Triptolide prevents bone loss via suppressing osteoclastogenesis through inhibiting PI3K-AKT-NFATc1 pathway

Bone loss (osteopenia) is a common complication in human solid tumour. In addition, after surgical treatment of gynaecological tumour, osteoporosis often occurs due to the withdrawal of oestrogen. The major characteristic of osteoporosis is the low bone mass with micro-architectural deteriorated bone tissue. And the main cause is the overactivation of osteoclastogenesis, which is one of the most important therapeutic targets. Inflammation could induce the interaction of RANKL/RANK, which is the promoter of osteoclastogenesis. Triptolide is derived from the traditional Chinese herb lei gong teng, presented multiple biological effects, including anti-cancer, anti-inflammation and immunosuppression. We hypothesized that triptolide could inhibits osteoclastogenesis by suppressing inflammation activation. In this study, we confirmed that triptolide could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells (BMMCs) and RAW264.7 cells and inhibited the osteoclast bone resorption functions. PI3K-AKT-NFATc1 pathway is one of the most important downstream pathways of RANKL-induced osteogenesis. The experiments in vitro indicated that triptolide suppresses the activation of PI3K-AKT-NFATc1 pathway and the target point located at the upstream of AKT because both NFATc1 overexpression and AKT phosphorylation could ameliorate the triptolide suppression effects. The expression of MDM2 was elevated, which demonstrated the MDM-p53-induced cell death might contribute to the osteoclastogenesis suppression. Ovariectomy-induced bone loss and inflammation activation were also found to be ameliorated in the experiments in vivo. In summary, the new effect of anti-cancer drug triptolide was demonstrated to be anti-osteoclastogenesis, and we demonstrated triptolide might be a promising therapy for bone loss caused by tumour.     

Neobavaisoflavone inhibits osteoclastogenesis through blocking RANKL signalling‐mediated TRAF6 and c‐Src recruitment and NF‐κB,MAPK and Akt pathways

Psoralea corylifolia (P corylifolia) has been popularly applied in traditional Chinese medicine decoction for treating osteoporosis and promoting fracture healing since centuries ago. However, the bioactive natural components remain unknown. In this study, applying comprehensive two‐dimensional cell membrane chromatographic/C18 column/time‐of‐flight mass spectrometry (2D CMC/C18 column/TOFMS) system, neobavaisoflavone (NBIF), for the first time, was identified for the bioaffinity with RAW 264.7 cells membranes from the extracts of P corylifolia. Here, we revealed that NBIF inhibited RANKL‐mediated osteoclastogenesis in bone marrow monocytes (BMMCs) and RAW264.7 cells dose dependently at the early stage. Moreover, NBIF inhibited osteoclasts function demonstrated by actin ring formation assay and pit‐formation assay. With regard to the underlying molecular mechanism, co‐immunoprecipitation showed that both the interactions of RANK with TRAF6 and with c‐Src were disrupted. In addition, NBIF inhibited the phosphorylation of P50, P65, IκB in NF‐κB pathway, ERK, JNK, P38 in MAPKs pathway, AKT in Akt pathway, accompanied with a blockade of calcium oscillation and inactivation of nuclear translocation of nuclear factor of activated T cells cytoplasmic 1 (NFATc1). In vivo, NBIF inhibited osteoclastogenesis, promoted osteogenesis and ameliorated bone loss in ovariectomized mice. In summary, P corylifolia‐derived NBIF inhibited RANKL‐mediated osteoclastogenesis by suppressing the recruitment of TRAF6 and c‐Src to RANK, inactivating NF‐κB, MAPKs, and Akt signalling pathways and inhibiting calcium oscillation and NFATc1 translocation. NBIF might serve as a promising candidate for the treatment of osteoclast‐associated osteopenic diseases.     

Circ_0075829 facilitates the progression of pancreatic carcinoma by sponging miR‐1287‐5p and activating LAMTOR3 signalling

Pancreatic cancer (PC) is a leading cause of cancer‐related mortality globally. Though increasing evidence has demonstrated that circular RNAs (circRNAs) are linked to the development and progression of cancers, the biological functions of circRNAs in PC remain largely unexplored so far. Based on previous studies, Hsc_circ_0075829 (circ_0075829) was screened out and then further identified in PC clinical specimens and cell lines by real‐time PCR. After the stability tests, a series of in vitro and in vivo functional experiments were performed to investigate the role of circ_0075829 in PC development. Furthermore, fluorescent in situ hybridization (FISH), bioinformatics tools, dual‐luciferase assays and rescue experiments were conducted to clarify the regulatory mechanisms of circ_0075829 in SW1990 and BxPC‐3 cells. Compared with paracancerous tissues, the expression of circ_0075829 was increased in PC tissues, which was positively correlated with the clinical features of PC. Knockdown of circ_0075829 significantly suppressed the proliferative, migratory and invasive rates of SW1990 and BxPC‐3 cells both in vitro and in vivo. Bioinformatics analysis and dual‐luciferase reporter gene assay indicated that circ_0075829 could bind to miR‐1287‐5p. Mechanism research and rescue experiments demonstrated that circ_0075829 could regulate the LAMTOR3/p‐ERK signalling pathway via sponging miR‐1287‐5p in PC cell lines. Our data reveal that the circ_0075829 could facilitate the proliferation and metastasis of PC through circ_0075829/miR‐1287‐5p/LAMTOR3 axis.     

