Pavneet Singh

Sonic hedgehog promotes autophagy of vascular smooth muscle cells

Sonic hedgehog (Shh) is a morphogen critically involved in development that is reexpressed in atherosclerotic lesions. It also stimulates proliferation of vascular smooth muscle cells (SMCs). Autophagy in vascular SMCs is known to promote SMC survival and increase plaque stability. The aim of this study was to investigate whether Shh induces autophagy of vascular SMCs. Our study showed that both Shh protein and microtubule-associated protein 1 light chain 3 (LC3)-II were increased in SMCs within neointimal lesions of mouse common carotid arteries. In cultured mouse aortic SMCs, recombinant mouse Shh stimulated LC3-II levels. Overexpression of wild-type mouse Shh through the tetracycline-regulated expression-inducible system in human aortic SMCs time-dependently increased the levels of LC3-II and also stimulated protein kinase B (AKT) phosphorylation. Pretreatment with AKT inhibitor IV (AKTI IV) inhibited AKT phosphorylation and the increase in LC3-II. Shh-induced autophagy was further confirmed by the formation of autophagosomes as detected by immunostaining and transmission electron microscopy, which was inhibited by AKTI IV. Shh further increased SMC LC3-II in the presence of bafilomycin A1, (2S,3S)-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester, and pepstatin A or siRNA for the autophagy-related gene 7 (ATG7). In addition, Shh induced SMC proliferation, which was inhibited not only by AKTI IV but also by cyclopamine, an inhibitor of Shh receptor. Inhibition of autophagy with 3-methyladenine (3-MA), bafilomycin A1, or ATG7 siRNA resulted in inhibition of cell proliferation. Treatment with 3-MA, AKTI IV, or cyclopamine inhibited neointima formation in mouse common carotid arteries. Taken together, our results have shown that Shh induces autophagy of vascular SMCs involving AKT activation, suggesting a role of autophagy in Shh-induced cellular responses.

Opposite Roles of Myocardin and Atrogin-1 in L6 Myoblast Differentiation

L6 rat myoblasts undergo differentiation and myotube formation when cultured in medium containing a low‐concentration of serum, but the underlying mechanism is not well understood. The role of atrogin‐1, an E3 ligase with well‐characterized roles in muscle atrophy, has not been defined in muscle differentiation. Myocardin is a coactivator of serum response factor (SRF), which together promotes smooth muscle differentiation. Myocardin is transiently expressed in skeletal muscle progenitor cells with inhibitory effects on the expression of myogenin and muscle differentiation. It remains unknown whether myocardin, which undergoes ubiquitination degradation, plays a role in L6 cell differentiation. The current study aimed to investigate the potential roles of myocardin and atrogin‐1 in differentiation of L6 cells. As reported by many others, shifting to medium containing 2% serum induced myotube formation of L6 cells. Differentiation was accompanied by up‐regulation of atrogin‐1 and down‐regulation of myocardin, suggesting that both may be involved in muscle differentiation. As expected, over‐expression of atrogin‐1 stimulated the expression of troponin T and myogenin and differentiation of the L6 myoblasts. Co‐expression of myocardin with atrogin‐1 inhibited atrogin‐1‐induced myogenin expression. Over‐expression of atrogin‐1 decreased myocardin protein level, albeit without affecting its mRNA level. Small‐interfering RNA‐mediated knockdown of atrogin‐1 increased myocardin protein. Consistently, ectopic expression of myocardin inhibited myogenic differentiation. Unexpectedly, myocardin decreased the expression of atrogin‐1 without involving Foxo1. Taken together, our results have demonstrated that atrogin‐1 plays a positive role in skeletal muscle differentiation through down‐regulation of myocardin. J. Cell. Physiol. 228: 1989–1995, 2013.

