Multi-target regulatory mechanism of Yang Xin Tang - a traditional Chinese medicine against dementia

BACKGROUND

Yang Xin Tang (YXT) is a traditional Chinese herbal preparation which has been reported to improve cognitive function and memory in patients with dementia. As the underlying mechanism of action of YXT has not been elucidated, we examined the effects of YXT and its major herbal components in regulating gene transcription and molecular targets related to Alzheimer's disease (AD).

METHODS

Aqueous and ethanol extracts of YXT and selected herbal components were prepared and validated by standard methods. A series of biochemical and cellular assays were employed to assess the ability of the herbal extracts to inhibit acetylcholinesterase, reduce β-amyloid aggregation, stimulate the differentiation of neural progenitor cells, suppress cyclooxygenase, and protect neurons against β-amyloid or N-methyl-D-aspartate-induced cytotoxicity. The effects of YXT on multiple molecular targets were further corroborated by a panel of nine reporter gene assays.

RESULTS

Extracts of YXT and two of its constituent herbs, Poria cocos and Poria Sclerotium pararadicis, significantly inhibited β-amyloid aggregation and β-amyloid-induced cytotoxicity. A protective effect of the YXT extract was similarly observed against N-methyl-D-aspartate-induced cytotoxicity in primary neurons, and this activity was shared by extracts of Radix Astragali and Rhizoma Chuanxiong. Although the YXT extract was ineffective, extracts of Poria cocos, Poria Sclerotium pararadicis and Radix Polygalae inhibited acetylcholine esterase, with the latter also capable of upregulating choline acetyltransferase. YXT and its components significantly inhibited the activities of the pro-inflammatory cyclooxygenases. Additionally, extracts of YXT and several of its constituent herbs significantly stimulated the phosphorylation of extracellular signal-regulated kinases and cAMP-responsive element binding protein, two molecular targets involved in learning and memory, as well as in the regulation of neurogenesis.

CONCLUSIONS

Several constituents of YXT possess multiple regulatory effects on known therapeutic targets of AD that range from β-amyloid to acetylcholinesterase. The demonstrated neuroprotective and neurogenic actions of YXT lend credence to its use as an alternative medicine for treating AD.

Adipocyte Fatty Acid Binding Protein Promotes the Onset and Progression of Liver Fibrosis via Mediating the Crosstalk between Liver Sinusoidal Endothelial Cells and Hepatic Stellate Cells

Development of liver fibrosis results in drastic changes in the liver microenvironment, which in turn accelerates disease progression. Although the pathological function of various hepatic cells in fibrogenesis is identified, the crosstalk between them remains obscure. The present study demonstrates that hepatic expression of adipocyte fatty acid binding protein (A-FABP) is induced especially in the liver sinusoidal endothelial cells (LSECs) in mice after bile duct ligation (BDL). Genetic ablation and pharmacological inhibition of A-FABP attenuate BDL- or carbon tetrachloride-induced liver fibrosis in mice associating with reduced collagen accumulation, LSEC capillarization, and hepatic stellate cell (HSC) activation. Mechanistically, elevated A-FABP promotes LSEC capillarization by activating Hedgehog signaling, thus impairs the gatekeeper function of LSEC on HSC activation. LSEC-derived A-FABP also acts on HSCs in paracrine manner to potentiate the transactivation of transforming growth factor β1 (TGFβ1) by activating c-Jun N-terminal kinase (JNK)/c-Jun signaling. Elevated TGFβ1 subsequently exaggerates liver fibrosis. These findings uncover a novel pathological mechanism of liver fibrosis in which LSEC-derived A-FABP is a key regulator modulating the onset and progression of the disease. Targeting A-FABP may represent a potential approach against liver fibrosis.

