A humanized version of Foxp2 affects cortico-basal ganglia circuits in mice.

It has been proposed that two amino acid substitutions in the transcription factor FOXP2 have been positively selected during human evolution due to effects on aspects of speech and language. Here, we introduce these substitutions into the endogenous Foxp2 gene of mice. Although these mice are generally healthy, they have qualitatively different ultrasonic vocalizations, decreased exploratory behavior and decreased dopamine concentrations in the brain suggesting that the humanized Foxp2 allele affects basal ganglia. In the striatum, a part of the basal ganglia affected in humans with a speech deficit due to a nonfunctional FOXP2 allele, we find that medium spiny neurons have increased dendrite lengths and increased synaptic plasticity. Since mice carrying one nonfunctional Foxp2 allele show opposite effects, this suggests that alterations in cortico-basal ganglia circuits might have been important for the evolution of speech and language in humans.

Improving Specialty Care Access via Telemedicine.

Introduction: Telehealth is a potential solution to persistent disparities in health and health care access by eliminating structural barriers to care. However, its adoption in urban underserved settings has been limited and remains poorly characterized. Methods: This is a prospective cohort study of patients receiving telemedicine (TM) consultation for specialty care of diabetes, hypertension, and/or kidney disease with a Federally Qualified Health Center (FQHC) as the originating site and an academic medical center (AMC) multispecialty group practice as the distant site in an urban setting. Primary data were collected onsite at a local FQHC and an urban AMC between March 2017 and March 2020, before the COVID-19 pandemic. Clinical outcomes of study participants were compared with matched controls (CON) from a sister FQHC site who were referred for traditional in-person specialty visits at the AMC. No-show rates for study participants were calculated and compared to their no-show rates for standard (STD) in-person specialty visits at the AMC during the study period. A patient satisfaction questionnaire was administered at the end of each TM visit. Results: Visit attendance data were analyzed for 104 patients (834 visits). The no-show rate was 15%. The adjusted odds ratio for no-show for TM versus STD visits was 1.03 [0.66-1.63], p = 0.87. There were no significant differences between TM and CON groups in the change from pre- to intervention periods for mean arterial pressure (p = 0.26), serum creatinine (p = 0.90), or estimated glomerular filtration rate (p = 0.56). The reduction in hemoglobin A1c was significant at a trend level (p = 0.053). Patients indicated high overall satisfaction with TM. Discussion: The study demonstrated improved glycemic control and equivalent outcomes in TM management of hypertension and kidney disease with excellent patient satisfaction. This supports ongoing efforts to increase the availability of TM to improve access to care for urban underserved populations.

Use of Premixed Insulin, Metformin, and a Glucagon-Like Peptide 1 Receptor Agonist as a Therapeutic Approach for Uncontrolled Type 2 Diabetes.

OBJECTIVE | To explore the use of premixed insulin, a glucagon-like peptide 1 (GLP-1) receptor agonist, and metformin as combination therapy for type 2 diabetes. DESIGN AND METHODS | All adult patients with type 2 diabetes who had been prescribed premixed insulin and a GLP-1 receptor agonist simultaneously at our outpatient clinic were selected for retrospective review. We reviewed A1C, weight, cumulative daily insulin dose, and adverse events over 12 months. RESULTS | A total of 72 patients received premixed insulin and a GLP-1 receptor agonist, of which 32 met inclusion criteria. The average duration of type 2 diabetes for these patients was 14.2 ± 7.1 years. Mean A1C at baseline was 10.5 ± 2.1%. At 12 months, mean A1C was 8.3 ± 1.9%. The change in mean A1C after 12 months was -2.2% (95% CI -3.433 to -1.014, P <0.0001). At 12 months, the mean cumulative insulin dose was 33.3 units less than before the therapy change (95% CI -57.13 to -9.46, P = 0.0030). Average weight change at 12 months was -2.2 kg (95% CI -27.6 to 37.6, P = NS). After 12 months, 61% of included patients (19 of 31) had an A1C ≤8%. Six additional patients were not included in analysis because they stopped the regimen after <3 months because of adverse events. CONCLUSION | Despite a decreased cumulative daily dose of insulin, patients with historically uncontrolled type 2 diabetes using metformin, premixed insulin, and a GLP-1 receptor agonist in combination experienced improved glycemic control over 12 months. Prospective randomized trials are needed to better assess the potential benefit of this combination therapy.

