Local public health under threat: Harassment faced by local health department leaders during the COVID-19 pandemic.

Background: Prior to the COVID-19 pandemic, local health departments (LHDs) faced several challenges including underfunding and understaffing. COVID-19 exacerbated these challenges and introduced new ones, including harassment of the agency, staff, and leadership. The objective of this study was to qualitatively understand the experiences and impact of harassment faced by LHDs during the pandemic and provide recommendations to prevent future harassment. Study design: A qualitative study was conducted utilizing focus groups for data collection. Methods: LHDs were sampled from the 2022 National Profile of Local Health Departments (Profile) study to ensure diversity in LHD size. Four virtual focus groups were conducted in Fall 2022 with a total of 16 LHD leaders surveyed in Profile, who were still in their positions. Focus group transcripts were then coded by two independent coders and analyzed using thematic analysis. Findings: Four common domains arose from the data: aggravating factors of harassment, content and formats of harassment, protective factors, and effects on individuals and on the workforce. Conclusion: Findings suggest that harassment was pervasive with many forms and impacts on the LHD leaders and workforce overall. Recommendations are proposed for the local as well as federal partners because the public health system is threatened without immediate, substantial, and coordinated solutions to address harassment and offer protection.

Defining and unpacking the core concepts of pharmacology: A global initiative.

BACKGROUND AND PURPOSE: Development of core concepts in disciplines such as biochemistry, microbiology and physiology have transformed teaching. They provide the foundation for the development of teaching resources for global educators, as well as valid and reliable approaches to assessment. An international research consensus recently identified 25 core concepts of pharmacology. The current study aimed to define and unpack these concepts. EXPERIMENTAL APPROACH: A two-phase, iterative approach, involving 60 international pharmacology education experts, was used. The first phase involved drafting definitions for core concepts and identifying key sub-concepts via a series of online meetings and asynchronous work. These were refined in the second phase, through a 2-day hybrid workshop followed by a further series of online meetings and asynchronous work. KEY RESULTS: The project produced consensus definitions for a final list of 24 core concepts and 103 sub-concepts of pharmacology. The iterative, discursive methodology resulted in modification of concepts from the original study, including change of 'drug-receptor interaction' to 'drug-target interaction' and the change of the core concept 'agonists and antagonists' to sub-concepts of drug-target interaction. CONCLUSIONS AND IMPLICATIONS: Definitions and sub-concepts of 24 core concepts provide an evidence-based foundation for pharmacology curricula development and evaluation. The next steps for this project include the development of a concept inventory to assess acquisition of concepts, as well as the development of case studies and educational resources to support teaching by the global pharmacology community, and student learning of the most critical and fundamental concepts of the discipline.

Co-created in vivo pharmacology practical classes using the novel organism Lumbriculus variegatus.

Co-creation within higher education emphasizes learner empowerment to promote collaboration between the students and staff, enabling students to become active participants in their learning process and the construction of resources with academic staff. Concurrently, a diminishing number of higher education institutions offer in vivo practical classes, resulting in an in vivo skills shortage. To address this, and to actively engage students in their own learning, we describe the co-creation of a student-led drug trial using Lumbriculus variegatus. Under blinded conditions, final-year undergraduate biomedical science students, under the tutelage of academic staff and fellow students, were involved in the co-creation of an in vivo practical class to determine the effects of histamine and histamine receptor inverse agonists mepyramine and loratadine. Throughout this process, undergraduate- and masters-level students played key roles in every aspect of practical delivery and data analysis. Herein, students demonstrated the test compounds, both in isolation and in combination, resulted in reduced stereotypical movements of L. variegatus (p < .05, n ≥ 6). 15% of students in the class responded to a feedback survey (n = 8) after the class. Students reported the class provided "real life" insights into in vivo research and enabled the development of hands-on skills which would be useful in applying in their future careers. All students reported that they enjoyed the class with 25% (n = 2) reporting concerns about animal use in research, enabling useful discussions about animals in research. Moreover, these student-led in vivo trials add to the pharmacological knowledge of L. variegatus promoting education-led research.

