Loss of chaperone-mediated autophagy does not alter age-related bone loss in male mice.

Chaperone-mediated autophagy (CMA) is a lysosome-dependent degradation pathway that eliminates proteins that are damaged, partially unfolded, or targeted for selective proteome remodeling. CMA contributes to several cellular processes, including stress response and proteostasis. Age-associated increase in cellular stressors and decrease in CMA contribute to pathologies associated with aging in various tissues. CMA contributes to bone homeostasis in young mice. An age-associated reduction in CMA was reported in osteoblast lineage cells; however, whether declining CMA contributes to skeletal aging is unknown. Herein we show that cellular stressors stimulate CMA in UAMS-32 osteoblastic cells. Moreover, the knockdown of an essential component of the CMA pathway, LAMP2A, sensitizes osteoblasts to cell death caused by DNA damage, ER stress, and oxidative stress. As elevations in these stressors are thought to contribute to age-related bone loss, we hypothesized that declining CMA contributes to the age-associated decline in bone formation by sensitizing osteoblast lineage cells to elevated stressors. To test this, we aged male CMA-deficient mice and controls up to 24 months of age and examined age-associated changes in bone mass and architecture. We showed that lack of CMA did not alter age-associated decline in bone mineral density as measured by dual x-ray absorptiometry (DXA). Moreover, microCT analysis performed at 24 months of age showed that vertebral cancellous bone volume, cortical thickness, and porosity of CMA-deficient and control mice were similar. Taken together, these results suggest that reduction of CMA does not contribute to age-related bone loss.

CRISPR interference provides increased cell type-specificity compared to the Cre-loxP system.

Cre-mediated recombination is frequently used for cell type-specific loss of function (LOF) studies. A major limitation of this system is recombination in unwanted cell types. CRISPR interference (CRISPRi) has been used effectively for global LOF in mice. However, cell type-specific CRISPRi, independent of recombination-based systems, has not been reported. To test the feasibility of cell type-specific CRISPRi, we produced two novel knock-in mouse models that achieve gene suppression when used together: one expressing dCas9::KRAB under the control of a cell type-specific promoter and the other expressing a single guide RNA from a safe harbor locus. We then compared the phenotypes of mice in which the same gene was targeted by either CRISPRi or the Cre-loxP system, with cell specificity conferred by Dmp1 regulatory elements in both cases. We demonstrate that CRISPRi is effective for cell type-specific LOF and that it provides improved cell type-specificity compared to the Cre-loxP system.

Prevalence of Immunomodulator Use as Combination Therapy With Vedolizumab or Ustekinumab in Inflammatory Bowel Disease.

INTRODUCTION: The benefit of adding an immunomodulator to vedolizumab and ustekinumab remains unclear and may compromise the safety of these biologics. We evaluated the prevalence and predictors of immunomodulator use with vedolizumab or ustekinumab in patients with inflammatory bowel disease in a large longitudinal cohort. METHODS: Clinical information was ascertained from electronic medical records of patients enrolled in TARGET-IBD, a prospective longitudinal observational cohort of patients with inflammatory bowel disease (IBD) at 34 sites. The prevalence of immunomodulator use with vedolizumab, ustekinumab, and antitumor necrosis factor therapies and predictors of immunomodulator use with vedolizumab and ustekinumab were estimated. Rates of combination therapy were additionally stratified by time from drug approval. RESULTS: Four thousand thirty-nine adults with IBD were identified, of whom 18.8% were treated with vedolizumab and 13.0% were treated with ustekinumab. Combination therapy with vedolizumab and ustekinumab exceeded 30% (30.7% and 36.2%, respectively) and was more likely in those with perianal disease or previous biologic exposure. Age and presence of extraintestinal manifestations did not consistently predict the use of an immunomodulator. Combination therapy decreased in the years after drug approval. DISCUSSION: Combination therapy with vedolizumab or ustekinumab was common and was associated with perianal disease and greater exposure to other biologics, although the practice is decreasing with time. Further data are needed to determine the efficacy and safety of combination therapy in patients initiating vedolizumab or ustekinumab for IBD.

