Rhodopsin mislocalization drives ciliary dysregulation in a novel autosomal dominant retinitis pigmentosa knock-in mouse model.

Rhodopsin mislocalization encompasses various blind conditions. Rhodopsin mislocalization is the primary factor leading to rod photoreceptor dysfunction and degeneration in autosomal dominant retinitis pigmentosa (adRP) caused by class I mutations. In this study, we report a new knock-in mouse model that harbors a class I Q344X mutation in the endogenous rhodopsin gene, which causes rod photoreceptor degeneration in an autosomal dominant pattern. In RhoQ344X/+ mice, mRNA transcripts from the wild-type (Rho) and RhoQ344X mutant rhodopsin alleles are expressed at equal levels. However, the amount of RHOQ344X mutant protein is 2.7 times lower than that of wild-type rhodopsin, a finding consistent with the rapid degradation of the mutant protein. Immunofluorescence microscopy indicates that RHOQ344X is mislocalized to the inner segment and outer nuclear layers of rod photoreceptors in both RhoQ344X/+ and RhoQ344X/Q344X mice, confirming the essential role of the C-terminal VxPx motif in promoting OS delivery of rhodopsin. The mislocalization of RHOQ344X is associated with the concurrent mislocalization of wild-type rhodopsin in RhoQ344X/+ mice. To understand the global changes in proteostasis, we conducted quantitative proteomics analysis and found attenuated expression of rod-specific OS membrane proteins accompanying reduced expression of ciliopathy causative gene products, including constituents of BBSome and axonemal dynein subunit. Those studies unveil a novel negative feedback regulation involving ciliopathy-associated proteins. In this process, a defect in the trafficking signal leads to a reduced quantity of the trafficking apparatus, culminating in a widespread reduction in the transport of ciliary proteins.

Dietary polyphenols suppress chronic inflammation by modulation of multiple inflammation-associated cell signaling pathways.

The high failure rate of the reductionist approach to discover effective and safe drugs to treat chronic inflammatory diseases has led scientists to seek alternative ways. Recently, targeting cell signaling pathways has been utilized as an innovative approach to discover drug leads from natural products. Cell signaling mechanisms have been identified playing key role in diverse diseases by inducing proliferation, cell survival and apoptosis. Phytochemicals are known to be able to modulate the cellular and molecular networks which are associated to chronic diseases including cancer-associated inflammation. In this review, the roles of dietary polyphenols (apigenin, kaempferol, quercetin, curcumin, genistein, isoliquiritigenin, resveratrol and gallic acid) in modulating multiple inflammation-associated cell signaling networks are deliberated. Scientific databases on suppressive effects of the polyphenols on chronic inflammation via modulation of the pathways especially in the recent five years are gathered and critically analyzed. The polyphenols are able to modulate several inflammation-associated cell signaling pathways, namely nuclear factor-kappa ß, mitogen activated protein kinases, Wnt/ß-catenin and phosphatidylinositol 3-kinase and protein kinase B via selective actions on various components of the networks. The suppressive effects of the polyphenols on the multiple cell signaling pathways reveal their potential use in prevention and treatment of chronic inflammatory disorders. Understanding the mechanistic effects involved in modulation of the signaling pathways by the polyphenols is necessary for lead identification and development of future functional foods for prevention and treatment of chronic inflammatory diseases.

A smartphone based method for mouse fundus imaging.

Noninvasive in vivo imaging of the mouse retina is essential for eye research. However, imaging the mouse fundus is challenging due to its small size and requires specialized equipment, maintenance, and training. These issues hinder the routine evaluation of the mouse retina. In this study, we developed a noncontact imaging system consisting of a smartphone, a 90D condensing lens, a homemade light diaphragm, a tripod, and a Bluetooth remote. With minimal training, examiners were able to capture fundus images from the mouse retina. We also found that fundus images captured using our system from wild type mice, mice with laser-induced retinal injury, and a mouse model of retinitis pigmentosa showed a quality similar to those captured using a commercial fundus camera. These images enabled us to identify normal structures and pathological changes in the mouse retina. Additionally, fluorescein angiography was possible with the smartphone system. We believe that the smartphone imaging system is low cost, simple, accessible, easy to operate, and suitable for the routine screening and examination of the mouse eye.

Standardized ethanol extract of Tinospora crispa upregulates pro-inflammatory mediators release in LPS-primed U937 human macrophages through stimulation of MAPK, NF-κB and PI3K-Akt signaling networks.

