Dendrobium officinale phenolic extract maintains proteostasis by regulating autophagy in a Caenorhabditis elegans model of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease, and accumulating evidence suggested that proteostatic imbalance is a key feature of the disease. Traditional Chinese medicine exhibits a multi-target therapeutic effect, making it highly suitable for addressing protein homeostasis imbalance in AD. Dendrobium officinale is a traditional Chinese herbs commonly used as tonic agent in China. In this study, we investigated protection effects of D. officinale phenolic extract (SH-F) and examined its underlying mechanisms by using transgenic Caenorhabditis elegans models. We found that treatment with SH-F (50 µg/mL) alleviated Aß and tau protein toxicity in worms, and also reduced aggregation of polyglutamine proteins to help maintain proteostasis. RNA sequencing results showed that SH-F treatment significantly affected the proteolytic process and autophagy-lysosomal pathway. Furthermore, we confirmed that SH-F showing maintainance of proteostasis was dependent on bec-1 by qRT-PCR analysis and RNAi methods. Finally, we identified active components of SH-F by LC-MS method, and found the five major compounds including koaburaside, tyramine dihydroferulate, N-p-trans-coumaroyltyramine, naringenin and isolariciresinol are the main bioactive components responsible for the anti-AD activity of SH-F. Our findings provide new insights to develop a treatment strategy for AD by targeting proteostasis, and SH-F could be an alternative drug for the treatment of AD.

Down-regulation of A20 mRNA expression in peripheral blood mononuclear cells from MDS patients.

Myelodysplastic syndrome (MDS) is characterized by activated inflammatory signaling and affects prognosis. Targeting inflammatory signaling may provide a way to treat the disease. We were curious whether there were changes in A20 in peripheral blood mononuclear cells (PBMC) of MDS patients. Therefore, we conducted a study with 60 clinical samples, including 30 MDS patients and 30 healthy controls. All patients with MDS were diagnosed and classified according to the criteria of the 2016 World Health Organization. The study was performed in accordance with the guidelines of the Declaration of Helsinki. Using Quantitative Real-Time RT-PCR, we discovered that A20 mRNA expression in PBMC of the MDS group was significantly lower than that in the control group (P < 0.001). Additionally, using Luminex Liquid Suspension Chip, we observed elevated plasma levels of pro-inflammatory IL-8 and TNF-α in the MDS group compared to the healthy control group (P < 0.001). We did not find a significant correlation between A20 mRNA and clinical characteristics (age, sex, concentration of hemoglobin, neutrophils count, platelets count, percent of blasts, and WHO classification) of the patients, nor between A20 mRNA and plasma cytokines (data not shown). Our study found down-regulated of A20 and increased levels of pro-inflammatory cytokines in the peripheral blood of MDS patients, providing further evidence for the activation of inflammatory signals in MDS.

Sec-O-Glucosylhamaudol Inhibits RANKL-Induced Osteoclastogenesis by Repressing 5-LO and AKT/GSK3ß Signaling.

Sec-O-glucosylhamaudol (SOG), an active flavonoid compound derived from the root of Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk., exhibits analgesic, anti-inflammatory, and high 5-lipoxygenase (5-LO) inhibitory effects. However, its effect on osteoclastogenesis was unclear. We demonstrated that SOG markedly attenuated RANKL-induced osteoclast formation, F-actin ring formation, and mineral resorption by reducing the induction of key transcription factors NFATc1, c-Fos, and their target genes such as TRAP, CTSK, and DC-STAMP during osteoclastogenesis. Western blotting showed that SOG significantly inhibited the phosphorylation of AKT and GSK3ß at the middle-late stage of osteoclastogenesis without altering calcineurin catalytic subunit protein phosphatase-2ß-Aα expression. Moreover, GSK3ß inhibitor SB415286 partially reversed SOG-induced inhibition of osteoclastogenesis, suggesting that SOG inhibits RANKL-induced osteoclastogenesis by activating GSK3ß, at least in part. 5-LO gene silencing by small interfering RNA in mouse bone marrow macrophages markedly reduced RANKL-induced osteoclastogenesis by inhibiting NFATc1. However, it did not affect the phosphorylation of AKT or GSK3ß, indicating that SOG exerts its inhibitory effects on osteoclastogenesis by suppressing both the independent 5-LO pathway and AKT-mediated GSK3ß inactivation. In support of this, SOG significantly improved bone destruction in a lipopolysaccharide-induced mouse model of bone loss. Taken together, these results suggest a potential therapeutic effect for SOG on osteoclast-related bone lysis disease.