Simultaneous blocking of the pan-RAF and S100B pathways as a synergistic therapeutic strategy against malignant melanoma

Melanoma is a very aggressive form of skin cancer. Although BRAF inhibitors have been utilized for melanoma therapy, advanced melanoma patients still face a low five-year survival rate. Recent studies have shown that CRAF can compensate for BRAF depletion via regulating DNA synthesis to remain melanoma proliferation. Hence, targeting CRAF either alone or in combination with other protein pathways is a potential avenue for melanoma therapy. Based on our previously reported CRAF-selective inhibitor for renal cancer therapy, we have herein discovered an analogue (complex 1) from the reported CRAF library suppresses melanoma cell proliferation and melanoma tumour growth in murine models of melanoma via blocking the S100B and RAF pathways. Intriguingly, we discovered that inhibiting BRAF together with S100B exerts a novel synergistic effect to significantly restore p53 transcription activity and inhibit melanoma cell proliferation, whereas blocking BRAF together with CRAF only had an additive effect. We envision that blocking the pan-RAF and S100B/p53 pathways might be a novel synergistic strategy for melanoma therapy and that complex 1 is a potential inhibitor against melanoma via blocking the pan-RAF and S100B pathways.

Role of sirtuins in bone biology: Potential implications for novel therapeutic strategies for osteoporosis

The decline in bone mass and bone strength and musculoskeletal problems associated with aging constitute a major challenge for affected individuals and the healthcare system globally. Sirtuins 1-7 (SIRT1-SIRT7) are a family of nicotinamide adenine dinucleotide-dependent deacetylases with remarkable abilities to promote longevity and counteract age-related diseases. Sirtuin knockout and transgenic models have provided novel insights into the function and signaling of these proteins in bone homeostasis. Studies have revealed that sirtuins play a critical role in normal skeletal development and homeostasis through their direct action on bone cells and that their dysregulation might contribute to different bone diseases. Preclinical studies have demonstrated that mice treated with sirtuin agonists show protection against age-related, postmenopausal, and immobilization-induced osteoporosis. These findings suggest that sirtuins could be potential targets for the modulation of the imbalance in bone remodeling and treatment of osteoporosis and other bone disorders. The aim of this review was to provide a comprehensive updated review of the current knowledge on sirtuin biology, focusing specifically on their roles in bone homeostasis and osteoporosis, and potential pharmacological interventions targeting sirtuins for the treatment of osteoporosis.

A six-plex droplet digital RT-PCR assay for seasonal influenza virus typing, subtyping, and lineage determination

BACKGROUND

There are two influenza A subtypes (H1 and H3) and two influenza B lineages (Victoria and Yamagata) that currently co-circulate in humans. In this study, we report the development of a six-plex droplet digital RT-PCR (ddRT-PCR) assay that can detect HA and M segments of influenza A (H1, H3, and M) and influenza B (Yamagata HA, Victoria HA, and M) viruses in a single reaction mixture. It can simultaneously detect six different nucleic acid targets in a ddRT-PCR platform.

METHODS

The six-plex ddRT-PCR used in this study is an amplitude-based multiplex assay. The analytical performance of the assay was evaluated. Correlation with standard qRT-PCR methodology was assessed using 55 clinical samples.

RESULTS

The assay has a wide dynamic range, and it has good reproducibility within and between runs. The limit of quantification of each target in this assay ranged from 15 copies/reaction for influenza B Victoria M gene to 45 copies/reaction for influenza B Yamagata M gene. In addition, this assay can accurately quantify each of these targets in samples containing viral RNAs from two different viruses that were mixed in a highly skewed ratio. Typing, subtyping, and lineage differentiation data of 55 tested clinical respiratory specimens were found to be identical to those deduced from standard monoplex qRT-PCR assays.

CONCLUSIONS

The six-plex ddRT-PCR test was demonstrated to be highly suitable for detecting dual influenza infection cases. This assay is expected to be a useful diagnostic tool for clinical and research use.

