Bone-derived MSCs encapsulated in alginate hydrogel prevent collagen-induced arthritis in mice through the activation of adenosine A_(2A/2B)receptors in tolerogenic dendritic cells

Tolerogenic dendritic cells(tol DCs)facilitate the suppression of autoimmune responses by differentiating regulatory T cells(Treg).The dysfunction of immunotolerance results in the development of autoimmune diseases,such as rheumatoid arthritis(RA).As multipotent progenitor cells,mesenchymal stem cells(MSCs),can regulate dendritic cells(DCs)to restore their immunosuppressive function and prevent disease development.However,the underlying mechanisms of MSCs in regulating DCs still need to be better defined.Simultaneously,the delivery system for MSCs also influences their function.Herein,MSCs are encapsulated in alginate hydrogel to improve cell survival and retention in situ,maximizing efficacy in vivo.The three-dimensional co-culture of encapsulated MSCs with DCs demonstrates that MSCs can inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines.In the collagen-induced arthritis(CIA)mice model,alginate hydrogel encapsulated MSCs induce a significantly higher expression of CD39^(+)CD73^(+)on MSCs.These enzymes hydrolyze ATP to adenosine and activate A_(2A/2B)receptors on immature DCs,further promoting the phenotypic transformation of DCs to tol DCs and regulating naive T cells to Tregs.Therefore,encapsulated MSCs obviously alleviate the inflammatory response and prevent CIA progression.This finding clarifies the mechanism of MSCs-DCs crosstalk in eliciting the immunosuppression effect and provides insights into hydrogel-promoted stem cell therapy for autoimmune diseases.

JAK inhibition ameliorated experimental autoimmune encephalomyelitis by blocking GM-CSF-driven inflammatory signature of monocytes

Monocytes are key effectors in autoimmunity-related diseases in the central nervous system(CNS)due to the critical roles of these cells in the production of proinflammatory cytokines,differentiation of T-helper(Th)cells,and antigen presentation.The JAK-STAT signaling is crucial for initiating monocytes induced immune responses by relaying cytokines signaling.However,the role of this pathway in modulating the communication between monocytes and Th cells in the pathogenesis of multiple sclerosis(MS)is unclear.Here,we show that the JAK1/2/3 and STAT1/3/5/6 subtypes involved in the demyelination mediated by the differentiation of pathological Th1 and Th17 and the CNS-infiltrating inflammatory monocytes in experimental autoimmune encephalomyelitis(EAE),a model for MS.JAK inhibition prevented the CNS-infiltrating CCR2-dependent Ly6^(Chi)monocytes and monocyte-derived dendritic cells in EAE mice.In parallel,the proportion of GM-CSF^(+)CD4^(+)T cells and GM-CSF secretion were decreased in pathological Th17 cells by JAK inhibition,which in turns converted CNS-invading monocytes into antigen-presenting cells to mediate tissue damage.Together,our data highlight the therapeutic potential of JAK inhibition in treating EAE by blocking the GM-CSF-driven inflammatory signature of monocytes.

Structural diversification of phenylspirodrimane lactams by employing a biosynthetic intermediate

Phenylspirodrimanes are a kind of meroterpenoids with structural diversity and complexity,exhibiting a wide of biological properties,especially for the lactam derivatives consisting a y-lactam moiety and N-linked side chains.These compounds were derived from multi-step combination of enzymatic and non-enzymatic conversions of intermediates in their biosynthetic pathways.Stachbotrydial(2)with an o-phthalaldehyde unit was supposed as the high-reactivity intermediate of phenylspirodrimane lactams via nonenzymatic reaction with amines.In the present work,an effective and non-enzymatic diversification strategy was developed for the structural diversification of phenylspirodrimane lactams including monomers and dimers from 2 by feeding structurally various mono-and diamines in the fungus Stachybotrys chartarum cultures.In total,24 phenylspirodrimane lactams(1,3-25)including 18 new compounds were synthesized.Among them,stachybocin A(1),a bioactive phenylspirodrimane lactam dimer,was produced with the yield of 18.7 mg/g of cell dry weight.The structures of these compounds were elucidated by extensive spectroscopic data,single-crystal X-ray diffraction(Cu Kα),and calculated electronic circular dichroism(ECD)analyses.Bioassay revealed that compounds 1,17,and 24 displayed significant inhibitory effect on the inactivated state of hNav 1.2 channels with IC_(50) values of 0.22,2.08,and 0.53μmol/L,respectively.In addition,1 showed potent protein tyrosine phosphatase 1B(PTP1B)inhibitory N-methyl-b-aspartate(NMDA)receptor antagonistic,and anti-inflammatory activities.

