Green mold, caused by Penicillium digitatum, is one of the most destructive postharvest diseases of citrus fruits, leading to significant rot and economic losses. In this study, the antifungal activity and underlying mechanism of the novel antimicrobial peptide (AMP) N1-6L7A against P. digitatum were investigated. Additionally, the potential application of N1-6L7A for controlling postharvest green mold in Citrus sinensis (L.) Osbeck was examined. N1-6L7A exhibited potential antifungal efficacy by inhibiting both mycelial growth and spore germination of P. digitatum. Furthermore, it demonstrated excellent thermal stability, pH tolerance, and biosafety. The results of fluorescence microscopy assay, cell component leakage, and microscopic observations revealed that N1-6L7A severely damaged the fungal membrane of P. digitatum, leading to the release of intracellular nucleic acids and proteins. N1-6L7A treatment also induced excessive intracellular reactive oxygen species (ROS) production, collapse of mitochondrial membrane potential, and decreased activities of malate dehydrogenase (MDH) and ATPase. Gel retardation assay indicated that P. digitatum-DNA was a target of N1-6L7A. Furthermore, transcriptomic analysis suggested that N1-6L7A might inhibit the growth of P. digitatum by blocking the expression of genes related to the ribosome, amino acid metabolism, and pyrimidine metabolism. Meanwhile, the peptide potentially promoted the expression of genes involved in steroid biosynthesis. Notably, in vivo assays confirmed that N1-6L7A effectively controlled P. digitatum infection in citrus fruits and enhanced host resistance by activating defense-related enzymes. Collectively, our results suggested that N1-6L7A could be used as an alternative fungicide to prevent green mold in citrus fruits.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder, which has recently been found to be closely associated with neuroinflammation. As an anti-inflammatory drug, triptolide (TP), a natural diterpenoid from Tripterygium wilfordii, was selected in the current study for treating PS19 (tauP301S transgenic) mice, tauopathy AD mice. In addition, we have previously found that TP had the ability to reduce the level of cholesterol. However, the roles and mechanisms of TP in the above processes are not clear. To this end, we found that elevated cholesterol in serum and brain tissues upregulated the expression of apolipoprotein E (APOE) and sialic acid-binding Ig-like lectin 3 (CD33), leading to the activation of SH2-containing protein tyrosine phosphatase 1 (SHP-1). The activation of SHP-1 inhibits the signaling pathways of Janus kinase 1 (JAK1) and signal transducer and activator of transcription 6 (STAT6), which results in inhibition of the M2 polarization of microglia, which exacerbates neuroinflammation and cognitive decline in high-cholesterol diet (HCD)-fed mice. Conversely, TP treatment significantly inhibited the hepatic sterol regulatory element-binding protein 2 (SREBP2)/3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) pathway, which reduced the cholesterol levels in the serum and brain. By depressing the levels of cholesterol, the axis of CD33 and SHP-1 was suppressed, which resulted in restoration of the activity of JAK1 and STAT6 pathways, leading to the transition of microglia from the M1 to the M2 phenotype. Of note, these observations demonstrate that TP alleviates the cognitive impairment of PS19 mice via depressing neuroinflammation. Altogether, our results revealed the mechanisms of TP in treating AD via CD33/SHP-1/JAK1/STAT6 pathways in a cholesterol-dependent manner.
Triptolide (TP) has shown its therapeutic effects on Alzheimer's disease (AD) via decreasing the overloading of β-amyloid protein (Aβ). However, the roles and mechanisms of TP in the pathogenesis of tau have not been revealed until now. To this end, the current study aimed to assess the effects of TP on AD via tau-associated mechanisms. In detail, TP treatment decreases the phosphorylation of tau, which results in attenuating the cognitive decline of PS19 mice. In the mechanisms, we found that TP treatment elevates the levels of insulin, which lowers the blood glucose, leading to superior performance in the glucose tolerance test, inhibition of AMP-activated protein kinase (AMPK), and the change of serum triglycerides and cholesterol. The in vitro studies demonstrating that TP increases insulin production via cAMP-response element binding protein (CREB)- and pancreatic-duodenal homeobox factor 1 (PDX-1)-dependent mechanisms in MIN6 cells further supported the in vivo findings. By enhancing insulin production, TP upregulates protein O-GlcNAc modification and inhibits Ca2+/calmodulin-dependent protein kinase 2 (CaMK2) activity to reduce tau phosphorylation in both in vivo and in vitro experiments. Additionally, metabolic changes decrease the activity of the CCAAT/enhancer binding protein beta (C/EBPβ)/asparagine endopeptidase (AEP) signaling pathway, significantly reducing the associated neuroinflammation. Guided by these mechanisms, TP shows inhibitory effects on tau phosphorylation via an insulin secretion-dependent pathway.
