 KD MM cells could lead to a reduction of p-JNK and an up-regulation of CDKN1A, and resulting inhibited cell proliferation and cell cycle progression. Furthermore, blockage of the JNK pathway by its inhibitor SP600125 resulted in significant inhibition of MM cell proliferation induced by SETD2 knockdown. Additionally, suppression of c-Myc using 10058-F4 inhibited proliferation, and induced cell cycle arrest as well as CDKN1A expression in SETD2 KD MM cells. These results indicate that BCMA/JNK and c-Myc pathways were involved in STED2 and H3K36me3 mediated cell proliferation in MM. Together, our data delineate that SETD2-dependent H3K36me3 modification plays a critical role in regulation cell proliferation and cell cycle by BCMA-JNK and c-Myc pathways in MM cells. Targeting the SETD2-H3K36me3 pathway represents a promising therapy for MM. Disclosures No relevant conflicts of interest to declare.

Gloeothece sp.—Exploiting a New Source of Antioxidant, Anti-Inflammatory, and Antitumor Agents

Bioactive lipidic compounds of microalgae, such as polyunsaturated fatty acids (PUFA) and carotenoids, can avoid or treat oxidation-associated conditions and diseases like inflammation or cancer. This study aimed to assess the bioactive potential of lipidic extracts obtained from Gloeothece sp.–using Generally Recognized as Safe (GRAS) solvents like ethanol, acetone, hexane:isopropanol (3:2) (HI) and ethyl lactate. The bioactive potential of extracts was assessed in terms of antioxidant (ABTS•+, DPPH•, •NO and O2•assays), anti-inflammatory (HRBC membrane stabilization and Cox-2 screening assay), and antitumor capacity (death by TUNEL, and anti-proliferative by BrdU incorporation assay in AGS cancer cells); while its composition was characterized in terms of carotenoids and fatty acids, by HPLC-DAD and GC-FID methods, respectively. Results revealed a chemopreventive potential of the HI extract owing to its ability to: (I) scavenge -NO• radical (IC50, 1258 ± 0.353 µg·mL−1); (II) inhibit 50% of COX-2 expression at 130.2 ± 7.4 µg·mL−1; (III) protect 61.6 ± 9.2% of lysosomes from heat damage, and (IV) induce AGS cell death by 4.2-fold and avoid its proliferation up to 40% in a concentration of 23.2 ± 1.9 µg·mL−1. Hence, Gloeothece sp. extracts, namely HI, were revealed to have the potential to be used for nutraceutical purposes.

Comparison of Allogenic and Autogenic Implantations of Dedifferentiated Fat Cells On Monoclonal Antibody 1-22-3-Induced Glomerulonephritis in Rats

Background We established an adipogenic progenitor cell line derived from mature adipocytes and named these cells dedifferentiated fat (DFAT) cells, which have been shown to have characteristics very similar to those of mesenchymal stem cells (MSCs). The potential application of DFAT cells to support cell-based therapies for regenerative and immunosuppressive therapies has been suggested. The present study was designed to address beneficial ways that DFAT implantation can be used clinically as immunosuppressive therapy to treat immunological glomerulonephritis. Methods We evaluated distribution of DFAT cells after intravenous injection through the tail vein in Wistar rats. We examined effects of allogenic implantation of DFAT cells on BrdU incorporation into kidney from rats with monoclonal antibody (mAb) 1-22-3-induced glomerulonephritis. We compared effects of allogenic and autogenic implantations of DFAT cells on excretion of urinary protein, renal function, and glomerular and nephrotubular injuries in these rats, and serum levels of tumor necrosis factor-stimulated gene-6 (TSG-6), and expression of TSG-6 mRNA in kidney. Results The allogenic implantations of DFAT cells trapped in lung improved excretion of urinary protein and renal function, and significantly suppressed glomerular and nephrotubular injuries in the rats with mAb1-22-3-induced glomerulonephritis compared with the autogenic implantations. The allogenic implantation of DFAT cells increased serum levels of TSG-6 especially in mAb 1-22-3-induced glomerulonephritis and significantly increased the expression of TSG-6 mRNA in kidney compared to the autogenic implantation. Conclusion These findings suggest that allogenic implantation of DFAT cells could be clinically useful immunosuppressive therapy for immunological glomerulonephritis.