Prevalence and burden of atopic dermatitis involving the head, neck, face, and hand: A cross sectional study from the TARGET-DERM AD cohort.

BACKGROUND: Atopic dermatitis (AD) is severely burdensome, and there has been poor characterization of any differences in impact based on the area affected. OBJECTIVE: To estimate the prevalence and HRQoL impact of head/face/neck/hand (HFNH) involvement among patients with moderate-to-severe atopic dermatitis. METHODS: All TARGET-DERM AD registry patients with moderate/severe Investigator Global Assessment (vIGA-AD) were assessed using the Patient Oriented SCORing Atopic Dermatitis, Patient Oriented Eczema Measure (POEM) and the (Children's) Dermatology Life Quality Index ((C)DLQI). RESULTS: 541 participants met the criteria (75.0% adults) and 84% (N = 453) reported HFNH involvement. HFNH and non-HFNH involved participants had similar characteristics; 55.2% female and 46.9% White. Compared to the non-HFNH involved, the involved had severe vIGA-AD (28.5% vs 16.3%, P = .02) and higher median body surface area affected (15% vs 10%, P ≤ .01) and were twice as likely to have higher (C)DLQI and POEM scores. LIMITATIONS: This was an analysis of real-world and patient reported outcome data. CONCLUSION: Real-world HFNH involved AD patients were associated with significantly worse quality of life, POEM/(C)DLQI, and more severe disease. Detailed assessments of specific areas affected by AD are needed to personalize treatment.

Do Atopic Dermatitis Patient-Reported Outcomes Correlate With Validated Investigator Global Assessment? Insights From TARGET-AD Registry.

BACKGROUND: Research examining associations between the clinician-reported validated Investigator Global Assessment for AD (vIGA-AD) and patient-reported disease burden is sparse. This study aims to evaluate the relationship between vIGA-AD with patient-reported disease severity and quality of life (QoL). METHODS: A cross-sectional analysis was conducted using a September 2021 data cut from the TARGET-DERM AD study, a real-world, longitudinal cohort of children, adolescents, and adults with AD enrolled at 44 academic and community dermatology and allergy sites in the US. Clinical AD severity was measured using vIGA-AD while disease severity and QoL were assessed by the Patient Oriented Eczema Measure (POEM) and (Children's) Dermatology Life Quality Index (C/DLQI), respectively. Patient characteristics, clinical- and patient reported-outcomes were assessed by stratified POEM and C/DLQI categories using descriptive statistics. Associations with vIGA-AD were evaluated using unadjusted and adjusted ordinal logistic regression and linear regression models. RESULTS: The analysis cohort (n=1,888) primarily consisted of adults (57%), females (56%), and patients with private insurance (63%). Unadjusted analyses suggest that clinical AD severity was associated with age, with more adolescents and adults having moderate/severe vIGA-AD than pediatric patients. Clinical AD severity was also associated with disease severity, with greater POEM scores observed at greater vIGA-AD severity levels (r = 0.496 and 0.45 for adults and pediatrics, respectively). Clinical AD severity and QoL were positively correlated, with greater CDLQI/DLQI scores at greater vIGA-AD severity levels (r = 0.458 and 0.334 for DLQI and CDLQI, respectively). After adjusting for demographics and other risk factors, vIGA-AD continued to show significant associations with POEM and DLQI/CDLQI. Compared to patients with clear/almost clear disease, adults and pediatrics with moderate-to-severe AD were 8.19 and 5.78 times as likely to be in a more severe POEM category, respectively. Similarly, compared to patients with clear/almost clear disease, adults and pediatrics with moderate/severe AD were 6.69 and 3.74 times as likely to be in a more severe DLQI/CDLQI category. Adjusted linear regression analyses of DLQI in adults showed significant differences by vIGA-AD level, with mild AD and moderate/severe AD associated with a 2.26-point and 5.42-point greater DLQI relative to clear/almost clear AD. CONCLUSIONS: In this real-world study of patients with AD, greater clinician-reported disease severity is positively correlated with higher patient-reported disease severity and lower QoL. J Drugs Dermatol. 2023;22(4): doi:10.36849/JDD.7473 Access Supplementary Material here Citation: Guttman-Yassky E, Bar J, Rothenberg Lausell C, et al. Do atopic dermatitis patient-reported outcomes correlate with validated investigator global assessment? Insights from TARGET-AD registry. J Drugs Dermatol. 2023;22(4):344-355. doi:10.36849/JDD.7473.