MMP-1 expression is detected in fluid shear stress (20 dyn/cm2)-activated and osteoarthritic human chondrocytes, however, the precise mechanisms underlying shear-induced MMP-1 synthesis remain unknown. Using primary chondrocytes and T/C-28a2 chondrocytic cells as model systems, we report that prolonged application of high fluid shear to human chondrocytes induced the synthesis of cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β) and fibroblast growth factor-2 (FGF-2), which led to a marked increase in MMP-1 expression. IL-1β, COX-2-dependent PGE2 activated the PI3-K/AKT and p38 signaling pathways, which were in turn responsible for MMP-1 synthesis via NF-κB- and c-Jun-transactivating pathways. Prolonged shear stress exposure (>12 h) induced 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) synthesis. Although 15d-PGJ2 suppressed PI3-K/AKT and p38 signaling pathways, it stimulated MMP-1 expression via activating heme oxygenase 1 (HO-1). The critical role of COX-2 in regulating MMP-1 expression in articular cartilage in vivo was demonstrated using COX-2+/− transgenic mice in the absence or presence of rofecoxib oral administration. These findings provide novel insights for developing therapeutic strategies to combat OA.
Aberrant activation of the complement system drives early synaptic loss and chronic neuroinflammation in Alzheimer's disease (AD). Here, we identified complement component C1q as a key upregulated target in AD and screened Alectinib (ALE), an FDA-approved kinase inhibitor, as a high-affinity C1q binder. To achieve brain-targeted delivery, ALE was encapsulated in nanostructured lipid carriers camouflaged with microglial membranes (ALE@MM-NLCs). This biomimetic design enhanced blood-brain barrier (BBB) penetration and microglial uptake. In APP/PS1 mice, ALE@MM-NLCs improved cognitive performance and reduced C1q expression, β-amyloid (Aβ) burden, and glial activation, while promoting microglial M2-like polarization. Mechanistically, ALE@MM-NLCs suppressed oxidative stress, NLRP3 inflammasome activation, and C1q-mediated synaptosome phagocytosis, thereby preventing proteasome-dependent synaptic degradation. These results highlight ALE@MM-NLCs as a promising immunomodulatory nanotherapy for synaptic preservation and early AD intervention.
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, which is pathologically characterized by impairing the motor neurons, leading to the disorders of motor function. Aspirin (ASP) has the ability to increase the survival time of SOD1G93A mice via concurrently reducing the activation of glial cells and restoring the number of neurons. Meanwhile, ASP treatment inhibited the activities of NF-κB pathway, which resulted in regulating the expression of complement system (CS), including C3, C1qb, and C4b in vivo. To reveal the inherent mechanisms, the in vitro experiments were carried out in SOD1G93A protein- and lipopolysaccharide (LPS)-treated BV2 cells. The results demonstrated that SOD1G93A protein or LPS induces the activation of NF-κB in BV2 cells, whose conditional medium induces the apoptosis of NSC34 cells. By blocking the activities of NF-κB by ASP, Bay 11–7082 or si NF-κB, the synthesis of CS molecules was suppressed, which results in alleviating the apoptosis of NSC34 cells. More importantly, Terminal complement complex (TCC) was identified to be the critical component of CS for mediating the effects of SOD1G93A protein or LPS on inducing the apoptosis of neurons, which was inhibited by the ASP or Bay 11–7082. On the basis of these observations, our findings novelly revealed that ASP delayed the progression of ALS via inhibiting the activities of microglia in a NF-κB-dependent CS-deactivating mechanisms.
