Postcard from H. C. Shoulders to B. R. Colson

Postcard from H. C. Shoulders to B. R. Colson. The handwritten note is dated 23 February 1910. There is a transcript of the correspondence in the item PDF

Letter from H. C. Shoulders to B. R. Colson

Letter from H. C. Shoulders to B. R. Colson. The three-page handwritten note is dated 19 February 1910. There is a transcript of the correspondence in the item PDF

Assessing the Efficacy of Using the PTSD Coach Mobile Application for Managing PTSD Symptoms: Results Using the PCL-5 Screening Tool

Background: Patients with psychiatric concerns primarily present in primary care settings before seeking a mental health provider. During Covid-19 mental health concerns increased requiring primary care to adapt new multidisciplinary interventions to assist patients. Hypothesis: Participants that use the PTSD Coach App for 30 days will have reduced PCL-5 follow-up scores compared to their intake. Methods: Patients were recruited from a family medicine office, where providers identified eligible patients. The PCL-5 was administered initially, then an app intervention was provided for Results: The study observed a decrease in average PCL scores from baseline, suggesting the app\u27s potential as a PTSD management tool. Conclusions: Limitations included a small sample size and patient attrition. Future research should address barriers to participation and retention and include a comprehensive analysis of demographic data

The disruption of proteostasis in neurodegenerative diseases

Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio

The 5' flanking region of human epsilon-globin gene

The structural analysis of the 2.0 kb region upstream from the έ-globin gene has been carried out. A genomic DNA map around the gene was worked out in some detail to ensure that the cloned DNA was representative of the actual chromosomal arrangement. Furthermore, a new technique was developed to precisely map a reiterated DNA sequence present 1.5 kb to the 5' side of the gene. The complete nucleotide sequence of the 2.0 kb 5' flanking region was then determined and overlapped with the gene. The sequence included the reiterated DNA sequence which is homologous to the so-called AluI family of repeats. Unusual stretches of sequence 50 nucleotides long, where A + T represent about 90% of the bases, are present at both the 5' and 3' sides of the repeat

Rational Design of Protein Stability: Effect of (2S,4R)-4-Fluoroproline on the Stability and Folding Pathway of Ubiquitin

BACKGROUND: Many strategies have been employed to increase the conformational stability of proteins. The use of 4-substituted proline analogs capable to induce pre-organization in target proteins is an attractive tool to deliver an additional conformational stability without perturbing the overall protein structure. Both, peptides and proteins containing 4-fluorinated proline derivatives can be stabilized by forcing the pyrrolidine ring in its favored puckering conformation. The fluorinated pyrrolidine rings of proline can preferably stabilize either a C(γ)-exo or a C(γ)-endo ring pucker in dependence of proline chirality (4R/4S) in a complex protein structure. To examine whether this rational strategy can be generally used for protein stabilization, we have chosen human ubiquitin as a model protein which contains three proline residues displaying C(γ)-exo puckering. METHODOLOGY/PRINCIPAL FINDINGS: While (2S,4R)-4-fluoroproline ((4R)-FPro) containing ubiquitinin can be expressed in related auxotrophic Escherichia coli strain, all attempts to incorporate (2S,4S)-4-fluoroproline ((4S)-FPro) failed. Our results indicate that (4R)-FPro is favoring the C(γ)-exo conformation present in the wild type structure and stabilizes the protein structure due to a pre-organization effect. This was confirmed by thermal and guanidinium chloride-induced denaturation profile analyses, where we observed an increase in stability of -4.71 kJ·mol(-1) in the case of (4R)-FPro containing ubiquitin ((4R)-FPro-ub) compared to wild type ubiquitin (wt-ub). Expectedly, activity assays revealed that (4R)-FPro-ub retained the full biological activity compared to wt-ub. CONCLUSIONS/SIGNIFICANCE: The results fully confirm the general applicability of incorporating fluoroproline derivatives for improving protein stability. In general, a rational design strategy that enforces the natural occurring proline puckering conformation can be used to stabilize the desired target protein

Stringency of the 2-His–1-Asp Active-Site Motif in Prolyl 4-Hydroxylase

The non-heme iron(II) dioxygenase family of enzymes contain a common 2-His–1-carboxylate iron-binding motif. These enzymes catalyze a wide variety of oxidative reactions, such as the hydroxylation of aliphatic C–H bonds. Prolyl 4-hydroxylase (P4H) is an α-ketoglutarate-dependent iron(II) dioxygenase that catalyzes the post-translational hydroxylation of proline residues in protocollagen strands, stabilizing the ensuing triple helix. Human P4H residues His412, Asp414, and His483 have been identified as an iron-coordinating 2-His–1-carboxylate motif. Enzymes that catalyze oxidative halogenation do so by a mechanism similar to that of P4H. These halogenases retain the active-site histidine residues, but the carboxylate ligand is replaced with a halide ion. We replaced Asp414 of P4H with alanine (to mimic the active site of a halogenase) and with glycine. These substitutions do not, however, convert P4H into a halogenase. Moreover, the hydroxylase activity of D414A P4H cannot be rescued with small molecules. In addition, rearranging the two His and one Asp residues in the active site eliminates hydroxylase activity. Our results demonstrate a high stringency for the iron-binding residues in the P4H active site. We conclude that P4H, which catalyzes an especially demanding chemical transformation, is recalcitrant to change

Linkage and association of haplotypes at the APOA1/C3/A4/A5 genecluster to familial combined hyperlipidemia

