Citations

Abstract The progression of osteoarthritis (OA) is fundamentally characterized by the aberrant transformation of chondrocytes into a fibrotic phenotype, although the precise molecular mechanisms involved remain inadequately understood. In this study, the interplay between epigenetic modifications and metabolic reprogramming during the activation of fibrocartilage cells in osteoarthritis was investigated. The findings demonstrate that FSTL1 markedly upregulates key glycolytic enzymes, including LDHA, HK2, and PKM, in chondrocytes, triggering a “glycolytic burst” that results in elevated intracellular lactate levels. This accumulated lactate acts as a precursor for epigenetic modifications, specifically promoting the lactylation of histone H3 lysine 18 (H3K18la) in fibrocartilage cells, thereby facilitating the transcriptional activation of critical fibrosis‐related genes such as Itga6, Cxcl10, and Parp16. Notably, pharmacological inhibition of the PI3K/mTOR pathway or lactate dehydrogenase significantly diminishes H3K18la levels and markers of chondrocyte fibrosis, while exogenous lactate supplementation can counteract this effect. In summary, this study unveils the core mechanism by which FSTL1 reshapes the epigenetic landscape of chondrocytes and drives the fibrotic process through the activation of the “glycolysis‐lactate‐H3K18la” cascade axis, offering a dual‐target intervention strategy for OA involving metabolic reprogramming and epigenetic modification.

Abstract Background and Objectives Lucid episodes (LEs) in advanced dementia are characterized by spontaneous, transient recovery of functional abilities. Despite recent increases in research on this previously understudied phenomenon, standard definitional criteria are lacking, presenting challenges for research. Researchers have proposed a preliminary framework to guide uniform labeling and operationalization of salient data elements for investigating LEs and developing definitional criteria. This study leverages this framework to characterize reports of LEs from caregivers and advance their definition and measurement. Research Design and Methods Family caregivers (N = 259) completed an electronic survey with quantitative and open-ended questions about LEs they witnessed (N = 479 episodes). Respondents were purposively sampled for qualitative interviews. Open-ended question responses (n = 208) and in-depth interviews (n = 24) were analyzed using content analysis. Results Caregiver descriptions suggest that the content and context of LEs are heterogeneous. Descriptions included observable changes from baseline, with behavior or communication that was distinguishable from routine cognitive fluctuations. LEs were sometimes, but not always specified by logically organized actions; recognition or awareness of people, emotions, and surroundings; and insight of their cognitive limitations. Many LEs required deep personal knowledge to attribute it as a meaningful shift. Discussion and Implications Findings suggest that definitional features may universally specify a significant return of ability with more flexible criteria for how this return manifests in observed actions and domains of recovery (i.e., insight, function, and communication). The impact of LEs on observers may be better measured separately, although further research should explore this.

Abstract Description Interactions between ST6GAL1-produced sialic acids and Siglec-2 (CD22) result in immune inactivation. CD22 is a well-characterized regulator of B cell function. We demonstrate that conventional type-2 dendritic cells (cDC2s) and hybrid macrophages express CD22 across the spleen and tumor microenvironment. To understand the function of CD22 on antigen-presenting cells, we generated novel CD22-floxed mice and crossed them with a) Zbtb46-Cre ones (those lacking CD22 on cDC2s and hybrid macrophages) as well as b) CX3CR1-Cre mice (without CD22 on hybrid macrophages nor microglia). From the former cross, we generated subcutaneous flank tumor and colitis-associated colorectal cancer models. CD22 expression on myeloid cells did not impact anti-tumor responses when tumors expressed low CD22 ligand levels. From here, we assess the impact of tumor cell CD22 ligand overexpression on tumor responses. Also, to evaluate CD8 T cell response to CD22, we challenged mice with Theiler’s murine encephalomyelitis virus (TMEV), modeling multiple sclerosis via CD8 T cell hyperactivation. CD22 did not mediate CD8 activation nor infiltration in brains of the latter cross. Thus, CD22 may be functionally redundant across myeloid and B cells. Topic Categories Innate Immune Responses and Host Defense: Cellular Mechanisms (INC)