The synthetic DSPE-PEG2000-C3 peptide and DSPE-PEG2000-TPP were designed to modify the exosomes (EXO) by incubation, through which guide the C3/TPP-EXO to target the injured mitochondria of neurons. Then, C3/TPP-EXO was further used to encapsulate the curcumin (CUR) to enhance the solubility and bioavailability of the drug. By intravenously injected (i.v) into taup301s mutant transgenic (Tg) mice, C3/TPP-EXO facilitated the CUR to target the mitochondria of neurons and increase the entry efficiency of medication. To further reveal the mechanisms of drug entry, sodium azide (NaN3), an energy inhibitor, was used to treat HT22 cells. The results demonstrated that the entrance efficiency of the engineered EXO is significantly affected suggesting that C3/TPP-EXO may target mitochondria through energy routes. To deeply study the exact molecular mechanisms of C3/TPP-EXO-CUR in treating AD, RNA-Seq was used to identify the relevant molecules. Through GO annotation, many genes are enriched in the pathways of mitochondria functions. Based on these RNA-Seq data, C3/TPP-EXO-CUR showed neuroprotective effects via modulating the protein expression of Bcl-2, Bax and caspase-3 in HT22 cells. To further confirm the in vitro results, the in vivo results revealed that C3/TPP-EXO-CUR treatment inhibited the phosphorylation of tau and protected neurons by inhibiting the apoptotic genes, leading to improve the memory decline of taup301s mice. Collectively, the current study revealed the benefits and mechanisms of C3/TPP-EXO-CUR for treating AD, which might provide a novel and effective therapeutic approach for the disease.
C5aR1 is a G protein-coupled receptor (GPCR) which is involved in exacerbating neurodegenerative diseases, including Alzheimer's disease (AD) and Amyotrophic Lateral Sclerosis (ALS). This review highlights the critical role of the C5-C5aR1 axis, in the pathogenesis of neurodegenerative diseases such as AD and ALS. In AD and ALS, abnormal protein aggregates activate the complement system (CS), leading to increased production of C5a. C5a activates C5aR1 on microglia, triggering the release of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) that induce synaptic loss. Concurrently, the C5-C5aR1 axis impairs microglial phagocytic capacity, promoting damage-associated molecular patterns (DAMPs) accumulation and forming a vicious cycle of inflammation and complement activation. Additionally, excessive complement molecule assembles into the terminal complement complex (TCC), which exerts direct neurotoxic effects and drives neuronal apoptosis. Preclinical studies show that C5aR1 antagonists, such as PMX205, mitigate disease progression in AD and ALS animal models by reducing neuroinflammation and preserving synaptic function. These findings underscore the C5-C5aR1 axis as a promising target for neurodegenerative disease therapy and highlight the need for further development of potential antagonists of C5aR1.
As a central molecule in complement system (CS), complement (C) 3 is upregulated in the patients and animal models of Alzheimer's disease (AD). C3 will metabolize to iC3b and C3a. iC3b is responsible for clearing β-amyloid protein (Aβ). In this scenario, C3 exerts neuroprotective effects against the disease via iC3b. However, C3a will inhibit microglia to clear the Aβ, leading to the deposition of Aβ and impair the functions of synapses. To their effects on AD, activation of C3a and C3a receptor (C3aR) will impair the mitochondria, leading to the release of reactive oxygen species (ROS), which activates the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasomes. The overloading of NLRP3 inflammasomes activate microglia, leading to the formation of inflammatory environment. The inflammatory environment will facilitate the deposition of Aβ and abnormal synapse pruning, which results in the progression of AD. Therefore, the current review will decipher the mechanisms of C3a inducing the synapse loss via C3aR in mitochondria-dependent NLRP3 activating mechanisms, which facilitates the understanding the AD.
