Therapeutic Effect of Desmodium caudatum Extracts on Alleviating Diabetic Nephropathy Mice.

Desmodium caudatum extracts (DCE) were investigated for their potential therapeutic effects on diabetic nephropathy (DN). In our study, the high-fat diet (HFD) / streptozotocin (STZ)-induced DN model in C57BL/6 mice was treated with 100 mg/kg, 200 mg/kg DCE. The results showed that DCE decreased biochemical parameters and proteinuria levels. The kidney sections staining indicated that DCE treatment recovered glomerular atrophy and alleviated lipid droplets in the glomerular. Additionally, DCE inhibited lipid and glycogen accumulation down-regulated the expression of sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FAS) proteins. DCE also reduced collagenous fibrous tissue and the expression of transforming growth factor-ß1 (TGF-ß1) and alpha-smooth muscle actin (α-SMA) through Masson's trichrome staining and immunohistochemical analysis. We found that DCE alleviated hydroxyproline content, and epithelial-mesenchymal transition (EMT). Besides, the results shown that DCE enhanced the antioxidant enzymes to mitigate fibrosis by reducing oxidative stress. In conclusion, our study provided evidence of the protective effect of DCE which down-regulated hyperglycemia, hyperlipidemia and inhibition of TGF-ß1 and EMT pathway but elevated antioxidant, suggesting its therapeutic implication for DN.

In vitro and in vivo protective potential of quercetin-3-glucuronide against lipopolysaccharide-induced pulmonary injury through dual activation of nuclear factor-erythroid 2 related factor 2 and autophagy.

In vitro and in vivo models of lipopolysaccharide (LPS)-induced pulmonary injury, quercetin-3-glucuronide (Q3G) has been previously revealed the lung-protective potential via downregulation of inflammation, pyroptotic, and apoptotic cell death. However, the upstream signals mediating anti-pulmonary injury of Q3G have not yet been clarified. It has been reported that concerted dual activation of nuclear factor-erythroid 2 related factor 2 (Nrf2) and autophagy may prove to be a better treatment strategy in pulmonary injury. In this study, the effect of Q3G on antioxidant and autophagy were further investigated. Noncytotoxic doses of Q3G abolished the LPS-caused cell injury, and reactive oxygen species (ROS) generation with inductions in Nrf2-antioxidant signaling. Moreover, Q3G treatment repressed Nrf2 ubiquitination, and enhanced the association of Keap1 and p62 in the LPS-treated cells. Q3G also showed potential in inducing autophagy, as demonstrated by formation of acidic vesicular organelles (AVOs) and upregulation of autophagy factors. Next, the autolysosomes formation and cell survival were decreased by Q3G under pre-treatment with a lysosome inhibitor, chloroquine (CQ). Furthermore, mechanistic assays indicated that anti-pulmonary injury effects of Q3G might be mediated via Nrf2 signaling, as confirmed by the transfection of Nrf2 siRNA. Finally, Q3G significantly alleviated the development of pulmonary injury in vivo, which may result from inhibiting the LPS-induced lung dysfunction and edema. These findings emphasize a toxicological perspective, providing new insights into the mechanisms of Q3G's protective effects on LPS-induced pulmonary injury and highlighting its role in dual activating Nrf2 and autophagy pathways.

Anti-Hypertensive Effect of Solanum muricatum Aiton Leaf Extract In Vivo and In Vitro.

Hypertension is a global health problem and leads to cardiovascular disease and renal injury. Solanum muricatum Aiton leaf extract, rich in flavonoids, is known for its antioxidant capacity. However, the effects of Solanum muricatum Aiton leaf extract on hypertension combined with inflammatory complications were unknown. This study aimed to investigate the impact of Solanum muricatum Aiton leaf extract on hypertension in vivo and in vitro. In vivo, Solanum muricatum Aiton leaf extract led to decrease high blood pressure, improve heart, aorta, and kidney pathology, and enhance the antioxidative activity in spontaneously hypertensive rats (SHR). Our study demonstrated Solanum muricatum Aiton leaf extract inhibited angiotensin-converting enzyme (ACE), epithelial sodium channel (ENaC), sodium glucose co-transporters-1 (SGLT-1), nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6). In vitro, Solanum muricatum Aiton leaf extract improved the angiotensin II-induced reactive oxygen species (ROS) and mitochondrial membrane depolarization in NRK-52E cells. Besides, Solanum muricatum Aiton leaf extract could also decrease the expressions of ENaC, SGLT-1, and NF-κB in angiotensin II-treated NRK-52E cells. Solanum muricatum Aiton leaf can be suggested as a novel antihypertensive agent ameliorating hypertension via ACE inhibition, inflammation reduction, and ROS. PLE is a novel anti-hypertensive agent to ameliorate hypertension and its complications, including inflammation.

