Macrolide sesquiterpene pyridine alkaloids from Celastrus monospermus and evaluation of their immunosuppressive and anti-osteoclastogenesis activities.

Phytochemical investigation of the stems of Celastrus monospermus Roxb enabled isolation and identification of fifteen new macrolide sesquiterpene pyridine alkaloids (1-15) along with five known analogues. Their structures were elucidated by comprehensive spectroscopic analysis (NMR, HRESIMS, IR, UV), chemical hydrolysis, and single crystal X-ray diffraction analysis. Bioassay of the abundant isolates revealed that seven compounds inhibited the proliferation of B lymphocytes with IC50 values ranging between 1.4 and 19.9 µM. Among them, celasmondine C (3) could significantly promote the apoptosis of activated B lymphocyte, especially late-stage apoptosis. Besides, compounds 3, 16, and 20 exhibited potent suppression of osteoclast formation at a concentration of 1.0 µM. This investigation enriched the chemical diversity of macrolide sesquiterpene pyridine alkaloids, and supported evidence for the development of new immunosuppressive and anti-osteoclastogenesis agents.

DZ2002 alleviates corneal angiogenesis and inflammation in rodent models of dry eye disease via regulating STAT3-PI3K-Akt-NF-κB pathway.

Dry eye disease (DED) is a prevalent ocular disorder with a multifactorial etiology. The pre-angiogenic and pre-inflammatory milieu of the ocular surface plays a critical role in its pathogenesis. DZ2002 is a reversible type III S-adenosyl-L-homocysteine hydrolase (SAHH) inhibitor, which has shown excellent anti-inflammatory and immunosuppressive activities in vivo and in vitro. In this study, we evaluated the therapeutic potential of DZ2002 in rodent models of DED. SCOP-induced dry eye models were established in female rats and mice, while BAC-induced dry eye model was established in female rats. DZ2002 was administered as eye drops (0.25%, 1%) four times daily (20 µL per eye) for 7 or 14 consecutive days. We showed that topical application of DZ2002 concentration-dependently reduced corneal neovascularization and corneal opacity, as well as alleviated conjunctival irritation in both DED models. Furthermore, we observed that DZ2002 treatment decreased the expression of genes associated with angiogenesis and the levels of inflammation in the cornea and conjunctiva. Moreover, DZ2002 treatment in the BAC-induced DED model abolished the activation of the STAT3-PI3K-Akt-NF-κB pathways in corneal tissues. We also found that DZ2002 significantly inhibited the proliferation, migration, and tube formation of human umbilical endothelial cells (HUVECs) while downregulating the activation of the STAT3-PI3K-Akt-NF-κB pathway. These results suggest that DZ2002 exerts a therapeutic effect on corneal angiogenesis in DED, potentially by preventing the upregulation of the STAT3-PI3K-Akt-NF-κB pathways. Collectively, DZ2002 is a promising candidate for ophthalmic therapy, particularly in treating DED.

Sesquiterpenoids and Cytochalasins with Immunosuppressive Activity from Sonchus wightianus.

The plant species, Sonchus wightianus DC., was historically used in China for both medicinal and dietary uses. In present study, seven new guaiane sesquiterpenoids (1-7) and one cytochalasin (8), along with five known guaianes (9-13) and two known cytochalasins (14 and 15), were isolated from the whole plants of S. wightianus. These guaianes showed structural variations in the substituents at C-8 and/or C-15, and compounds 6 and 7 are two sesquiterpenoid glycoside derivatives. Their structures were determined by extensive analysis of spectroscopic, electronic circular dichroism, and X-ray diffraction data, and chemical method. Biological tests revealed that compounds 5 and 8 are potent and selective immunosuppressive reagents.

Chemical constituents from the twigs with leaves of Tetradium trichotomum.