BACKGROUND: Immunomodulatory effects of Tinospora crispa have been investigated due to its traditional use to treat several inflammatory disorders associated to the immune system. The present study reports the underlying mechanisms involved in the stimulation of 80% ethanol extract of T. crispa stems on pro-inflammatory mediators release in lipopolysaccharide (LPS)-primed U937 human macrophages via MyD88-dependent pathways. METHODS: Release of interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, and production of prostaglandin E2 (PGE2) were determined by using enzyme-linked immunosorbent assay (ELISA). Immunoblot technique was executed to determine the activation of MAPKs molecules, NF-κB, PI3K-Akt and cyclooxygenase-2 (COX-2) protein. Determination of pro-inflammatory cytokines and COX-2 relative gene expression levels was by performing the real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). A reversed-phase HPLC method was developed and validated to standardize the T. crispa extract and chemical profiling of its secondary metabolites was performed by LC-MS/MS. RESULTS: Qualitative and quantitative analyses of chromatographic data indicated that syringin and magnoflorine were found as the major components of the extract. T. crispa-treatment prompted activation of NF-κB by enhancing IKKα/ß and NF-κB (p65) phosphorylation, and degradation of IκBα. The extract upregulated COX-2 protein expression, release of pro-inflammatory mediators and MAPKs (ERK, p38 and JNK) phosphorylation as well as Akt dose-dependently. T. crispa extract also upregulated the upstream signaling adaptor molecules, toll-like receptor 4 (TLR4) and MyD88. T. crispa-treatment also upregulated the pro-inflammatory markers mRNA expression. CONCLUSION: The results suggested that T. crispa extract stimulated the MyD88-dependent signaling pathways by upregulating the various immune inflammatory related parameters.

Modulation of cell signaling pathways by Phyllanthus amarus and its major constituents: potential role in the prevention and treatment of inflammation and cancer.

The causal and functional connection between inflammation and cancer has become a subject of much research interest. Modulation of cell signaling pathways, such as those involving mitogen activated protein kinases (MAPKs), nuclear factor kappa ß (NF-κB), phosphatidylinositol 3-kinase and protein kinase B (PI3K/Akt), and Wnt, and their outcomes play a fundamental role in inflammation and cancer. Activation of these cell signaling pathways can lead to various aspects of cancer-related inflammation. Hence, compounds able to modulate inflammation-related molecular targets are sought after in anticancer drug development programs. In recent years, plant extracts and their metabolites have been documented with potential in the prevention and treatment of cancer and inflammatory ailments. Plants possessing anticancer and anti-inflammatory properties due to their bioactive constituents have been reported to modulate the molecular and cellular pathways which are related to inflammation and cancer. In this review we focus on the flavonoids (astragalin, kaempferol, quercetin, rutin), lignans (phyllanthin, hypophyllanthin, and niranthin), tannins (corilagin, geraniin, ellagic acid, gallic acid), and triterpenes (lupeol, oleanolic acid, ursolic acid) of Phyllanthus amarus, which exert various anticancer and anti-inflammatory activities via perturbation of the NF-κB, MAPKs, PI3K/Akt, and Wnt signaling networks. Understanding the underlying mechanisms involved may help future research to develop drug candidates for prevention and new treatment for cancer and inflammatory diseases.

Standardized extract of Zingiber zerumbet suppresses LPS-induced pro-inflammatory responses through NF-κB, MAPK and PI3K-Akt signaling pathways in U937 macrophages.