Exon Junction Complex Mediates the Cap-Independent Translation of Circular RNA.

Evidence that circular RNAs (circRNA) serve as protein template is accumulating. However, how the cap-independent translation is controlled remains largely uncharacterized. Here, we show that the presence of intron and thus splicing promote cap-independent translation. By acquiring the exon junction complex (EJC) after splicing, the interaction between circRNA and ribosomes was promoted, thereby facilitating translation. Prevention of splicing by treatment with spliceosome inhibitor or mutating splicing signal hindered cap-independent translation of circRNA. Moreover, EJC-tethering using Cas13 technology reconstituted EJC-dependent circRNA translation. Finally, the level of a coding circRNA from succinate dehydrogenase assembly factor 2 (circSDHAF2) was found to be elevated in the tumorous tissues from patients with colorectal cancer, and shown to be critical in tumorigenesis of colorectal cancer in both cell and murine models. These findings reveal that EJC-dependent control of circSDHAF2 translation is involved in the regulation of oncogenic pathways. IMPLICATIONS: EJC-mediated cap-independent translation of circRNA is implicated in the tumorigenesis of colorectal cancer.

The inhibitory effect of quercetin-3-glucuronide on pulmonary injury in vitro and in vivo.

Pulmonary injury is defined as a progressive inflammation. Extensive pro-inflammatory cytokines are secreted from alveolus, associated with the production of reactive oxygen species (ROS) and apoptosis. The model of endotoxin lipopolysaccharide (LPS)-stimulated lung cells has been applied to mimic the pulmonary injury. Some antioxidants and anti-inflammatory compounds can be used as chemopreventive agents of pulmonary injury. Quercetin-3-glucuronide (Q3G) has been showed to exert antioxidant, anti-inflammatory, anti-cancer, anti-aging and anti-hypertension effects. The aim of the study is to examine the inhibitory potential of Q3G on pulmonary injury and inflammation in vitro and in vivo. Firstly, human lung fibroblasts MRC-5 cells pre-treated with LPS were demonstrated to cause survival loss and ROS generation, were recovered by Q3G. Q3G also exhibited the anti-inflammatory effects on the LPS-treated cells with a reduction in the activation of NLRP3 [nucleotide-binding and oligomerization domain (NOD)-like receptor protein 3] inflammasome, leading to pyroptosis. Also, Q3G showed the anti-apoptotic effect in the cells might be mediated via inhibition of mitochondrial apoptosis pathway. To further explore in vivo pulmonary-protective effect of Q3G, C57BL/6 mice were intranasally exposed to a combination of LPS and elastase (LPS/E) to perform the pulmonary injury model. The results revealed that Q3G ameliorated pulmonary function parameters and lung edema in the LPS/E-induced mice. Q3G also suppressed the LPS/E-stimulated inflammation, pyroptosis and apoptosis in the lungs. Taken together, this study suggested the lung-protective potential of Q3G via downregulation of inflammation, pyroptotic and apoptotic cell death, contributing to its chemopreventive activity of pulmonary injury.

The effect of isovitexin on lipopolysaccharide-induced renal injury and inflammation by induction of protective autophagy.