Twelve compounds, comprising of four new ones, 6ß,7α-limondiol (1) and ethyl 19-hydroxyisoobacunoate diosphenol (2), N-benzoyl 3-prenyltyramine (9) and 9-O-methyl integrifoliodiol (12), were isolated from the twigs with leaves of Tetradium trichotomum. The structures were elucidated by analysis of MS, NMR, and single-crystal X-ray diffraction. Compounds 1, 6, 8, 9 and 12 exhibited immunosuppressive activities in vitro against the proliferation of ConA-induced T lymphocytes and LPS-induced B cells.

Enzymatic Synthesis of Noncanonical α-Amino Acids Containing γ-Tertiary Alcohols.

Noncanonical amino acids (ncAAs) containing tertiary alcohols are valuable as precursors of natural products and active pharmaceutical ingredients. However, the assembly of such ncAA scaffolds from simple material by C-C bond formation remains a challenging task due to the presence of multiple stereocenters and large steric hindrance. In this study, we present a novel solution to this problem through highly selective enzymatic decarboxylative aldol addition. This method allows for the streamlined assembly of multifunctionalized ncAAs with γ-tertiary alcohols from readily available materials, such as L -aspartatic acid and isatins, vicinal diones and keto esters. The modularity of electrophiles furnished four classes of ncAAs with decent efficiency as well as excellent site and stereocontrol. Computational modeling was employed to gain detailed insight into the catalytic mechanism and to provide a rationale for the observed selectivities. The method offers a single-step approach to producing multifunctionalized ncAAs, which can be directly utilized in peptide synthesis and bioactivity assessment.

TERT transcription and translocation into mitochondria regulate benzo[a]pyrene/BPDE-induced senescence and mitochondrial damage in mouse spermatocytes.

Telomere and mitochondria may be the targets of Benzo[a]pyrene (BaP) -induced male reproductive damage, and further elucidation of the toxic molecular mechanisms is necessary. In this study, we used in vivo and in vitro exposure models to explore the molecular mechanisms of TERT regulation in BaP-induced telomere and mitochondrial damage in spermatocytes. The results showed that the treatment of benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), the active metabolite of BaP, caused telomere dysfunction in mouse spermatocyte-derived GC-2 cells, resulting in S-phase arrest and increased senescence-associated secretory phenotype (SASP). These effects were significantly alleviated by telomerase agonist (ABG) pretreatment in GC-2 cells. SIRT1, FOXO3a, or c-MYC overexpressing GC-2 cell models were established to demonstrate that BPDE inhibited TERT transcriptional expression through the SIRT1/FOXO3a/c-MYC pathway, leading to telomere dysfunction. We also observed that BPDE induced mitochondrial compromise, including complex I damage, accompanied by reduced mitochondrial TERT expression. Based on this, we constructed wild-type TERT-overexpressing (OE-TERTwt) and mitochondria targeting TERT-overexpressing (OE-TERTmst) GC-2 cell models and found that OE-TERTmst GC-2 cells improved mitochondrial function better than OE-TERTwt GC-2 cells. Finally, ICR mice were given BaP by intragastric administration for 35 days, which verified the results of the in vitro study. The results shown that BaP exposure can lead to spermatogenesis disturbance, which is related to the telomere and mitochondrial damage in spermatocytes. In conclusion, our results suggest that BPDE causes telomere and mitochondrial damage in spermatocytes by inhibiting TERT transcription and mitochondrial TERT expression. This study elucidates the molecular mechanism of male reproductive toxicity due to environmental pollutant BaP, and also provides a new perspective for the exploration of interventions and protective measures against male reproductive damage by BaP.

Baccaramiones A-D, Four Highly Oxygenated and Rearranged Trinorditerpenoids from Baccaurea ramiflora.