Developing an international concept-based curriculum for pharmacology education: The promise of core concepts and concept inventories.

Over recent years, studies have shown that science and health profession graduates demonstrate gaps in their fundamental pharmacology knowledge and ability to apply pharmacology concepts in practice. This article reviews the current challenges faced by pharmacology educators, including the exponential growth in discipline knowledge and competition for curricular time. We then argue that pharmacology education should focus on essential concepts that enable students to develop beyond 'know' towards 'know how to'. A concept-based approach will help educators prioritize and benchmark their pharmacology curriculum, facilitate integration of pharmacology with other disciplines in the curriculum, create alignment between universities and improve application of pharmacology knowledge to professional contexts such as safe prescribing practices. To achieve this, core concepts first need to be identified and unpacked, and methods for teaching and assessment using concept inventories developed. The International Society for Basic and Clinical Pharmacology Education Section (IUPHAR-Ed) Core Concepts of Pharmacology (CCP) initiative involves over 300 educators from the global pharmacology community. CCP has identified and defined the core concepts of pharmacology, together with key underpinning sub-concepts. To realize these benefits, pharmacology educators must develop methods to teach and assess core concepts. Work to develop concept inventories is ongoing, including identifying student misconceptions of the core concepts and creating a bank of multiple-choice questions to assess student understanding. Future work aims to develop and validate materials and methods to help educators embed core concepts within curricula. Potential strategies that educators can use to overcome factors that inhibit adoption of core concepts are presented.

The Role of Harassment in the Mental Well-being of Local Public Health Professionals and Its Relationship With an Intent to Leave Their Organization During the COVID-19 Pandemic.

Since the onset of the COVID-19 pandemic, news and nationwide survey efforts have reported harassment and bullying among local health officials, departments, and personnel, concurrent to a shortage of public health staff in the United States. We examined a nationally representative sample of local public health professionals (LPHPs) from the 2021 Public Health Workforce Interests and Needs Survey (PH WINS) data set to explore reported experiences with harassment, threats, and bullying; self-rated mental and emotional well-being; and intent to leave an organization. Results indicated that experience of harassment was negatively associated with ratings of mental and emotional health and positively associated with an intent to leave an organization. We discuss implications and recommendations to mitigate these risks for the nation's local public health workforce.

Identifying the core concepts of pharmacology education: A global initiative.

BACKGROUND AND PURPOSE: In recent decades, a focus on the most critical and fundamental concepts has proven highly advantageous to students and educators in many science disciplines. Pharmacology, unlike microbiology, biochemistry, or physiology, lacks a consensus list of such core concepts. EXPERIMENTAL APPROACH: We sought to develop a research-based, globally relevant list of core concepts that all students completing a foundational pharmacology course should master. This two-part project consisted of exploratory and refinement phases. The exploratory phase involved empirical data mining of the introductory sections of five key textbooks, in parallel with an online survey of over 200 pharmacology educators from 17 countries across six continents. The refinement phase involved three Delphi rounds involving 24 experts from 15 countries across six continents. KEY RESULTS: The exploratory phase resulted in a consolidated list of 74 candidate core concepts. In the refinement phase, the expert group produced a consensus list of 25 core concepts of pharmacology. CONCLUSION AND IMPLICATIONS: This list will allow pharmacology educators everywhere to focus their efforts on the conceptual knowledge perceived to matter most by experts within the discipline. Next steps for this project include defining and unpacking each core concept and developing resources to help pharmacology educators globally teach and assess these concepts within their educational contexts.

New Mexico Sponsors Identify Time and Money as Factors Affecting Home-Based Provider Child and Adult Care Food Program Engagement.