Effectiveness of Remdesivir Treatment Protocols Among Patients Hospitalized with COVID-19: A Target Trial Emulation.

BACKGROUND: Remdesivir is recommended for certain hospitalized patients with COVID-19. However, these recommendations are based on evidence from small randomized trials, early observational studies, or expert opinion. Further investigation is needed to better inform treatment guidelines with regard to the effectiveness of remdesivir among these patients. METHODS: We emulated a randomized target trial using chargemaster data from 333 US hospitals from 1 May 2020 to 31 December 2021. We compared three treatment protocols: remdesivir within 2 days of hospital admission, no remdesivir within the first 2 days of admission, and no remdesivir ever. We used baseline comorbidities recorded from encounters up to 12 months before admission and identified the use of in-hospital medications, procedures, and oxygen supplementation from charges. We estimated the cumulative incidence of mortality or mechanical ventilation/extracorporeal membrane oxygenation with an inverse probability of censoring weighted estimator. We conducted analyses in the total population as well as in subgroups stratified by level of oxygen supplementation. RESULTS: A total of 274,319 adult patients met the eligibility criteria for the study. Thirty-day in-hospital mortality risk differences for patients adhering to the early remdesivir protocol were -3.1% (95% confidence interval = -3.5%, -2.7%) compared to no early remdesivir and -3.7% (95% confidence interval -4.2%, -3.2%) compared to never remdesivir, with the strongest effect in patients needing high-flow oxygen. For mechanical ventilation/extracorporeal membrane oxygenation, risk differences were minimal. CONCLUSIONS: We estimate that, among hospitalized patients with COVID-19, remdesivir treatment within 2 days of admission reduced 30-day in-hospital mortality, particularly for patients receiving supplemental oxygen on the day of admission.

Utilizing a High-Fidelity COVID-19 Simulation to Develop Collaboration Skills Among Multispecialty Cohorts.

ABSTRACT: Nursing students rarely have the opportunity to witness nurse-to-nurse collaboration with nurses from differing specialties. Simulation can provide students with an opportunity to practice this important skill. In this simulation, students from a critical care course and students from a maternal/newborn course worked together to care for a pregnant client with COVID-19. The client's condition required expertise from both an obstetrical nurse and a critical care nurse. Although the design of the simulation was aimed at collaboration, various other important observations and teaching moments were uncovered during the implementation of the simulation.

Loss of chaperone-mediated autophagy is associated with low vertebral cancellous bone mass.

Chaperone-mediated autophagy (CMA) is a protein degradation pathway that eliminates soluble cytoplasmic proteins that are damaged, incorrectly folded, or targeted for selective proteome remodeling. However, the role of CMA in skeletal homeostasis under physiological and pathophysiological conditions is unknown. To address the role of CMA for skeletal homeostasis, we deleted an essential component of the CMA process, namely Lamp2a, from the mouse genome. CRISPR-Cas9-based genome editing led to the deletion of both Lamp2a and Lamp2c, another Lamp2 isoform, producing Lamp2AC global knockout (L2ACgKO) mice. At 5 weeks of age female L2ACgKO mice had lower vertebral cancellous bone mass compared to wild-type (WT) controls, whereas there was no difference between genotypes in male mice at this age. The low bone mass of L2ACgKO mice was associated with elevated RANKL expression and the osteoclast marker genes Trap and Cathepsin K. At 18 weeks of age, both male and female L2ACgKO mice had lower vertebral cancellous bone mass compared to WT controls. The low bone mass of L2ACgKO mice was associated with increased osteoclastogenesis and decreased mineral deposition in cultured cells. Consistent with these findings, specific knockdown of Lamp2a in an osteoblastic cell line increased RANKL expression and decreased mineral deposition. Moreover, similar to what has been observed in other cell types, macroautophagy and proteasomal degradation were upregulated in CMA-deficient osteoblasts in culture. Thus, an increase in other protein degradation pathways may partially compensate for the loss of CMA in osteoblasts. Taken together, our results suggest that CMA plays a role in vertebral cancellous bone mass accrual in young adult mice and that this may be due to an inhibitory role of CMA on osteoclastogenesis or a positive role of CMA in osteoblast formation or function.