Baccaramiones A-D (1-4), four highly oxygenated and rearranged trinorditerpenoids, were isolated from Baccaurea ramiflora. Compound 1 is a 1(10 → 5)-abeo-15,16,17-trinor-ent-abietane featuring a unique 5/6/6 spirocyclic scaffold, and 2-4 are the first example of a novel 20(10 → 5)-abeo-15,16,17-trinor-ent-abietane skeleton. Their structures were established by spectroscopic analysis, X-ray crystallography, and electronic circular dichroism calculations. A plausible biosynthetic pathway for 1-4 was proposed. Interestingly, compounds 3 and 4 exhibited significant immunosuppressive activities against concanavalin A-induced T cell proliferation and lipopolysaccharide-induced B cell proliferation in vitro.

Synthesis and biological evaluation of pyrazole-fused oleanolic acid derivatives as novel inhibitors of inflammatory and osteoclast differentiation.

A series of pyrazole-fused oleanolic acid derivatives were designed and synthesized. The modification of these analogues focused on the substituents screening on the pyrazole ring. The cytotoxicity of these compounds and their anti-inflammatory activities via inhibiting interleukin-1ß (IL-1ß) production were evaluated in RAW264.7 cells. Most of the derivatives showed significantly improved potency compared with oleanolic acid. Among them, compound 7n exhibited the most potent anti-inflammatory activity on decreasing IL-1ß production with low cytotoxicity. Moreover, the further study found 7n could inhibit RANKL-induced osteoclast differentiation on bone marrow-derived macrophages (BMMs). These findings may provide a potential direction for the drug development of osteoarthritis.

Sumatranins A-J: Lignans with Immunosuppressive Activity from Cleistanthus sumatranus.

Chemical investigation of the twigs of Cleistanthus sumatranus (Phyllanthaceae) led to the isolation of 10 undescribed lignans, sumatranins A-J (1-10). Compounds 1-4 are unprecedented furopyran lignans characterized by a unique 2,3,3a,9a-tetrahydro-4H-furo[2,3-b]chromene heterotricyclic framework. Compounds 9 and 10 are rare 9'-nor-dibenzylbutane lignans. Structures were established based on analyses of spectroscopic data, X-ray crystallographic data, and experimental ECD spectra. Immunosuppressive assays revealed compounds 3 and 9 displayed moderate inhibitory effects with good selectivity indexes against LPS-induced B lymphocyte proliferation.

Dihydro-ß-agarofuran-type sesquiterpenoids from the seeds of Tripterygium wilfordii (Thunder God Vine) and evaluation of their anti-osteoclastogenesis and immunosuppressive activities.

Extensive phytochemical investigation of the seeds of Tripterygium wilfordii led to the identification of 54 polyesterified dihydro-ß-agarofuran-type sesquiterpenoids, including 27 previously undescribed ones, named Tripwilin I-XXVII (1-27). Comprehensive spectroscopic and single-crystal X-ray diffraction analyses, along with electronic circular dichroism (ECD) calculations were used for the structural elucidation of the new compounds. Biological assay revealed that 37 compounds among the isolates exhibited significant inhibition against osteoclastogenesis induced by receptor activator of nuclear factor-κB ligand (RANKL) at 10 µM. Further investigation indicated that Triptogelin C-3 (54), with the most potent osteoclastogenesis inhibitory activity, regulated the osteoclast marker genes (MMP-9, c-Fos, CTSK, and TRAP) and proteins in a dose-dependent manner in vitro. Besides, celaforin D-1 (28), 1α,6ß,15-triacetoxy-8α,9α-dibenzoyloxy-2α-hydroxydihydro-ß-agarofuran (34), triptogelin A-2 (37), and chiapen D (49) showed moderate suppressive effects on the proliferation of T and B lymphocytes with IC50 values ranging between 8.1 ± 0.8 and 19.0 ± 0.9 µM.

A pilot study on pyroptosis related genes in peripheral blood mononuclear cells of non-small cell lung cancer patients.