EXTH-15. MULTI-FACETED INHIBITION OF TET PATHWAY WITH CELL-PERMEABLE 2HG AND BOBCAT 339 REDUCES PROLIFERATION AND INDUCES APOPTOSIS IN DIPG

Diffuse Intrinsic Pontine Glioma (DIPG) is one of the worst forms of pediatric brain tumors, with a 100% mortality-rate. A prominent mutation observed in them is a lysine to methionine change in histone3 which causes trapping of the repressive-chromatin-complex, leading to genome-level hypomethylation, affecting global epigenetic-regulation. Ten-Eleven Translocation (TET) proteins are alpha-ketoglutarate (α-KG) dependent dioxygenases that mediate the conversion of 5-methylcytosine to 5-hydroxymethylcytosine (5hmC), a key-step in removing DNA methylation-marks. We previously identified increased levels of 5hmC and TETs in DIPG. In IDH mutant glioma, the R132H-IDH produces an oncometabolite, 2-hydroxyglutarate (2HG), instead of α-KG. 2HG competitively inhibits TET function, resulting in a hypermethylated genome. Bobcat339, a cytosine-analog targets TETs by blocking the cytosine binding-site on TETs. We hypothesized that cell-permeable 2HG and Bobcat339 would synergize to block TET activity in DIPG, restore epigenetic-balance by increasing genomic methylation, and induce cell-death. 2HG induced apoptosis in DIPG cells at concentrations ranging from 100-300uM, as measured by cleaved-PARP western and cleaved-caspase3 immunofluorescence (2-7fold increase in CC3, depending on cell line). Cell-permeable 2HG also decreased proliferation, measured by phospho-RB western in DIPG cells (30-50% reduction in pRB band intensity, depending on cell line). Similarly, Bobcat339 suppressed proliferation at concentrations from 10-50uM, measured by BrdU incorporation (25% reduction in BrdU+ at 50uM, p= 0.02 compared to control). Bobcat339 induced apoptosis, measured by cPARP western and CC3 immunofluorescence (4-10fold more of CC3+ compared to control p< 0.0004). In combination, cell-permeable 2HG (100-200uM) and Bobcat339 (10-20uM) combined to suppress cell-viability, measured by CellTiterBlue assay, producing ZIP scores of ~20 in DIPG cells (indicating high-level synergy). In combination, 2HG and Bobcat339 increased apoptosis in DIPG (3-fold increase in cleaved-PARP band intensity in JHH-DIPG1 cells treated with 20uM Bobcat339 + 100uM 2HG, compared to single-treated cells). Our results may lead to new approaches that target TET pathway in DIPG tumors.

miR-514a-3p: a novel SHP-2 regulatory miRNA that modulates human cytotrophoblast proliferation

Src homology-2 (SH2) domain containing protein tyrosine phosphatase 2 (SHP-2), encoded by the PTPN11 gene, forms a central component of multiple signalling pathways and is required for insulin-like growth factor (IGF) induced placental growth. Altered expression of SHP-2 is associated with aberrant placental and fetal growth indicating that drugs modulating SHP-2 expression may improve adverse pregnancy outcome associated with altered placental growth. Placental PTPN11/SHP-2 expression is controlled by microRNAs (miRNAs) so SHP-2 regulatory miRNAs may have therapeutic potential, however the individual miRNA(s) regulating placental SHP-2 expression remain to be established. We performed in-silico analysis of 3’UTR target prediction databases to identify libraries of HeLa cells transfected with individual miRNA-mimetics, enriched in potential SHP-2 regulatory miRNAs. Analysis of PTPN11 levels by qPCR revealed that miR-758-3p increased, whilst miR-514a-3p reduced PTPN11 expression. miR-514a-3p and miR-758-3p expression within the human placenta was confirmed by qPCR; miR-514a-3p (but not miR-758-3p) levels inversely correlated with PTPN11 expression. To assess the interaction between these miRNAs and PTPN11/SHP-2, specific mimetics were transfected into first trimester human placental explants and explants cultured for up to 4 days. Overexpression of miR-514a-3p, but not miR-758-3p, significantly reduced PTPN11 and SHP-2 expression. microRNA-ribonucleoprotein complex (miRNP)-associated mRNA assays confirmed that this interaction was direct. miR-514a-3p overexpression attenuated IGF-I induced trophoblast proliferation (BrdU incorporation). miR-758-3p did not alter trophoblast proliferation. These data demonstrate that by modulating SHP-2 expression, miR-514a-3p is a novel regulator of IGF- signalling and proliferation in the human placenta and may have therapeutic potential in pregnancies complicated by altered placental growth.