Chronic kidney disease (CKD) is a systemic inflammatory syndrome that includes tubulointerstitial inflammation. Lipopolysaccharide (LPS), the outer membrane of Gram-negative bacteria, can increase reactive oxygen species production (ROS) that triggers cell inflammation. Isovitexin (IV) is a flavone that has the potential for anticancer, antioxidant, and anti-inflammatory. This study aimed to hypothesize that IV inhibited LPS-induced renal injury in vitro and in vivo. In vitro study, IV prevented LPS-induced ROS production and increased cell viability on SV40-MES-13 cells. Additionally, IV ameliorated mitochondrial membrane potential, downregulated inflammation and pyroptosis factors on LPS treatment. We found that LPS treatment reduced the expression of autophagy, however, this effect was reversed by IV. In vivo study, the renal injury model in C57BL/6 mice cotreatment with IV was examined. In addition, IV decreased LPS-induced glomerular atrophy and reduced inflammation-related cytokines releases. Further showed that IV could significantly reduce LPS-induced inflammation and pyroptosis factors in mice. Under the immunostaining, increased fluorescence of LC3 autophagy-related protein was recovered by IV. In summary, IV ameliorated renal injury, inflammation and increased protected autophagy by anti-ROS production, anti-inflammation, and anti-pyroptosis. In the future, the safety of isovitexin as a novel perspective for CKD patients should be evaluated in further clinical studies.

The Nephroprotective Effects of Hibiscus sabdariffa Leaf and Ellagic Acid in Vitro and in Vivo Models of Hyperuricemic Nephropathy.

Hyperuricemic nephropathy (HN) is caused by urate crystals that get deposited in the kidney and contribute to renal fibrosis. Uric acid (UA) has been proven to directly cause renal mesangial cell oxidative stress and fibrosis in the pathogenesis of HN. Some antioxidants can be used as chemopreventive agents of HN. Hibiscus sabdariffa leaf extracts (HLE), rich in polyphenol, have been shown to possess hypoglycemic, antioxidant, hypolipidemic, antiatherosclerotic, and anticancer effects. The aim of the study is to examine the inhibitory effect of HLE and its main component ellagic acid (EA) on renal fibrosis. In vitro, mouse renal glomerular mesangial SV40MES13 cells pretreated with UA were demonstrated to trigger obvious morphological changes and viability loss, as well as affect matrix metalloproteinases (MMPs) activities. Noncytotoxic doses of HLE and EA abolished the UA-induced cell injury and MMP-2/9 secretion. In addition, HLE and EA exhibited antioxidant and anti-inflammatory effects on the UA-treated cells with a reduction in transforming growth factor-beta (TGF-ß) production. Next, the UA-activated pro-fibrotic factors, extracellular matrix (ECM) deposition, and epithelial-mesenchymal-transition (EMT) were inhibited by HLE or EA. Mechanistic assays indicated that antifibrotic effects of HLE might be mediated via TGF-ß/Smad signaling, as confirmed by the transfection of Smad7 siRNA. In vivo, HLE and EA supplementations significantly alleviated HN development, which may result from inhibiting adenine-induced TGF-ß production accompanying oxidative stress and inflammation, as well as fibrogenesis. Our data imply that EA-enriched HLE regulates the TGF-ß/Smad signaling, which in turn led to reduced renal mesangial cell injury and fibrosis in HN and provided a new mechanism for its nephroprotective activity.

In Vitro and In Vivo Nephroprotective Effects of Nelumbo nucifera Seedpod Extract against Cisplatin-Induced Renal Injury.

Cisplatin has been considered a chemotherapeutic drug for treating human tumors, and one of the noteworthy side effects of cisplatin is nephrotoxicity. Amelioration of cisplatin-induced nephrotoxicity is necessary. Lotus seedpod extract (LSE) mainly composed of quercetin-3-glucuronide has been revealed for antioxidant and anti-tumor effects. However, the effects of LSE on cisplatin-induced nephrotoxicity are still unknown. This study aims to explore the in vitro and in vivo protective effect and possible mechanism of LSE on cisplatin-induced nephrotoxicity. Results showed that co-treatment of LSE with cisplatin raised the viability of rat renal tubular epithelial NRK-52E cells and decreased oxidative stress and cell apoptosis when compared to the cells treated with cisplatin alone. The molecular mechanisms analyzed found that LSE could reduce the expressions of apoptotic factors, including Bax, Bad, t-Bid, and caspases. In the in vivo study, LSE improved the cisplatin-induced levels of serum markers of kidney function, glomerular atrophy, and the degree of apoptosis in the kidneys. This is the first study to display that LSE prevents cisplatin-induced nephrotoxicity by reducing oxidative stress and apoptosis. Thus, LSE could be a novel and natural chemoprotective agent for cisplatin chemotherapy in the future.

