Differences in liver and mortality outcomes of non-alcoholic fatty liver disease by race and ethnicity: A longitudinal real-world study.

BACKGROUND/AIMS: Understanding of nonalcoholic fatty liver disease (NAFLD) continues to expand, but the relationship between race and ethnicity and NAFLD outside the use of cross-sectional data is lacking. Using longitudinal data, we investigated the role of race and ethnicity in adverse outcomes in NAFLD patients. METHODS: Patients with NAFLD confirmed by imaging via manual chart review from any clinics at Stanford University Medical Center (1995-2021) were included. Primary study outcomes were incidence of liver events and mortality (overall and non-liver related). RESULTS: The study included 9,340 NAFLD patients: White (44.1%), Black (2.29%), Hispanic (27.9%), and Asian (25.7%) patients. For liver events, the cumulative 5-year incidence was highest among White (19.1%) patients, lowest among Black (7.9%) patients, and similar among Asian and Hispanic patients (~15%). The 5-year and 10-year cumulative overall mortality was highest for Black patients (9.2% and 15.0%, respectively, vs. 2.5-3.5% and 4.3-7.3% in other groups) as well as for non-liver mortality. On multivariable regression analysis, compared to White patients, only Asian group was associated with lower liver-related outcomes (aHR: 0.83, P=0.027), while Black patients were at more than two times higher risk of both non-liver related (aHR: 2.35, P=0.010) and overall mortality (aHR: 2.13, P=0.022) as well as Hispanic patients (overall mortality: aHR: 1.44, P=0.022). CONCLUSION: Compared to White patients, Black patients with NAFLD were at the highest risk for overall and non-liver-related mortality, followed by Hispanic patients with Asian patients at the lowest risk for all adverse outcomes. Culturally sensitive and appropriate programs may be needed for more successful interventions.

Differential Mortality Outcomes in Real-world Patients with Lean, Nonobese, and Obese Nonalcoholic Fatty Liver Disease.

Background and Aims: Nonalcoholic fatty liver disease (NAFLD) is commonly associated with obesity but can develop in normal-weight people (lean NAFLD). We compared outcomes in lean, overweight, and obese NAFLD. Methods: This retrospective chart review included patients at Stanford University Medical Center with NAFLD confirmed by imaging between March 1995 and December 2021. Lean, overweight, and obese patients had body mass index of <25.0, >25.0 and <29.9, and ≥30.0 kg/m2 for non-Asian and >23.0 and ≥27.5 for overweight and obese Asian patients. Results: A total of 9061 lean (10.2%), overweight (31.7%), and obese (58.1%) patients were included. Lean patients were 5 years older than obese patients (53±17.4 vs. 48.7±15.1 years), more were female (59.6% vs. 55.2%), white (49.1% vs. 46.5%), had NASH (29.2% vs. 22.5%), cirrhosis (25.3% vs.19.2%), or nonliver cancer (25.3% vs. 18.3%). Fewer had diabetes (21.7% vs. 35.8%) or metabolic comorbidities (all p<0.0001). Lean NAFLD patients had liver-related mortality similar to other groups but higher overall (p=0.01) and nonliver-related (p=0.02) mortality. After multivariable model adjustment for covariates, differences between lean and obese NAFLD in liver-related, nonliver-related, and overall mortality (adjusted hazard ratios of 1.34, 1.00, and 1.32; p=0.66, 0.99, and 0.20, respectively) were not significant. Conclusions: Lean NAFLD had fewer metabolic comorbidities but similar adverse or worse outcomes, suggesting that it is not benign. Healthcare providers should provide the same level of care and intervention as for overweight and obese NAFLD.

Three-Dimensional Adult Cardiac Extracellular Matrix Promotes Maturation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

Pluripotent stem cell-derived cardiomyocytes (CMs) have great potential in the development of new therapies for cardiovascular disease. In particular, human induced pluripotent stem cells (iPSCs) may prove especially advantageous due to their pluripotency, their self-renewal potential, and their ability to create patient-specific cell lines. Unfortunately, pluripotent stem cell-derived CMs are immature, with characteristics more closely resembling fetal CMs than adult CMs, and this immaturity has limited their use in drug screening and cell-based therapies. Extracellular matrix (ECM) influences cellular behavior and maturation, as does the geometry of the environment-two-dimensional (2D) versus three-dimensional (3D). We therefore tested the hypothesis that native cardiac ECM and 3D cultures might enhance the maturation of iPSC-derived CMs in vitro. We demonstrate that maturation of iPSC-derived CMs was enhanced when cells were seeded into a 3D cardiac ECM scaffold, compared with 2D culture. 3D cardiac ECM promoted increased expression of calcium-handling genes, Junctin, CaV1.2, NCX1, HCN4, SERCA2a, Triadin, and CASQ2. Consistent with this, we find that iPSC-derived CMs in 3D adult cardiac ECM show increased calcium signaling (amplitude) and kinetics (maximum upstroke and downstroke) compared with cells in 2D. Cells in 3D culture were also more responsive to caffeine, likely reflecting an increased availability of calcium in the sarcoplasmic reticulum. Taken together, these studies provide novel strategies for maturing iPSC-derived CMs that may have applications in drug screening and transplantation therapies to treat heart disease.