BACKGROUND: Zingiber zerumbet rhizome has been used as spices and in traditional medicine to heal various immune-inflammatory related ailments. Although the plant was reported to have potent anti-inflammatory and immunosuppressive properties by several studies, the molecular mechanisms underlying the effects have not been well justified. PURPOSE: The study was carried out to investigate the molecular mechanisms underlying the anti-inflammatory properties of the standardized 80% ethanol extract of Z. zerumbet through its effect on mitogen-activated protein kinase (MyD88)-dependent nuclear factor-kappa B (NF-кB), mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/Akt (PI3K-Akt) signaling pathways in lipopolysaccharide (LPS)-induced U937 human macrophages. METHODS: Standardization of the 80% ethanol extract of Z. zerumbet was performed by using a validated reversed-phase HPLC method, while LC-MS/MS was used to profile the secondary metabolites. The release of pro-inflammatory markers, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and prostaglandin E2 (PGE2) was evaluated by enzyme-linked immunosorbent assay (ELISA), while the Western blot technique was executed to elucidate the expression of mediators linked to MyD88-dependent respective signaling pathways. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay was carried out to quantify the relative gene expression of cyclooxygenase (COX)-2 and pro-inflammatory mediators at the transcriptional level. RESULTS: The quantitative and qualitative analyses of Z. zerumbet extract showed the presence of several compounds including the major chemical marker zerumbone. Z. zerumbet extract suppressed the release of pro-inflammatory mediators, COX-2 protein expression and downregulated the mRNA expression of pro-inflammatory markers. Z. zerumbet-treatment also blocked NF-κB activation by preventing the phosphorylation of IKKα/ß and NF-κB (p65) as well as the phosphorylation and degradation of IκBα. Z. zerumbet extract concentration-dependently inhibited the phosphorylation of respective MAPKs (JNK, ERK, and p38) as well as Akt. Correspondingly, Z. zerumbet extract suppressed the upstream signaling adaptor molecules, TLR4 and MyD88 prerequisite for the NF-κB, MAPKs, and PI3K-Akt activation. CONCLUSION: The findings suggest that Z. zerumbet has impressive role in suppressing inflammation and related immune disorders by inhibition of various pro-inflammatory markers through the imperative MyD88-dependent NF-κB, MAPKs, and PI3K-Akt activation.

Phyllanthin from Phyllanthus amarus inhibits LPS-induced proinflammatory responses in U937 macrophages via downregulation of NF-κB/MAPK/PI3K-Akt signaling pathways.

Phyllanthin, a lignan from Phyllanthus species, has been reported to possess potent immunosuppressive properties on immune cells and on adaptive and innate immune responses in animal models. Herein, we investigated the inhibitory effects of phyllanthin isolated from Phyllanthus amarus on nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and PI3K-Akt signal transducing pathways in LPS-activated U937 cells. The lipopolysaccharide-stimulated excess production of prostaglandin was significantly suppressed by phyllanthin via the mechanisms linked to the modulatory effects of cyclooxygenase 2 protein and gene expression. Phyllanthin also significantly inhibited the release and mRNA expression of proinflammatory cytokines (interleukin-1 beta and tumor necrosis factor-alpha). Phyllanthin also significantly downregulated the phosphorylation of IκBα, NF-κB (p65), and IKKα/ß and suppressed the activation of JNK, ERK, p38MAPK, and Akt in a concentration-dependent manner. Additionally, phyllanthin downregulated the expression of upstream signaling molecules including MyD88 and toll-like receptor 4 that are essential for the activation of NF-κB, MAPKs, and PI3K-Akt signal transducing pathways. Based on these observations, phyllanthin may exert their suppressive effects on inflammatory process by mediating the release of inflammatory signaling molecules via the NF-κB, MAPKs, and PI3K-Akt signal transducing pathways. Thus, phyllanthin holds a great promise as a potential anti-inflammatory agent to treat various inflammatory diseases.

Anti-inflammatory effects of Phyllanthus amarus Schum. & Thonn. through inhibition of NF-κB, MAPK, and PI3K-Akt signaling pathways in LPS-induced human macrophages.

