Scd1 and monounsaturated lipids are required for autophagy and survival of adipocytes.

OBJECTIVE: Exposure of adipocytes to 'cool' temperatures often found in the periphery of the body induces expression of Stearoyl-CoA Desaturase-1 (Scd1), an enzyme that converts saturated fatty acids to monounsaturated fatty acids. The goal of this study is to further investigate the roles of Scd in adipocytes. METHOD: In this study, we employed Scd1 knockout cells and mouse models, along with pharmacological Scd1 inhibition to dissect the enzyme's function in adipocyte physiology. RESULTS: Our study reveals that production of monounsaturated lipids by Scd1 is necessary for fusion of autophagosomes to lysosomes and that with a Scd1-deficiency, autophagosomes accumulate. In addition, Scd1-deficiency impairs lysosomal and autolysosomal acidification resulting in vacuole accumulation and eventual cell death. Blocking autophagosome formation or supplementation with monounsaturated fatty acids maintains vitality of Scd1-deficient adipocytes. CONCLUSION: This study demonstrates the indispensable role of Scd1 in adipocyte survival, with its inhibition in vivo triggering autophagy-dependent cell death and its depletion in vivo leading to the loss of bone marrow adipocytes.

Patient-centered communication, disparities, and patient portals in the US, 2017-2022.

OBJECTIVES: To identify the relationship between patient-centered communication and portal offers and use among insured adult patients and to understand the role of patient-centered communication in equitable access to portals. STUDY DESIGN: Using data from 4 cycles of the Health Information National Trends Survey across 2017-2022, we determined how patient-centered communication and sociodemographic characteristics of adult insured patients in the US are associated with offers of and access to online patient portals. METHODS: We conducted multivariable logistic regression analysis to examine associations of patient-centered communication and sociodemographic characteristics of adult insured patients in the US with offers of and access to online patient portals. RESULTS: Across the period of 2017-2022, approximately two-thirds of insured adult patients on average reported being offered a patient portal, and approximately half reported accessing a portal. Patients with lower-than-average patient-centered communication and those who are men, are Hispanic, have less than a college degree, and have no internet are less likely than their counterparts to report being offered or accessing a portal. CONCLUSIONS: Although patient-centered communication is an important factor in facilitating patient portal offers and access, it does not appear to be a driver of demographic divides in portal use.

SCD1 and monounsaturated lipids are required for autophagy and survival of adipocytes.

Exposure of adipocytes to 'cool' temperatures often found in the periphery of the body induces expression of Stearoyl-CoA Desaturase-1 (SCD1), an enzyme that converts saturated fatty acids to monounsaturated fatty acids. In this study, we employed Scd1 knockout cells and mouse models, along with pharmacological SCD1 inhibition, to investigate further the roles of SCD1 in adipocytes. Our study reveals that production of monounsaturated lipids by SCD1 is necessary for fusion of autophagosomes to lysosomes and that with a SCD1-deficiency, autophagosomes accumulate. In addition, SCD1-deficiency impairs lysosomal and autolysosomal acidification resulting in vacuole accumulation and eventual cell death. Blocking autophagosome formation or supplementation with monounsaturated fatty acids maintains vitality of SCD1-deficient adipocytes. Taken together, our results demonstrate that in vitro inhibition of SCD1 in adipocytes leads to autophagy-dependent cell death, and in vivo depletion leads to loss of bone marrow adipocytes.

Disparities in patient portal access by US adults before and during the COVID-19 pandemic.

Objective: Online patient portals become important during disruptions to in-person health care, like when cases of coronavirus disease 2019 (COVID-19) and other respiratory viruses rise, yet underlying structural inequalities associated with race, socio-economic status, and other socio-demographic characteristics may affect their use. We analyzed a population-based survey to identify disparities within the United States in access to online portals during the early period of COVID-19 in 2020. Materials and Methods: The National Cancer Institute fielded the 2020 Health and Information National Trends Survey from February to June 2020. We conducted multivariable analysis to identify socio-demographic characteristics of US patients who were offered and accessed online portals, and reasons for nonuse. Results: Less than half of insured adult patients reported accessing an online portal in the prior 12 months, and this was less common among patients who are male, are Hispanic, have less than a college degree, have Medicaid insurance, have no regular provider, or have no internet. Reasons for nonuse include: wanting to speak directly to a provider, not having an online record, concerns about privacy, and discomfort with technology. Discussion: Despite the rapid expansion of digital health technologies due to COVID-19, we found persistent socio-demographic disparities in access to patient portals. Ensuring that digital health tools are secure, private, and trustworthy would address some patient concerns that are barriers to portal access. Conclusion: Expanding the use of online portals requires explicitly addressing fundamental inequities to prevent exacerbating existing disparities, particularly during surges in cases of COVID-19 and other respiratory viruses that tax health care resources.