Can Self‐Compassion Promote Healthcare Provider Well‐Being and Compassionate Care to Others? Results of a Systematic Review

BACKGROUND This meta-narrative review, conducted according to the RAMESES (Realist And Meta-narrative Evidence Syntheses: Evolving Standards) standards, critically examines the construct of self-compassion to determine if it is an accurate target variable to mitigate work-related stress and promote compassionate caregiving in healthcare providers. METHODS PubMed, Medline, CINAHL, PsycINFO, and Web of Science databases were searched. Studies were coded as referring to: (1) conceptualisation of self-compassion; (2) measures of self-compassion; (3) self-compassion and affect; and (4) self-compassion interventions. A narrative approach was used to evaluate self-compassion as a paradigm. RESULTS Sixty-nine studies were included. The construct of self-compassion in healthcare has significant limitations. Self-compassion has been related to the definition of compassion, but includes limited facets of compassion and adds elements of uncompassionate behavior. Empirical studies use the Self-Compassion Scale, which is criticised for its psychometric and theoretical validity. Therapeutic interventions purported to cultivate self-compassion may have a broader effect on general affective states. An alleged outcome of self-compassion is compassionate care; however, we found no studies that included patient reports on this primary outcome. CONCLUSION We critically examine and delineate self-compassion in healthcare providers as a composite of common facets of self-care, healthy self-attitude, and self-awareness rather than a construct in and of itself.

Dual Regulation of Myocardin Expression by Tumor Necrosis Factor-α in Vascular Smooth Muscle Cells

De-differentiation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis, a chronic inflammatory disease involving various cytokines such as tumor necrosis factor-α (TNFα). Myocardin is a co-factor of serum response factor (SRF) and is considered to be the master regulator of VSMC differentiation. It binds to SRF and regulates the expression of contractile proteins in VSMCs. Myocardin is also known to inhibit VSMC proliferation by inhibiting the NF-κB pathway, whereas TNFα is known to activate the NF-κB pathway in VSMCs. NF-κB activation has also been shown to inhibit myocardin expression and smooth muscle contractile marker genes. However, it is not definitively known whether TNFα regulates the expression and activity of myocardin in VSMCs. The current study aimed to investigate the role of TNFα in regulating myocardin and VSMC function. Our studies showed that TNFα down-regulated myocardin expression and activity in cultured VSMCs by activating the NF-κB pathway, resulting in decreased VSMC contractility and increased VSMC proliferation. Surprisingly, we also found that TNFα prevented myocardin mRNA degradation, and resulted in a further significant increase in myocardin expression and activity in differentiated VSMCs. Both the NF-κB and p44/42 MAPK pathways were involved in TNFα regulation of myocardin, which further increased the contractility of VSMCs. These differential effects of TNFα on myocardin seemingly depended on whether VSMCs were in a differentiated or de-differentiated state. Taken together, our results demonstrate that TNFα differentially regulates myocardin expression and activity, which may play a key role in regulating VSMC functions.

Potential Role of Glycogen Synthase Kinase‐3β in Regulation of Myocardin Activity in Human Vascular Smooth Muscle Cells

Glycogen synthase kinase (GSK)‐3β, a serine/threonine kinase with an inhibitory role in glycogen synthesis in hepatocytes and skeletal muscle, is also expressed in cardiac and smooth muscles. Inhibition of GSK‐3β results in cardiac hypertrophy through reducing phosphorylation and increasing transcriptional activity of myocardin, a transcriptional co‐activator for serum response factor. Myocardin plays critical roles in differentiation of smooth muscle cells (SMCs). This study, therefore, aimed to examine whether and how inhibition of GSK‐3β regulates myocardin activity in human vascular SMCs. Treatment of SMCs with the GSK‐3β inhibitors AR‐A014418 and TWS 119 significantly reduced endogenous myocardin activity, as indicated by lower expression of myocardin target genes (and gene products), CNN1 (calponin), TAGLN1 (SM22), and ACTA2 (SM α‐actin). In human SMCs overexpressing myocardin through the T‐REx system, treatment with either GSK‐3β inhibitor also inhibited the expression of CNN1, TAGLN1, and ACTA2. These effects of GSK‐3β inhibitors were mimicked by transfection with GSK‐3β siRNA. Notably, both AR‐A014418 and TWS 119 decreased the serine/threonine phosphorylation of myocardin. The chromatin immunoprecipitation assay showed that AR‐A014418 treatment reduced myocardin occupancy of the promoter of the myocardin target gene ACTA2. Overexpression of a dominant‐negative GSK‐3β mutant in myocardin‐overexpressing SMCs reduced the expression of calponin, SM22, and SM α‐actin. As expected, overexpression of constitutively active or wild‐type GSK‐3β in SMCs without myocardin overexpression increased expression of these proteins. In summary, our results indicate that inhibition of GSK‐3β reduces myocardin transcriptional activity, suggesting a role for GSK‐3β in myocardin transcriptional activity and smooth muscle differentiation. J. Cell. Physiol. 231: 393–402, 2016.

