Endogenous l- to d-amino acid residue isomerization modulates selectivity between distinct neuropeptide receptor family members.

The l- to d-amino acid residue isomerization of neuropeptides is an understudied post-translational modification found in animals across several phyla. Despite its physiological importance, little information is available regarding the impact of endogenous peptide isomerization on receptor recognition and activation. As a result, the full roles peptide isomerization play in biology are not well understood. Here, we identify that the Aplysia allatotropin-related peptide (ATRP) signaling system utilizes l- to d-residue isomerization of one amino acid residue in the neuropeptide ligand to modulate selectivity between two distinct G protein-coupled receptors (GPCRs). We first identified a novel receptor for ATRP that is selective for the D2-ATRP form, which bears a single d-phenylalanine residue at position 2. Using cell-based receptor activation experiments, we then characterized the stereoselectivity of the two known ATRP receptors for both endogenous ATRP diastereomers, as well as for homologous toxin peptides from a carnivorous predator. We found that the ATRP system displayed dual signaling through both the Gαq and Gαs pathways, and each receptor was selectively activated by one naturally occurring ligand diastereomer over the other. Overall, our results provide insights into an unexplored mechanism by which nature regulates intercellular communication. Given the challenges in detecting l- to d-residue isomerization from complex mixtures de novo and in identifying receptors for novel neuropeptides, it is likely that other neuropeptide-receptor systems may also utilize changes in stereochemistry to modulate receptor selectivity in a manner similar to that discovered here.

Potential Protective Mechanisms of S-equol, a Metabolite of Soy Isoflavone by the Gut Microbiome, on Cognitive Decline and Dementia.

S-equol, a metabolite of soy isoflavone daidzein transformed by the gut microbiome, is the most biologically potent among all soy isoflavones and their metabolites. Soy isoflavones are phytoestrogens and exert their actions through estrogen receptor-ß. Epidemiological studies in East Asia, where soy isoflavones are regularly consumed, show that dietary isoflavone intake is inversely associated with cognitive decline and dementia; however, randomized controlled trials of soy isoflavones in Western countries did not generally show their cognitive benefit. The discrepant results may be attributed to S-equol production capability; after consuming soy isoflavones, 40-70% of East Asians produce S-equol, whereas 20-30% of Westerners do. Recent observational and clinical studies in Japan show that S-equol but not soy isoflavones is inversely associated with multiple vascular pathologies, contributing to cognitive impairment and dementia, including arterial stiffness and white matter lesion volume. S-equol has better permeability to the blood-brain barrier than soy isoflavones, although their affinity to estrogen receptor-ß is similar. S-equol is also the most potent antioxidant among all known soy isoflavones. Although S-equol is available as a dietary supplement, no long-term trials in humans have examined the effect of S-equol supplementation on arterial stiffness, cerebrovascular disease, cognitive decline, or dementia.

Potential Protective Effects of Equol (Soy Isoflavone Metabolite) on Coronary Heart Diseases-From Molecular Mechanisms to Studies in Humans.

Equol, a soy isoflavone-derived metabolite of the gut microbiome, may be the key cardioprotective component of soy isoflavones. Systematic reviews have reported that soy isoflavones have no to very small effects on traditional cardiovascular disease risk factors. However, the potential mechanistic mode of action of equol on non-traditional cardiovascular risk factors has not been systematically reviewed. We searched the PubMed through to July 2021 by using terms for equol and each of the following markers: inflammation, oxidation, endothelial function, vasodilation, atherosclerosis, arterial stiffness, and coronary heart disease. Of the 231 records identified, 69 articles met the inclusion criteria and were summarized. Our review suggests that equol is more lipophilic, bioavailable, and generally more potent compared to soy isoflavones. Cell culture, animal, and human studies show that equol possesses antioxidative, anti-inflammatory, and vasodilatory properties and improves arterial stiffness and atherosclerosis. Many of these actions are mediated through the estrogen receptor ß. Overall, equol may have a greater cardioprotective benefit than soy isoflavones. Clinical studies of equol are warranted because equol is available as a dietary supplement.

2'-5'-Oligoadenylate synthetase-like protein inhibits intracellular M. tuberculosis replication and promotes proinflammatory cytokine secretion.