TrustEd: A Tool for Developing Intraoperative Entrustment Skills.

OBJECTIVE: Toolkits to assess progressive resident autonomy are integral to the movement toward competency-based surgical education. OpTrust is one such tool validated for intraoperative assessment of both faculty and resident entrustment behaviors. We developed a supplementary tool to OpTrust that would aid faculty and residents in making meaningful improvements in entrustment behavior by providing talking points and reflection items tailored to different motivational styles as defined by Regulatory Focus Theory (RFT). DESIGN: Existing literature about surgical entrustment was used to build a list of sample dialogue and self-reflection items to use in the operating room. This list was distributed as a survey to individuals familiar with OpTrust and RFT, asking them to categorize each item as Promotion-oriented, Prevention-oriented, or Either. The respondents then met to discuss survey items that did not reach a consensus until the group agreed on their categorization. SETTING: University of Wisconsin, School of Medicine and Public Health, Madison, Wisconsin Michigan Medicine, Ann Arbor, Michigan PARTICIPANTS: Clinician and education researchers familiar with intraoperative entrustment and RFT RESULTS: Eight respondents completed the survey categorizing the talking points and reflection items by RFT (100% response rate). Six of these respondents attended the additional meeting to discuss discordant items. The input from this panel was used to develop "TrustEd," the supplementary tool that faculty and residents can quickly reference before beginning a case. CONCLUSION: Although tools such as OpTrust allow intraoperative entrustment behaviors to be quantified, TrustEd offers concrete strategies for faculty and residents who are interested in improving those behaviors over time. Further study is needed to assess whether the use of TrustEd does in fact lead to durable behavior change and improvement in OpTrust scores.

BAd-CRISPR: Inducible gene knockout in interscapular brown adipose tissue of adult mice.

CRISPR/Cas9 has enabled inducible gene knockout in numerous tissues; however, its use has not been reported in brown adipose tissue (BAT). Here, we developed the brown adipocyte CRISPR (BAd-CRISPR) methodology to rapidly interrogate the function of one or multiple genes. With BAd-CRISPR, an adeno-associated virus (AAV8) expressing a single guide RNA (sgRNA) is administered directly to BAT of mice expressing Cas9 in brown adipocytes. We show that the local administration of AAV8-sgRNA to interscapular BAT of adult mice robustly transduced brown adipocytes and ablated expression of adiponectin, adipose triglyceride lipase, fatty acid synthase, perilipin 1, or stearoyl-CoA desaturase 1 by >90%. Administration of multiple AAV8 sgRNAs led to simultaneous knockout of up to three genes. BAd-CRISPR induced frameshift mutations and suppressed target gene mRNA expression but did not lead to substantial accumulation of off-target mutations in BAT. We used BAd-CRISPR to create an inducible uncoupling protein 1 (Ucp1) knockout mouse to assess the effects of UCP1 loss on adaptive thermogenesis in adult mice. Inducible Ucp1 knockout did not alter core body temperature; however, BAd-CRISPR Ucp1 mice had elevated circulating concentrations of fibroblast growth factor 21 and changes in BAT gene expression consistent with heat production through increased peroxisomal lipid oxidation. Other molecular adaptations predict additional cellular inefficiencies with an increase in both protein synthesis and turnover, and mitochondria with reduced reliance on mitochondrial-encoded gene expression and increased expression of nuclear-encoded mitochondrial genes. These data suggest that BAd-CRISPR is an efficient tool to speed discoveries in adipose tissue biology.

The molecular and metabolic program by which white adipocytes adapt to cool physiologic temperatures.

Although visceral adipocytes located within the body's central core are maintained at approximately 37°C, adipocytes within bone marrow, subcutaneous, and dermal depots are found primarily within the peripheral shell and generally exist at cooler temperatures. Responses of brown and beige/brite adipocytes to cold stress are well studied; however, comparatively little is known about mechanisms by which white adipocytes adapt to temperatures below 37°C. Here, we report that adaptation of cultured adipocytes to 31°C, the temperature at which distal marrow adipose tissues and subcutaneous adipose tissues often reside, increases anabolic and catabolic lipid metabolism, and elevates oxygen consumption. Cool adipocytes rely less on glucose and more on pyruvate, glutamine, and, especially, fatty acids as energy sources. Exposure of cultured adipocytes and gluteal white adipose tissue (WAT) to cool temperatures activates a shared program of gene expression. Cool temperatures induce stearoyl-CoA desaturase-1 (SCD1) expression and monounsaturated lipid levels in cultured adipocytes and distal bone marrow adipose tissues (BMATs), and SCD1 activity is required for acquisition of maximal oxygen consumption at 31°C.