Retention of Ethnic Participants in Longitudinal Studies

We aimed to identify effective participant retention strategies utilized in longitudinal studies of ethnic groups, specifically those from South Asian and Chinese communities. We conducted a systematic review of the literature focusing on the retention of ethnic minorities in longitudinal studies, up until April 2017. Only peer-reviewed research was included. 11,316 citations were retrieved, of which 4808 were duplicates and 51 met the inclusion criteria. Financial incentives, involving key community members, flexible scheduling, developing trust and personal connections with participants, and having extensive participant contact information are key facilitators. We also describe our extensive experience of retaining South Asian and Chinese participants in longitudinal studies. Key retention strategies for these groups include involving family members, informing participants about potential personal and community benefits, being flexible in how and when the interviews are conducted, and providing multiple language options. There is little published evidence or direction regarding how to retain study participants from South Asian or Chinese communities. However, there can be some learning from studies focused on other ethnic groups. Establishing an evidence-based approach, including facilitators and barriers to retention of these groups in longitudinal studies would help to determine study feasibility, validity, and ultimately to reduce health disparities among South Asian or Chinese communities.

What are healthcare providers’ understandings and experiences of compassion? The healthcare compassion model: a grounded theory study of healthcare providers in Canada

Background Healthcare providers are considered the primary conduit of compassion in healthcare. Although most healthcare providers desire to provide compassion, and patients and families expect to receive it, an evidence-based understanding of the construct and its associated dimensions from the perspective of healthcare providers is needed. Objectives The aim of this study was to investigate healthcare providers’ perspectives and experiences of compassion in order to generate an empirically derived, clinically informed model. Design Data were collected via focus groups with frontline healthcare providers and interviews with peer-nominated exemplary compassionate healthcare providers. Data were independently and collectively analysed by the research team in accordance with Straussian grounded theory. Setting and participants 57 healthcare providers were recruited from urban and rural palliative care services spanning hospice, home care, hospital-based consult teams, and a dedicated inpatient unit within Alberta, Canada. Results Five categories and 13 associated themes were identified, illustrated in the Healthcare Provider Compassion Model depicting the dimensions of compassion and their relationship to one another. Compassion was conceptualised as—a virtuous and intentional response to know a person, to discern their needs and ameliorate their suffering through relational understanding and action. Conclusions An empirical foundation of healthcare providers’ perspectives on providing compassionate care was generated. While the dimensions of the Healthcare Provider Compassion Model were congruent with the previously developed Patient Model, further insight into compassion is now evident. The Healthcare Provider Compassion Model provides a model to guide clinical practice and research focused on developing interventions, measures and resources to improve it.

Atrogin-1 Increases Smooth Muscle Contractility Through Myocardin Degradation.