Host cytoplasmic surveillance pathways are known to elicit type I interferon (IFN) responses which are crucial to antimicrobial defense mechanisms. Oligoadenylate synthetase-like (OASL) protein has been extensively characterized as a part of the anti-viral mechanism, however a number of transcriptomic studies reveal its upregulation in response to infection with a wide variety of intracellular bacterial pathogens. To date, there is no evidence documenting the role (if any) of OASL during mycobacterium tuberculosis infection. Using two pathogenic strains differing in virulence only, as well as the non-pathogenic M. bovis BCG strain, we observed that pathogenicity and virulence strongly induced OASL expression after 24 h of infection. Further, we observed that OASL knock down led to a significant increase in M. tb CFU counts 96 h post-infection in comparison to the respective controls. Luminex revealed that OASL silencing significantly decreased IL-1ß, TNF-α and MCP-1 secretion in THP-1 cells and had no effect on IL-10 secretion. We therefore postulate that OASL regulates pro-inflammatory mediators such as cytokines and chemokines which suppress intracellular mycobacterial growth and survival.

Competitive Interactions between PIRT, the Cold Sensing Ion Channel TRPM8, and PIP2 Suggest a Mechanism for Regulation.

TRPM8 is a member of the transient receptor potential ion channel family where it functions as a cold and pain sensor in humans and other higher organisms. Previous studies show that TRPM8 requires the signaling phosphoinositide lipid PIP2 to function. TRPM8 function is further regulated by other diverse mechanisms, including the small modulatory membrane protein PIRT (phosphoinositide regulator of TRP). Like TRPM8, PIRT also binds PIP2 and behavioral studies have shown that PIRT is required for normal TRPM8-mediated cold-sensing. To better understand the molecular mechanism of PIRT regulation of TRPM8, solution nuclear magnetic resonance (NMR) spectroscopy was used to assign the backbone resonances of full-length human PIRT and investigate the direct binding of PIRT to PIP2 and the human TRPM8 S1-S4 transmembrane domain. Microscale thermophoresis (MST) binding studies validate the NMR results and identify a competitive PIRT interaction between PIP2 and the TRPM8 S1-S4 domain. Computational PIP2 docking to a human TRPM8 comparative model was performed to help localize where PIRT may bind TRPM8. Taken together, our data suggest a mechanism where TRPM8, PIRT, and PIP2 form a regulatory complex and PIRT modulation of TRPM8 arises, at least in part, by regulating local concentrations of PIP2 accessible to TRPM8.

Extending chemical perturbations of the ubiquitin fitness landscape in a classroom setting reveals new constraints on sequence tolerance.

Although the primary protein sequence of ubiquitin (Ub) is extremely stable over evolutionary time, it is highly tolerant to mutation during selection experiments performed in the laboratory. We have proposed that this discrepancy results from the difference between fitness under laboratory culture conditions and the selective pressures in changing environments over evolutionary timescales. Building on our previous work (Mavor et al., 2016), we used deep mutational scanning to determine how twelve new chemicals (3-Amino-1,2,4-triazole, 5-fluorocytosine, Amphotericin B, CaCl2, Cerulenin, Cobalt Acetate, Menadione, Nickel Chloride, p-Fluorophenylalanine, Rapamycin, Tamoxifen, and Tunicamycin) reveal novel mutational sensitivities of ubiquitin residues. Collectively, our experiments have identified eight new sensitizing conditions for Lys63 and uncovered a sensitizing condition for every position in Ub except Ser57 and Gln62. By determining the ubiquitin fitness landscape under different chemical constraints, our work helps to resolve the inconsistencies between deep mutational scanning experiments and sequence conservation over evolutionary timescales.

Treatment of paediatric trigger finger: a systematic review and treatment algorithm.

PURPOSE: Paediatric trigger finger (PTF) is a rare condition as seen by the lack of studies published about paediatric populations. Due to this general lack of information, the steps to employ to correct this disorder, whether surgically or non-surgically, have not yet reached consensus status. The objective of this study is to review the published literature regarding treatment options for PTF in order to develop a proposed step-wise treatment algorithm for children presenting with trigger finger. METHODS: A systematic review of the literature was conducted on PubMed to locate English language studies reporting on treatment interventions of PTF. Data was collected on number of patients/fingers seen in the study, the category of the fingers involved, the number of patients/fingers undergoing each intervention and reported outcomes. RESULTS: Seven articles reporting on 118 trigger fingers were identified. In all, 64 fingers were treated non-surgically, with 57.8% (37/64) resolving. In all, 54 fingers were initially surgically treated, with 87% (47/54) resolving. In total, 34 fingers did not have resolution of symptoms following primary treatment, and 27 fingers received follow-up treatment, with 92.6% (25/27) resolving. Overall, 92.4% (109/118) of fingers achieved resolution of symptoms after all treatments were completed. CONCLUSION: Limitations for this study included few prospective studies and small sample sizes. This is likely due to the rarity of PTF. This review of the literature indicated that a step-wise approach, including non-operative and surgical techniques, should be employed in the management of PTF. LEVEL OF EVIDENCE III: This work meets the requirements of the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).