Agrimophol suppresses RANKL-mediated osteoclastogenesis through Blimp1-Bcl6 axis and prevents inflammatory bone loss in mice.

Excessive activity of osteoclasts causes many bone-related diseases, such as rheumatoid arthritis and osteoporosis. Agrimophol (AGR), a phenolic compound, originated from Agrimonia pilosa Ledeb. In prior studies, AGR is reported to possess schistosomicidal and mycobactericidal activities. However, no reports covered its anti-osteoclastogenesis characteristic. In this study, we found that AGR inhibited RANKL-induced osteoclastogenesis, bone-resorption, F-actin ring formation, and the mRNA expression of osteoclast-associated genes such as CTSK, TRAP, MMP-9, and ATP6v0d2 in vitro. In addition, AGR suppressed RANKL-induced expression of c-Fos and NFATc1. However, AGR treatment did not affect NF-κB activation and MAPKs phosphorylation in RANKL-stimulated BMMs, which implicated that AGR might not influence the initial expression of NFATc1 mediated by NF-κB and MAPKs signaling. Our results further indicated that AGR did not alter phosphorylation levels of GSK3ß and the expression of calcineurin, which implicated that AGR treatment might not interfere with phosphorylation and de-phosphorylation of NFATc1 mediated by GSK3ß and calcineurin, respectively. B-lymphocyte-induced maturation protein-1 (Blimp1), which was regarded as a transcriptional repressor of negative regulators of osteoclastogenesis, was markedly attenuated in the presence of AGR, leading to the enhanced expression of B-cell lymphoma 6 (Bcl-6). Meanwhile, Blimp1 knockdown in BMMs by siRNA strongly enhanced the expression of Bcl6 and reduced NFATc1 induction by RANKL. These findings suggested that AGR inhibited RANKL-induced osteoclast differentiation through Blimp1-Bcl-6 signaling mediated modulation of NFATc1 and its target genes. Consistent with these in vitro results, AGR exhibited a protective influence in an in vivo mouse model of LPS-induced bone loss by suppressing excessive osteoclast activity and attenuating LPS-induced bone destruction. Hence, these results identified that AGR could be considered as a potential therapeutic agent against bone lysis disease.

Coix seed oil prolongs lifespan and enhances stress resistance in Caenorhabditis elegans.

Coix seed oil (CSO) has many beneficial effects, but there is limited research on its influence on the processes and mechanisms related to senescence. Here, we used Caenorhabditis elegans as an in vivo model to investigate CSO's bioeffects on longevity. CSO (1 mg/mL) significantly extended the mean lifespan of C. elegans by over 22.79% and markedly improved stress resistance. Gene-specific mutant studies showed that the CSO-mediated increase in life expectancy was dependent on mev-1, hsf-1 and daf-16, but not daf-2. Furthermore, CSO significantly upregulated stress-inducible genes, including daf-16 and its downstream genes (sod-3, hsp-16.2 and gst-4). In addition, four major fatty acids, linoleic, oleic, palmitic and stearic, played leading roles in C. elegans' extended lifespan. Thus, CSO increased the life expectancy of, and enhanced the stress resistance in, C. elegans mainly through daf-16 and its downstream genes, but not through the insulin/insulin-like growth factor 1 signaling pathway.

Echinacoside, a phenylethanoid glycoside from Cistanche deserticola, extends lifespan of Caenorhabditis elegans and protects from Aß-induced toxicity.

Cistanche deserticola has been found to exert protection against aging and age-related diseases, but mechanisms underlying its longevity effects remain largely unclear. Here, the multicellular model organism Caenorhabditis elegans was employed to identify lifespan extending and protective effects against ß-amyloid (Aß) induced toxicity by echinacoside (ECH), a phenylethanoid glycoside isolated from C. deserticola. Our results showed that ECH extends the mean lifespan of worms and increases their survival under oxidative stress. Levels of intracellular reactive oxygen species and fat accumulation were also significantly suppressed by ECH. Moreover, ECH-mediated lifespan extension was found to be dependent on mev-1, eat-2, daf-2, and daf-16, but not sir-2.1 or hsf-1 genes. Furthermore, ECH triggered DAF-16 nuclear localization and upregulated two of its downstream targets, sod-3 and hsp-16.2. In addition, ECH significantly improved the survival of CL4176 worms in response to proteotoxic stress induced by Aß protein aggregation. Collectively, these findings suggested that reactive oxygen species scavenging, dietary restriction, and insulin/insulin-like growth factor signaling pathways could be partly involved in ECH-mediated lifespan extension. Thus, ECH may target multiple longevity mechanisms to extend lifespan and have a potency to prevent Alzheimer's disease progression.