Nidogen 1-Enriched Extracellular Vesicles Facilitate Extrahepatic Metastasis of Liver Cancer by Activating Pulmonary Fibroblasts to Secrete Tumor Necrosis Factor Receptor 1

In hepatocellular carcinoma (HCC) patients with extrahepatic metastasis, the lung is the most frequent site of metastasis. However, how the lung microenvironment favors disseminated cells remains unclear. Here, it is found that nidogen 1 (NID1) in metastatic HCC cell-derived extracellular vesicles (EVs) promotes pre-metastatic niche formation in the lung by enhancing angiogenesis and pulmonary endothelial permeability to facilitate colonization of tumor cells and extrahepatic metastasis. EV-NID1 also activates fibroblasts, which secrete tumor necrosis factor receptor 1 (TNFR1), facilitate lung colonization of tumor cells, and augment HCC cell growth and motility. Administration of anti-TNFR1 antibody effectively diminishes lung metastasis induced by the metastatic HCC cell-derived EVs in mice. In the clinical perspective, analysis of serum EV-NID1 and TNFR1 in HCC patients reveals their positive correlation and association with tumor stages suggesting the potential of these molecules as noninvasive biomarkers for the early detection of HCC. In conclusion, these results demonstrate the interplay of HCC EVs and activated fibroblasts in pre-metastatic niche formation and how blockage of their functions inhibits distant metastasis to the lungs. This study offers promise for the new direction of HCC treatment by targeting oncogenic EV components and their mediated pathways.

Effectiveness of WhatsApp online group discussion for smoking relapse prevention: protocol for a pragmatic randomized controlled trial

BACKGROUND AND AIMS

Sustained psychosocial support via online social groups may help former tobacco users maintain abstinence. This study aims to examine the effectiveness of participating in a WhatsApp social group for long-term smoking cessation.

DESIGN

Two-arm, open-labelled, pragmatic, individually randomized controlled trial.

SETTING

All participants are service users of smoking cessation clinics, and all interventions are delivered via mobile phones.

PARTICIPANTS

Participants included 1008 adult quitters who self-report no tobacco use in the past 3-30 days.

INTERVENTIONS

The intervention group (n = 504) will join a WhatsApp social group to receive standardized and theory-based reminders of smoking relapse prevention and participate in discussion with other WhatsApp group members using their own mobile phones. All social groups will be led by counselors or specialist nurse practitioners. The control group (n = 504) will receive similar reminders via short messages to their own mobile phones but will not interact with other participants. The intervention duration for both groups is 8 weeks. Both groups will receive a booklet at baseline about how to prevent smoking relapse.

MEASUREMENTS

The primary outcome is biochemically validated tobacco abstinence at 12 months after consent.

COMMENTS

The findings will provide evidence concerning the utility of operating online social group discussion for prevention of smoking relapse and sustaining long-term abstinence.

Photoelectrons Mediating Angiogenesis and Immunotherapy through Heterojunction Film for Noninvasive Disinfection

A light-inspired hydroxyapatite (Hap)/nitrogen-doped carbon dots (NCDs) modified graphene oxide (GO) heterojunction film is developed, which shows a promoted separation of interfacial electrons and holes and an inhibited recombination efficiency via hole depletion. The metabolism of bacteria on this film is significantly inhibited under light irradiation, due to the enhanced photocatalytic and photothermal effects. In addition, the electron transfer from the plasmonic membrane to the GO/NCD/Hap film further inhibits the adenosine triphosphate process of bacteria, thus leading to the synergetic antibacterial efficacy. Meanwhile, the electron transfer between film and cell membrane induces the Ca2+ flow after irradiation, which can promote the migration and proliferation of cells and alkaline phosphatase enhancement, thus favoring the tissue reconstruction. An in vivo test discloses that the vascular injury repair is achieved through the Ca2+-activated PLCγ1/ERK pathway, identified by the enhanced CD31 expression. Moreover, the increased CD4+/CD8+ lymphocytes are ameliorative by activating the PI3K/P-AKT pathway. Consequently, the electron transfer boosts the synergic photodynamic and photothermal therapeutic effects for bacterial infection by Ca2+ flow for immunotherapy. This mild phototherapy approach with GO/NCDs/Hap, which can simultaneously repair injured vessels and relieve inflammation reactions, will increase the clinical application of noninvasive phototherapy in the near future.