Abstract Description B7-H3 is a member of the B7 superfamily, which includes co-inhibitory receptors such as B7-H1/PD-L1 and co-stimulatory receptors such as B7-1/CD80 and B7-2/CD86. B7-H3 is upregulated by almost all types of tumors and is associated with worse prognosis. However, the exact mechanism by which B7-H3 suppresses anti-tumor immune response remains to be discovered as its ligand has yet to be identified. Sialic acid modifications are also increased in many cancers and are similarly associated with poor outcome. Here, we demonstrate for the first time that sialylated B7-H3 binds to the immune inhibitory receptor Siglec-9. Siglec-9 is expressed on many immune cells, including NK cells and T cells. We have shown that B7-H3 expression on target cells reduces killing by Siglec-9 expressing NK cells in vitro. We then hypothesized that antibodies that block B7-H3 binding to Siglec-9 will be an effective intervention to boost anti-tumor immunity. We have generated a high affinity anti-B7-H3 monoclonal antibody, F7, which blocks B7-H3 binding to Siglec-9. F7 functions to enhance NK cell killing of B7-H3 expressing target cells in vitro. F7 also dramatically enhances CART19 mediated killing of B7-H3 expressing Nalm6 cells in a relapse model in NSG mice in vivo. In summary, our work has demonstrated that B7-H3 binds Siglec-9, and blockade of such interaction can enhance anti-tumor immunity. Funding Sources • Mayo Clinic Center for Biomedical Discovery • NIH Glycobiology Common Fund supplement to R01CA243545-01A1 to VSS Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Background: Qualification of non-invasive tests (NITs) and blood biomarkers for fibrosis severity and risk assessment is an unmet need in clinical care for cirrhosis. The paucity of reproducibility data for imaging and blood biomarkers in cirrhosis hinders their application for longitudinal monitoring. The aim of this study was to evaluate the reproducibility of imaging and blood biomarkers in a prospective cohort of adults with cirrhosis. Methods: We prospectively enrolled adults with cirrhosis in an observational, longitudinal cohort study. Participants completed a research visit with vibration-controlled transient elastography (VCTE) with liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) and blood testing, including AST, ALT, platelets, alpha-fetoprotein (AFP), and the Fibrosis-4 Index (FIB-4). Biomarkers were repeated a median of 3 months apart without any interim intervention. The primary outcome was the reproducibility of each biomarker as assessed by the reproducibility coefficient (RDC%), within-participant coefficient of variation (wCV), intraclass correlation coefficient (ICC), and Bland–Altman analysis. Results: In total, 40 participants (mean age 62, 60% female, mean BMI 28.6 kg/m 2 ) had VCTE/CAP, 38 AST/ALT, and 26 had AFP at both time points. The RDC% for VCTE-LSM was 54.4, wCV 0.19, and ICC 0.91. VCTE CAP had an RDC% of 56, a wCV of 0.30, and ICC 0.47. AFP had an RDC% of 58, a wCV of 0.21, and an ICC of 0.95. RDC% for AST, ALT, and FIB-4 ranged from 70% to 79%. On Bland–Altman analyses, VCTE-LSM demonstrated the lowest relative bias (0.4%). Conclusions: Prospective assessment of repeat biomarkers in adults with cirrhosis found that VCTE-LSM and CAP provide consistent assessments across individuals but may yield substantial within-individual variation. Blood-based biomarkers had poor reproducibility within individuals but were consistent in detecting between-patient variability. These data can inform ultrasound-based non-invasive testing qualification by defining thresholds that may reflect measurement variability rather than true biologic change over time.

