Whole-body molecular imaging is able to directly map spatial distribution of molecules and monitor its biotransformation in intact biological tissue sections. Imaging mass spectrometry (IMS), a label-free molecular imaging method, can be used to image multiple molecules in a single measurement with high specificity. Herein, a novel easy-toimplement, whole-body IMS method was developed with air flow-assisted ionization in a desorption electrospray ionization mode. The developed IMS method can effectively image molecules in a large whole-body section in open air without sample pretreatment, such as chemical labeling, section division, or matrix deposition. Moreover, the signal levels were improved, and the spatial assignment errors were eliminated; thus, high-quality whole-body images were obtained. With this novel IMS method, in situ mapping analysis of molecules was performed in adult rat sections with picomolar sensitivity under ambient conditions, and the dynamic information of molecule distribution and its biotransformation was provided to uncover molecular events at the whole-animal level. A global view of the differential distribution of an anticancer agent and its metabolites was simultaneously acquired in whole-body rat and model mouse bearing neuroglioma along the administration time. The obtained drug distribution provided rich information for identifying the targeted organs and predicting possible tumor spectrum, pharmacological activity, and potential toxicity of drug candidates.
Inosine monophosphate dehydrogenase (IMPDH) of human is an attractive target for immunosuppressive agents. Currently, smallmolecule inhibitors do not show good selectivity for different IMPDH isoforms (IMPDH1 and IMPDH2), resulting in some adverse effects, which limit their use. Herein, we used a small-molecule probe specifically targeting IMPDH2 and identified Cysteine residue 140 (Cys140) as a selective druggable site. On covalently binding to Cys140, the probe exerts an allosteric regulation to block the catalytic pocket of IMPDH2 and further induces IMPDH2 inactivation, leading to an effective suppression of neuroinflammatory responses. However, the probe does not covalently bind to IMPDH1. Taken together, our study shows Cys140 as a druggable site for selectively inhibiting IMPDH2, which provides great potential for development of therapy agents for autoimmune and neuroinflammatory diseases with less unfavorable tolerability profile.nosine monophosphate dehydrogenase (IMPDH) is a major rate-limiting enzyme involved in guanosine and deoxyguanosine biosynthesis and widely expressed in immunocytes (1). There exist two IMPDH isoforms (IMPDH1 and IMPDH2), which are encoded by distinct genes (2, 3). Many inflammation-relevant diseases have been specially characterized by the high expression of isoform II of IMPDH (IMPDH2) in rapidly proliferating immunocytes, rather than the "housekeeping" type I isoform (IMPDH1) in normal human leukocytes and lymphocytes (4, 5). Therefore, selective targeting of IMPDH2 with small molecules is an attractive topic for development of antiinflammation agents with low side effects.Both IMPDH isoforms contain two major domains: the catalytic domain for substrate interaction and the Bateman domain, which is not required for catalytic activity but exerts an important allosteric regulation effect on IMPDH activity by communicating with the catalytic domain (6, 7). By influencing catalytic domain activity, the Bateman domain can regulate IMPDH function and further blocks the downstream-of-inflammation signaling pathways (8, 9). Currently, IMPDH inhibitors are divided into two major categories. One kind of inhibitor, including 6-chloropurine riboside ribavirin and mizoribine, targets the binding pocket of the natural substrate, inosine monophosphate (IMP). Another kind of inhibitor (e.g., mycophenolic acid and thiazole-4-carboxamide adenine dinucleotide) targets the site of the cofactor, NAD + / NADH, which usually leads to low selectivity or even side effects in clinical trials, such as diarrhea and leukopenia (10, 11). Moreover, a third ligand has been speculated to bind to a possible site far from the IMP and NAD + pockets as an allosteric inhibitor. However, an allosteric site for designing selective IMPDH2 inhibitors has been largely unexplored.Natural small molecules remain promising drug sources (12, 13). In the present study, we report that a natural small-molecule probe, sappanone A (SA, Fig.1A), demonstrated significant inhibitory effects on neuroinflammation by directly targetin...
Nine new grayanoids (1-9), together with 11 known compounds, were isolated from the roots of Rhododendron molle. The structures of the new compounds (1-9) were determined on the basis of spectroscopic analysis, including HRESIMS, and 1D and 2D NMR data. Compounds 4, 6, 12, and 14-20 showed significant antinociceptive activities in an acetic acid-induced writhing test. In particular, 14 and 15 were found to be more potent than morphine for both acute and inflammatory pain models and 100-fold more potent than gabapentin in a diabetic neuropathic pain model.
