Search

NF-κB-inducing kinase (NIK) is a key enzyme in the noncanonical NF-κB pathway, of interest in the treatment of a variety of diseases including cancer. Validation of NIK as a drug target requires potent and selective inhibitors. The protein contains a cysteine residue at position 444 in the back pocket of the active site, unique within the kinome. Analysis of existing inhibitor scaffolds and early structure–activity relationships (SARs) led to the design of C444-targeting covalent inhibitors based on alkynyl heterocycle warheads. Mass spectrometry provided proof of the covalent mechanism, and the SAR was rationalized by computational modeling. Profiling of more potent analogues in tumor cell lines with constitutively activated NIK signaling induced a weak antiproliferative effect, suggesting that kinase inhibition may have limited impact on cancer cell growth. This study shows that alkynyl heterocycles are potential cysteine traps, which may be employed where common Michael acceptors, such as acrylamides, are not tolerated.

In a contribution to a symposium on Nick Barber’s book, The Principles of Constitutionalism, I argue that Barber is right to explain the principles of constitutionalism by reference to the purpose of a state, but I defend a restatement of that purpose. Barber says that it is to advance the well-being of the citizens. I argue that the purpose is more open-ended: it is to make the political community a good one. The state has duties that are not grounded in the well-being of its citizens, and it may legitimately pursue good public purposes that do not advance its citizens’ well-being. The state is forits citizens, not primarily in the sense that it is there to make them better off, but in the sense that it is a way for citizens(and not for outsiders) to act as an organized community.

ABSTRACTPTEN is a negative modulator of the INS-PI3K-AKT pathway and is an essential regulator of metabolism and cell growth. PTEN is one of the most commonly mutated tumor suppressors in cancer. However, PTEN overexpression extends the lifespan of both sexes of mice. We recently showed that PTEN is necessary and sufficient to activate chaperone-mediated autophagy (CMA) in the mouse liver and cultured cells. Selective protein degradation via CMA is required to suppress glycolysis and fatty acid synthesis when PTEN is overexpressed. Thus, activation of CMA downstream of PTEN might modulate health and metabolism through selective degradation of key metabolic enzymes.

The effects of domestication selection on fitness are of serious concern in hatchery‐reared anadromous salmonids, which often experience selection for rapid growth and associated deviations from natural agonistic and feeding behaviors. The high rations that are used to raise age‐1 smolts and the reduced rations that are used to produce age‐2 smolts potentially result in very different behavioral tactics and social dynamics of competition in hatchery tanks. Consequently, steelhead Oncorhynchus mykisshatchery programs with recovery or conservation goals may need to change their aquaculture practices to minimize domestication selection. This study investigated how the feeding rate (proportion of presented food items that were successfully captured) and relative competitive ability (ability to monopolize food items in small groups) of age‐1 and age‐2 steelhead corresponded to feeding location (surface or bottom) and growth rate in hatchery rearing tanks. We raised steelhead from a common broodstock to smolt at age 1 or age 2 by manipulating their rations (age‐1 fish received the high ration, age‐2 the low ration). The fish in the age‐1 treatment had a lower feeding rate than did those in the age‐2 treatment. Feeding rate was positively correlated with both body size and with growth rate in the rearing tanks at both rations. The age‐2 steelhead were more likely to be detected at a single feeding location than were the age‐1 fish, which were more frequently detected at both locations. The more competitive age‐1 fish were more frequently detected at both feeding locations, and the less competitive fish were detected at only one location. Relative competitive ability was not associated with feeding location in the age‐2 treatment, nor was it associated with growth rate in either treatment. Age‐2 steelhead that were detected only at the bottom or at both feeding locations had higher growth rates than those that were detected only at the surface, suggesting greater scramble competition near the point of food delivery under the restricted ration. Feeding location was not associated with growth rate in the age‐1 treatment. The results indicate that ration directly affects feeding rate and that ration and relative competitive ability interact to influence feeding rate. Because feeding rate was positively associated with growth rate at both ration levels in the hatchery tanks, behaviors that are associated with feeding motivation may be an important trait under selection in salmonid hatcheries.