Identification of promotion and prevention associated surgeon behaviors in the operating room to facilitate resident self-regulated learning.

BACKGROUND: The regulatory focus theory (RFT) posits that people can pursue goals with a promotion or prevention focus. Greater alignment of RFT motivational styles between faculty and residents may enhance resident operative autonomy. This study establishes a set of faculty behaviors residents can identify to infer faculty motivational styles. METHODS: 10 behaviors associated with promotion and prevention motivational styles were identified. General surgery residents rated faculty on how strongly they exhibit these behaviors. Faculty conducted a self-assessment of how strongly they exhibit these behaviors. RESULTS: There is a positive correlation between resident and faculty ratings for the promotion-associated behaviors of "works quickly," "high energy," and "mostly provides broad oversight," and for the prevention-associated behaviors of "works slowly and deliberately," "quiet and calm," and "preference for vigilant strategies." CONCLUSION: Residents can observe faculty operative behaviors to infer faculty motivational styles. Residents may use this knowledge to adjust to faculty motivational styles and enhance operative interactions.

Wnt/ß-catenin signaling regulates adipose tissue lipogenesis and adipocyte-specific loss is rigorously defended by neighboring stromal-vascular cells.

OBJECTIVE: Canonical Wnt/ß-catenin signaling is a well-studied endogenous regulator of mesenchymal cell fate determination, promoting osteoblastogenesis and inhibiting adipogenesis. However, emerging genetic evidence in humans links a number of Wnt pathway members to body fat distribution, obesity, and metabolic dysfunction, suggesting that this pathway also functions in adipocytes. Recent studies in mice have uncovered compelling evidence that the Wnt signaling pathway plays important roles in adipocyte metabolism, particularly under obesogenic conditions. However, complexities in Wnt signaling and differences in experimental models and approaches have thus far limited our understanding of its specific roles in this context. METHODS: To investigate roles of the canonical Wnt pathway in the regulation of adipocyte metabolism, we generated adipocyte-specific ß-catenin (ß-cat) knockout mouse and cultured cell models. We used RNA sequencing, ChIP sequencing, and molecular approaches to assess expression of Wnt targets and lipogenic genes. We then used functional assays to evaluate effects of ß-catenin deficiency on adipocyte metabolism, including lipid and carbohydrate handling. In mice maintained on normal chow and high-fat diets, we assessed the cellular and functional consequences of adipocyte-specific ß-catenin deletion on adipose tissues and systemic metabolism. RESULTS: We report that in adipocytes, the canonical Wnt/ß-catenin pathway regulates de novo lipogenesis (DNL) and fatty acid monounsaturation. Further, ß-catenin mediates effects of Wnt signaling on lipid metabolism in part by transcriptional regulation of Mlxipl and Srebf1. Intriguingly, adipocyte-specific loss of ß-catenin is sensed and defended by CD45-/CD31- stromal cells to maintain tissue-wide Wnt signaling homeostasis in chow-fed mice. With long-term high-fat diet, this compensatory mechanism is overridden, revealing that ß-catenin deletion promotes resistance to diet-induced obesity and adipocyte hypertrophy and subsequent protection from metabolic dysfunction. CONCLUSIONS: Taken together, our studies demonstrate that Wnt signaling in adipocytes is required for lipogenic gene expression, de novo lipogenesis, and lipid desaturation. In addition, adipose tissues rigorously defend Wnt signaling homeostasis under standard nutritional conditions, such that stromal-vascular cells sense and compensate for adipocyte-specific loss. These findings underscore the critical importance of this pathway in adipocyte lipid metabolism and adipose tissue function.

Lessons from a Minimal Genome: What Are the Essential Organizing Principles of a Cell Built from Scratch?

One of the primary challenges facing synthetic biology is reconstituting a living system from its component parts. A particularly difficult landmark is reconstituting a self-organizing system that can undergo autonomous chromosome compaction, segregation, and cell division. Here, we discuss how the syn3.0 minimal genome can inform us of the core self-organizing principles of a living cell and how these self-organizing processes can be built from the bottom up. The review underscores the importance of fundamental biology in rebuilding life from its molecular constituents.