Continuous Glucose Monitoring As a Behavior Modification Tool.

Real-time continuous glucose monitoring (CGM) use may lead to behavioral modifications in food selection and physical activity, but there are limited data on the utility of CGM in facilitating lifestyle changes. This article describes an 18-item survey developed to explore whether patients currently using CGM believe the technology has caused them to change their behavior.

Hepatic Tm6sf2 overexpression affects cellular ApoB-trafficking, plasma lipid levels, hepatic steatosis and atherosclerosis.

The human transmembrane 6 superfamily member 2 (TM6SF2) gene has been implicated in plasma lipoprotein metabolism, alcoholic and non-alcoholic fatty liver disease and myocardial infarction in multiple genome-wide association studies. To investigate the role of Tm6sf2 in metabolic homeostasis, we generated mice with elevated expression using adeno-associated virus (AAV)-mediated gene delivery. Hepatic overexpression of mouse Tm6sf2 resulted in phenotypes previously observed in Tm6sf2-deficient mice including reduced plasma lipid levels, diminished hepatic triglycerides secretion and increased hepatosteatosis. Furthermore, increased hepatic Tm6sf2 expression protected against the development of atherosclerosis in LDL-receptor/ApoB48-deficient mice. In cultured human hepatocytes, Tm6sf2 overexpression reduced apolipoprotein B secretion and resulted in its accumulation within the endoplasmic reticulum (ER) suggesting impaired ER-to-Golgi trafficking of pre-very low-density lipoprotein (VLDL) particles. Analysis of two metabolic trait-associated coding polymorphisms in the human TM6SF2 gene (rs58542926 and rs187429064) revealed that both variants impact TM6SF2 expression by affecting the rate of protein turnover. These data demonstrate that rs58542926 (E167K) and rs187429064 (L156P) are functional variants and suggest that they influence metabolic traits through altered TM6SF2 protein stability. Taken together, our results indicate that cellular Tm6sf2 level is an important determinant of VLDL metabolism and further implicate TM6SF2 as a causative gene underlying metabolic disease and trait associations at the 19p13.11 locus.

Lipase maturation factor 1 (lmf1) is induced by endoplasmic reticulum stress through activating transcription factor 6α (Atf6α) signaling.

Lipase maturation factor 1 (Lmf1) is a critical determinant of plasma lipid metabolism, as demonstrated by severe hypertriglyceridemia associated with its mutations in mice and human subjects. Lmf1 is a chaperone localized to the endoplasmic reticulum (ER) and required for the post-translational maturation and activation of several vascular lipases. Despite its importance in plasma lipid homeostasis, the regulation of Lmf1 remains unexplored. We report here that Lmf1 expression is induced by ER stress in various cell lines and in tunicamycin (TM)-injected mice. Using genetic deficiencies in mouse embryonic fibroblasts and mouse liver, we identified the Atf6α arm of the unfolded protein response as being responsible for the up-regulation of Lmf1 in ER stress. Experiments with luciferase reporter constructs indicated that ER stress activates the Lmf1 promoter through a GC-rich DNA sequence 264 bp upstream of the transcriptional start site. We demonstrated that Atf6α is sufficient to induce the Lmf1 promoter in the absence of ER stress, and this effect is mediated by the TM-responsive cis-regulatory element. Conversely, Atf6α deficiency induced by genetic ablation or a dominant-negative form of Atf6α abolished TM stimulation of the Lmf1 promoter. In conclusion, our results indicate that Lmf1 is an unfolded protein response target gene, and Atf6α signaling is sufficient and necessary for activation of the Lmf1 promoter. Importantly, the induction of Lmf1 by ER stress appears to be a general phenomenon not restricted to lipase-expressing cells, which suggests a lipase-independent cellular role for this protein in ER homeostasis.

Neurobeachin, a regulator of synaptic protein targeting, is associated with body fat mass and feeding behavior in mice and body-mass index in humans.