OBJECTIVE: To investigate the GSDMD, CASP1, CASP4 and CASP5 expression in peripheral blood mononuclear cells of non-small cell lung cancer patients and analyze their clinical significance. METHODS: 71 non-small cell lung cancer patients were selected as the study group and 50 healthy individuals as the control group. The GSDMD, CASP1, CASP4 and CASP5 expression in peripheral blood mononuclear cells of the two groups were detected by real-time fluorescence quantitative PCR. The GSDMD, CASP1, CASP4, CASP5 expression and their relationship with the clinical characteristics of the patients were analyzed. RESULTS: Compared with the control group, the GSDMD, CASP4 and CASP5 expression in PBMCs of lung cancer patients was significantly higher(P < 0.05). Lymph node metastasis had significant difference with the CASP4 and GSDMD expression (P < 0.05); tumor volume had significant difference with CASP1 and CASP5 expression (P < 0.05). The areas under predictive ROC curve of the GSDMD, CASP1, CASP4, and CASP5 mRNA expression were 0.629(P < 0.05), 0.574(p > 0.05), 0.701(P < 0.05) and 0.628(P < 0.05), the sensitivity values were 84.5%, 67.6% 43.7%, and 84.3%;the specificity values were 42%, 52%, 84% and 64%, respectively. CONCLUSION: GSDMD, CASP1, CASP4 and CASP5 gene expression are highly increased in PBMCs of non-small cell lung cancer patients and their expression are closely related to the clinical characteristics of patients. The early enhanced pyroptosis-related gene expression may be potential molecular markers for early diagnosis of non-small cell lung cancer.

Dolabrane-Type Diterpenoids with Immunosuppressive Activity from Koilodepas hainanense.

Thirteen new dolabrane-type diterpenoids, koilodenoids A-M (1-13), including a chlorinated congener (2), along with six known analogues, were isolated from Koilodepas hainanense. The structures were determined by analysis of spectroscopic data, ECD spectra, and X-ray crystallographic studies. The absolute configuration of C-15 in the 15,16-diol unit of compounds 4 and 5 was established by using the dimolybdenum tetraacetate [Mo2(AcO)4]-induced ECD method. Compounds 4, 7, 16, 17, and 19 showed moderate to significant immunosuppressive activities against the proliferation of T and B lymphocytes in vitro, with compound 16 being the most potent (IC50 0.86 and 0.29 µM, respectively).

Artemisinin derivative SM934 in the treatment of autoimmune and inflammatory diseases: therapeutic effects and molecular mechanisms.

Artemisinin and its derivatives are the well-known anti-malarial drugs derived from a traditional Chinese medicine. In addition to antimalarial, artemisinin and its derivatives possess distinguished anti-cancer, anti-oxidant, anti-inflammatory and anti-viral activities, but the poor solubility and low bioavailability hinder their clinical application. In the last decades a series of new water-soluble and oil-soluble derivatives were synthesized. Among them, we have found a water-soluble derivative ß-aminoarteether maleate (SM934) that exhibits outstanding suppression on lymphocytes proliferation in immunosuppressive capacity and cytotoxicity screening assays with 35-fold higher potency than dihydroartemisinin. SM934 displays significant therapeutic effects on various autoimmune and inflammatory diseases, including systemic lupus erythematosus, antiphospholipid syndrome nephropathy, membranous nephropathy, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, and dry eye disease. Here, we summarize the immunomodulatory effects, anti-inflammatory, anti-oxidative and anti-fibrosis activities of SM934 in disease-relevant animal models and present the probable pharmacological mechanisms involved in its therapeutic efficacy. This review also delineates a typical example of natural product-based drug discovery, which might further vitalize natural product exploration and development in pharmacotherapy.

PKCß Inhibition Promotes TXNIP Degradation to Ameliorate Pancreatic ß-Cell Dysfunction.