Hepatoprotective Activity of Nelumbo nucifera Gaertn. Seedpod Extract Attenuated Acetaminophen-Induced Hepatotoxicity.

The aim is to investigate the effect of lotus (Nelumbo nucifera Gaertn.) seedpod extract (LSE) on acetaminophen (APAP)-induced hepatotoxicity. LSE is rich in polyphenols and has potent antioxidant capacity. APAP is a commonly used analgesic, while APAP overdose is the main reason for drug toxicity in the liver. Until now, there has been no in vitro test of LSE in drug-induced hepatotoxicity responses. LSEs were used to evaluate the effect on APAP-induced cytotoxicity, ROS level, apoptotic rate, and molecule mechanisms. The co-treatment of APAP and LSEs elevated the survival rate and decreased intracellular ROS levels on HepG2 cells. LSEs treatment could significantly reduce APAP-induced HepG2 apoptosis assessed by DAPI and Annexin V/PI. The further molecule mechanisms indicated that LSEs decreased Fas/FasL binding and reduced Bax and tBid to restore mitochondrial structure and subsequently suppress downstream apoptosis cascade activation. These declines in COX-2, NF-κB, and iNOS levels were observed in co-treatment APAP and LSEs, which indicated that LSEs could ameliorate APAP-induced inflammation. LSE protected APAP-induced apoptosis by preventing extrinsic, intrinsic, and JNK-mediated pathways. In addition, the restoration of mitochondria and inflammatory suppression in LSEs treatments indicated that LSEs could decrease oxidative stress induced by toxic APAP. Therefore, LSE could be a novel therapeutic option for an antidote against overdose of APAP.

The Functional Roles and Regulation of Circular RNAs during Cellular Stresses.

Circular RNAs (circRNAs) are a novel class of regulatory RNA involved in many biological, physiological and pathological processes by functioning as a molecular sponge, transcriptional/epigenetic/splicing regulator, modulator of protein-protein interactions, and a template for encoding proteins. Cells are constantly dealing with stimuli from the microenvironment, and proper responses rely on both the precise control of gene expression networks and protein-protein interactions at the molecular level. The critical roles of circRNAs in the regulation of these processes have been heavily studied in the past decades. However, how the microenvironmental stimulation controls the circRNA biogenesis, cellular shuttling, translation efficiency and degradation globally and/or individually remains largely uncharacterized. In this review, how the impact of major microenvironmental stresses on the known transcription factors, splicing modulators and epitranscriptomic regulators, and thereby how they may contribute to the regulation of circRNAs, is discussed. These lines of evidence will provide new insight into how the biogenesis and functions of circRNA can be precisely controlled and targeted for treating human diseases.

CircVIS: a platform for circRNA visual presentation.

BACKGROUND: The collection of circRNAs mostly focused on their sequence composition such as protein/miRNA binding motif, and/or regulatory elements such as internal ribosome entry site. However, less attention was paid to subcellular localization. CircVIS aimed to provide a collection of circRNAs with information of subcellular compartments and also integrated the circRNA entries from previous circRNA databases. RESULTS: A collection of circRNAs from public circRNA databases and de novo identification were annotated according to subcellular localizations including nucleoplasm, chromatin-associated parts, cytoplasm and polyribosome. All circRNAs were aligned to a selected major transcript, and if presence, the circRNA-derived open reading frame with annotation of functional domain were compared to its parental protein. The results showed that distinct circRNAs may exert their molecular and cellular functions in different subcellular compartments. The web service is made freely available at http://lab-x-omics.nchu.edu.tw/circVIS . CONCLUSIONS: CircVIS allows users to visualize the alignment between a given circRNA and its most relevant reference transcript along with information of subcellular localization.

Anti-Atherosclerotic Effect of Gossypetin on Abnormal Vascular Smooth Muscle Cell Proliferation and Migration.