Objective disease activity assessment and therapeutic drug monitoring prior to biologic therapy changes in routine inflammatory bowel disease clinical practice: TARGET-IBD.

BACKGROUND: Inflammatory bowel disease (IBD) treatment paradigms recommend objective disease activity assessment and reactive therapeutic drug monitoring (TDM) prior to changes in biologic therapy. We aimed to describe objective marker and TDM assessment in routine clinical practice prior to biologic therapeutic changes in adult IBD patients. METHODS: TARGET-IBD is a prospective longitudinal cohort of over 2100 IBD patients receiving usual care at 34 US academic or community centers enrolled between June 2017 and October 2019 who received biologic therapy and had a dose change or biologic discontinuation for lack of efficacy. Objective markers of disease activity within 12 weeks prior included fecal calprotectin, C-reactive protein (CRP), endoscopy, computed tomography (CT) and magnetic resonance imaging (MRI). TDM data for infliximab or adalimumab was obtained. RESULTS: 525 patients (71.4% Crohn's disease [CD], 28.6% ulcerative colitis [UC]) receiving biologic therapy underwent dose change (55.6%) or discontinuation (44.4%) for lack of efficacy. The majority were Caucasian (85.7%), 18-39 years old (52.2%), privately insured (81.5%), and at academic centers (73.7%). For dose changes, 67.5% had at least one objective disease activity assessment or TDM in the 12 weeks prior (CD 67.9%, UC 66.2%; P = 0.79). The most common objective marker was CRP in both CD (39.1%) and UC (54.5%). CRP and calprotectin were used significantly more in UC (P = 0.02 and P = 0.03). TDM was obtained in 30.7% (28.8% UC, 31.4% CD; P = 0.72) prior to dose change. For biologic discontinuation, 79.4% patients underwent objective assessment or TDM prior. In CD, CRP (46.3%) was most common, and CT (P = 0.03) and MRI (P < 0.001) were significantly more frequent than in UC. TDM was performed in 40.1% of patients (43.5% UC, 38.0% CD, P = 0.49) prior to discontinuation. Among all participants with dose change or discontinuation, endoscopy was performed in 29.3% with CD and 31.3% with UC. Academic care setting was associated with objective assessment before therapy change (OR 1.59, 95% CI 1.01-2.50). CONCLUSION: Nearly one-third of patients undergoing a biologic dose change or discontinuation do not undergo objective disease activity assessment or TDM. Assessment choice differs by disease. Future studies assessing the impact of such practices on long-term outcomes are needed.

Older Adult Patients Use More Aminosalicylate Monotherapy Compared With Younger Patients With Inflammatory Bowel Disease: TARGET-IBD.