Neurobeachin (Nbea) regulates neuronal membrane protein trafficking and is required for the development and functioning of central and neuromuscular synapses. In homozygous knockout (KO) mice, Nbea deficiency causes perinatal death. Here, we report that heterozygous KO mice haploinsufficient for Nbea have higher body weight due to increased adipose tissue mass. In several feeding paradigms, heterozygous KO mice consumed more food than wild-type (WT) controls, and this consumption was primarily driven by calories rather than palatability. Expression analysis of feeding-related genes in the hypothalamus and brainstem with real-time PCR showed differential expression of a subset of neuropeptide or neuropeptide receptor mRNAs between WT and Nbea+/- mice in the sated state and in response to food deprivation, but not to feeding reward. In humans, we identified two intronic NBEA single-nucleotide polymorphisms (SNPs) that are significantly associated with body-mass index (BMI) in adult and juvenile cohorts. Overall, data obtained in mice and humans suggest that variation of Nbea abundance or activity critically affects body weight, presumably by influencing the activity of feeding-related neural circuits. Our study emphasizes the importance of neural mechanisms in body weight control and points out NBEA as a potential risk gene in human obesity.

CIN85 regulates dopamine receptor endocytosis and governs behaviour in mice.

Despite extensive investigations of Cbl-interacting protein of 85 kDa (CIN85) in receptor trafficking and cytoskeletal dynamics, little is known about its functions in vivo. Here, we report the study of a mouse deficient of the two CIN85 isoforms expressed in the central nervous system, exposing a function of CIN85 in dopamine receptor endocytosis. Mice lacking CIN85 exon 2 (CIN85(Deltaex2)) show hyperactivity phenotypes, characterized by increased physical activity and exploratory behaviour. Interestingly, CIN85(Deltaex2) animals display abnormally high levels of dopamine and D2 dopamine receptors (D2DRs) in the striatum, an important centre for the coordination of animal behaviour. Importantly, CIN85 localizes to the post-synaptic compartment of striatal neurons in which it co-clusters with D2DRs. Moreover, it interacts with endocytic regulators such as dynamin and endophilins in the striatum. Absence of striatal CIN85 causes insufficient complex formation of endophilins with D2DRs in the striatum and ultimately decreased D2DR endocytosis in striatal neurons in response to dopamine stimulation. These findings indicate an important function of CIN85 in the regulation of dopamine receptor functions and provide a molecular explanation for the hyperactive behaviour of CIN85(Deltaex2) mice.

Transgenic expression and genetic variation of Lmf1 affect LPL activity in mice and humans.

OBJECTIVE: Lipoprotein lipase (LPL) is a principal enzyme in lipoprotein metabolism, tissue lipid utilization, and energy metabolism. LPL is synthesized by parenchymal cells in adipose, heart, and muscle tissues followed by secretion to extracellular sites, where lipolyic function is exerted. The catalytic activity of LPL is attained during posttranslational maturation, which involves glycosylation, folding, and subunit assembly within the endoplasmic reticulum. A lipase-chaperone, lipase maturation factor 1 (Lmf1), has recently emerged as a critical factor in this process. Previous studies demonstrated that loss-of-function mutations of Lmf1 result in diminished lipase activity and severe hypertriglyceridemia in mice and human subjects. The objective of this study is to investigate whether, beyond its role as a required factor in lipase maturation, variation in Lmf1 expression is sufficient to modulate LPL activity in vivo. METHODS AND RESULTS: To assess the effects of Lmf1 overexpression in adipose and muscle tissues, we generated aP2-Lmf1 and Mck-Lmf1 transgenic mice. Characterization of relevant tissues revealed increased LPL activity in both mouse strains. In the omental and subcutaneous adipose depots, Lmf1 overexpression was associated with increased LPL specific activity without changes in LPL mass. In contrast, increased LPL activity was due to elevated LPL protein level in heart and gonadal adipose tissue. To extend these studies to humans, we detected association between LMF1 gene variants and postheparin LPL activity in a dyslipidemic cohort. CONCLUSIONS: Our results suggest that variation in Lmf1 expression is a posttranslational determinant of LPL activity.

Effectiveness of a culturally tailored diabetes education curriculum with real-time continuous glucose monitoring in a Latinx population with type 2 diabetes: the CUT-DM with CGM for Latinx randomised controlled trial study protocol.