ABSTRACTChaperone-mediated autophagy (CMA) is the most selective form of lysosomal proteolysis. CMA modulates proteomic organization through selective protein degradation, with targets including metabolic enzymes, cell growth regulators, and neurodegeneration-related proteins. CMA activity is low in ad libitum-fed rodents but is increased by prolonged fasting. AKT negatively regulates CMA at the lysosomal membrane by phosphorylating and inhibiting the CMA regulator GFAP. We have previously reported that long-lived Pou1f1/Pit1mutant (Snell) mice and ghr(growth hormone receptor) knockout mice (ghrKO) have lower AKT activity when fed compared to littermate controls, suggesting the hypothesis that these mice have increased baseline CMA activity. Here, we report that liver lysosomes from fed Snell dwarf mice and ghrKO mice have decreased GFAP phosphorylation and increased CMA substrate uptake activity. Liver lysosomes isolated from fed Snell dwarf mice and ghrKO mice injected with the protease inhibitor leupeptin had increased accumulation of endogenous CMA substrates, compared to littermate controls, suggesting an increase in CMA in vivo. Mice with liver-specific ablation of GH (growth hormone) signaling did not have increased liver CMA, suggesting that a signaling effect resulting from a loss of growth hormone in another tissue causes enhanced CMA in Snell dwarf and ghrKO mice. Finally, we find Snell dwarf mice have decreased protein levels (in liver and kidney) of CIP2A, a well-characterized CMA target protein, without an associated change in Cip2amRNA. Collectively, these data suggest that CMA is enhanced downstream of an endocrine change resulting from whole-body ablation of GH signaling.Abbreviations:CMA: chaperone-mediated autophagy; GH: growth hormone; ghrKO: growth hormone receptor knockout; LAMP2A: splice variant 1 of Lamp2transcript; LC3-I: non-lipidated MAP1LC3; LC3-II: lipidated MAP1LC3; Li-ghrKO: liver-specific ghrknockout; MA: macroautophagy; MTORC1: mechanistic target of rapamycin kinase complex 1; MTORC2: mechanistic target of rapamycin kinase complex 2; PBS: phosphate-buffered saline.

Endovascular treatment of mesenteric lesions has become increasingly prevalent. Mesenteric bypass, however, remains the optimal treatment in the cases of chronic mesenteric ischemia (CMI) in young, medically fit patients given its durability. Endarterectomy has gone by the wayside, but in certain situations, this technique remains surgically relevant and should still be used. Herein, we present 2 cases of distal superior mesenteric artery (SMA) endarterectomy for mesenteric revascularization.

A 55-year-old woman with COPD, heart failure with preserved ejection fraction (congestive heart failure), diabetes mellitus, and hypertension presented with baseline dyspnea at rest that had worsened over the last week. She reported associated runny nose, congestion, and cough productive of green sputum. She smoked six cigarettes per day and denied alcohol, drugs, or occupational exposure. She was admitted and initiated on treatment for acute exacerbation of COPD; however, her condition did not improve with steroid, ceftriaxone, and nebulized albuterol and budesonide treatments. She had been diagnosed with asthma and COPD without ever undergoing pulmonary function testing. She presented 11 times to the ED with six hospital admissions in the last 1.5 years for worsening dyspnea at rest, wheezing, and lower extremity edema deemed secondary to exacerbation of her COPD or congestive heart failure. She reported medication compliance, which included fluticasone-vilanterol, tiotropium bromide, and furosemide. She repeatedly demonstrated mild vascular congestion on imaging without hyperinflation, a normal to mildly elevated brain natriuretic peptide (<10 to 200 pg/mL), and dyspnea without hypoxia. She was treated normally for both COPD and congestive heart failure exacerbations simultaneously with methylprednisolone, albuterol, and furosemide with rapid improvement over the course of 1 to 2 days. No significant improvement was noted with steroid therapy, despite receiving them as an inpatient and outpatient. At the time of discharge, her symptoms would be at her baseline.

Siderophores are small-molecule high-affinity multidentate chelators selective for ferric iron that are produced by pathogenic microbes to aid in nutrient sequestration and enhance virulence. In Gram-positive bacteria, the currently accepted paradigm in siderophore-mediated iron acquisition is that effluxed metal-free siderophores extract ferric iron from biological sources and the resulting ferric siderophore complex undergoes diffusion-controlled association with a surface-displayed siderophore-binding protein (SBP) followed by ABC permease-mediated translocation across the cell envelope powered by ATP hydrolysis. Here we show that a more efficient paradigm is possible in Gram-positive bacteria where extracellular metal-free siderophores associate directly with apo-SBPs on the cell surface and serve as non-covalent cofactors that enable the holo-SBPs to non-reductively extract ferric iron directly from host metalloproteins with so-called “ferrichelatase” activity. The resulting SBP-bound ferric siderophore complex is ready for import through an associated membrane permease and enzymatic turnover is achieved through cofactor replacement from the readily available pool of extracellular siderophores. This new “iron shuttle” model closes a major knowledge gap in microbial iron acquisition and defines new roles of the siderophore and SBP as cofactor and enzyme, respectively, in addition to the classically accepted roles as a transport substrate and receptor pair. We propose the formal name “siderophore-dependent ferrichelatases” for this new class of catalytic SBPs.

Abstract:The Orang Asli (Malay for ‘Original People’) are the indigenous minorities of Peninsular Malaysia. Today they are among the poorest and most disadvantaged category of Malaysian citizens. Their problems are based in large part on their lack of secure rights over the land on which their ancestors lived and supported themselves. In this article, we argue that their land issues are rooted in the relevant concepts, policies and regulations introduced by the British when they colonized the mainland Malay states of the peninsula beginning in 1874. Based on an examination of colonial policies and laws regarding state land, aboriginal reserves, private land ownership and interests, Malay reservations, forest reserves and wildlife reserves, we argue that the colonial government classified land ownership and development rights in ways that prioritised plantation agriculture, forestry, mining, wildlife, and the needs of Malay peasants over those of the Orang Asli. Moreover, the laws, policies, and practices of the colonial administration are little changed in the present day and are in need of government-led legal, institutional and practical reform if Orang Asli are to gain secure land rights and the protections guaranteed to them under the Federal Constitution.