BACKGROUND: Phyllanthus amarus has been used widely in various traditional medicines to treat swelling, sores, jaundice, inflammatory diseases, kidney disorders, diabetes and viral hepatitis, while its pharmacological and biochemical mechanisms underlying its anti-inflammatory properties have not been well investigated. The present study was carried out to investigate the effects of 80% ethanolic extract of P. amarus on pro-inflammatory mediators release in nuclear factor-kappa B (NF-кB), mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/Akt (PI3K-Akt) signaling activation in lipopolysaccharide (LPS)-induced U937 human macrophages. METHODS: The release of prostaglandin E2 (PGE2) and pro-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1ß in a culture supernatant was determined by ELISA. Determination of cyclooxygenase-2 (COX-2) protein and the activation of MAPKs molecules (JNK, ERK and p38 MAPK), NF-κB and Akt in LPS-induced U937 human macrophages were investigated by immunoblot technique. The relative gene expression levels of COX-2 and pro-inflammatory cytokines were measured by using qRT-PCR. The major metabolites of P. amarus were qualitatively and quantitatively analyzed in the extract by using validated reversed-phase high performance liquid chromatography (HPLC) methods. RESULTS: P. amarus extract significantly inhibited the production of pro-inflammatory mediators (TNF-α, IL-1ß, PGE2) and COX-2 protein expression in LPS-induced U937 human macrophages. P. amarus-pretreatment also significantly downregulated the increased mRNA transcription of pro-inflammatory markers (TNF-α, IL-1ß, and COX-2) in respective LPS-induced U937 macrophages. It downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/ß and restored the degradation of IκBα, and attenuated the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a dose-dependent manner. P. amarus extract also downregulated the expression of upstream signaling molecules, TLR4 and MyD88, which play major role in activation of NF-κB, MAPK and PI3K-Akt signaling pathways. The quantitative amounts of lignans, phyllanthin, hypophyllahtin and niranthin, and polyphenols, gallic acid, geraniin, corilagin, and ellagic acid in the extract were determined by HPLC analysis. CONCLUSION: The study revealed that P. amarus targeted the NF-κB, MAPK and PI3K-Akt signaling pathways to exert its anti- inflammatory effects by downregulating the prospective inflammatory signaling mediators.

Magnoflorine Enhances LPS-Activated Pro-Inflammatory Responses via MyD88-Dependent Pathways in U937 Macrophages.

Magnoflorine, a major bioactive metabolite isolated from Tinospora crispa, has been reported for its diverse biochemical and pharmacological properties. However, there is little report on its underlying mechanisms of action on immune responses, particularly on macrophage activation. In this study, we aimed to investigate the effects of magnoflorine, isolated from T. crispa on the pro-inflammatory mediators generation induced by LPS and the concomitant NF-κB, MAPKs, and PI3K-Akt signaling pathways in U937 macrophages. Differentiated U937 macrophages were treated with magnoflorine and the release of pro-inflammatory mediators was evaluated through ELISA, while the relative mRNA expression of the respective mediators was quantified through qRT-PCR. Correspondingly, western blotting was executed to observe the modulatory effects of magnoflorine on the expression of various markers related to NF-κB, MAPK and PI3K-Akt signaling activation in LPS-primed U937 macrophages. Magnoflorine significantly enhanced the upregulation of TNF-α, IL-1ß, and PGE2 production as well as COX-2 protein expression. Successively, magnoflorine prompted the mRNA transcription level of these pro-inflammatory mediators. Magnoflorine enhanced the NF-κB activation by prompting p65, IκBα, and IKKα/ß phosphorylation as well as IκBα degradation. Besides, magnoflorine treatments concentration-dependently augmented the phosphorylation of JNK, ERK, and p38 MAPKs as well as Akt. The immunoaugmenting effects were further confirmed by investigating the effects of magnoflorine on specific inhibitors, where the treatment with specific inhibitors of NF-κB, MAPKs, and PI3K-Akt proficiently blocked the magnoflorine-triggered TNF-α release and COX-2 expression. Magnoflorine furthermore enhanced the MyD88 and TLR4 upregulation. The results suggest that magnoflorine has high potential on augmenting immune responses.

Anti-Inflammatory Effects of Hypophyllanthin and Niranthin Through Downregulation of NF-κB/MAPKs/PI3K-Akt Signaling Pathways.

Hypophyllanthin (HYP) and niranthin (NIR) are major lignans in Phyllanthus spp. and have been shown to possess strong anti-inflammatory activity. In this study, we investigated the anti-inflammatory effects and the underlying molecular mechanisms of HYP and NIR in in vitro cellular model of LPS-induced U937 macrophages. The effects of HYP and NIR on the production of prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) were measured by using ELISA, Western blot, and qRT-PCR. The expressions of signaling molecules related to nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), and phosphatidylinositol 3'-kinase-Akt (PI3K-Akt) signaling pathways were examined. The role of NF-κB, MAPKs, and Akt signaling pathways was confirmed by using specific inhibitors (BAY 11-7082, U0126, SB202190, SP600125, and LY294002) mediated suppression of TNF-α and COX-2 production. HYP and NIR significantly inhibited the protein and gene levels of COX-2 as well as the downstream signaling products of PGE2, TNF-α, and IL-1ß. HYP and NIR also suppressed the inhibitors of kappa B (IκB), IkB kinases (Ikkα/ß), NF-κB phosphorylation, and IκB degradation. HYP suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38 while NIR only suppressed JNK and ERK but did not have effect on p38. These results demonstrate that HYP and NIR downregulated COX-2, TNF-α, and IL-1ß gene expressions in U937 macrophages by interfering with the activation of NF-κB, MAPKs, and Akt. In conclusion, these lignans have potential to be developed as anti-inflammatory agents targeting the NF-κB, MAPK, and PI3K-Akt pathways.

