Cladophorol-A is an inhibitor of cyclic GMP-AMP synthase.

Cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS) is an enzyme sensor of double-stranded DNA (dsDNA) that serves to trigger activation of the cGAS-stimulator of interferon genes (STING) pathway. Excessive activation of this pathway has been demonstrated to contribute to various forms of inflammatory disease. As such, cGAS has arisen as a potential therapeutic target with broad potential applications.

Hydroxyproline metabolism enhances IFN-γ-induced PD-L1 expression and inhibits autophagic flux.

The immune checkpoint protein PD-L1 plays critical roles in both immune system homeostasis and tumor progression. Impaired PD-1/PD-L1 function promotes autoimmunity and PD-L1 expression within tumors promotes immune evasion. If and how changes in metabolism or defined metabolites regulate PD-L1 expression is not fully understood.

Targeting STING to promote antitumor immunity.

Pharmacology-based methods that promote antitumor immunity have the potential to be highly efficacious while avoiding the systemic cytotoxicity associated with traditional chemotherapies. Activation of type I interferon (IFN) signaling in antigen-presenting cell types [e.g.

An Activity-Guided Map of Electrophile-Cysteine Interactions in Primary Human T Cells.

Electrophilic compounds originating from nature or chemical synthesis have profound effects on immune cells. These compounds are thought to act by cysteine modification to alter the functions of immune-relevant proteins; however, our understanding of electrophile-sensitive cysteines in the human immune proteome remains limited. Here, we present a global map of cysteines in primary human T cells that are susceptible to covalent modification by electrophilic small molecules.

Electronic complementarity permits hindered butenolide heterodimerization and discovery of novel cGAS/STING pathway antagonists.

sp-hybridized attached-rings are common motifs in secondary metabolites and represent tetrahedral equivalents to the biaryl substructures that overpopulate synthetic libraries. Few methods are available that can link fully substituted carbon atoms of two rings with stereocontrol. Here we have developed a stereoselective, heteroselective butenolide coupling that exhibits an unusually fast rate of C-C bond formation driven by exquisite complementarity of the reacting π systems.

A cell type-selective apoptosis-inducing small molecule for the treatment of brain cancer.

Glioblastoma multiforme (GBM; grade IV astrocytoma) is the most prevalent and aggressive form of primary brain cancer. A subpopulation of multipotent cells termed GBM cancer stem cells (CSCs) play a critical role in tumor initiation, tumor maintenance, metastasis, drug resistance, and recurrence following surgery. Here we report the identification of a small molecule, termed RIPGBM, from a cell-based chemical screen that selectively induces apoptosis in multiple primary patient-derived GBM CSC cultures.

A metabolite-derived protein modification integrates glycolysis with KEAP1-NRF2 signalling.

Mechanisms that integrate the metabolic state of a cell with regulatory pathways are necessary to maintain cellular homeostasis. Endogenous, intrinsically reactive metabolites can form functional, covalent modifications on proteins without the aid of enzymes, and regulate cellular functions such as metabolism and transcription. An important 'sensor' protein that captures specific metabolic information and transforms it into an appropriate response is KEAP1, which contains reactive cysteine residues that collectively act as an electrophile sensor tuned to respond to reactive species resulting from endogenous and xenobiotic molecules.

Small molecule-mediated inhibition of myofibroblast transdifferentiation for the treatment of fibrosis.

Fibrosis, a disease in which excessive amounts of connective tissue accumulate in response to physical damage and/or inflammatory insult, affects nearly every tissue in the body and can progress to a state of organ malfunction and death. A hallmark of fibrotic disease is the excessive accumulation of extracellular matrix-secreting activated myofibroblasts (MFBs) in place of functional parenchymal cells. As such, the identification of agents that selectively inhibit the transdifferentiation process leading to the formation of MFBs represents an attractive approach for the treatment of diverse fibrosis-related diseases.

Lrp5 Has a Wnt-Independent Role in Glucose Uptake and Growth for Mammary Epithelial Cells.

Lrp5 is typically described as a Wnt signaling receptor, albeit a less effective Wnt signaling receptor than the better-studied sister isoform, Lrp6. Here we show that Lrp5 is only a minor player in the response to Wnt3a-type ligands in mammary epithelial cells; instead, Lrp5 is required for glucose uptake, and glucose uptake regulates the growth rate of mammary epithelial cells in culture. Thus, a loss of Lrp5 leads to profound growth suppression, whether growth is induced by serum or by specific growth factors, and this inhibition is not due to a loss of Wnt signaling.

Two Isoforms of the RNA Binding Protein, Coding Region Determinant-binding Protein (CRD-BP/IGF2BP1), Are Expressed in Breast Epithelium and Support Clonogenic Growth of Breast Tumor Cells.

CRD-BP/IGF2BP1 has been characterized as an "oncofetal" RNA binding protein typically highly expressed in embryonic tissues, suppressed in normal adult tissues, but induced in many tumor types. In this study, we show that adult breast tissues express ubiquitous but low levels of CRD-BP protein and mRNA. Although CRD-BP mRNA expression is induced in breast tumor cells, levels remain ∼1000-fold lower than in embryonic tissues.