Tidal amplitude and fish abundance in the mouth region of a small estuary.

Using an acoustic underwater camera (Dual Frequency IDentification SONar, DIDSON), the abundance and direction of movement of fishes > 80 mm total length (LT ) in the mouth of a small South African estuary during spring and neap tidal cycles were observed. While the sizes of fishes recorded were consistent across both tide cycles, the number of fishes passing the camera was significantly greater during the smaller neap tides. Schooling behaviour was more pronounced for fishes that were travelling into the estuary compared to fishes swimming towards the ocean.

Understanding thermosensitive transient receptor potential channels as versatile polymodal cellular sensors.

Transient receptor potential (TRP) ion channels are eukaryotic polymodal sensors that function as molecular cellular signal integrators. TRP family members sense and are modulated by a wide array of inputs, including temperature, pressure, pH, voltage, chemicals, lipids, and other proteins. These inputs induce signal transduction events mediated by nonselective cation passage through TRP channels. In this review, we focus on the thermosensitive TRP channels and highlight the emerging view that these channels play a variety of significant roles in physiology and pathophysiology in addition to sensory biology. We attempt to use this viewpoint as a framework to understand the complexity and controversy of TRP channel modulation and ultimately suggest that the complex functional behavior arises inherently because this class of protein is exquisitely sensitive to many diverse and distinct signal inputs. To illustrate this idea, we primarily focus on TRP channel thermosensing. We also offer a structural, biochemical, biophysical, and computational perspective that may help to bring more coherence and consensus in understanding the function of this important class of proteins.

Upregulation of protein S by progestins.

BACKGROUND: Users of progestin-only contraceptives have raised protein S (PS) levels compared with baseline. This contrasts with the reduction in PS levels observed in users of combined oral contraceptives, which contain both a progestin and an estrogen. OBJECTIVES: To determine the effect of progesterone and other progestin isoforms on the expression of PS and to describe the mechanism involved. METHODS: Promoter activity of the PROS1 gene that encodes PS was assessed in vitro using breast and liver carcinoma cell lines grown in the presence of various progestins, with and without the addition of excess progesterone receptors. An electromobility shift assay (EMSA) was also performed to identify the progesterone receptor binding element. RESULTS: PROS1 transcriptional levels were directly upregulated by 25% by progesterone via a mechanism that was progesterone receptor isoform B (PR-B)-dependent. The process was blocked by the progesterone receptor modulator RU486. Results for the EMSA demonstrated that a probe comprising nucleotides -397 to -417 of the PROS1 promoter bound to ligand-activated PR-B, suggesting that the domain is a progesterone response element (PRE). The type of progestin isoform greatly influenced the level of PROS1 promoter upregulation, with medroxyprogesterone able to stimulate a > 2-fold stronger response compared with progesterone. CONCLUSIONS: The PROS1 promoter is responsive to progesterone and other progestins via a mechanism involving PR-B interacting with a PRE. The type of progestin is important as some elicit stronger upregulatory effects than others, which may influence the choice of progestin used for hormonal contraception by PS-deficient individuals.

Association between phosphodiesterase 4D gene and ischaemic stroke.