GOAL: The goal of this study was to describe medication utilization patterns in older inflammatory bowel disease (IBD) patients. BACKGROUND: Despite a growing population of older patients with Crohn's disease (CD) and ulcerative colitis (UC), questions remain regarding medication utilization patterns in comparison to younger populations. MATERIALS AND METHODS: We collected data from the 34 sites in TARGET-IBD, a multicenter, observational cohort. The primary outcome in this study was the IBD-specific therapy utilized among older patients with IBD compared with younger age groups. Therapy use was analyzed using pairwise comparisons and then the odds of IBD-specific therapy use among patients older than age 65 were evaluated using multivariable logistic regression models. RESULTS: We identified 2980 patients with IBD (61% CD). In multivariable analysis, younger patients with UC were significantly less likely to utilize aminosalicylate monotherapy when compared with patients above 65 years [age 18 to 29: adjusted odds ratio (aOR)=0.51, 95% confidence interval (CI): 0.33-0.78]. In patients with CD, younger patients were significantly less likely to use aminosalicylate monotherapy when compared with patients above 65 (greatest difference age 18 to 29: aOR=0.31, 95% CI: 0.18-0.52). Younger patients with CD and UC were significantly more likely to use anti-tumor necrosis factor monotherapy than patients above 65 years (age 18 to 29: aOR=3.87, 95% CI: 2.47-6.06 and aOR=2.68, 95% CI: 1.29-5.58, respectively). CONCLUSIONS: Older patients with IBD demonstrate significant differences in medication utilization, including more aminosalicylate monotherapy and less anti-tumor necrosis factor monotherapy compared with younger age groups. Given the aging population in the United States, these utilization patterns may have long-term implications for disease control.

Factors Associated With Readmission in the United States Following Hospitalization With Coronavirus Disease 2019.

BACKGROUND: Patients hospitalized for coronavirus disease 2019 (COVID-19) may experience complications following hospitalization and require readmission. In this analysis, we estimated the rate and risk factors associated with COVID-19-related readmission and inpatient mortality. METHODS: In this retrospective cohort study, we used deidentified chargemaster data from 297 hospitals across 40 US states on patients hospitalized with COVID-19 from 15 February 2020 through 9 June 2020. Demographics, comorbidities, acute conditions, and clinical characteristics of first hospitalization are summarized. Multivariable logistic regression was used to measure risk factor associations with 30-day readmission and in-hospital mortality. RESULTS: Among 29 659 patients, 1070 (3.6%) were readmitted. Readmitted patients were more likely to have diabetes, hypertension, cardiovascular disease (CVD), or chronic kidney disease (CKD) vs those not readmitted (P < .0001) and to present on first admission with acute kidney injury (15.6% vs 9.2%), congestive heart failure (6.4% vs 2.4%), or cardiomyopathy (2.1% vs 0.8%) (P < .0001). Higher odds of readmission were observed in patients aged >60 vs 18-40 years (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.48-2.50) and those admitted in the Northeast vs West (OR, 1.43; 95% CI, 1.14-1.79) or South (OR, 1.28; 95% CI, 1.11-1.49). Comorbidities including diabetes (OR, 1.34; 95% CI, 1.12-1.60), CVD (OR, 1.46; 95% CI, 1.23-1.72), CKD stage 1-5 (OR, 1.51; 95% CI, 1.25-1.81), and CKD stage 5 (OR, 2.27; 95% CI, 1.81-2.86) were associated with higher odds of readmission; 12.3% of readmitted patients died during second hospitalization. CONCLUSIONS: Among this large US population of patients hospitalized with COVID-19, readmission was associated with certain comorbidities and acute conditions during first hospitalization. These findings may inform strategies to mitigate risks of readmission due to COVID-19 complications.

Methodology and Initial Results From a Real-World Observational Cohort of Patients With Inflammatory Bowel Disease: TARGET-IBD.