Aims: The increasing incidence of chronic kidney disease (CKD) urgently calls for effective nephroprotective agents. Traditional Chinese Medicine Angelica sinensis and its formula are well known for CKD therapy, but the underlying mechanisms and effective substances of reno-protective effects remain unclear. To this end, we isolated eleven ligustilide dimers (1-11) from A. sinensis and examined the molecular mechanism of their nephroprotective effects.Main methods: Because of internal RAS playing an important role in CKD, we used renin expression as a target and screened preliminarily for antifibrotic effects of ligustilide dimers (1-11) by constructing a dual luciferase reporter gene in vitro. Furthermore, the reno-protective effects of the ligustilides and their underlying mechanism were investigated in TGF-beta 1-stimulated HK-2 cells and 5/6 nephrectomy (Nx) mice.Key findings: The ligustilide dimers exhibited anti-fibrotic effects by inhibiting human renin (hREN) promoter activity to decrease renin expression and down-regulate the expression of fibrosis-related factors, including alpha-SMA, collagen I, and fibronectin in vitro. Levistolide A (LA) and angeolide keto ester (AK) were screened out to identify their ability and underlying mechanism for treating CKD. Experimental validation further indicated that LA or AK treatment inhibited the expression of key molecules in RAS, TGF-beta 1/Smad, and MAPK pathways to downregulate ECM deposition. Furthermore, LA obviously meliorated renal injury in 5/6 Nx mice through ameliorating oxidant stress, inflammation, apoptosis and renal fibrosis.Significance: The experimental results demonstrated that ligustilide dimers were potential nephroprotective agents. LA might be an attractive drug candidate for renin-targeted CKD therapy.
To discover ulcerative colitis (UC) treatment agents, 28 oleanane-type triterpenoid saponins (1-28) including three new saponins, pulsatillosides P-R (1-3), were isolated from Pulsatilla chinensis. The isolated saponins could observably ameliorate UC by improving the intestinal epithelial cell barrier and intestinal flora in vivo. The structure-activity relationship indicated that the oligosaccharide chain at C-28 was essential for their anti-UC activities; the methyl group at the C-23 site of triterpene saponins showed important effects on anti-UC efficacy; the chain length of oligosaccharides at position C-28 had little effect on their anti-UC activities. In vivo investigation of representative saponins 1 and 13 further confirmed that 23-methyl-3,28-bisdesmosidic oleanane-type saponins inhibited the TNFα-NFκB-MLCK axis to improve the intestinal epithelial cell barrier of the colon in UC mice. These findings revealed the potential of 23-methyl-3,28-bisdesmosidic oleanane-type saponins from P. chinensis as promising candidates for the treatment of UC.
Post-translational modifications (PTMs) have been recently reported to be involved in the development and progression of Alzheimer’s disease (AD). In detail, PTMs include phosphorylation, glycation, acetylation, sumoylation, ubiquitination, methylation, nitration, and truncation, which are associated with pathological functions of AD-related proteins, such as β-amyloid (Aβ), β-site APP-cleavage enzyme 1 (BACE1), and tau protein. In particular, the roles of aberrant PTMs in the trafficking, cleavage, and degradation of AD-associated proteins, leading to the cognitive decline of the disease, are summarized under AD conditions. By summarizing these research progress, the gaps will be filled between PMTs and AD, which will facilitate the discovery of potential biomarkers, leading to the establishment of novel clinical intervention methods against AD.
Neuronal apoptosis is considered to be a critical cause of Alzheimer’s disease (AD). Recently, meloxicam has shown neuroprotective effects; however, the inherent mechanisms are highly overlooked. Using APP/PS1 transgenic (Tg) mice as in vivo animal models, we found that meloxicam inhibits apoptosis in neurons by deactivating tumor necrosis factor receptor superfamily member 25 (TNFRSF25), leading to the suppression of the expression of fas-associated protein with death domain (FADD) and the cleavage of DNA fragmentation factor subunit α (DFFA) and cysteine aspartic acid protease-3 (caspase 3) via β-amyloid protein (Aβ)-depressing mechanisms. Moreover, the meloxicam treatment blocked the effects of β-amyloid protein oligomers (Aβo) on stimulating the synthesis of tumor necrosis factor α (TNF-α) and TNF-like ligand 1A (TL1A) in neuroblastoma (N) 2a cells. TNF-α and TL1A induce apoptosis in neurons via TNFR- and TNFRSF25-dependent caspase 3-activating mechanisms, respectively. Knocking down the expression of TNFRSF25 blocked the effects of TL1A on inducing apoptosis in neurons by deactivating the signaling cascades of FADD, caspase 3, and DFFA. Consistently, TNFRSF25 shRNA blocked the effects of Aβo on inducing neuronal apoptosis, which was corroborated by the efficacy of meloxicam in inhibiting Aβo-induced neuronal apoptosis. By ameliorating neuronal apoptosis, meloxicam improved memory loss in APP/PS1 Tg mice.