BACKGROUND: An association between the phosphodiesterase 4D (PDE4D) gene and risk of ischaemic stroke in an Icelandic population has been suggested by the deCODE group. METHODS: A case-control study of 151 hospitalised patients with first-ever ischaemic stroke and 164 randomly selected age-matched and sex-matched community controls was conducted. PDE4D genotypes for the six single-nucleotide polymorphisms (SNPs) previously reported to be independently associated with stroke were determined, common haplotypes were inferred using the expectation-maximisation algorithm, and SNP and haplotype associations with stroke were examined. A meta-analysis of published studies examining the association between PDE4D and stroke was also carried out. RESULTS: Our study of Australian patients with stroke showed an independent association between ischaemic stroke and PDE4D SNP 89 (CC: odds ratio (OR) 5.55, 95% confidence interval (CI) 1.02 to 30.19; CA: OR 1.68, 95% CI 0.96 to 2.96; AA: OR 1 (reference)), SNP 87 (CC: OR 2.13, 95% CI 1.08 to 4.20; TC: OR 1.64, 95% CI 0.89 to 3.00; TT: OR 1 (reference)) and SNP 83 (TT: OR 2.16, 95% CI 1.08 to 4.32; TC: OR 1.37, 95% CI 0.77 to 2.43; CC: OR 1 (reference)), and between ischaemic stroke and PDE4D haplotypes at SNP 89-87-83 (A-C-C: OR 2.13, 95% CI 1.15 to 3.96; C-C-T: OR 2.25, 95% CI 1.29 to 3.92), but no association between ischaemic stroke and PDE4D SNP 56, SNP 45 or SNP 41, or with PDE4D haplotypes at SNP 56-45-41. A meta-analysis of nine case-control studies (including our current results) of 3808 stroke cases and 4377 controls confirmed a significant association between stroke and PDE SNP 87 (pooled p = 0.002), SNP 83 (0.003) and SNP 41 (0.003). However, there was statistical heterogeneity (p < 0.1) among the studies in the direction of association for each of the individual SNPs tested. CONCLUSIONS: Our results and the pooled analyses from all the studies indicate a strong association between PDE4D and ischaemic stroke. This strengthens the evidence that PDE4D plays a key part in the pathogenesis of ischaemic stroke. Heterogeneity among the studies in the direction of association between individual SNPs and stroke suggests that the SNPs tested are in linkage disequilibrium with the causal allele(s).

Protein Z gene polymorphisms, protein Z concentrations, and ischemic stroke.

BACKGROUND AND PURPOSE: We aimed to determine whether A-13G or G79A polymorphisms of the protein Z gene that have been reported to be an important determinant of blood concentrations of protein Z are associated with risk of ischemic stroke in a broad range of stroke patients and controls. METHODS: We conducted a case control study of 151 hospital cases of first-ever ischemic stroke and 164 randomly selected community controls. Protein Z genotype was determined for the A-13G promoter polymorphism and the G79A intron F polymorphism, and plasma protein Z concentrations were measured during the first 7 days and at 3 to 6 months after the acute stroke event. RESULTS: Geometric mean concentrations of protein Z measured within 7 days of acute stroke were significantly higher in cases compared with controls (1.51 microg/mL versus 1.13 microg/mL; P<0.0001). Protein Z concentrations were highest among subjects with the A-13G AA genotype, intermediate among those with the AG genotype, and lowest among those with the GG genotype (1.39 microg/mL versus 1.05 microg/mL versus 0.76 microg/mL; P<0.0001); and highest among those with the G79A GG genotype, intermediate among those with the GA genotype, and lowest among those with the AA genotype (1.47 microg/mL versus 1.13 microg/mL versus 0.66 microg/mL; P<0.0001). The prevalence of A-13G and G79A genotypes was not significantly different between cases of ischemic stroke and controls. However, compared with the G79A GG genotype (reference), the odds of ischemic stroke was progressively lower for the heterozygote GA (odds ratio [OR], 0.83; 95% CI, 0.52 to 1.33) and the homozygote AA genotype (OR, 0.63; 95% CI, 0.20 to 1.98). A pooled analysis showed that compared with the G79A GG genotype (reference), the odds of ischemic stroke was progressively lower for the heterozygote GA (OR, 0.78; 95% CI, 0.57 to 1.07) and the homozygote AA genotype (OR, 0.31; 95% CI, 0.14 to 0.69). CONCLUSIONS: The consistency of the association between protein Z genotypes, blood concentrations of protein Z, and ischemic stroke, determined using 2 different methods that have different sources of bias strengthens the evidence that increased blood concentrations of protein Z concentrations are associated causally with an increased risk of ischemic stroke.

Collagen platelet receptor polymorphisms integrin alpha2beta1 C807T and GPVI Q317L and risk of ischemic stroke.