Gossypetin (GTIN), known as 3,5,7,8,3',4'-hexahydroxyflavone, has been demonstrated to exert anti-atherosclerotic potential against apoptotic injury in oxidized low-density lipoprotein-incubated endothelial cells, and atherosclerotic lesions of cholesterol-fed rabbits. However, the effect and underlying mechanism of GTIN on abnormal vascular smooth muscle cells (VSMCs) proliferation and migration, a major event in the pathogenesis of atherosclerosis, is still unknown. In this study, non-cytotoxic doses of GTIN abolished the VSMCs A7r5 proliferation and cell-cycle S phase distribution. The GTIN-arrested G0/G1 phase might be performed by increasing the expressions of phosphorylated p53 and its downstream molecules that inhibit the activation of cyclin E/cyclin-dependent kinase (cdk)-2, blocking retinoblastoma protein (Rb) phosphorylation and the subsequent dissociation of Rb/transcription factor E2F1 complex. In addition, the results indicated that GTIN inhibited VSMCs wound-healing and migratory abilities through reducing matrix metalloproteinase (MMP)-9 activity and expression, as well as down-regulating protein kinase B (PKB)/nuclear factor-kappaB (NF-κB) signaling. GTIN also revealed potential in diminishing reactive oxygen species (ROS) generation. These findings suggested the inhibitory effects of GTIN on VSMCs dysfunction could likely lead to the containment of atherosclerosis and other cardiovascular illness.

Aqueous Extract of Pepino Leaves Ameliorates Palmitic Acid-Induced Hepatocellular Lipotoxicity via Inhibition of Endoplasmic Reticulum Stress and Apoptosis.

Saturated fatty acid is one of the important nutrients, but contributes to lipotoxicity in the liver, causing hepatic steatosis. Aqueous pepino leaf extract (AEPL) in the previous study revealed alleviated liver lipid accumulation in metabolic syndrome mice. The study aimed to investigate the mechanism of AEPL on saturated long-chain fatty acid-induced lipotoxicity in HepG2 cells. Moreover, the phytochemical composition of AEPL was identified in the present study. HepG2 cells treated with palmitic acid (PA) were used for exploring the effect of AEPL on lipid accumulation, apoptosis, ER stress, and antioxidant response. The chemical composition of AEPL was analyzed by HPLC-ESI-MS/MS. AEPL treatment reduced PA-induced ROS production and lipid accumulation. Further molecular results revealed that AEPL restored cytochrome c in mitochondria and decreased caspase 3 activity to cease apoptosis. In addition, AEPL in PA-stressed HepG2 cells significantly reduced the ER stress and suppressed SREBP-1 activation for decreasing lipogenesis. For defending PA-induced oxidative stress, AEPL promoted Nrf2 expression and its target genes, SOD1 and GPX3, expressions. The present study suggested that AEPL protected from PA-induced lipotoxicity through reducing ER stress, increasing antioxidant ability, and inhibiting apoptosis. The efficacy of AEPL on lipotoxicity was probably concerned with kaempferol and isorhamnetin derived compounds.

Anti-Melanogenesis Effects of Lotus Seedpod In Vitro and In Vivo.

Melanogenesis has many important physiological functions. However, abnormal melanin production causes various pigmentation disorders. Melanin synthesis is stimulated by α-melanocyte stimulating hormone (α-MSH) and ultraviolet (UV) irradiation. Lotus seedpod extract (LSE) has been reported as possessing antioxidative, anti-aging, and anticancer activities. The present study examined the effect of LSE on melanogenesis and the involved signaling pathways in vitro and in vivo. Results showed that non-cytotoxic doses of LSE and its main component epigallocatechin (EGC) reduced both tyrosinase activity and melanin production in the α-MSH-induced melanoma cells. Western blotting data revealed that LSE and EGC inhibited expressions of tyrosinase and tyrosinase-related protein 1 (TRP-1). Phosphorylation of p38 and protein kinase A (PKA) stimulated by α-MSH was efficiently blocked by LSE treatment. Furthermore, LSE suppressed the nuclear level of cAMP-response element binding protein (CREB) and disturbed the activation of melanocyte inducing transcription factor (MITF) in the α-MSH-stimulated B16F0 cells. The in vivo study revealed that LSE inhibited melanin production in the ear skin of C57BL/6 mice after exposure to UVB. These findings suggested that the anti-melanogenesis of LSE involved both PKA and p38 signaling pathways. LSE is a potent novo natural depigmenting agent for cosmetics or pharmaceutical applications.