Significance Thin endometrium is the most common reason for uterine infertility and refractory gynecological diseases due to its complexity in pathogenesis and adverse pregnancy outcomes. Here, we profile cells from normal and thin endometrium at single-cell resolution to investigate the sophisticated alterations in the local microenvironment that occur in thin endometrium. Increased cellular senescence, collagen overdeposition, and significant down-regulation of gene expression related to cell proliferation are observed and confirmed. Moreover, we demonstrate aberrant activation of the SEMA3 pathway accompanied by dampened EGF, PTN, and TWEAK signaling pathways in thin endometrium. These findings aid in understanding the mechanisms of thin endometrium and provide new tools to rejuvenate the atrophic endometrium for female fertility preservation and successful pregnancy.
Two new rare 8-methylbenzo[h]coumarins, muralatins A and B (1, 2), nine new C-8-substituted coumarins, muralatins C-K (3-11), and 22 known analogues (12-33) were isolated from the leaves of Murraya alata. The absolute configurations of compounds 5, 11, 23, 24, 27, 30, and 33 were assigned via comparison of their specific rotations, by Mosher's method, and by single-crystal X-ray diffraction and electronic circular dichroism (ECD) data of the in situ formed transition metal complexes. A putative biosynthesis pathway to 1 and 2 is proposed, and the chemical synthesis of 1 was accomplished through electrocyclization of 5,7-dimethoxy-8-[(Z)-3-methylbut-1,3-dienyl)]coumarin (12). Compounds 1, 2, 8, 12, and 31 showed inhibition of nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages with IC50 values of 6.0-14.5 μM.
Diarylheptanoids, natural products with a 1,7-diphenylheptane structural skeleton, are mainly distributed in the roots, rhizomes and bark of Alpinia, Zingiber, Curcuma and Alnus species. They have become of interest in natural product research over the past twenty years because of their remarkable anticancer, anti-emetic, estrogenic, antimicrobial and antioxidant activity. This paper compiles all 307 naturally occurring diarylheptanoids from 46 plants as reported in 137 references with their distributions, physiological activities and 13C-NMR spectral data.
Heat shock protein 70 (Hsp70) is widely involved in immune disorders, making it as an attractive drug target for inflammation diseases. Nonselective induction of Hsp70 upregulation for inflammation therapy could cause extensive interference in inflammation-unrelated protein functions, potentially resulting in side effects. Nevertheless, direct pharmacological activation of Hsp70 via targeting specific functional amino acid residue may provide an insight into precise Hsp70 function regulation and a more satisfactory treatment effect for inflammation, which has not been extensively focused. Here we show a cysteine residue (Cys306) for selective Hsp70 activation using natural small-molecule handelin. Covalent modification of Cys306 significantly elevates Hsp70 activity and shows more satisfactory anti-neuroinflammation effects. Mechanism study reveals Cys306 modification by handelin induces an allosteric regulation to facilitate adenosine triphosphate hydrolysis capacity of Hsp70, which leads to the effective blockage of subsequent inflammation signaling pathway. Collectively, our study offers some insights into direct pharmacological activation of Hsp70 by specially targeting functional cysteine residue, thus providing a powerful tool for accurately modulating neuroinflammation pathogenesis in human with fewer undesirable adverse effects.
Brusatol, a biologically active natural product, was modified in four distinct positions through the covalent attachment of a furoxan moiety, which acts as a nitric oxide (NO) donor. Forty derivatives were synthesized and evaluated for their inhibitory effects on excess NO biosynthesis in activated macrophages. Among them, compound 75 demonstrated inhibition (IC50 = 0.067 μM) comparable to that of brusatol but were less cytotoxic. More importantly, even at very low doses (2 μmol/kg/day), compound 75 also showed substantial inhibitory efficacy against chronic obstructive pulmonary disease (COPD)-like inflammation in the mouse model induced by cigarette smoke (CS) and lipopolysaccharide (LPS). Particularly, this compound was over 100-fold less toxic (LD50 > 3852 μmol/kg) than brusatol and could be a promising lead for further studies. Notably, the improved properties of this derivative are associated with its NO-releasing capability.
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