INTRODUCTION: Pancreatic ß-cell dysfunction is largely regulated by TXNIP accumulation, we have previously disclosed the role of PKA in TXNIP degradation during ß-cell dysfunction. However, whether other kinases (PKCs) still regulate TXNIP is unclear, which is beneficial to alleviate ß-cell dysfunction. METHODS: Thapsigargin (ER stress inducer) was used to induce ß-cell dysfunction. PKC's inhibitors were screened by Western blotting indicated by TXNIP. Also RT-qPCR and Co-immunoprecipitation were applied for evaluating the ß-cell improvement ability of PKC's inhibitors, and the insulin secretion ability was evaluated by glucose-stimulated insulin secretion assay. RESULTS: PKC's pan-inhibitor, Ro31-8220, decreased ß-cell apoptosis and improved insulin secretion under ER stress or high glucose (HG) conditions. Further studies showed that Ro31-8220 reduced ER stress or HG-induced TXNIP levels. On the other side, PKCß activation or overexpression could reverse the effect of Ro31-8220 on TXNIP. Also, PKCß selective inhibitor, ruboxistaurin, induced TXNIP degradation as significantly as Ro31-8220 did. CONCLUSION: This study reveals the regulating mechanism of PKCß inhibitor on TXNIP degradation to improve ß-cell dysfunction. These data indicated PKCß inhibitor is a promising agent for ameliorating ß-cell dysfunction through TXNIP.

Rh-Catalyzed C-H alkylation enabling modular synthesis of CF3-substituted benzannulated macrocyclic inhibitors of B cell responses.

Inspired by aspirin and chalcone, herein, we describe a modular biomimetic strategy to achieve a new class of CF3-bearing benzannulated macrolactams. The key to the success of macrolactams was the utilization of a highly chemoselective Rh(iii)-catalyzed native carboxylic acid-directed C-H alkylation. Moreover, the unique CF3-containing benzannulated macrocycles showed decent immunosuppressive effects on B cells in vitro, including proliferation, activation, and antibody production upon specific stimulation implicating TLR and BCR signaling.

Synthesis and pharmacological evaluation of choroquine derivatives bearing long aminated side chains as antivirus and anti-inflammatory agents.

Starting from the antimalarial drugs chloroquine and hydroxychloroquine, we conducted a structural optimization on the side chain of chloroquine by introducing amino substituted longer chains thus leading to a series of novel aminochloroquine derivatives. Anti-infectious effects against SARS-Cov2 spike glycoprotein as well as immunosuppressive and anti-inflammatory activities of the new compounds were evaluated. Distinguished immunosuppressive activities on the responses of T cell, B cell and macrophages upon mitogen and pathogenic signaling were manifested. Compounds 9-11 displayed the most promising inhibitory effects both on cellular proliferation and on the production of multiple pro-inflammatory cytokines, including IL-17, IFN-γ, IL-6, IL-1ß and TNF-α, which might be insightful in the pursuit of treatment for immune disorders and inflammatory diseases.

Minor immunosuppressive spiroorthoester group-containing pregnane glycosides from the root barks of Periploca sepium.

LC-MS guided chemical investigation of the periploside-rich extract of the root barks of Periploca sepium afforded six new minor pregnane glycosides, named periplosides A1-A6 (1-6). Their structures were characterized on the basis of extensive spectroscopic analysis. Compounds 1-6 were evaluated for their inhibitory activities against the proliferation of T and B lymphocytes in vitro, among them, compound 5 exhibited significant inhibitory activities and the most favorite selective index (SI) values against the proliferation of T lymphocyte (IC50 = 0.30 µM, SI = 176) and B lymphocyte (IC50 = 0.55 µM, SI = 97).

NOD-like receptors in autoimmune diseases.

Autoimmune diseases are chronic immune diseases characterized by dysregulation of immune system, which ultimately results in a disruption in self-antigen tolerance. Cumulative data show that nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) play essential roles in various autoimmune diseases, such as inflammatory bowel disease (IBD), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, multiple sclerosis (MS), etc. NLR proteins, consisting of a C-terminal leucine-rich repeat (LRR), a central nucleotide-binding domain, and an N-terminal effector domain, form a group of pattern recognition receptors (PRRs) that mediate the immune response by specifically recognizing cellular pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs) and triggering numerous signaling pathways, including RIP2 kinase, caspase-1, nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and so on. Based on their N-terminal domain, NLRs are divided into five subfamilies: NLRA, NLRB, NLRC, NLRP, and NLRX1. In this review, we briefly describe the structures and signaling pathways of NLRs, summarize the recent progress on NLR signaling in the occurrence and development of autoimmune diseases, as well as highlight numerous natural products and synthetic compounds targeting NLRs for the treatment of autoimmune diseases.