Background: Data on care patterns for inflammatory bowel disease (IBD) from large-scale, diverse clinical cohorts in real-world practice are sparse. We developed a real-world cohort of patients receiving care at academic and community sites, for comparative study of therapies and natural history of IBD. Methods: We describe novel methodology of central abstraction of clinical data into a real-world IBD registry with patient reported outcomes (PROs). Baseline demographics, clinical characteristics, healthcare utilization, and disease metrics were assessed. Bivariate statistics were used to compare demographic and clinical data by Crohn disease (CD) or ulcerative colitis (UC) and site of care (academic, community). Results: In 1 year, 1343 IBD patients (60.1% CD, 38.9% UC) were recruited from 27 academic (49.5%) and community (50.5%) sites, exceeding expectations (110% enrolled). Most participants also consented to provide PROs (59.5%) or biosamples (85.7%). Overall, 48.7% of the cohort provided a baseline PRO, and 62.6% provided a biosample. Compared to UC, CD subjects had higher prior (34.1% CD vs 7.7% UC; P < 0.001) and current (72.1% vs 47.9%; P < 0.001) biologic utilization. CD participants from academic sites had more complicated disease than those from community sites (62.5% vs 46.8% stricturing/penetrating; 33.5% vs 27% perianal; 36.8% vs 14.5% prior biologic, respectively). Nearly all (90.4%) participants had endoscopic data of whom 37.7% were in remission. One-year retention was 98.4%. Conclusions: Centralized data abstraction and electronic PRO capture provided efficient recruitment into a large real-world observational cohort. This novel platform provides a resource for clinical outcomes and comparative effectiveness research in IBD.

Ibrutinib for central nervous system lymphoma: the Australasian Lymphoma Alliance/MD Anderson Cancer Center experience.

Primary and secondary central nervous system lymphomas (PCNSL/SCNSL) are aggressive rare malignancies with dismal outcomes. Encouraging data have emerged from Phase I/II clinical trials treating relapsed/refractory PCNSL/SCNSL with ibrutinib. We analysed 33 patients who received ibrutinib, alone or with other therapies, for PCNSL (n = 9) or SCNSL (n = 24). The objective response rate was 58% (complete response 55%). The median progression-free survival and overall survival for patients with PCNSL were both 3·1 months; for SCNSL, 10·2 and 11·5 months respectively. Only one invasive fungal infection was observed, despite concurrent or recent use of dexamethasone 8-16 mg daily in 14 patients (42%). Ibrutinib has encouraging activity in these aggressive malignancies.

Patient Characteristics and Outcomes of 11 721 Patients With Coronavirus Disease 2019 (COVID-19) Hospitalized Across the United States.

BACKGROUND: As coronavirus disease 2019 (COVID-19) disseminates throughout the United States, a better understanding of the patient characteristics associated with hospitalization, morbidity, and mortality in diverse geographic regions is essential. METHODS: Hospital chargemaster data on adult patients with COVID-19 admitted to 245 hospitals across 38 states between 15 February and 20 April 2020 were assessed. The clinical course from admission, through hospitalization, and to discharge or death was analyzed. RESULTS: A total of 11 721 patients were included (majority were >60 years of age [59.9%] and male [53.4%]). Comorbidities included hypertension (46.7%), diabetes (27.8%), cardiovascular disease (18.6%), obesity (16.1%), and chronic kidney disease (12.2%). Mechanical ventilation was required by 1967 patients (16.8%). Mortality among hospitalized patients was 21.4% and increased to 70.5% among those on mechanical ventilation. Male sex, older age, obesity, geographic region, and the presence of chronic kidney disease or a preexisting cardiovascular disease were associated with increased odds of mechanical ventilation. All aforementioned risk factors, with the exception of obesity, were associated with increased odds of death (all P values < .001). Many patients received investigational medications for treatment of COVID-19, including 48 patients on remdesivir and 4232 on hydroxychloroquine. CONCLUSIONS: This large observational cohort describes the clinical course and identifies factors associated with the outcomes of hospitalized patients with COVID-19 across the United States. These data can inform strategies to prioritize prevention and treatment for this disease.

International observational atopic dermatitis cohort to follow natural history and treatment course: TARGET-DERM AD study design and rationale.