Weak protein-protein interactions revealed by immiscible filtration assisted by surface tension.

Biological mechanisms are often mediated by transient interactions between multiple proteins. The isolation of intact protein complexes is essential to understanding biochemical processes and an important prerequisite for identifying new drug targets and biomarkers. However, low-affinity interactions are often difficult to detect.

Ex vivo SIV-specific CD8 T cell responses in heterozygous animals are primarily directed against peptides presented by a single MHC haplotype.

The presence of certain MHC class I alleles is correlated with remarkable control of HIV and SIV, indicating that specific CD8 T cell responses can effectively reduce viral replication. It remains unclear whether epitopic breadth is an important feature of this control. Previous studies have suggested that individuals heterozygous at the MHC class I loci survive longer and/or progress more slowly than those who are homozygous at these loci, perhaps due to increased breadth of the CD8 T cell response.

Chondrocyte-intrinsic Smad3 represses Runx2-inducible matrix metalloproteinase 13 expression to maintain articular cartilage and prevent osteoarthritis.

Objective: To identify mechanisms by which Smad3 maintains articular cartilage and prevents osteoarthritis.

Methods: A combination of in vivo and in vitro approaches was used to test the hypothesis that Smad3 represses Runx2-inducible gene expression to prevent articular cartilage degeneration. Col2-Cre;Smad3(fl/fl) mice allowed study of the chondrocyte-intrinsic role of Smad3 independently of its role in the perichondrium or other tissues.

Low-cost ultra-wide genotyping using Roche/454 pyrosequencing for surveillance of HIV drug resistance.

Background: Great efforts have been made to increase accessibility of HIV antiretroviral therapy (ART) in low and middle-income countries. The threat of wide-scale emergence of drug resistance could severely hamper ART scale-up efforts. Population-based surveillance of transmitted HIV drug resistance ensures the use of appropriate first-line regimens to maximize efficacy of ART programs where drug options are limited.

Specific CD8+ T cell responses correlate with control of simian immunodeficiency virus replication in Mauritian cynomolgus macaques.

Specific major histocompatibility complex (MHC) class I alleles are associated with an increased frequency of spontaneous control of human and simian immunodeficiency viruses (HIV and SIV). The mechanism of control is thought to involve MHC class I-restricted CD8(+) T cells, but it is not clear whether particular CD8(+) T cell responses or a broad repertoire of epitope-specific CD8(+) T cell populations (termed T cell breadth) are principally responsible for mediating immunologic control. To test the hypothesis that heterozygous macaques control SIV replication as a function of superior T cell breadth, we infected MHC-homozygous and MHC-heterozygous cynomolgus macaques with the pathogenic virus SIVmac239.

Both LRP5 and LRP6 receptors are required to respond to physiological Wnt ligands in mammary epithelial cells and fibroblasts.

A canonical Wnt signal maintains adult mammary ductal stem cell activity, and this signal requires the Wnt signaling reception, LRP5. However, previous data from our laboratory have shown that LRP5 and LRP6 are co-expressed in mammary basal cells and that LRP6 is active, leading us to question why LRP6 is insufficient to mediate canonical signaling in the absence of LRP5. Here, we show that at endogenous levels of LRP5 and LRP6 both receptors are required to signal in response to some Wnt ligands both in vitro (in mouse embryonic fibroblasts and mammary epithelial cells) and in vivo (in mammary outgrowths).

Conditional CD8+ T cell escape during acute simian immunodeficiency virus infection.

CD8+ T cell responses rapidly select viral variants during acute human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) infection. We used pyrosequencing to examine variation within three SIV-derived epitopes (Gag₃₈₆₋₃₉₄GW9, Nef₁₀₃₋₁₁₁RM9, and Rev₅₉₋₆₈SP10) targeted by immunodominant CD8+ T cell responses in acutely infected Mauritian cynomolgus macaques. In animals recognizing all three epitopes, variation within Rev₅₉₋₆₈SP10 was associated with delayed accumulation of variants in Gag₃₈₆₋₃₉₄GW9 but had no effect on variation within Nef₁₀₃₋₁₁₁RM9.

Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-β and Runx2 in bone is required for hearing.

Physical cues, such as extracellular matrix stiffness, direct cell differentiation and support tissue-specific function. Perturbation of these cues underlies diverse pathologies, including osteoarthritis, cardiovascular disease and cancer. However, the molecular mechanisms that establish tissue-specific material properties and link them to healthy tissue function are unknown.

Whole-genome characterization of human and simian immunodeficiency virus intrahost diversity by ultradeep pyrosequencing.

Rapid evolution and high intrahost sequence diversity are hallmarks of human and simian immunodeficiency virus (HIV/SIV) infection. Minor viral variants have important implications for drug resistance, receptor tropism, and immune evasion. Here, we used ultradeep pyrosequencing to sequence complete HIV/SIV genomes, detecting variants present at a frequency as low as 1%.