Active constituent of Polygala tenuifolia attenuates cognitive deficits by rescuing hippocampal neurogenesis in APP/PS1 transgenic mice

Background Alzheimer’s disease (AD) is the most common dementia worldwide, and there is still no satisfactory drug or therapeutic strategy. Polygala tenuifolia is a traditional Chinese medicine with multiple neuroprotective effects. In present study, we investigated the effects of three active constituents [3,6′-disinapoyl sucrose (DISS), onjisaponin B (OB) and tenuifolin (TEN)] of Polygala tenuifolia (PT) on the proliferation and differentiation of neural stem cells (NSCs) to identify the potential active constituent of PT promoting hippocampal neurogenesis. Methods NSCs were isolated from hippocampi of newborn C57BL/6 mice, and transfected with mutant amyloid precursor protein (APP) gene to establish an AD cell model (APP-NSCs). 3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays were performed, and the proliferation and differentiation of NSCs were assessed by neurosphere formation assay, 5-bromo-2′-deoxyuridine (BrdU) incorporation assay and immunofluorescence (IF) staining analysis. APP/PS1 transgenic mice were administrated with the potential active constituent DISS for 4 weeks. Morris water maze (MWM), Nissl staining assay and IF staining assays were carried out to evaluate the cognitive function, neural damages and hippocampal neurogenesis, respectively. Results DISS exerted the optimal ability to strengthen APP-NSCs proliferation and neuronal differentiation, followed by OB and TEN. Furthermore, DISS treatment for 4 weeks strikingly rescued the cognitive deficits, neuronal injures, and neurogenesis disorder in adult APP/PS1 transgenic mice. Conclusions Our findings demonstrated that DISS is the constituent of PT that triggers the most potent increase of hippocampal neurogenesis in our mouse model of AD.

Selective inhibition of the PI3K isoform p110alpha using BYL719 protects against tyrosine kinase-mediated processes in PASMCs and reduces experimental pulmonary hypertension in mice and rats

Rationale Pulmonary arterial hypertension (PAH) is a vascular disease characterized by chronic increases in pulmonary vascular resistance (PVR), pulmonary arterial pressure (PAP), and right ventricular (RV) hypertrophy. Increased activation of receptor tyrosine kinase (RTK) -mediated signaling pathways leads to increased proliferation and migration of pulmonary smooth vascular muscle cells (PASMCs) which promote vascular remodeling processes. We identified the catalytic subunit p110alpha of phosphatidylinositol-3-kinase as a key enzyme for these processes and showed that both genetic ablation of p110alpha in SMCs and pharmacological inhibition can prevent experimental PH. Here, the effects of the orally bioavailable p110alpha selective PI3K inhibitor BYL719 on the RTK-mediated proliferation and chemotaxis of PASMCs, as well as the effects in the hypoxia-induced mouse and in the Sugen / hypoxia (SuHx) -induced rat model of PH were investigated. Methods Human and murine PASMCs were pretreated with different concentrations of BYL719 and stimulated with a mixture of growth factors (PDGF [30ng/ml], EGF [0,5ng/ml], bFGF [2ng/ml], insulin [0,5ng/ml], and FBS [5%]). Proliferation was investigated using a BrdU incorporation ELISA assay (Roche). Chemotaxis was quantified using modified Boyden chambers. Male BL/6 mice were subjected to hypoxia (10% O2) for 21 days. Treatment with BYL719 (or vehicle) was carried out via daily gavage of 50mg/kg bodyweight. In addition, a therapeutic approach was investigated using male Sprague Dawley rats in the SuHx model, which were treated with BYL719 (20 mg / kg body weight) or vehicle for 2 weeks after a three-week hypoxia phase. The RV pressure (RVSP) was measured using a Millar® or liquid-filled catheter. The RV hypertrophy is shown as the quotient of the weights of the RV to the LV + septum (RV / (LV + S)). Results Growth factor-induced proliferation and chemotaxis of the PASMCs were significantly and concentration-dependently inhibited by BYL719. The exposure to hypoxia led to an increase of the RVSP (24.5±0.95 to 35.2±1.28 mmHg) and the development of right ventricular hypertrophy (RV / LV + S 0.24±0.01 to 0.37±0.073), which was significantly reduced in the BYL719 treated group (RVSP 31.4±0.53 mmHg; RV / LV + S 0.31±0.01) (p<0.05). In addition, SuHx led to a robust increase of the RVSP (129.2±5.4 mmHg) and pronounced RV hypertrophy (RV / (LV + S): 0.86±0.04), which were significantly reduced by the therapeutic BYL719 treatment (102.0±6.1 mmHg or 0.64±0.03). Conclusion These results show that inhibition of p110alpha using the BYL719 reduced growth factor-mediated pathological processes in PASMCs in vitro, as well as hypoxia-induced (mouse) and already established SuHx-induced PH (rat). Thus, the inhibition of p110a using BYL719 represents a promising approach for the treatment of PAH. FUNDunding Acknowledgement Type of funding sources: None.