INTRODUCTION: The prevalence of type 2 diabetes (T2D) is increasing in the Latinx community. Despite telehealth and technology becoming more available, these resources are not reaching the Latinx population. Diabetes education is a cornerstone of treatment; however, access to culturally tailored content is a barrier to the Latinx population. Real-time continuous glucose monitoring (RT-CGM) is a patient-empowering tool that can improve glycaemic control, but it is not readily available for Latinx patients with T2D. We aim to evaluate a culturally tailored diabetes self-management education and support (DSMES) curriculum, using a team-based approach to improve glycaemic control, promote healthy behaviours and enhance patient access with the use of telehealth in Latinx individuals. The primary aim of the study is to evaluate the additive effectiveness of RT-CGM on glycaemia and behavioural changes among Latinx patients undergoing a culturally tailored DSMES. A sub aim of the study is to evaluate family members' change in behaviours. METHODS: We propose a randomised controlled trial of blinded versus RT-CGM with 100 Latinx participants with T2D who will receive DSMES via telemedicine over 12 weeks (n=50 per group). The study will be conducted at a single large federally qualified health centre system. The control group will receive culturally tailored DSMES and blinded CGM. The intervention group will receive DSMES and RT-CGM. The DSMES is conducted by community health educators weekly over 12 weeks in Spanish or English, based on participant's language preference. Patients in the RT-CGM group will have cyclical use with a goal of 50 days wear time. The primary outcomes are changes in haemoglobin A1c and CGM-derived metrics at 3 and 6 months. The secondary outcomes include participants' self-management knowledge and behaviour and household members' change in lifestyle. ETHICS AND DISSEMINATION: The study proposal was approved by the University of Washington ethics/institutional review board (IRB) Committee as minimal risk (IRB ID: STUDY00014396) and the Sea Mar IRB committee. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT05394844.

Telementoring With Project ECHO: A New Era in Diabetes-Related Continuing Education for Primary Care to Address Health Disparities.

Project ECHO® is a telementoring workforce development model that targets under-resourced communities lacking access to specialty care. The model builds virtual communities of practice, including specialists and community primary care professionals (PCPs) to combat clinical inertia and health disparities. While the ECHO model has gained global recognition, implementation of the model related to diabetes is lagging compared to other specialty conditions. This review highlights diabetes-endocrine (ENDO)-focused ECHOs using data reported in the ECHO Institute's centralized data repository (iECHO) and the learning collaborative for diabetes ECHOs. It also describes the implementation of diabetes ECHOs and their evaluation. Learner and patient-centered outcomes related to diabetes ECHOs are reviewed. Program implementation and evaluations have demonstrated utility of the ECHO model for diabetes programs to (1) address unmet needs of diabetes care in the primary care setting, (2) improve knowledge and confidence in managing complex diabetes and change provider prescribing habits, (3) improve patient outcomes, and (4) address diabetes quality improvement practices in primary care. More studies with broader collaboration among sites are needed to evaluate the model related to diabetes, especially applied to addressing therapeutic inertia, adoption of diabetes technology, and reducing health disparities.

Long-term proteasomal inhibition in transgenic mice by UBB(+1) expression results in dysfunction of central respiration control reminiscent of brainstem neuropathology in Alzheimer patients.

Aging and neurodegeneration are often accompanied by a functionally impaired ubiquitin-proteasome system (UPS). In tauopathies and polyglutamine diseases, a mutant form of ubiquitin B (UBB(+1)) accumulates in disease-specific aggregates. UBB(+1) mRNA is generated at low levels in vivo during transcription from the ubiquitin B locus by molecular misreading. The resulting mutant protein has been shown to inhibit proteasome function. To elucidate causative effects and neuropathological consequences of UBB(+1) accumulation, we used a UBB(+1) expressing transgenic mouse line that models UPS inhibition in neurons and exhibits behavioral phenotypes reminiscent of Alzheimer's disease (AD). In order to reveal affected organs and functions, young and aged UBB(+1) transgenic mice were comprehensively phenotyped for more than 240 parameters. This revealed unexpected changes in spontaneous breathing patterns and an altered response to hypoxic conditions. Our findings point to a central dysfunction of respiratory regulation in transgenic mice in comparison to wild-type littermate mice. Accordingly, UBB(+1) was strongly expressed in brainstem regions of transgenic mice controlling respiration. These regions included, e.g., the medial part of the nucleus of the tractus solitarius and the lateral subdivisions of the parabrachial nucleus. In addition, UBB(+1) was also strongly expressed in these anatomical structures of AD patients (Braak stage #6) and was not expressed in non-demented controls. We conclude that long-term UPS inhibition due to UBB(+1) expression causes central breathing dysfunction in a transgenic mouse model of AD. The UBB(+1) expression pattern in humans is consistent with the contribution of bronchopneumonia as a cause of death in AD patients.

Stepping Forward With Real-Time Continuous Glucose Monitoring in the Primary Care Practice.