OBJECTIVE: Describe Child and Adult Care Food Program (CACFP) sponsor perspectives on barriers and facilitators to home-based provider CACFP eligibility, enrollment, and participation and ways to improve provider support. METHODS: Semistructured interviews were conducted with 11 New Mexico CACFP sponsor staff representing 9 out of 13 agencies (69% response rate) from August to September, 2020. Interviews were analyzed using thematic analysis with an essentialist/realist epistemological approach. RESULTS: Sponsor-perceived barriers to provider CACFP: eligibility (costs, background checks, fear/stigma, and delays in becoming state-approved providers); enrollment (lack of translated/low-literacy materials and cumulative systems requirements); and participation (challenges maintaining qualifying menus and documentation and accessing qualifying food, inadequate reimbursements, and unannounced visits). Sponsors suggested systems changes to improve provider support (eg, more assistance with becoming state-approved and for start-up costs and accessible, progressive nutrition training opportunities). CONCLUSIONS AND IMPLICATIONS: Sponsors noted CACFP barriers for home-based providers and identified corresponding systems changes that could be tested.

A new model for regulation of sphingosine kinase 1 translocation to the plasma membrane in breast cancer cells.

The translocation of sphingosine kinase 1 (SK1) to the plasma membrane (PM) is crucial in promoting oncogenesis. We have previously proposed that SK1 exists as both a monomer and dimer in equilibrium, although it is unclear whether these species translocate to the PM via the same or different mechanisms. We therefore investigated the structural determinants involved to better understand how translocation might potentially be targeted for therapeutic intervention. We report here that monomeric WT mouse SK1 (GFP-mSK1) translocates to the PM of MCF-7L cells stimulated with carbachol or phorbol 12-myristate 13-acetate, whereas the dimer translocates to the PM in response to sphingosine-1-phosphate; thus, the equilibrium between the monomer and dimer is sensitive to cellular stimulus. In addition, carbachol and phorbol 12-myristate 13-acetate induced translocation of monomeric GFP-mSK1 to lamellipodia, whereas sphingosine-1-phosphate induced translocation of dimeric GFP-mSK1 to filopodia, suggesting that SK1 regulates different cell biological processes dependent on dimerization. GFP-mSK1 mutants designed to modulate dimerization confirmed this difference in localization. Regulation by the C-terminal tail of SK1 was investigated using GFP-mSK1 truncations. Removal of the last five amino acids (PPEEP) prevented translocation of the enzyme to the PM, whereas removal of the last ten amino acids restored translocation. This suggests that the penultimate five amino acids (SRRGP) function as a translocation brake, which can be released by sequestration of the PPEEP sequence. We propose that these determinants alter the arrangement of N-terminal and C-terminal domains in SK1, leading to unique surfaces that promote differential translocation to the PM.

Different responses of the blockade of the P2Y1 receptor with BPTU in human and porcine intestinal tissues and in cell cultures.

BACKGROUND: Gastrointestinal smooth muscle relaxation is accomplished by activation of P2Y1 receptors, therefore this receptor plays an important role in regulation of gut motility. Recently, BPTU was developed as a negative allosteric modulator of the P2Y1 receptor. Accordingly, the aim of this study was to assess the effect of BPTU on purinergic neurotransmission in pig and human gastrointestinal tissues. METHODS: Ca2+ imaging in tSA201 cells that express the human P2Y1 receptor, organ bath and microelectrodes in tissues were used to evaluate the effects of BPTU on purinergic responses. KEY RESULTS: BPTU concentration dependently (0.1 and 1 µmol L-1 ) inhibited the rise in intracellular Ca2+ evoked by ADP in tSA201 cells. In the pig small intestine, 30 µmol L-1 BPTU reduced the fast inhibitory junction potential by 80%. Smooth muscle relaxations induced by electrical field stimulation were reduced both in pig ileum (EC50  = 6 µmol L-1 ) and colon (EC50  = 35 µmol L-1 ), but high concentrations of BPTU (up to 100 µmol L-1 ) had no effect on human colonic muscle. MRS2500 (1 µmol L-1 ) abolished all responses. Finally, 10 µmol L-1 ADPßS inhibited spontaneous motility and this was partially reversed by 30 µmol L-1 BPTU in pig, but not human colonic tissue and abolished by MRS2500 (1 µmol L-1 ). CONCLUSIONS & INFERENCES: BPTU blocks purinergic responses elicited via P2Y1 receptors in cell cultures and in pig gastrointestinal tissue. However, the concentrations needed are higher in pig tissue compared to cell cultures and BPTU was ineffective in human colonic tissue.