Abstract BACKGROUND Some persons with late‐stage Alzheimer's disease and related dementias (ADRD) and seemingly very minimal cognitive abilities have transient episodes of unexpected, spontaneous, meaningful, and relevant communication or behavior. This phenomenon, referred to as lucidity, is not well understood, although it is frequently observed by family caregivers. METHODS An exploratory study using 24 qualitative interviews and 140 open‐ended response data documented family caregiver perspectives and experiences with lucid episodes during late‐stage ADRD. RESULTS Caregivers detailed their experiences witnessing a lucid episode and the resulting impacts. Caregivers revealed reasons they felt positive or upset about the lucid episode, discussed changes the lucid episode prompted, and shared the range of emotions they experienced. IMPLICATIONS Lucid episodes have a significant, enduring, and not always positive impact on caregivers. To better navigate and face sequelae associated with lucid episodes, caregivers should receive psychoeducation or consultation to help increase their understanding, set expectations, and cope with changes. Highlights Little is known about lucid episodes in late‐stage dementia and even less is known about how dementia family caregivers react to and are impacted by these episodes. Qualitative interviews can garner rich data on dementia family caregiving experiences with understudied phenomena such as lucidity. Lucid episodes have a varying but marked and long‐lasting impact on dementia family caregivers. The dementia care field must explore strategies for enhancing education and support to caregivers to build awareness and shape expectations of lucid episodes, a complex experience.

Abstract Background Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous entity including patients with different phenotypes of near normal, normal, and supernormal left ventricular (LV) function. Objectives To assess the value of resting LV elastance (also known as force) with transthoracic echocardiography (TTE) to identify HFpEF phenotypes. Methods In a prospective, observational, multicenter study, 2380 HFpEF patients were recruited from July 2016 to May 2024. Systolic blood pressure (SBP) was measured. We assessed LV end-diastolic volume (EDV), end-systolic volume (ESV), EF, force (SBP/ESV), stroke volume (SV), arterial elastance (AE), ventricular-arterial coupling (VAC), and left atrial volume index (LAVI). Global longitudinal strain (GLS) was available in 1164 (48.9%) patients. 680 patients finished follow-up with a composite end-point of major adverse cardiac events (MACEs). Patients were divided into three groups: low force (< 25th percentile, Group 1, < 3.24 mmHg/ml), intermediate force (≥ 25th percentile and ≤ 75 thpercentile, Group 2, 3.24-5.48 mmHg/ml), and high force (> 75 th percentile, Group 3, >5.48 mmHg/ml). Results The 3 groups showed a gradient with descending values (Group 3>2>1) for SBP, EF, GLS, AE, and VAC, with the opposite gradient (Group 1> 2> 3) for EDV, ESV, SV, and LAVI values (all P<0.01). After a median follow-up of 16 months, 205 MACEs occurred in 138 patients. Cumulative MACEs rate was lowest in group 2 (14.7% person-year), higher in group 1 (16.1% person-year) and 3 (22.9% person-year, log rank p = 0.036). Conclusions HFpEF patients present with different LV contractile phenotypes, easily identified with resting LV force and volumetric TTE. The dominant hemodynamic feature of hypocontractile phenotype is a preload recruitment with larger LV EDV and normal SV, while the hypercontractile phenotype is characterized by a small LV with reduced SV. The hypercontractile and hypocontractile phenotypes are associated with a higher risk of subsequent events.

Abstract Backgrounds Transthoracic echocardiography (TTE) identifies a peculiar hypercontractile phenotype (HP) in patients with heart failure and preserved ejection fraction (HFpEF) with high resting left ventricular (LV) elastance (also called force). Objectives To assess the functional response and its prognosis associated with HP in HFpEF by stress echocardiography (SE). Methods In a prospective, observational, multicenter study, 1213 patients with HFpEF were divided into two groups based on the highest quartile of rest force: non-hypercontractile phenotype group (non-HP, < 5.64 mmHg/mL, Group 1, n= 910), and HP group (≥5.64 mmHg/mL, Group 2, n= 303). All patients underwent SE with at least 4 of the following stress parameters assessed: wall motion score index (WMSI), B-lines (4-site score), force-based LV contractile reserve, coronary flow velocity reserve (CFVR), and heart rate reserve (HRR). The employed stress was exercise (n=687), dobutamine (n=195), or vasodilators (n=331). SE score ranged from 0 (all steps normal) to 1-5, according to the number of abnormal steps. Follow-up was completed in a subset of 260 patients. Results The 2 groups showed similar values of peak stress WMSI but the global functional burden was higher in Group 2 patients: see table. In a subset of 260 patients who finished follow-up, there were 212 non-HP patients and 48 HP patients. During a median follow-up of 15 months (interquartile range: 10-20), 26 deaths, 20 heart failure (HF) rehospitalizations, and 64 major adverse cardiovascular events (MACEs) occurred. The cumulative HF rehospitalization rate and MACEs rate were higher in HP group (log-rank p<0.01): see figure. Rest force (HR, 1.17; 95% CI: 1.06-1.29; P: 0.040), rest SPAP (HR, 1.08; 95% CI: 1.02-1.14; P: 0.007) and ABCDE score (HR, 1.15; 95% CI: 1.01-1.66; P: 0.032) were independently associated with MACEs. Conclusions HFpEF patients with HP are functionally weaker with multiple vulnerabilities during stress and at higher risk of subsequent events compared to non-HP patients.Relation between resting values of force