C1q, the initiator of the classical pathway of the complement system, is activated during Alzheimer's disease (AD) development and progression and is especially associated with the production and deposition of β-amyloid protein (Aβ) and phosphorylated tau in β-amyloid plaques (APs) and neurofibrillary tangles (NFTs). Activation of C1q is responsible for induction of synapse loss, leading to neurodegeneration in AD. Mechanistically, C1q could activate glial cells, which results in the loss of synapses via regulation of synapse pruning and phagocytosis in AD. In addition, C1q induces neuroinflammation by inducing proinflammatory cytokine secretion, which is partially mediated by inflammasome activation. Activation of inflammasomes might mediate the effects of C1q on induction of synapse apoptosis. On the other hand, activation of C1q impairs mitochondria, which hinders the renovation and regeneration of synapses. All these actions of C1q contribute to the loss of synapses during neurodegeneration in AD. Therefore, pharmacological, or genetic interventions targeting C1q may provide potential therapeutic strategies for combating AD.
ABATRACTNine compounds, five phenolic glycosides (1, 2, 4-6), three phenylpropanoids (7-9), and a furanone glycoside (3), were isolated from aqueous soluble extract of the dried roots of Anemone chinensis Bunge. The structures of new compounds (1-4) were elucidated by comprehensive spectroscopic data analysis as well as chemical evidence. Pulsatillanin A (1) demonstrated significant antioxidant effects through scavenging free radical in DPPH assay, and relieved the oxidative stress in LPS-induced RAW 264.7 cells by reducing ROS production, enhancing antioxidant enzyme SOD activity, replenishing depleted GSH in a dose-dependent manner. Western blot analysis revealed that 1 showed antioxidant activity via activating Nrf2 signaling pathway.[Formula: see text].
Alzheimer's disease (AD) is a neurodegenerative disorder accompanied by the loss and apoptosis of neurons. Neurons abnormally enter the cell cycle, which results in neuronal apoptosis during the course of AD development and progression. However, the mechanisms underlying cell cycle re-entry have been poorly studied. Using neuroblastoma (N) 2a SW and APP/PS1 transgenic (Tg) mice as in vitro and in vivo AD models, we found that the expression of cyclin-dependent kinase (CDK)1/2/4 and cyclin A2/B1/D3/E1 was increased while the protein expression of p18 and p21 was decreased, which led to enhanced cell cycle re-entry in a β-amyloid protein (Aβ)-dependent mechanism. By preparing and treating with the temperature-sensitive chitosan-encapsulated drug delivery system (CS), the abnormal expression of CDK1/2/4, cyclin A2/B1/D3/E1 and p18/21 was partially restored by acetylsalicylic acid (ASA), which decreased the apoptosis of neurons in APP/PS1 Tg mice. Moreover, CDK4 and p21 mediated the effects of ASA on activating transcription factor (TF) EB via peroxisome proliferator-activated receptor (PPAR) α, thus leading to the uptake of Aβ by astrocytes in a low-density lipoprotein receptor (Ldlr)-dependent mechanism. Moreover, the mechanisms of Aβ-degrading mechanisms are activated, including the production of microtubule-associated protein light chain (LC) 3II and Lamp2 protein by ASA in a PPARα-activated TFEB-dependent manner. All these actions contribute to decreasing the production and deposition of Aβ, thus leading to improved cognitive decline in APP/PS1 Tg mice.
Riligustilide (RG), one of the dimeric phthalides of Angelica sinensis and Ligusticum chuanxiong, was confirmed effective against many diseases. However, its effects on type 2 diabetes mellitus (T2DM) and the underlying molecular mechanisms have not been clearly elucidated yet. The current study was designed to investigate the hypoglycemic potential by which RG affects the pathogenesis of T2DM. Comprehensive insights into the effects and underlying molecular mechanisms of RG on attenuating aberrant metabolism of glucose were determined in high-fat diet-induced T2DM mice and insulin-resistant (IR) HepG2 cells. In high-fat diet-induced C57BL/6J mice, RG administration significantly reduced hyperglycemia, decreased hyperinsulinemia, and ameliorated glucose intolerance. Mechanistically, RG activated PPARγ and insulin signaling pathway to improve insulin sensitivity, and increase glucose uptake as well as glycogenesis. In addition, RG also upregulated AMPK-TORC2-FoxO1 axis to attenuate gluconeogenesis in vivo and in vitro. According to the findings, RG may be a promising candidate for the treatment of T2DM.