The development of proteinase-activated receptor-2 modulators and the challenges involved.

Protease-activated receptor-2 (PAR2) has been extensively studied since its discovery in the mid-1990. Despite the advances in understanding PAR2 pharmacology, it has taken almost 25 years for the first inhibitor to reach clinical trials, and so far, no PAR2 antagonist has been approved for human use. Research has employed classical approaches to develop a wide array of PAR2 agonists and antagonists, consisting of peptides, peptoids and antibodies to name a few, with a surge in patent applications over this period. Recent breakthroughs in PAR2 structure determination has provided a unique insight into proposed PAR2 ligand binding sites. Publication of the first crystal structures of PAR2 resolved in complex with two novel non-peptide small molecule antagonists (AZ8838 and AZ3451) revealed two distinct binding pockets, originally presumed to be allosteric sites, with a PAR2 antibody (Fab3949) used to block tethered ligand engagement with the peptide-binding domain of the receptor. Further studies have proposed orthosteric site occupancy for AZ8838 as a competitive antagonist. One company has taken the first PAR2 antibody (MEDI0618) into phase I clinical trial (NCT04198558). While this first-in-human trial is at the early stages of the assessment of safety, other research into the structural characterisation of PAR2 is still ongoing in an attempt to identify new ways to target receptor activity. This review will focus on the development of novel PAR2 modulators developed to date, with an emphasis placed upon the advances made in the pharmacological targeting of PAR2 activity as a strategy to limit chronic inflammatory disease.

Sunitinib and Imatinib Display Differential Cardiotoxicity in Adult Rat Cardiac Fibroblasts That Involves a Role for Calcium/Calmodulin Dependent Protein Kinase II.

Background: Tyrosine kinase inhibitors (TKIs) have dramatically improved cancer treatment but are known to cause cardiotoxicity. The pathophysiological consequences of TKI therapy are likely to manifest across different cell types of the heart, yet there is little understanding of the differential adverse cellular effects. Cardiac fibroblasts (CFs) play a pivotal role in the repair and remodeling of the heart following insult or injury, yet their involvement in anti-cancer drug induced cardiotoxicity has been largely overlooked. Here, we examine the direct effects of sunitinib malate and imatinib mesylate on adult rat CF viability, Ca2+ handling and mitochondrial function that may contribute to TKI-induced cardiotoxicity. In particular, we investigate whether Ca2+/calmodulin dependent protein kinase II (CaMKII), may be a mediator of TKI-induced effects. Methods: CF viability in response to chronic treatment with both drugs was assessed using MTT assays and flow cytometry analysis. Calcium mobilization was assessed in CFs loaded with Fluo4-AM and CaMKII activation via oxidation was measured via quantitative immunoblotting. Effects of both drugs on mitochondrial function was determined by live mitochondrial imaging using MitoSOX red. Results: Treatment of CFs with sunitinib (0.1-10 µM) resulted in concentration-dependent alterations in CF phenotype, with progressively significant cell loss at higher concentrations. Flow cytometry analysis and MTT assays revealed increased cell apoptosis and necrosis with increasing concentrations of sunitinib. In contrast, equivalent concentrations of imatinib resulted in no significant change in cell viability. Both sunitinib and imatinib pre-treatment increased Angiotensin II-induced intracellular Ca2+ mobilization, with only sunitinib resulting in a significant effect and also causing increased CaMKII activation via oxidation. Live cell mitochondrial imaging using MitoSOX red revealed that both sunitinib and imatinib increased mitochondrial superoxide production in a concentration-dependent manner. This effect in response to both drugs was suppressed in the presence of the CaMKII inhibitor KN-93. Conclusions: Sunitinib and imatinib showed differential effects on CFs, with sunitinib causing marked changes in cell viability at concentrations where imatinib had no effect. Sunitinib caused a significant increase in Angiotensin II-induced intracellular Ca2+ mobilization and both TKIs caused increased mitochondrial superoxide production. Targeted CaMKII inhibition reversed the TKI-induced mitochondrial damage. These findings highlight a new role for CaMKII in TKI-induced cardiotoxicity, particularly at the level of the mitochondria, and confirm differential off-target toxicity in CFs, consistent with the differential selectivity of sunitinib and imatinib.