Aqueous extract from Pepino (Solanum muricatum Ait.) leaves ameliorated insulin resistance, hyperlipidemia, and hyperglycemia in mice with metabolic syndrome.

Solanum muricatum Ait. (Pepino) is a plant food commonly cultivated in the Penghu Island, Taiwan. This present study aimed to investigate the protective effects of aqueous extract of Pepino leaves (AEPL) in mice with metabolic syndrome. Metabolic syndrome animal model was induced by continuous high-fat diet feeding and low-dose streptozotocin (40 mg/ml) for 5 days. A 1% AEPL or metformin were given for 6 weeks after streptozotocin injection. The results revealed that 1% AEPL effectively reduced fasting blood glucose, insulin resistance, and hyperlipidemia in metabolic syndrome mice. Histologic examination revealed lipid accumulation in liver decreased by 1% AEPL treatment. Further, western blot analysis revealed 1% AEPL treatment managed enzymes related to lipid synthesis and oxidation pathways and hepatic glucose production. Besides, 1% AEPL treatment increased liver antioxidant activities to against oxidative stress. These results concluded that AEPL treatment attenuated insulin resistance, hyperlipidemia, and hyperglycemia of metabolic syndrome. PRACTICAL APPLICATIONS: Metabolic syndrome (MS) is a multifactorial chronic disease which is characterized by dyslipidemia, insulin resistance, and hyperglycemia. However, there is no single drug or defined medication for MS so far. The present study revealed that AEPL treatment was able to regulate lipid metabolism and glycemic control at the molecular level to alleviate MS. AEPL has the potential to be a novo complementary medication for metabolic syndrome.

Flavonoids Identification and Pancreatic Beta-Cell Protective Effect of Lotus Seedpod.

Oxidative stress is highly associated with the development of diabetes mellitus (DM), especially pancreatic beta-cell injury. Flavonoids derived from plants have caused important attention in the prevention or treatment of DM. Lotus seedpod belongs to a traditional Chinese herbal medicine and has been indicated to possess antioxidant, anti-age, anti-glycative, and hepatoprotective activities. The purpose of this study was to demonstrate the pancreatic beta-cell protective effects of lotus seedpod aqueous extracts (LSE) against oxidative injury. According to HPLC/ESI-MS-MS method, LSE was confirmed to have flavonoids derivatives, especially quercetin-3-glucuronide (Q3G). In vitro, LSE dose-dependently improved the survival and function of rat pancreatic beta-cells (RIN-m5F) from hydrogen peroxide (H2O2)-mediated loss of cell viability, impairment of insulin secretion, and promotion of oxidative stress. LSE showed potential in decreasing the H2O2-induced occurrence of apoptosis. In addition, H2O2-triggered acidic vesicular organelle formation and microtubule-associated protein light chain 3 (LC3)-II upregulation, markers of autophagy, were increased by LSE. Molecular data explored that antiapoptotic and autophagic effects of LSE, comparable to that of Q3G, might receptively be mediated via phospho-Bcl-2-associated death promoter (p-Bad)/B-cell lymphoma 2 (Bcl-2) and class III phosphatidylinositol-3 kinase (PI3K)/LC3-II signal pathway. In vivo, LSE improved the DM symptoms and pancreatic cell injury better than metformin, a drug that is routinely prescribed to treat DM. These data implied that LSE induces the autophagic signaling, leading to protect beta-cells from oxidative stress-related apoptosis and injury.

Oxaliplatin-Induced DHX9 Phosphorylation Promotes Oncogenic Circular RNA CCDC66 Expression and Development of Chemoresistance.