Several polymorphisms of integrin alpha2beta1 and glycoprotein (GP) VI that may modify platelet-collagen interactions or subsequent signaling have been described. We conducted a case-control study involving 180 stroke patients and 172 controls to determine whether the alpha2 C807T and GPVI Q317L polymorphisms were associated with an increased risk of ischemic stroke. We found no statistically significant differences in the distribution of alpha2 C807T and GPVI Q317L in patients and controls overall or after stratification by etiological subtype. The GPVI 317QQ genotype was found to be over-represented in a subgroup of patients >/=60 years compared to corresponding controls. However, this association did not remain significant after adjustment for other cardiovascular risk factors. Our results do not support a role for the integrin alpha2 C807T and GPVI Q317L polymorphisms in the development of first-ever ischemic stroke. However, larger studies are required to confirm this.

Treatment of depression following myocardial infarction with interpersonal psychotherapy.

A case history involving the treatment of a depressed patient who had suffered a recent myocardial infarction is described. The patient was successfully treated using a short, time-limited course of interpersonal psychotherapy for depression. The implications of postinfarction depression are discussed, as are the implications of the successful nonpharmacologic treatment.

Different uses of chromatic signals in patients with congenital and acquired colour vision deficiencies.

Chromatic signals can be used to generate perceived colour and also to detect spatially structured objects defined only by chromatic differences. These two attributes have previously been investigated in dichromats and cerebral achromatopsic patients using a new colour vision test developed at City University that makes possible the isolation of pure chromatic signals (Barbur et al. Proc. R. Soc. London B 258, 327-334, 1994). We have investigated acquired colour vision changes in a 69-year-old patient, after conventional colour vision tests gave ambiguous results. His ability to detect an object using chromatic signals was impaired more than his ability to detect a colour change, and this impairment was greater in the right eye than in the left eye. This dissociation suggests parallel pathways may be involved in the two processes of coding chromatic signals. Recent neurological testing on the same patient has indicated the onset of multiple sclerosis. Our much earlier finding based on colour vision testing may therefore have useful diagnostic implications.

Agranulocytosis associated with etodolac.

OBJECTIVE: To report a case of probable etodolac-induced agranulocytosis. CASE SUMMARY: A 72-year-old woman who had been taking etodolac 300 mg bid for approximately six weeks presented to the emergency department with symptoms of urosepsis. She was found to be profoundly granulocytopenic. Etodolac was discontinued and broad-spectrum intravenous antibiotic therapy was administered for the next 17 days. Results of bone marrow biopsy revealed marked hypocellularity consistent with drug-induced agranulocytosis. Following etodolac withdrawal, the total white blood cell count reached a low value of 0.9 x 10(9)/L and then returned to a pre-etodolac baseline after 15 days. Her hemoglobin concentration also decreased significantly during hospitalization. DISCUSSION: Agranulocytosis has rarely been reported in association with nonsteroidal antiinflammatory drugs (NSAIDs), and there are no literature reports associating etodolac with agranulocytosis. This case involving etodolac is consistent with the pattern described with other NSAIDs. Factors correlating etodolac as the causative agent are identified. Details of patient history, treatment, follow-up, and assessment are discussed. CONCLUSIONS: Detailed case assessment demonstrated probable etodolac-induced agranulocytosis in our patient. Clinicians should be aware that etodolac, like other NSAIDs, has potential to cause agranulocytosis.

Perceived parental social support and academic achievement: an attachment theory perspective.

The study tested the extent to which parental social support predicted college grade point average among undergraduate students. A sample of 418 undergraduates completed the Social Provisions Scale--Parent Form (C.E. Cutrona, 1989) and measures of family conflict and achievement orientation. American College Testing Assessment Program college entrance exam scores (ACT; American College Testing Program, 1986) and grade point average were obtained from the university registrar. Parental social support, especially reassurance of worth, predicted college grade point average when controlling for academic aptitude (ACT scores), family achievement orientation, and family conflict. Support from parents, but not from friends or romantic partners, significantly predicted grade point average. Results are interpreted in the context of adult attachment theory.

A homogeneous electrode-based bioelectrochemical immunoassay for human chorionic gonadotrophin.

An amperometric, electrode-based technique for the quantification of human chorionic gonadotrophin (HCG) is described. Glucose oxidase and an anti-HCG monoclonal antibody are co-immobilised onto a glassy carbon electrode. The activity of the enzyme is measured electrochemically by use of an electron transfer mediator (dimethylaminomethyl ferrocene). Binding of HCG to the antibody modulates the activity of the immobilised glucose oxidase, permitting quantification of HCG. Sensitivity of the assay is 7 mIU HCG ml-1 in serum (First International Reference Preparation). Soaking in 50% ethylene glycol permits reuse of the electrode. Cross-reactivity of the electrode with other hormones has been examined.