The goal of this activity is that learners will be better able to use real-time CGM (rtCGM) in appropriate patients with type 2 diabetes.

Lipase maturation factor 1 is required for endothelial lipase activity.

Lipase maturation factor 1 (Lmf1) is an endoplasmic reticulum (ER) membrane protein involved in the posttranslational folding and/or assembly of lipoprotein lipase (LPL) and hepatic lipase (HL) into active enzymes. Mutations in Lmf1 are associated with diminished LPL and HL activities ("combined lipase deficiency") and result in severe hypertriglyceridemia in mice as well as in human subjects. Here, we investigate whether endothelial lipase (EL) also requires Lmf1 to attain enzymatic activity. We demonstrate that cells harboring a (cld) loss-of-function mutation in the Lmf1 gene are unable to generate active EL, but they regain this capacity after reconstitution with the Lmf1 wild type. Furthermore, we show that cellular EL copurifies with Lmf1, indicating their physical interaction in the ER. Finally, we determined that post-heparin phospholipase activity in a patient with the LMF1(W464X) mutation is reduced by more than 95% compared with that in controls. Thus, our study indicates that EL is critically dependent on Lmf1 for its maturation in the ER and demonstrates that Lmf1 is a required factor for all three vascular lipases, LPL, HL, and EL.

Lipase maturation factor 1: structure and role in lipase folding and assembly.

PURPOSE OF REVIEW: Lipase maturation factor 1 (LMF1) is a membrane-bound protein located in the endoplasmic reticulum. It is essential to the folding and assembly (i.e., maturation) of a selected group of lipases that include lipoprotein lipase, hepatic lipase and endothelial lipase. The purpose of this review is to examine recent studies that have begun to elucidate the structure and function of LMF1 and to place it in the context of lipase folding and assembly. RECENT FINDINGS: Recent studies identified mutations in LMF1 that cause combined lipase deficiency and hypertriglyceridemia in humans. These mutations result in the truncation of a large, evolutionarily conserved domain (DUF1222), which is essential for interaction with lipases and their attainment of enzymatic activity. The structural complexity of LMF1 has been further characterized by solving its topology in the endoplasmic reticulum membrane. Recent studies indicate that in addition to lipoprotein lipase and hepatic lipase, the maturation of endothelial lipase is also dependent on LMF1. Based on its apparent specificity for dimeric lipases, LMF1 is proposed to play an essential role in the assembly and/or stabilization of head-to-tail lipase homodimers. SUMMARY: LMF1 functions in the maturation of a selected group of secreted lipases that assemble into homodimers in the endoplasmic reticulum. These dimeric lipases include lipoprotein lipase, hepatic lipase and endothelial lipase, all of which contribute significantly to plasma triglyceride and high-density lipoprotein cholesterol levels in humans. Future studies involving genetically engineered mouse models will be required to fully elucidate the role of LMF1 in normal physiology and diseases.

Systemic first-line phenotyping.

With the completion of the mouse genome sequence an essential task for biomedical sciences in the twenty-first century will be the generation and functional analysis of mouse models for every gene in the mammalian genome. More than 30,000 mutations in ES cells will be engineered and thousands of mouse disease models will become available over the coming years by the collaborative effort of the International Mouse Knockout Consortium. In order to realize the full value of the mouse models proper characterization, archiving and dissemination of mouse disease models to the research community have to be performed. Phenotyping centers (mouse clinics) provide the necessary capacity, broad expertise, equipment, and infrastructure to carry out large-scale systemic first-line phenotyping. Using the example of the German Mouse Clinic (GMC) we will introduce the reader to the different aspects of the organization of a mouse clinic and present selected methods used in first-line phenotyping.

Behavior Modification in Prediabetes and Diabetes: Potential Use of Real-Time Continuous Glucose Monitoring.

Real-time continuous glucose monitoring (RT-CGM) provides real time glucose readings to participants wearing the device. The ability to see changes in glucose has the potential to provide immediate feedback to users on food choices and physical activity. The National Diabetes Prevention Program is currently the only reimbursable intervention for diabetes prevention and weight loss. The purpose of this article is to review the CGM literature on measurements other than Hemoglobin A1c (HbA1c) changes and hypoglycemia and discuss RT-CGM potential use as a behavior modification tool for lifestyle changes and weight reduction in people with prediabetes and type 2 diabetes (T2D).