Military veteran engagement with mental health and well-being services: a qualitative study of the role of the peer support worker.

Background: Many UK military veterans experiencing mental health and well-being difficulties do not engage with support services to get the help they need. Some mental health clinics employ Peer Support Workers (PSWs) to help veteran patients engage, however it is not known how the role influences UK veteran engagement.Aims: To gain insight into the role of peer support in UK veteran engagement with mental health and well-being services.Method: A qualitative study based on 18 semi-structured interviews with veterans, PSWs and mental health clinicians at a specialist veteran mental health and well-being clinic in Scotland.Results: Four themes of the PSW role as positive first impression, understanding professional friend, helpful and supportive connector, and an open door were identified across all participants. The PSWs' military connection, social and well-being support and role in providing veterans with an easily accessible route to dis-engage and re-engage with the service over multiple engagement attempts were particularly crucial.Conclusions: The Peer Support role enhanced veteran engagement in the majority of instances. Study findings mirrored existing peer support literature, provided new evidence in relation to engaging UK veterans, and made recommendations for future veteran research and service provision.

CaMKIIδ interacts directly with IKKß and modulates NF-κB signalling in adult cardiac fibroblasts.

Calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) acts as a molecular switch regulating cardiovascular Ca2+ handling and contractility in health and disease. Activation of CaMKIIδ is also known to regulate cardiovascular inflammation and is reported to be required for pro-inflammatory NF-κB signalling. In this study the aim was to characterise how CaMKIIδ interacts with and modulates NF-κB signalling and whether this interaction exists in non-contractile cells of the heart. Recombinant or purified CaMKIIδ and the individual inhibitory -κB kinase (IKK) proteins of the NF-κB signalling pathway were used in autoradiography and Surface Plasmon Resonance (SPR) to explore potential interactions between both components. Primary adult rat cardiac fibroblasts were then used to study the effects of selective CaMKII inhibition on pharmacologically-induced NF-κB activation as well as interaction between CaMKII and specific IKK isoforms in a cardiac cellular setting. Autoradiography analysis suggested that CaMKIIδ phosphorylated IKKß but not IKKα. SPR analysis further supported a direct interaction between CaMKIIδ and IKKß but not between CaMKIIδ and IKKα or IKKγ. CaMKIIδ regulation of IκΒα degradation was explored in adult cardiac fibroblasts exposed to pharmacological stimulation. Cells were stimulated with agonist in the presence or absence of a CaMKII inhibitor, autocamtide inhibitory peptide (AIP). Selective inhibition of CaMKII resulted in reduced NF-κB activation, as measured by agonist-stimulated IκBα degradation. Importantly, and in agreement with the recombinant protein work, an interaction between CaMKII and IKKß was evident following Proximity Ligation Assays in adult cardiac fibroblasts. This study provides new evidence supporting direct interaction between CaMKIIδ and IKKß in pro-inflammatory signalling in cardiac fibroblasts and could represent a feature that may be exploited for therapeutic benefit.

Conflicting evidence for the role of JNK as a target in breast cancer cell proliferation: Comparisons between pharmacological inhibition and selective shRNA knockdown approaches.