Abstract Radix Astragali (RA) is an important Traditional Chinese Medicine widely used in the treatment of various diseases, such as pneumonia, atherosclerosis, diabetes, kidney and liver fibrosis. The role of isoflavonoids from RA in the treatment of liver injury remains unclear. The study aimed to explore hepatoprotective and anti-inflammatory effects of isoflavonoids from Astragalus mongholicus . Network pharmacological analysis showed that RA had a multi-target regulating effect on alleviating liver injury and inhibiting inflammation through its active ingredients, among which isoflavones were closely related to its key molecular targets. The anti-inflammatory and liver protection effects of isoflavonoids of RA were investigated using lipopolysaccharide (LPS)-induced RAW 264.7 cells in vitro and LPS/D-galactosamine (D-gal)-induced acute liver injury mice in vivo . The experimental results showed that methylnissolin (ML) and methylnissolin-3- O-β -D-glucoside (MLG) presented more notable anti-inflammatory effects. Both of them suppressed the release of pro-inflammatory cytokines, such as iNOS, COX-2, IL-1 β , IL-6, and TNF- α in LPS-stimulated RAW 264.7 cells. In vivo investigation demonstrated that ML markedly meliorated liver injury in LPS/D-gal-induced mice. Western blot results revealed that ML and MLG down-regulated the expression of proinflammatory cytokines via NF- κ B signaling pathway. The isoflavonoids, methylnissolin (ML), and methylnissolin-3- O-β -D-glucoside (MLG), play a vital role in the hepatoprotective and anti-inflammatory effects of RA.
Twenty seven dihydro-β-agarofuran sesquiterpenoids, including fifteen new congeners, wilforsinines I-W (1-9, 12-13, 24-27), and twelve known compounds were isolated from the dried root of Tripterygium wilfordii. The structures of the new sesquiterpenoids, wilforsinines I-W, were elucidated by extensive spectroscopic data analysis. The anti-inflammatory activity of isolates 1-27 were evaluated by examining their inhibitory effects on nitric oxide (NO) production in LPS-induced RAW 264.7 macrophage cells. Among them, wilforsinine K (3) and angulatin M (16) exerted optimal inhibitory effects on the production of NO in LPS-induced RAW 264.7 cells. Moreover, Western blot results revealed that their anti-inflammatory activities were correlated with the suppression of the expression of nitric oxide synthase (iNOS) and down-regulation of the level of NF-κB p65 phosphorylation.
Alzheimer’s disease (AD) is a neurodegenerative disease with a high incidence rate. The main pathological features of AD are β-amyloid plaques (APs), which are formed by β-amyloid protein (Aβ) deposition, and neurofibrillary tangles (NFTs), which are formed by the excessive phosphorylation of the tau protein. Although a series of studies have shown that the accumulation of metal ions, including calcium ions (Ca2+), can promote the formation of APs and NFTs, there is no systematic review of the mechanisms by which Ca2+ affects the development and progression of AD. In view of this, the current review summarizes the mechanisms by which Ca2+ is transported into and out of cells and organelles, such as the cell, endoplasmic reticulum, mitochondrial and lysosomal membranes to affect the balance of intracellular Ca2+ levels. In addition, dyshomeostasis of Ca2+ plays an important role in modulating the pathogenesis of AD by influencing the production and aggregation of Aβ peptides and tau protein phosphorylation and the ways that disrupting the metabolic balance of Ca2+ can affect the learning ability and memory of people with AD. In addition, the effects of these mechanisms on the synaptic plasticity are also discussed. Finally, the molecular network through which Ca2+ regulates the pathogenesis of AD is introduced, providing a theoretical basis for improving the clinical treatment of AD.