Atrogin‐1, an E3 ligase present in skeletal, cardiac and smooth muscle, down‐regulates myocardin protein during skeletal muscle differentiation. Myocardin, the master regulator of smooth muscle cell (SMC) differentiation, induces expression of smooth muscle marker genes through its association with serum response factor (SRF), which binds to the CArG box in the promoter. Myocardin undergoes ubiquitylation and proteasomal degradation. Evidence suggests that proteasomal degradation of myocardin is critical for myocardin to exert its transcriptional activity, but there is no report about the E3 ligase responsible for myocardin ubiquitylation and subsequent transactivation. Here, we showed that overexpression of atrogin‐1 increased contractility of cultured SMCs and mouse aortic tissues in organ culture. Overexpression of dominant‐negative myocardin attenuated the increase in SMC contractility induced by atrogin‐1. Atrogin‐1 overexpression increased expression of the SM contractile markers while downregulated expression of myocardin protein but not mRNA. Atrogin‐1 also ubiquitylated myocardin for proteasomal degradation in vascular SMCs. Deletion studies showed that atrogin‐1 directly interacted with myocardin through its amino acids 284–345. Immunostaining studies showed nuclear localization of atrogin‐1, myocardin, and the Rpt6 subunit of the 26S proteasome. Atrogin‐1 overexpression not only resulted in degradation of myocardin but also increased recruitment of RNA Polymerase II onto the promoters of myocardin target genes. In summary, our results have revealed the roles for atrogin‐1 in the regulation of smooth muscle contractility through enhancement of myocardin ubiquitylation/degradation and its transcriptional activity. J. Cell. Physiol. 232: 806–817, 2017.

The colours and contours of compassion: A systematic review of the perspectives of compassion among ethnically diverse patients and healthcare providers

Objective To identify and describe the perspectives, experiences, importance, and impact of compassionate care among ethnically diverse population groups. Methods A systematic search of peer-reviewed research focused on compassionate care in ethnically diverse populations published between 1946 and 2017 was conducted. Results A total of 2296 abstracts were retrieved, out of which 23 articles met the inclusion criteria. Synthesis of the literature identified the perspectives, facilitators and barriers of compassion in healthcare within ethnic groups. Compassion was described as being comprised of healthcare provider (HCP) virtues (honesty, kindness, helpful, non-judgment) and actions (smile, touch, care, support, flexibility) aimed at relieving the suffering of patients. The importance and impact of providing compassion to ethnically diverse patients was also identified which included overcoming cultural differences, alleviating distress at end-of-life, promoting patient dignity and improving patient care. This review also identified the need for more contextual studies directly exploring the topic of compassion from the perspectives of individuals within diverse ethnic groups, rather than superimposing a pre-defined, enculturated and researcher-based definition of compassion. Conclusions This review synthesizes the current evidence related to perceptions of compassion in healthcare among diverse ethnic groups and the role that compassion can play in bridging ethno-cultural differences and associated challenges, along with identifying gaps in literature related to compassionate care within diverse ethnic groups. Establishing an evidence base grounded in the direct accounts of members of diverse ethnic communities can enhance culturally sensitive compassionate care and improve compassion related health outcomes among diverse ethnic groups.

Assessing the credibility and transferability of the patient compassion model in non-cancer palliative populations

BackgroundA lack of evidence and psychometrically sound measures of compassion necessitated the development of the first known, empirically derived, theoretical Patient Compassion Model (PCM) generated from qualitative interviews with advanced cancer inpatients. We aimed to assess the credibility and transferability of the PCM across diverse palliative populations and settings.MethodsSemi-structured, audio-recorded qualitative interviews were conducted with 20 patients with life-limiting diagnoses, recruited from 4 settings (acute care, homecare, residential care, and hospice). Participants were first asked to share their understandings and experiences of compassion. They were then presented with an overview of the PCM and asked to determine whether: 1) the model resonated with their understanding and experiences of compassion; 2) the model required any modification(s); 3) they had further insights on the model’s domains and/or themes. Members of the research team analyzed the qualitative data using constant comparative analysis.ResultsBoth patients’ personal perspectives of compassion prior to viewing the model and their specific feedback after being provided an overview of the model confirmed the credibility and transferability of the PCM. While new codes were incorporated into the original coding schema, no new domains or themes emerged from this study sample. These additional codes provided a more comprehensive understanding of the nuances within the domains and themes of the PCM that will aid in the generation of items for an ongoing study to develop a patient reported measure of compassion.ConclusionsA diverse palliative patient population confirmed the credibility and transferability of the PCM within palliative care, extending the rigour and applicability of the PCM that was originally developed within an advanced cancer population. The views of a diverse palliative patient population on compassion helped to validate previous codes and supplement the existing coding schema, informing the development of a guiding framework for the generation of a patient-reported measure of compassion.