The 77 K emission spectra of cyclometalated ruthenium(II)-2,2′-bipyridine (CM-Ru-bpy) chromophores are very similar to those of related Ru-bpy complexes with am(m)ine or diimmine ancillary ligands, and density functional theory (DFT) modeling confirms that the lowest energy triplet metal to ligand charge transfer (3MLCT) excited states of CM-Ru-bpy and related Ru-bpy complexes have very similar electronic configurations. However, the phosphorescence decay efficiencies of CM-Ru-bpy excited states are about twice those of the conventional Ru-bpy analogues. In contrast to the similar 3MLCT excited state electronic configurations of the two classes of complexes, the CM-Ru-bpy chromophores have much broader visible region MLCT absorptions resulting from several overlapping transitions, even at 87 K. The emitting excited-state emission efficiencies depend on spin–orbit coupling (SOC) mediated intensity stealing from singlet excited states, and this work explores the relationship between the phosphorescence efficiency and visible region absorption spectra of Ru-bpy 3MLCT excited states in the weak SOC limit. The intrinsic 3MLCT emission efficiency, ιem, depends on mixing with singlet excited states whose RuIII-dπ-orbital angular momenta differ from that of the emitting state. DFT modeling of the 1MLCT excited-state electronic configurations that contribute significantly to the lowest energy absorption bands have RuIII-dπ orbitals that differ from those of their emitting 3MLCT excited states. This leads to a very close relationship between ιemand the lowest energy MLCT band absorptivities in Ru-bpy chromophores. Thus, the larger number of 1MLCT transitions that contribute to the lowest energy absorption bands accounts for the enhanced phosphorescence efficiency of Ru-bpy complexes with cyclometalated ancillary ligands.

Identifying ligand binding sites on proteins is a critical step in target-based drug discovery. Current approaches to this require resource-intensive screening of large libraries of lead-like or fragment molecules. Here, we describe an efficient and effective experimental approach to mapping interaction sites using a set of halogenated compounds expressing paired hydrogen-bonding motifs, termed FragLites. The FragLites identify productive drug-like interactions, which are identified sensitively and unambiguously by X-ray crystallography, exploiting the anomalous scattering of the halogen substituent. This mapping of protein interaction surfaces provides an assessment of druggability and can identify efficient start points for the de novo design of hit molecules incorporating the interacting motifs. The approach is illustrated by mapping cyclin-dependent kinase 2, which successfully identifies orthosteric and allosteric sites. The hits were rapidly elaborated to develop efficient lead-like molecules. Hence, the approach provides a new method of identifying ligand sites, assessing tractability and discovering new leads.

A series of pyridine- and phenol-based ruthenium(II)-containing amphiphiles with bidentate ligands of the following types are reported: [(LPyI)RuII(bpy)2](PF6)2(1), [(LPyA)RuII(bpy)2](PF6)2(2), [(LPhBuI)RuII(bpy)2](PF6) (3), and [(LPhClI)RuII(bpy)2](PF6) (4). Species 1and 2are obtained by treatment of [Ru(bpy)2Cl2] with the ligands LPyI(N-(pyridine-2-ylmethylene)octadecan-1-amine) and LPyA(N-(pyridine-2-ylmethyl)octadecan-1-amine). The imine species 3and 4are synthesized by reaction of [Ru(bpy)2(CF3SO3)2] with the amine ligands HLPhBuA(2,4-di-tert-butyl-6-((octadecylamino)methyl)phenol), and HLPhClA(2,4-dichloro-6-((octadecylamino)methyl)phenol). Compounds 1−4are characterized by means of electrospray ionization (ESI+) mass spectrometry, elemental analyses, as well as electrochemical methods, infrared and UV−visible absorption and emission spectroscopies. The cyclic voltammograms (CVs) of 1−2are marked by two successive processes around −1.78 and −2.27 V versus Fc+/Fc attributed to bipyridine reduction. A further ligand-centered reductive process is seen for 1. The RuII/RuIIIcouple appears at 0.93 V versus Fc+/Fc. The phenolato-containing 3and 4species present relatively lower reduction potentials and more reversible redox behavior, along with RuII/IIIand phenolate/phenoxyl oxidations. The interpretation of observed redox behavior is supported by density functional theory (DFT) calculations. Complexes 1−4are surface-active as characterized by compression isotherms and Brewster angle microscopy. Species 1and 2show collapse pressures of about 29−32 mN·m−1, and are strong candidates for the formation of redox-responsive monolayer films.

The article concerns about the management of housing crisis by the administration of U.S. President Joe Biden, as of February 2021. It presents views of Priya Jayachandran, president of the National Housing Trust, on investments of U.S. government in housing. It also reports on Affordable Housing Fund to be released by Biden for affordable housing production and preservation.