A novel tricyclic BTK inhibitor suppresses B cell responses and osteoclastic bone erosion in rheumatoid arthritis.

Rheumatoid arthritis (RA) is characterized by joint leukocyte infiltration, synovial inflammation and bone damage result from osteoclastogenesis. Bruton's tyrosine kinase (BTK) is a key regulator of B cell receptor (BCR) and Fc gamma receptor (FcγR) signaling involved in the pathobiology of RA and other autoimmune disorders. SOMCL-17-016 is a potent and selective tricyclic BTK inhibitor, structurally distinct from other known BTK inhibitors. In present study we investigated the therapeutic efficacy of SOMCL-17-016 in a mouse collagen-induced arthritis (CIA) model and underlying mechanisms. CIA mice were administered SOMCL-17-016 (6.25, 12.5, 25 mg·kg-1·d-1, ig), or ibrutinib (25 mg·kg-1·d-1, ig) or acalabrutinib (25 mg·kg-1·d-1, ig) for 15 days. We showed that oral administration of SOMCL-17-016 dose-dependently ameliorated arthritis severity and bone damage in CIA mice; it displayed a higher in vivo efficacy than ibrutinib and acalabrutinib at the corresponding dosage. We found that SOMCL-17-016 administration dose-dependently inhibited anti-IgM-induced proliferation and activation of B cells from CIA mice, and significantly decreased anti-IgM/anti-CD40-stimulated RANKL expression in memory B cells from RA patients. In RANKL/M-CSF-stimulated RAW264.7 cells, SOMCL-17-016 prevented osteoclast differentiation and abolished RANK-BTK-PLCγ2-NFATc1 signaling. In summary, this study demonstrates that SOMCL-17-016 presents distinguished therapeutic effects in the CIA model. SOMCL-17-016 exerts a dual inhibition of B cell function and osteoclastogenesis, suggesting that it to be a promising drug candidate for RA treatment.

The artemisinin analog SM934 alleviates dry eye disease in rodent models by regulating TLR4/NF-κB/NLRP3 signaling.

Dry eye disease (DED) is a multifactorial disorder of the tears and ocular surface characterized by manifestations of dryness and irritation. Although the pathogenesis is not fully illuminated, it is recognized that inflammation has a prominent role in the development and deterioration of DED. ß-aminoarteether maleate (SM934) is a water-soluble artemisinin derivative with anti-inflammatory and immunosuppressive activities. In this study, we established scopolamine hydrobromide (SCOP)-induced rodent model as well as benzalkonium chloride (BAC)-induced rat model to investigate the therapeutic potential of SM934 for DED. We showed that topical application of SM934 (0.1%, 0.5%) significantly increased tear secretion, maintained the number of conjunctival goblet cells, reduced corneal damage, and decreased the levels of inflammatory mediators (TNF-α, IL-6, IL-10, or IL-1ß) in conjunctiva in SCOP-induced and BAC-induced DED models. Moreover, SM934 treatment reduced the accumulation of TLR4-expressing macrophages in conjunctiva, and suppressed the expression of inflammasome components, i.e., myeloid differentiation factor88 (MyD88), Nod-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), and cleaved caspase 1. In LPS-treated RAW 264.7 cells, we demonstrated that pretreatment with SM934 (10 µM) impeded the upregulation of TLR4 and downstream NF-κB/NLRP3 signaling proteins. Collectively, artemisinin analog SM934 exerts therapeutic benefits on DED by simultaneously reserving the structural integrity of ocular surface and preventing the corneal and conjunctival inflammation, suggested a further application of SM934 in ophthalmic therapy, especially for DED.