Chemical Composition and Antioxidant Activity of Essential Oil of Chinese Propolis

The chemical composition and in vitro antioxidant activity of the essential oil of propolis (EOP) collected from 25 locations in China was investigated. Steam‐distillation extraction was used to extract the EOP, and chemical composition was identified by GC/MS. The antioxidant activities of EOP were also measured. The result showed that a total of 406 compounds were detected in EOP. The major compounds of Chinese EOP were cedrol, γ‐eudesmol, benzyl alcohol, phenethyl alcohol, 2‐methoxy‐4‐vinylphenol, 3,4‐dimethoxystyrene and guaiol. Principal component analysis revealed the significant correlation between EOP compositions and their origins, and certain correlation was detected between EOP and their color. Linear discriminant analysis showed that 88 % and 84 % of the propolis samples were predicted correctly as the groupings identified by climatic zone and the color, respectively. Furthermore, the differences of antioxidant activities of EOP were significant. EOP of Shandong had the strongest antioxidant activities, whereas EOP of Guangdong, Yunnan and Hunan showed the poorest.     

MicroRNA‐29b‐3p suppresses oral squamous cell carcinoma cell migration and invasion via IL32/AKT signalling pathway

Oral squamous cell carcinoma (OSCC) is aggressive accompanied with poor prognosis. We previously isolated the most invasive cells resembling the invasive tumour front by microfluidic technology and explored their differentially expressed microRNAs (miRNAs) in our previous work. Here, we verified the miR‐29b‐3p as a guarder that suppressed migration and invasion of OSCC cells and was down‐regulated in the most invasive cells. Besides that, the invasion suppression role of miR‐29b‐3p was achieved through the IL32/AKT pathway. Thus, miR‐29b‐3p and IL32 might serve as therapeutic targets for blocking the progression and improving the outcome of OSCC.     

Linc01014 regulates gefitinib resistance in oesophagus cancer via EGFR‐PI3K‐AKT‐mTOR signalling pathway

This study aimed to explore the underlying mechanism of linc01014 in oesophagus cancer gefitinib resistance. Gefitinib‐resistant oesophagus squamous cell carcinoma (ESCC gefitinibR) cell lines were constructed by using different gefitinib treatment in FLO‐1, KYAE‐1, TE‐8 and TE‐5 cell lines and confirmed by MTS50 and proliferation assays. Expression of linc01014 was overexpressed/silenced in FLO‐1 cells followed by gefitinib treatment, and then, the apoptosis‐associated markers Bax and Bcl‐2, and PI3KCA in PI3K signalling pathway were determined using Western blotting. MST50 and morphology analyses showed that ESCC gefitinibR cell lines presented obvious gefitinib resistance than their parental ESCC cell lines. ESCC gefitinibR cell lines showed significantly higher proliferation abilities than their parental ESCC cell lines after treating with gefitinib. Overexpression of linc01014 significantly inhibited the apoptosis of FLO‐1 cells induced by gefitinib and silencing linc01014 obviously promoted the apoptosis of FLO‐1 cells induced by gefitinib. Silencing linc01014 could significantly increase the gefitinib chemotherapy sensitivity of oesophagus cancer via PI3K‐AKT‐mTOR signalling pathway.     

Role of leptin in the regulation of food intake in fasted mice

Leptin is well acknowledged as an anorexigenic hormone that plays an important role in feeding control. Hypothalamic GABA system plays a significant role in leptin regulation on feeding and metabolism control. However, the pharmacological relationship of leptin and GABA receptor is still obscure. Therefore, we investigated the effect of leptin or combined with baclofen on the food intake in fasted mice. We detected the changes in hypothalamic c‐Fos expression, hypothalamic TH, POMC and GAD67 expression, plasma insulin, POMC and GABA levels to demonstrate the mechanisms. We found that leptin inhibit fasting‐induced increased food intake and activated hypothalamic neurons. The inhibitory effect on food intake induced by leptin in fasted mice can be reversed by pretreatment with baclofen. Baclofen reversed leptin's inhibition on c‐Fos expression of PAMM in fasted mice. Therefore, these results indicate that leptin might inhibit fasting‐triggered activation of PVN neurons via presynaptic GABA synaptic functions which might be partially blocked by pharmacological activating GABA‐B. Our findings identify the role of leptin in the regulation of food intake.