Zerumbone suppresses the activation of inflammatory mediators in LPS-stimulated U937 macrophages through MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways.

Zerumbone (ZER), isolated mainly from the Zingiber zerumbet (Z. zerumbet) rhizomes was found to be effective against numerous inflammatory and immune disorders, however, the molecular and biochemical mechanisms underlying its anti-inflammatory and immunosuppressive properties have not been well studied. This study was carried out to examine the profound effects of ZER on inflammatory mediated MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways in LPS-stimulated U937 human macrophages. ZER significantly suppressed the up-regulation pro-inflammatory mediators, TNF-α, IL-1ß, PGE2, and COX-2 protein in LPS-induced human macrophages. Moreover, ZER significantly downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/ß as well as restored the degradation of IκBα. ZER correspondingly showed remarkable attenuation of the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a concentration-dependent manner. ZER also diminished the expression of upstream signaling molecules TLR4 and MyD88, which are prerequisite for the NF-κB, MAPK and PI3K-Akt activation. Additionally, quantification of relative gene expression of TNF-α, IL-1ß, and COX-2 indicated that, at a higher dose (50µM), ZER significantly downregulated the elevated mRNA transcription levels of the stated pro-inflammatory markers in LPS-stimulated U937 macrophages. The strong suppressive effects of ZER on the activation of inflammatory markers in the macrophages via MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways suggest that ZER can be a preventive and potent therapeutic candidate for the management of various inflammatory-mediated immune disorders.

Outer membrane proteins analysis of Shigella sonnei and evaluation of their antigenicity in Shigella infected individuals.

Bacillary dysentery caused by infection with Shigella spp. remains as serious and common health problem throughout the world. It is a highly multi drug resistant organism and rarely identified from the patient at the early stage of infection. S. sonnei is the most frequently isolated species causing shigellosis in industrialized countries. The antigenicity of outer membrane protein of this pathogen expressed during human infection has not been identified to date. We have studied the antigenic outer membrane proteins expressed by S. sonnei, with the aim of identifying presence of specific IgA and IgG in human serum against the candidate protein biomarkers. Three antigenic OMPs sized 33.3, 43.8 and 100.3 kDa were uniquely recognized by IgA and IgG from patients with S. sonnei infection, and did not cross-react with sera from patients with other types of infection. The antigenic proteome data generated in this study are a first for OMPs of S. sonnei, and they provide important insights of human immune responses. Furthermore, numerous prime candidate proteins were identified which will aid the development of new diagnostic tools for the detection of S. sonnei.

Temperature-regulated expression of outer membrane proteins in Shigella flexneri.

BACKGROUND: Bacteria exist widely in a diversity of natural environments. In order to survive adverse conditions such as nutrient depletion, biochemical and biological disturbances, and high temperature, bacteria have developed a wide variety of coping mechanisms. Temperature is one of the most important factors that can enhance the expression of microbial proteins. This study was conducted to investigate how outer membrane proteins (OMPs) of the bacterium Shigella flexneri respond to stress, especially during fever when the host's body temperature is elevated. METHODS: OMPs of S. flexneri ATCC 12022 and clinical isolate SH057 were extracted from an overnight culture grown at 37, 38.5, and 40°C. Comparisons of the expressed proteins under the different growth conditions were based on equal numbers of bacterial cells loaded in the SDS-PAGE gels. Separated proteins were stained with Coomassie brilliant blue. Selected proteins showing increased expression at 38.5 and 40°C were characterized by performing MALDI-ToF-ToF. RESULTS: Different degrees of expression were demonstrated for different proteins expressed at 37°C compared to 38.5 and 40°C. The proteins with molecular sizes of 18.4, 25.6, and 57.0 kDa showed increased expression level at increasing temperature and were identified as Dps, WrbA, and PepA, respectively. CONCLUSION: This study revealed that strains of S. flexneri respond at the proteomic level during stress caused by elevated temperature by decreasing the expression of proteins, maintaining the level of important proteins, or enhancing the levels of proteins presumably involved in survival and virulence.