Abstract Senile osteoporosis (SOP) is a systemic bone disease characterized by increased susceptibility to fractures. In this study, it is found that senescent bone marrow mesenchymal stem cells (BMSCs) exhibit increased sensitivity to ferroptosis, a phenomenon associated with Steap4, a nicotinamide adenine dinucleotide phosphate hydrogen (NADPH)‐dependent metalloreductase that reduces Fe 3+ to Fe 2+ . Therefore, it is aimed to innovatively elucidate how Steap4 affects ferroptosis in senescent BMSCs. These findings indicate that Steap4 promotes intracellular Fe 2+ accumulation and elevates reactive oxygen species (ROS) levels, collectively driving the upregulation of CCAAT/enhancer binding protein beta (C/EBPβ) expression. Interestingly, a functional C/EBPβ binding site is identified within the Steap4 promoter region. Mechanistically, knockdown studies demonstrated that C/EBPβ depletion attenuated Steap4 expression, whereas C/EBPβ overexpression conversely upregulated Steap4 levels. These regulatory processes establish a self‐amplifying Steap4/Fe 2+ ‐ROS/C/EBPβ positive feedback loop. Notably, a large number of adipocytes are also observed in the bone marrow of aged mice. Knockdown of Steap4 and C/EBPβ suppressed the differentiation of BMSCs into adipocytes. Knockdown of Steap4 or deferoxamine (DFO) treatment in animal experiments effectively relieves SOP. In conclusion, Steap4 accelerates the onset of ferroptosis in senescent BMSCs and promotes their differentiation to adipocytes through the Steap4/Fe 2+ ‐ROS/C/EBPβ axis, ultimately impairing their osteogenic capacity.

ABSTRACT Purpose Abnormal restrictions at myofascial interfaces are a key factor in chronic low back pain (CLBP) with myofascial pain syndrome (MPS), but no established imaging method exists for quantitative assessment. This pilot study evaluated the clinical feasibility of MR elastography (MRE)‐based slip interface imaging (SII) for visualizing myofascial mobility in CLBP‐MPS patients versus age−/sex‐/BMI‐matched healthy participants. A new SII biomarker, maximal normalized displacement discontinuity (), was introduced, and the previously developed normalized octahedral shear strain (NOSS) map was used for comparison. Preliminary assessments of vibration‐frequency effects, repeatability, and group differences in inter‐muscular mobility were conducted. Methods MRE was conducted at 30, 60, and 90 Hz to compare with NOSS for visualizing inter‐muscular slip interfaces at the quadratus lumborum‐erector spinae (QL‐ES) and erector spinae‐multifidus (ES‐M) muscle boundaries at L3‐L4. Repeatability of and NOSS was assessed at 30 Hz (identified as the best‐performing frequency) using within‐subject coefficients of variation and a linear mixed‐effects model from within‐ and between‐day scans. Clinical feasibility was then assessed via Wilcoxon rank‐sum tests in six CLBP‐MPS patients and matched controls. Results at 30 Hz exhibited superior delineation of slip interfaces compared to higher frequencies and NOSS. demonstrated significantly lower variation and better repeatability than NOSS. Healthy participants showed continuous, well‐defined slip interfaces, whereas CLBP‐MPS patients displayed disrupted interfaces with significant mobility reduction at L4 ES‐M. Conclusion SII with lower vibration frequency and map enhances visualization of lower back myofascial mobility and shows potential for assessing differences between healthy individuals and CLBP‐MPS patients.