Circular RNA (circRNA), generated through backsplicing in which the downstream splice donor joins the upstream splice acceptor, is a novel class of RNA molecules. Our previous study found that a novel oncogenic circRNA-consisting exon 8-10 of CCDC66-is aberrantly expressed in colorectal cancer (CRC) tissues and cells. The failure of treatment for colorectal cancer is typically associated with recurrent and chemoresistant cancerous tissues. In this study, we aimed to investigate the role(s) of circCCDC66 during the development of chemoresistance. We discovered that the expression level of circCCDC66 is elevated in colorectal cancer cells with resistance to oxaliplatin. Knockdown of circCCDC66 caused the downregulation of a subset of genes which are regulated by circCCDC66-associated miRNAs and related to the modulation of apoptosis and the cell cycle, suppressing cell survival, promoting oxaliplatin-induced apoptosis and, thus, hindering the development of oxaliplatin-resistance (OxR). The induction of circCCDC66 was dependent on the time-course and dose of oxaliplatin treatment. Our analyses revealed that DHX9 harbors two phosphorylation sites of phosphatidylinositol 3-kinase-related kinases (PI3KKs) close to substrate-binding domains. Blockage of phosphorylation by either PI3KK inhibitors or nonphosphorable mutants of DHX9 decreased the oxaliplatin-induced circCCDC66 expression and the ability to develop chemoresistant cells. Taken together, we demonstrated and linked the functional role of DHX9 phosphorylation to oncogenic circCCDC66 expression during the development of resistance to oxaliplatin, providing a mechanistic insight for the development of therapeutic strategies to recurring/chemoresistant colorectal cancer.

Anti-Atherosclerotic Effect of Hibiscus Leaf Polyphenols against Tumor Necrosis Factor-alpha-Induced Abnormal Vascular Smooth Muscle Cell Migration and Proliferation.

The proliferation and migration of vascular smooth muscle cells (VSMCs) are major events in the development of atherosclerosis following stimulation with proinflammatory cytokines, especially tumor necrosis factor-alpha (TNF-α). Plant-derived polyphenols have attracted considerable attention in the prevention of atherosclerosis. Hibiscus leaf has been showed to inhibit endothelial cell oxidative injury, low-density lipoprotein oxidation, and foam cell formation. In this study, we examined the anti-atherosclerotic effect of Hibiscus leaf polyphenols (HLPs) against abnormal VSMC migration and proliferation in vitro and in vivo. Firstly, VSMC A7r5 cells pretreated with TNF-α were demonstrated to trigger abnormal proliferation and affect matrix metalloproteinase (MMP) activities. Non-cytotoxic doses of HLPs abolished the TNF-α-induced MMP-9 expression and cell migration via inhibiting the protein kinase PKB (also known as Akt)/activator protein-1 (AP-1) pathway. On the other hand, HLP-mediated cell cycle G0/G1 arrest might be exerted by inducing the expressions of p53 and its downstream factors that, in turn, suppress cyclin E/cdk2 activity, preventing retinoblastoma (Rb) phosphorylation and the subsequent dissociation of Rb/E2F complex. HLPs also attenuated reactive oxygen species (ROS) production against TNF-α stimulation. In vivo, HLPs improved atherosclerotic lesions, and abnormal VSMC migration and proliferation. Our data present the first evidence of HLPs as an inhibitor of VSMC dysfunction, and provide a new mechanism for its anti-atherosclerotic activity.

Lotus Seedpod Extracts Reduced Lipid Accumulation and Lipotoxicity in Hepatocytes.

Non-alcoholic fatty liver disease (NAFLD) is closely associated with metabolic disorders, including hepatic lipid accumulation and lipotoxicity. Plant-derived polyphenols have attracted considerable attention in the prevention of NAFLD. Lotus seedpod, rich in polyphenols, is a traditional Chinese herbal medicine. Previous studies have showed that lotus seedpod possess radioprotective, antioxidant, anti-cancer, and anti-inflammatory activities. In this study, the in vitro hepatoprotective effect of lotus seedpod extract (LSE) and its main component epigallocatechin (EGC) was examined. Firstly, oleic acid (OA), an unsaturated fatty acid, was used to induce the phenotype of NAFLD in human hepatocytes, HepG2 cells. LSE dose-dependently improved the OA-induced viability loss of HepG2 cells. Non-cytotoxic concentrations of LSE or EGC abolished intracellular lipid accumulation and oxidative stress in the OA-treated cells. In addition, LSE and EGC showed a minor effect on autophagy, and potential in reducing OA-induced occurrence of apoptosis confirmed by morphological and biochemical features, including an increase in the formation of apoptotic bodies, the exposure of phosphatidylserine, and activation of caspases. Molecular data showed the anti-apoptotic effect of LSE might be mediated via downregulation of the mitochondrial pathway. Our data imply that EGC-enriched LSE potentially could be developed as an anti-NAFLD agent.