Combined hyperlipidemia (CHL) is a common disorder of lipidmetabolism that leads to an increased risk of cardiovascular disease. Thelipid profile of CHL is characterised by high levels of atherogeniclipoproteins and low levels of high-density-lipoprotein-cholesterol.Apolipoprotein (APO) A5 is a newly discovered gene involved in lipidmetabolism located within 30kbp of the APOA1/C3/A4 gene cluster. Previousstudies have indicated that sequence variants in this cluster areassociated with increased plasma lipid levels. To establish whethervariation at the APOA5 gene contributes to the transmission of CHL, weperformed linkage and linkage disequilibrium (LD) tests on a large cohortof families (n=128) with familial CHL (FCHL). The linkage data producedevidence for linkage of the APOA1/C3/A4/A5 genomic interval to FCHL (NPL= 1.7, P = 0.042). The LD studies substantiated these data. Twoindependent rare alleles, APOA5c.56G and APOC3c.386G of this gene clusterwere over-transmitted in FCHL (P = 0.004 and 0.007, respectively), andthis was associated with a reduced transmission of the most commonAPOA1/C3/A4/A5 haplotype (frequency 0.4425) to affected subjects (P =0.013). The APOA5c.56G allele was associated with increased plasmatriglyceride levels in FCHL probands, whereas the second, andindependent, APOC3c.386G allele was associated with increased plasmatriglyceride levels in FCHL pedigree founders. Thus, this allele (or anallele in LD) may mark a quantitative trait associated with FCHL, as wellas representing a disease susceptibility locus for the condition. Thisstudy establishes that sequence variation in the APOA1/C3/A4/A5 genecluster contributes to the transmission of FCHL in a substantialproportion of affected families, and that these sequence variants mayalso contribute to the lipid abnormalities of the metabolic syndrome,which is present in up to 40 percent of persons with cardiovasculardisease

Myeloid Tribbles 1 induces early atherosclerosis via enhanced foam cell expansion.

Macrophages drive atherosclerotic plaque progression and rupture; hence, attenuating their atherosclerosis-inducing properties holds promise for reducing coronary heart disease (CHD). Recent studies in mouse models have demonstrated that Tribbles 1 (Trib1) regulates macrophage phenotype and shows that Trib1 deficiency increases plasma cholesterol and triglyceride levels, suggesting that reduced TRIB1 expression mediates the strong genetic association between the TRIB1 locus and increased CHD risk in man. However, we report here that myeloid-specific Trib1 (mTrib1) deficiency reduces early atheroma formation and that mTrib1 transgene expression increases atherogenesis. Mechanistically, mTrib1 increased macrophage lipid accumulation and the expression of a critical receptor (OLR1), promoting oxidized low-density lipoprotein uptake and the formation of lipid-laden foam cells. As TRIB1 and OLR1 RNA levels were also strongly correlated in human macrophages, we suggest that a conserved, TRIB1-mediated mechanism drives foam cell formation in atherosclerotic plaque and that inhibiting mTRIB1 could be used therapeutically to reduce CHD

TRIB3 links endoplasmic reticulum stress to impaired efferocytosis in atherosclerosis

BACKGROUND: Defective macrophage efferocytosis is a key driver of chronic nonresolving inflammation in dyslipidemia-associated diseases, such as obesity and atherosclerosis. However, the mechanism by which intracellular lipid accumulation impairs macrophage efferocytosis remains unclear. We hypothesized that lipid-induced endoplasmic reticulum (ER) stress mediates defective macrophage efferocytosis. METHODS: Bone marrow–derived macrophages were exposed to 7-ketocholesterol or palmitate to induce ER stress, and efferocytosis was quantified by measuring uptake of fluorescently labeled apoptotic cells with microscopy and flow cytometry. Key pathways were interrogated with pharmacological inhibitors, siRNA, and in vivo models, including obese mice and in Ldlr−/− mice with hematopoietic-specific deletion of TRIB3 (Tribbles pseudokinase-3). Human relevance was assessed by testing efferocytosis in macrophages from individuals carrying the TRIB3 Q84R coronary artery disease risk variant (rs2295490) and by examining carotid endarterectomy samples. RESULTS: Activation of the ATF4 (activating transcription factor 4) branch of the ER stress pathway in lipid-loaded foamy macrophages led to upregulation of TRIB3, which triggered the downregulation of Rab27a, resulting in impaired focal exocytosis of intracellular membrane pools towards nascent, apoptotic cell–containing phagosomes. The resultant delay in phagosome closure stalled efferocytosis. In obese mice, this impairment was reversed using an ER stress–relieving chemical chaperone and via macrophage-specific knockdown of ATF4 or TRIB3. In atherosclerotic mice, hematopoietic cell–specific deletion of TRIB3 led to increased lesional efferocytosis, decreased plaque necrosis, and increased collagen, which are characteristic of stable plaques. In humans, TRIB3 expression was higher in vulnerable regions of carotid plaques, and macrophages from individuals carrying the gain-of-function TRIB3 Q84R risk variant expressed more TRIB3 and displayed decreased efferocytosis. CONCLUSIONS: Lipid-induced ER stress impairs macrophage efferocytosis via activation of the ATF4-TRIB3-Rab27a signaling axis, leading to exacerbated plaque necrosis. Targeted disruption of TRIB3 signaling in macrophages represents a novel therapeutic approach to promote efferocytosis and stabilize atherosclerotic plaques