Interferon-induced transmembrane protein 1 regulates endothelial lumen formation during angiogenesis.

OBJECTIVE: It is well established that angiogenesis is a complex and coordinated multistep process. However, there remains a lack of information about the genes that regulate individual stages of vessel formation. Here, we aimed to define the role of human interferon-induced transmembrane protein 1 (IFITM1) during blood vessel formation. APPROACH AND RESULTS: We identified IFITM1 in a microarray screen for genes differentially regulated by endothelial cells (ECs) during an in vitro angiogenesis assay and found that IFITM1 expression was strongly induced as ECs sprouted and formed lumens. We showed by immunohistochemistry that human IFITM1 was expressed by stable blood vessels in multiple organs. siRNA-mediated knockdown of IFITM1 expression spared EC sprouting but completely disrupted lumen formation, in both in vitro and in an in vivo xeno-transplant model. ECs lacking IFITM1 underwent early stages of lumenogenesis (ie, intracellular vacuole formation) but failed to mature or expand lumens. Coimmunoprecipitation studies confirmed occludin as an IFITM1 binding partner in ECs, and immunocytochemistry showed a lack of occludin at endothelial tight junctions in the absence of IFITM1. Finally, time-lapse video microscopy revealed that IFITM1 is required for the formation of stable cell-cell contacts during endothelial lumen formation. CONCLUSIONS: IFITM1 is essential for the formation of functional blood vessels and stabilizes EC-EC interactions during endothelial lumen formation by regulating tight junction assembly.

Angiogenic sprouting is regulated by endothelial cell expression of Slug.

The Snail family of zinc-finger transcription factors are evolutionarily conserved proteins that control processes requiring cell movement. Specifically, they regulate epithelial-to-mesenchymal transitions (EMT) where an epithelial cell severs intercellular junctions, degrades basement membrane and becomes a migratory, mesenchymal-like cell. Interestingly, Slug expression has been observed in angiogenic endothelial cells (EC) in vivo, suggesting that angiogenic sprouting may share common attributes with EMT. Here, we demonstrate that sprouting EC in vitro express both Slug and Snail, and that siRNA-mediated knockdown of either inhibits sprouting and migration in multiple in vitro angiogenesis assays. We find that expression of MT1-MMP, but not of VE-Cadherin, is regulated by Slug and that loss of sprouting as a consequence of reduced Slug expression can be reversed by lentiviral-mediated re-expression of MT1-MMP. Activity of MMP2 and MMP9 are also affected by Slug expression, likely through MT1-MMP. Importantly, we find enhanced expression of Slug in EC in human colorectal cancer samples compared with normal colon tissue, suggesting a role for Slug in pathological angiogenesis. In summary, these data implicate Slug as an important regulator of sprouting angiogenesis, particularly in pathological settings.

The high incidence of steroid-induced hyperglycaemia in hospital.

AIM: The objective of this study was to systematically evaluate the incidence of steroid-induced hyperglycaemia in a tertiary referral hospital. We conducted a glucometric audit of a prospective protocol where glucose monitoring was routinely performed on patients treated with high-dose steroids. METHODS: The protocol specified routine fingerprick glucose monitoring for patients commencing high-dose steroid therapy (prednisone 25mg/day, dexamethasone 4 mg/day, hydrocortisone 100mg/day, or more) for a minimum of 48 h. The medical records and charts of these patients were audited after a 6 month period. RESULTS: There were 80 non-diabetic patients treated with high-dose steroids and 862 blood glucose (BG) readings were recorded. The mean BG was ≥8 mmol/L in 38 (48%) patients and ≥10 mmol/L in 11 (14%) subjects. Sixty-nine (86%) subjects had at least one BG ≥8 mmol/L, and 56 (70%) subjects had at least one BG ≥10 mmol/L. Among those with hyperglycaemia, it had developed within 48 h in 94% of subjects. When prednisone was administered as a once daily morning dose, glucose levels peaked in the afternoon, and would return to baseline by the next morning. CONCLUSIONS: We conclude that steroid-induced hyperglycaemia is common in hospital. Patients should be monitored for hyperglycaemia upon commencement of high-dose steroid therapy and treatment commenced as indicated.