INTRODUCTION: As new topical and systemic treatments become available for atopic dermatitis (AD), there is a need to understand how treatments are being used in routine clinical practice, their comparative effectiveness and their long-term safety in diverse clinical settings. METHODS AND ANALYSIS: The TARGET-DERM AD cohort is a longitudinal, observational study of patients with AD of all ages, designed to provide practical information on long-term effectiveness and safety unobtainable in traditional registration trials. Patients with physician-diagnosed AD receiving prescription treatment (topical or systemic) will be enrolled at academic and community clinical centres. Up to 3 years of retrospective medical records, 5 years of prospective medical records, and optional biological samples and patient-reported outcomes will be collected. The primary aims include characterisation of AD treatment regimens, evaluation of response to therapy, and description of adverse events. ETHICS AND DISSEMINATION: TARGET-DERM has been approved by a central IRB (Copernicus Group IRB, 5000 Centregreen Way Suite 200, Cary, North Carolina 27513) as well as local and institutional IRBs. No additional Ethics Committee reviews. Results will be reviewed by a publications committee and submitted to peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03661866, pre-results.

GATA4 represses RANKL in osteoblasts via multiple long-range enhancers to regulate osteoclast differentiation.

GATA4 is a transcription factor that is responsible for tissue-specific gene regulation in many tissues, and more recent studies showed that it is necessary for osteoblast differentiation. Previously, we showed that in vivo deletion of Gata4 using Cre-recombinase under the control of the Col1a1 2.3 kb promoter, showed significantly reduced trabecular bone properties. To understand the role of GATA4 in more differentiated cells, GATA4fl/fl mice were crossed with mice expressing Cre-recombinase under the control of the osteocalcin promoter. MicroCT analysis of trabecular bone properties of the femur and tibia from 14-week-old female osteocalcin-Cre/GATA4fl/fl (OCN-cKO) mice showed a significant reduction in percentage bone volume, a decrease in trabecular number and an increase in trabecular spacing. In vivo, histomorphometric analysis revealed a decrease in the number of osteoblasts and an increase in the number of osteoclasts in the tibiae of OCN-cKO mice. In vivo and in vitro systems correlated a decrease in Gata4 mRNA with increased RANKL gene expression. To determine if RANKL is a direct target of GATA4, chromatin immunoprecipitation (ChIP)-sequencing was performed, and it demonstrated that GATA4 is recruited to seven enhancers near RANKL. Furthermore, when Gata4 is knocked down, the chromatin at the RANKL region is further opened, as detected by a reduction in histone 3 lysine 27 trimethylation (H3K27me3) and an increase in histone 3 lysine 4 dimethylation (H3K4me2) in the RANKL locus. In vitro, TRAP staining of cells from bone marrow cultures from Gata4 knockout cells show that the increased levels of RANKL are sufficient for osteoclast formation. Together, the data suggest that GATA4 directly represses RANKL expression via seven cis-regulatory regions and plays an important role in maintaining proper bone development and osteoclast formation.

A real-world observational cohort of patients with primary biliary cholangitis: TARGET-primary biliary cholangitis study design and rationale.

Primary biliary cholangitis (PBC) is a rare chronic cholestatic liver disease that may progress to biliary cirrhosis if left untreated. The first-line therapy for PBC is ursodeoxycholic acid (UDCA). Unfortunately, 1 of 3 patients does not respond to UDCA. These patients are at risk for developing clinical events, including cirrhosis, complications of portal hypertension, hepatocellular carcinoma, liver transplant, or death. Recently, the U.S. Food and Drug Administration approved obeticholic acid to be used in certain patients with PBC. Off-label therapies are also used, and several other therapies are currently under evaluation. Real-world effectiveness of newly approved and off-label therapies remains unknown. TARGET-PBC is a 5-year, longitudinal, observational study of patients with PBC that will evaluate the effectiveness of clinical practice interventions and provide practical information unobtainable in registration trials. Enrollment will take place at both academic and community sites. In addition to consenting to medical records review, participants will be asked to provide an annual blood sample and complete patient reported outcome surveys at predetermined intervals. Any available liver biopsies will be digitally preserved. Conclusion: Key study outcomes will be the evaluation of the safety and effectiveness of PBC interventions and the assessment of disease progression under real-world conditions. (Hepatology Communications 2018;2:484-491).