Genipin attenuates mitochondrial-dependent apoptosis, endoplasmic reticulum stress, and inflammation via the PI3K/AKT pathway in acute lung injury.

The protective effects of genipin against lipopolysaccharide (LPS)-induced acute lung injury (ALI) have been reported; however, the mechanism is unclear. Genipin performs its pharmacological effects via activation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. In the present study, we aimed to determine whether the PI3K/AKT pathway is involved in the protective effects of genipin against mitochondrial-dependent apoptosis, endoplasmic reticulum stress (ERS), and inflammation in ALI. We constructed in vivo and in vitro models of LPS-induced ALI. PI3K/AKT signaling was inhibited using LY294002. Pretreatment with genipin increased AKT phosphorylation, indicating that PI3K/AKT signaling was upregulated. Genipin pretreatment prevented LPS-induced histopathological deterioration, increased pulmonary edema, and decreased oxygenation index, all of which were inhibited using LY294002. In addition, genipin pretreatment attenuated LPS-mediated mitochondrial apoptosis, as indicated by improved mitochondrial dysfunction, downregulation of BAX (BCL2 associated X, apoptosis regulator), upregulation of BCL2 (BCL2 apoptosis regulator), inhibited the release of cytochrome c, activation of caspase-3, and cell apoptosis. Genipin pretreatment inhibited the LPS-induced upregulation of AF4/FMR2 family member 4 (CHOP), glucose-regulated protein, 78 kDa (GRP78), and X-box binding protein 1 (XBP1) levels, indicating ERS suppression. Moreover, genipin pretreatment alleviated LPS-induced inflammation, indicating by blockade of nuclear factor kappa b (NF-κB) signaling activation and reduced tumor necrosis factor alpha (TNF-α), interleukin (IL)-1ß, and IL-6 levels in the lung and bronchoalveolar lavage fluid. LY294002 could inhibit these genipin-induced protective effects against apoptosis, ERS, and inflammation. Thus, genipin significantly activates PI3K/AKT signaling to ameliorate mitochondria-dependent apoptosis, ERS, and inflammation in LPS-induced ALI.

miR-618 Inhibits Prostate Cancer Migration and Invasion by Targeting FOXP2.

miRNAs play critical role in the development and progression of prostate cancer. Here we studied the role of miR-618 in prostate cancer migration and invasion. miR-618 was downregulated in metastatic androgen-independent prostate cancer (AIPC), patients with low miR-618 had poor outcome. Overexpression of miR-618 inhibited migration and invasion and induced mesenchymal to epithelial transition (MET). Conversely, knockdown of miR-618 promoted migration and invasion and induced epithelial to mesenchymal transition (EMT). FOXP2 was the direct target of miR-618, and promoted TGF-ß expression, inhibition of TGF-ß reversed the effect of miR-618 knockdown. We further analyzed the correlation between miR-618 expression and FOXP2 in human prostate cancer tissues, and found there was a negative correlation between miR-618 expression and FOXP2 levels. In conclusion, we found miR-618 inhibited prostate cancer migration and invasion by targeting FOXP2 and inhibiting TGF-ß.

Neuroprotective effects of polydatin against mitochondrial-dependent apoptosis in the rat cerebral cortex following ischemia/reperfusion injury.

The neuroprotective effect of polydatin (PD) against hemorrhagic shock-induced mitochondrial injury has been described previously, and mitochondrial dysfunction and apoptosis were reportedly involved in ischemic stroke. In the present study the neuroprotective effect of PD in preventing apoptosis was evaluated following induction of focal cerebral ischemia by middle cerebral artery occlusion (MCAO) in rats. PD (30 mg/kg) was administered by caudal vein injection 10 min prior to ischemia/reperfusion (I/R) injury. 24 h following I/R injury, ameliorated modified neurological severity scores (mNSS) and reduced infarct volume were observed in the PD treated group. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Annexin V/propidium iodide assays demonstrated the anti-apoptotic effect of PD in the ischemic cortex. In addition, PD improved I/R injury­induced mitochondrial dysfunction, reflected by morphological observations and measurements of mitochondrial membrane potential and intracellular ATP measurement. Western blot analysis revealed an increase in B­cell lymphoma 2 apoptosis regulator (Bcl-2) expression, and a decrease in Bcl­2­associated protein X apoptosis regulator expression in the PD group in comparison with the vehicle treated group. PD treatment also prevented the release of cytochrome c from mitochondria into the cytoplasm, and blunted the activities of caspase­9 and caspase­3. Furthermore, PD treatment decreased the levels of reactive oxygen species in neurons isolated from the ischemic cortex. The findings of this study, therefore, suggest that PD has a dual effect, ameliorating both oxidative stress and mitochondria­dependent apoptosis, making it a promising new therapy for the treatment of ischemic stroke.

[Optimization of streptozotocin dosing for establishing tumor-bearing diabetic mouse models].

OBJECTIVE: To determine the optimal dosing of streptozotocin (STZ) for establishing lymphoma-bearing diabetic mouse models. METHODS: A total of 200 healthy male Balb/c mice were randomized into 4 groups (n=50) for intraperitoneal injection of a single dose of vehicle solution (control) or 75, 150, or 200 mg/kg STZ. The changes of body weight and blood glucose were observed regularly, and the success rate of modeling, mortality rate, and survival of the mice were recorded after the injections. The mice with successfully induced diabetes received subcutaneous or tail vein injection of A20 lymphoma cells, and the rate of tumorigenesis, mortality rate, and survival time were observed at 1 month and 3 months after tumor cell injection. RESULTS: Compared with the control group, the mice receiving STZ injection at 150 and 200 mg/kg showed significantly decreased body weight and increased blood glucose (P<0.05), while STZ at 75 mg/kg did not produced such obvious changes. STZ injection at 200 mg/kg resulted in a significantly higher mortality rate and shorter survival time than STZ at 150 mg/kg (P<0.05). In the control group and 150 and 200 mg/kg STZ groups, the rate of tumorigenesis or mortality rate showed no significant differences after subcutaneous injection of A20 lymphoma cells (P>0.05), but differed significantly at 3 months after tail vein injection of the tumor cells (P<0.05). CONCLUSION: Intraperitoneal injection of STZ at 150 mg/kg is associated with a low mortality rate, a high successful modeling rate of diabetes and a long survival time in mice, and is therefore optimal for establishing diabetic mouse models bearing transplanted tumors.