As a target, the JNK pathway has been implicated in roles including cell death, proliferation, and inflammation in variety of contexts which span cardiovascular disease, neurodegenerative pathologies, and cancer. JNK1 and JNK2 have recently been demonstrated to function independently, highlighting a new parameter in the study of the JNK pathway. In order for JNK1 and JNK2-specific roles to be defined, better tools need to be employed. Previous studies have relied upon the broad spectrum JNK inhibitor, SP600125, to characterize the role of JNK signaling in a number of cell lines, including the breast cancer cell line MCF-7. In line with previous literature, our study has demonstrated that SP600125 treatment inhibited c-Jun and JNK phosphorylation and MCF-7 proliferation. However, in addition to targeting JNK1, JNK2, and JNK3, SP600125 has been previously demonstrated to suppress the activity of a number of other serine/threonine kinases, making SP600125 an inadequate tool for JNK isoform-specific roles to be determined. In this study, lentiviral shRNA was employed to selectively knockdown JNK1, JNK2, and JNK1/2 in MCF-7 cells. Using this approach, JNK phosphorylation was fully inhibited following stable knockdown of respective JNK isoforms. Interestingly, despite suppression of JNK phosphorylation, MCF-7 cell proliferation, cell cycle progression, or cell death remained unaffected. These findings raise the question of whether JNK phosphorylation really is pivotal in MCF-7 cell growth and death or if suppression of these events is a result of one of the many off-targets cited for SP600125.

Nosocomial Outbreak of Extensively Drug-Resistant Acinetobacter baumannii Isolates Containing blaOXA-237 Carried on a Plasmid.

Carbapenem antibiotics are among the mainstays for treating infections caused by Acinetobacter baumannii, especially in the Northwest United States, where carbapenem-resistant A. baumannii remains relatively rare. However, between June 2012 and October 2014, an outbreak of carbapenem-resistant A. baumannii occurred in 16 patients from five health care facilities in the state of Oregon. All isolates were defined as extensively drug resistant. Multilocus sequence typing revealed that the isolates belonged to sequence type 2 (international clone 2 [IC2]) and were >95% similar as determined by repetitive-sequence-based PCR analysis. Multiplex PCR revealed the presence of a blaOXA carbapenemase gene, later identified as blaOXA-237 Whole-genome sequencing of all isolates revealed a well-supported separate branch within a global A. baumannii phylogeny. Pacific Biosciences (PacBio) SMRT sequencing was also performed on one isolate to gain insight into the genetic location of the carbapenem resistance gene. We discovered that blaOXA-237, flanked on either side by ISAba1 elements in opposite orientations, was carried on a 15,198-bp plasmid designated pORAB01-3 and was present in all 16 isolates. The plasmid also contained genes encoding a TonB-dependent receptor, septicolysin, a type IV secretory pathway (VirD4 component, TraG/TraD family) ATPase, an integrase, a RepB family plasmid DNA replication initiator protein, an alpha/beta hydrolase, and a BrnT/BrnA type II toxin-antitoxin system. This is the first reported outbreak in the northwestern United States associated with this carbapenemase. Particularly worrisome is that blaOXA-237 was carried on a plasmid and found in the most prominent worldwide clonal group IC2, potentially giving pORAB01-3 great capacity for future widespread dissemination.

Failure to Communicate: Transmission of Extensively Drug-Resistant bla OXA-237-Containing Acinetobacter baumannii-Multiple Facilities in Oregon, 2012-2014.