Review on the molecular epidemiology of sexually acquired hepatitis C virus infection in the Asia-Pacific region

INTRODUCTION

Sexual acquisition has emerged as a transmission route for hepatitis C virus (HCV) of growing importance among human immunodeficiency virus (HIV)-positive populations. In Western countries, HCV epidemics have been increasingly detected among men who have sex with men (MSM). This review describes the molecular epidemiology of sexually acquired HCV infection in the Asia-Pacific region.

METHODS

A systematic search was performed on PubMed in March 2019. Either abstract or full-text of each publication in the search results was screened for eligibility. Studies from different countries/cities involving eligible cases, who acquired HCV sexually with identified subtype, were synthesized for the evaluation of molecular epidemiology in the Asia-Pacific region. Two large-scale systematic reviews on the genotype distribution of HCV at a population level and among PWID were used as references for comparison.

RESULTS AND DISCUSSION

Overall, 13 full-text articles with 549 subjects originating from nine countries/cities were reviewed. A total of five genotypes and 14 subtypes were identified, dominated by subtypes 1b (23.0%), 2a (19.1%) and 3a (29.5%). A majority of the infected cases occurred in HIV-positive MSM. In some places, notably Hong Kong, India and Indonesia, the predominant subtype in sexually acquired HCV infection in MSM was different from that circulating in the general population. Shared transmission networks between people who inject drugs (PWID) and MSM were shown in Australia and New Zealand, whereas overlapping risk elicited from a small number of subjects existed in Tokyo, Taipei and Guangxi. MSM-specific clusters were identified in Hong Kong, Taipei and Hubei.

CONCLUSIONS

The distribution of sexually acquired HCV was sparsely scattered across countries/cities in the Asia-Pacific region. The threat of overlapping risk differed by locations, whereas transnational outbreaks remained uncommon. The paucity of information has hindered progress with comprehensive assessment in the Asia-Pacific region, where seroprevalence of HCV among HIV-positive MSM was relatively high.

Cross-reactive antibody-dependent cellular cytotoxicity antibodies are increased by recent infection in a household study of influenza transmission

OBJECTIVES

Influenza causes a spectrum of disease from asymptomatic infection to fatal outcome, and pre-existing immunity can alter susceptibility and disease severity. In a household transmission study, we recruited outpatients with confirmed influenza virus infection and prospectively identified secondary infections in their household contacts, therefore identifying infection cases with baseline samples for determining immune-mediated protection from influenza infection.

METHODS

We examined baseline broadly reactive immune correlates of relevance to universal vaccine development, specifically antibody-dependent cytotoxic (ADCC) antibodies and T-cell responses in functional assays. Antibodies were assessed in a cell-based NK cell degranulation assay by flow cytometry, and T-cell responses were assessed by IFN-γ intracellular cytokine staining flow cytometry assay.

RESULTS

The magnitude of antibody responses and ADCC function for multiple influenza-specific proteins was lower in participants who became infected, consolidating the role of pre-existing antibodies in protection from seasonal influenza virus infection. Among H1N1-infected contacts, we found that higher levels of pre-existing H1-haemagglutinin ADCC responses correlated with reduced symptom severity. Recent infection boosted the titre and magnitude of haemagglutinin-, neuraminidase- and nucleoprotein-specific ADCC antibodies. Limited T-cell samples precluded conclusions on the role of pre-existing T-cell responses.

CONCLUSIONS

Overall, ADCC responses are a protective correlate against influenza virus infection that should be considered in future vaccine development and evaluation.Influenza-specific ADCC responses are elevated in uninfected subjects, associated with reduced symptoms and boosted by recent infection, whilst HA stem and NA IgG are also elevated in uninfected participants irrespective of ADCC function.