C_(19)-Diterpenoid alkaloid arabinosides from an aqueous extract of the lateral root of Aconitum carmichaelii and their analgesic activities

Eight new C_(19)-diterpenoid alkaloid arabinosides, named aconicarmichosides E–L(1–8), were isolated from an aqueous extract of the lateral roots of Aconitum carmichaelii(Fu Zi). Their structures were determined by spectroscopic and chemical methods including 2D NMR experiments and acid hydrolysis. Compounds 1–8, together with the previously reported four neoline 14-O-arabinosides from the same plant, represent the only examples of glycosidic diterpenoid alkaloids so far. At a dose of 1.0 mg/kg(i.p.), as compared with the black control, compounds 1, 2, and 4–6 exhibited analgesic effects with 465.6% inhibitions against acetic acid-induced writhing of mice. Structure–activity relationship was also discussed.

Aconapelsulfonines A and B,seco C_(20)-diterpenoid alkaloids deriving via Criegee rearrangements of napelline skeleton from Aconitum carmichaelii

Two sulfo nated seco C_(20)-diterpenoid alkaloids,aconapelsulfonines A(1) and B(2),were isolated from an aqueous extract of the raw material of "Fu Zi"(the Aconitum carmichaelii lateral roots),of which the structures were elucidated by various spectroscopic data,combined with X-ray crystallogra phic analysis.The unprecedented skeletons are biogenetically proposed to be derived via Criegee rearrangements of the napelline-type architecture.The two compounds exhibited dose-depended analgesic activities on an acetic acid-induced mice writhing test.

Structure, property, biogenesis, and activity of diterpenoid alkaloids containing a sulfonic acid group from Aconitum carmichaelii

Three new C20-diterpenoid alkaloids with a sulfonic acid unit,named aconicarmisulfonines B and C(1 and 2)and chuanfusulfonine A(3),respectively,were isolated from the Aconitum carmichaelii lateral roots("fu zi"in Chinese).Structures of 1-3 were determined by spectroscopic data analysis.Intriguing chemical properties and reactions were observed for the C20-diterpenoid alkaloids:(a)specific selective nucleophilic addition of the carbonyl(C-12)in 1 with CD3 OD;(b)interconversion between 1 and 2 in D2 O;(c)stereo-and/or regioselective deuterations of H-11αin 1-3 and both H-11αand H-11βin aconicarmisulfonine A(4);(d)TMSP-2,2,3,3-d4 promoted cleavage of the C-12-C-13 bond of 4 in D2 O;(e)dehydrogenation of 4 in pyridine-d5,and(f)Na2 SO3-assisted dehydrogenation and N-deethylation of songorine(5,a putative precursor of 1-4).Biogenetically,1 and 2 are correlated with 4,for which the same novel carbon skeleton is proposed to be derived from semipinacol rearrangements via migrations of C-13-C-16 and C-15-C-16 bonds of the napelline-type skeleton,respectively.Meanwhile,3 is a highly possible precursor or a concurrent product in the biosynthetic pathways of 1,2,and 4.In the acetic acid-induced mice writhing assay,at 1.0 mg/kg(i.p.),compounds 1,2,5,5 a,and 5 b exhibited analgesic effects against mice writhing.

Two unique C21-diterpenoid alkaloids from Aconitum carmichaelii

Two sulfonated diterpenoid alkaloids possessing different but related novel carbon skeletons,named aconidenusulfonine A(1)and 12,16-secoaconidenusulfonine A(2),respectively,were isolated as minor components from an aqueous extract of the lateral roots of Aconitum carmichaelii("Fu Zi").The structures of 1 and 2,representing the first two C21-diterpenoid alkaloids from nature,were determined by analysis of various spectroscopic data and chemical transformation,of which 1 was further proved by single-crystal X-ray diffraction.Especially,1 exhibited dose-depended analgesic activity consistent with the clinical function of Fu Zi.

Quercetin protects human brain microvascular endothelial cells from fibrillarβ-amyloid_(1–40)-induced toxicity

Amyloid beta-peptides(Aβ) are known to undergo active transport across the blood-brain barrier, and cerebral amyloid angiopathy has been shown to be a prominent feature in the majority of Alzheimer's disease. Quercetin is a natural flavonoid molecule and has been demonstrated to have potent neuroprotective effects, but its protective effect on endothelial cells under Aβ-damaged condition is unclear. In the present study, the protective effects of quercetin on brain microvascular endothelial cells injured by fibrillar Aβ_(1–40)(f Aβ_(1–40)) were observed. The results show that f Aβ_(1–40)-induced cytotoxicity in human brain microvascular endothelial cells(h BMECs) can be relieved by quercetin treatment. Quercetin increases cell viability, reduces the release of lactate dehydrogenase, and relieves nuclear condensation.Quercetin also alleviates intracellular reactive oxygen species generation and increases superoxide dismutase activity. Moreover, it strengthens the barrier integrity through the preservation of the transendothelial electrical resistance value, the relief of aggravated permeability, and the increase of characteristic enzyme levels after being exposed to f Aβ_(1–40). In conclusion, quercetin protects h BMECs from f Aβ_(1–40)-induced toxicity.