Analysis of stromal cell secretomes reveals a critical role for stromal cell-derived hepatocyte growth factor and fibronectin in angiogenesis.

OBJECTIVE: Angiogenesis requires tightly coordinated crosstalk between endothelial cells (ECs) and stromal cells, such as fibroblasts and smooth muscle cells. The specific molecular mechanisms moderating this process are still poorly understood. METHODS AND RESULTS: Stromal cell-derived factors are essential for EC sprouting and lumen formation. We therefore compared the abilities of 2 primary fibroblast isolates and a primary smooth muscle cell isolate to promote in vitro angiogenesis, and analyzed their secretomes using a combination of nano liquid chromatography-mass spectrometry/mass spectrometry, quantitative PCR, and ELISA. Each isolate exhibited a different level of angiogenic ability. Using quantitative MS, we then compared the secretomes of a fibroblast isolate exhibiting low angiogenic activity, a fibroblast isolate exhibiting high angiogenic activity, and human umbilical vein ECs. High angiogenic fibroblast supernatants exhibited an overabundance of proteins associated with extracellular matrix constituents compared with low angiogenic fibroblasts or ECs. Finally, small interfering RNA technology and purified protein were used to confirm a role for stromal cell-derived hepatocyte growth factor and fibronectin in inducing EC sprouting. CONCLUSIONS: Differences in stromal cell ability to induce angiogenesis are a result of differences in the secreted proteomes of both extracellular matrix proteins and proangiogenic growth factors.

Digital probabilistic atlas of the border region between the middle and posterior cerebral arteries.

BACKGROUND AND PURPOSE: The diagnosis of external borderzone infarction is made when the stroke is located at the border between the arterial territories. Recent studies have raised questions regarding the location of this borderzone given the variability in the arterial territories. We examined the location of this region using a digital approach and its correspondence with the 'traditional' template. METHODS: Infarcts resulting from occlusion of the middle cerebral artery (MCA) or posterior cerebral artery (PCA) trunk or branches were segmented from T(2)-weighted MR images and linearly registered into a common stereotaxic coordinate space. For MCA infarcts and PCA infarcts, maps of voxels in a rim surrounding the infarct were created. The maps of individual rims were averaged to create images of the probability of each voxel lying in the MCA and PCA rims. The MCA and PCA rims were used to create a digital atlas of the probability of each voxel lying concurrently in both rims. RESULTS: The MCA group consisted of 36 patients (16 males) with a median age of 73 (range 25-87) years. The PCA territory group consisted of 30 patients (24 males) with a median age of 61 (range 22-86) years. The probability of involvement in the digital atlas was higher in the posterior putamen (probability 0.12-0.29) and optic tract (probability 0.13-0.0.20) than in the angular gyrus (probability 0.01). CONCLUSION: We have created a digital model of the border region between the MCA and PCA territories. This approach may be useful for evaluating the likelihood of a stroke mechanism from topography.

Digital map of posterior cerebral artery infarcts associated with posterior cerebral artery trunk and branch occlusion.

BACKGROUND AND PURPOSE: Knowledge of the extent and distribution of infarcts of the posterior cerebral artery (PCA) may give insight into the limits of the arterial territory and infarct mechanism. We describe the creation of a digital atlas of PCA infarcts associated with PCA branch and trunk occlusion by magnetic resonance imaging techniques. METHODS: Infarcts were manually segmented on T(2)-weighted magnetic resonance images obtained >24 hours after stroke onset. The images were linearly registered into a common stereotaxic coordinate space. The segmented images were averaged to yield the probability of involvement by infarction at each voxel. Comparisons were made with existing maps of the PCA territory. RESULTS: Thirty patients with a median age of 61 years (range, 22 to 86 years) were studied. In the digital atlas of the PCA, the highest frequency of infarction was within the medial temporal lobe and lingual gyrus (probability=0.60 to 0.70). The mean and maximal PCA infarct volumes were 55.1 and 128.9 cm(3), respectively. Comparison with published maps showed greater agreement in the anterior and medial boundaries of the PCA territory compared with its posterior and lateral boundaries. CONCLUSIONS: We have created a probabilistic digital atlas of the PCA based on subacute magnetic resonance scans. This approach is useful for establishing the spatial distribution of strokes in a given cerebral arterial territory and determining the regions within the arterial territory that are at greatest risk of infarction.