OBJECTIVE To determine the scope, source, and mode of transmission of a multifacility outbreak of extensively drug-resistant (XDR) Acinetobacter baumannii. DESIGN Outbreak investigation. SETTING AND PARTICIPANTS Residents and patients in skilled nursing facilities, long-term acute-care hospital, and acute-care hospitals. METHODS A case was defined as the incident isolate from clinical or surveillance cultures of XDR Acinetobacter baumannii resistant to imipenem or meropenem and nonsusceptible to all but 1 or 2 antibiotic classes in a patient in an Oregon healthcare facility during January 2012-December 2014. We queried clinical laboratories, reviewed medical records, oversaw patient and environmental surveillance surveys at 2 facilities, and recommended interventions. Pulsed-field gel electrophoresis (PFGE) and molecular analysis were performed. RESULTS We identified 21 cases, highly related by PFGE or healthcare facility exposure. Overall, 17 patients (81%) were admitted to either long-term acute-care hospital A (n=8), or skilled nursing facility A (n=8), or both (n=1) prior to XDR A. baumannii isolation. Interfacility communication of patient or resident XDR status was not performed during transfer between facilities. The rare plasmid-encoded carbapenemase gene bla OXA-237 was present in 16 outbreak isolates. Contact precautions, chlorhexidine baths, enhanced environmental cleaning, and interfacility communication were implemented for cases to halt transmission. CONCLUSIONS Interfacility transmission of XDR A. baumannii carrying the rare blaOXA-237 was facilitated by transfer of affected patients without communication to receiving facilities. Infect Control Hosp Epidemiol 2017;38:1335-1341.

Pathophysiological consequences of receptor mistraffic: Tales from the platelet P2Y12 receptor.

Genetic variations in G protein-coupled receptor (GPCR) genes can disrupt receptor function in a wide variety of human genetic diseases, including platelet bleeding disorders. Platelets are critical for haemostasis with inappropriate platelet activation leading to the development of arterial thrombosis, which can result in heart attack and stroke whilst decreased platelet activity is associated with an increased risk of bleeding. GPCRs expressed on the surface of platelets play key roles in regulating platelet activity and therefore function. Receptors include purinergic receptors (P2Y1 and P2Y12), proteinase-activated receptor (PAR1 and PAR4) and thromboxane receptors (TPα), among others. Pharmacological blockade of these receptors forms a powerful therapeutic tool in the treatment and prevention of arterial thrombosis. With the advance of genomic technologies, there has been a substantial increase in the identification of naturally occurring rare and common GPCR variants. These variants include single-nucleotide polymorphisms (SNPs) and insertion or deletions that have the potential to alter GPCR expression or function. A number of defects in platelet GPCRs that disrupt receptor function have now been characterized in patients with mild bleeding disorders. This review will focus on rare, function-disrupting variants of platelet GPCRs with particular emphasis upon mutations in the P2Y12 receptor gene that affect receptor traffic to modulate platelet function. Further this review will outline how the identification and characterization of function-disrupting GPCR mutations provides an essential link in translating our detailed understanding of receptor traffic and function in cell line studies into relevant human biological systems.

Proteinase-activated receptors (PARs) as targets for antiplatelet therapy.

Since the identification of the proteinase-activated receptor (PAR) family as mediators of serine protease activity in the 1990s, there has been tremendous progress in the elucidation of their pathophysiological roles. The development of drugs that target PARs has been the focus of many laboratories for the potential treatment of thrombosis, cancer and other inflammatory diseases. Understanding the mechanisms of PAR activation and G protein signalling pathways evoked in response to the growing list of endogenous proteases has yielded great insight into receptor regulation at the molecular level. This has led to the development of new selective modulators of PAR activity, particularly PAR1. The mixed success of targeting PARs has been best exemplified in the context of inhibiting PAR1 as a new antiplatelet therapy. The development of the competitive PAR1 antagonist, vorapaxar (Zontivity), has clearly shown the value in targeting PAR1 in acute coronary syndrome (ACS); however the severity of associated bleeding with this drug has limited its use in the clinic. Due to the efficacy of thrombin acting via PAR1, strategies to selectively inhibit specific PAR1-mediated G protein signalling pathways or to target the second thrombin platelet receptor, PAR4, are being devised. The rationale behind these alternative approaches is to bias downstream thrombin activity via PARs to allow for inhibition of pro-thrombotic pathways but maintain other pathways that may preserve haemostatic balance and improve bleeding profiles for widespread clinical use. This review summarizes the structural determinants that regulate PARs and the modulators of PAR activity developed to date.