Remodeling Changes Research Articles

Update on Adipose Tissue and Cancer.

Adipose tissue is the largest endocrine organ and an accepted contributor to overall energy homeostasis. There is strong evidence linking increased adiposity to the development of 13 types of cancer. With increased adiposity comes metabolic dysfunction and insulin resistance, and increased systemic insulin and glucose support the growth of many cancers, including those of the colon and endometrium. There is also an important direct crosstalk between adipose tissue and various organs. For instance, the healthy development and function of the mammary gland, as well as the development, growth, and progression of breast cancer, are heavily impacted by the breast adipose tissue in which breast epithelial cells are embedded. Cells of the adipose tissue are responsive to external stimuli, including overfeeding, leading to remodeling and important changes in the secretion of factors known to drive the development and growth of cancers. Loss of factors like adiponectin and increased production of leptin, endotrophin, steroid hormones, and inflammatory mediators have been determined to be important mediators of the obesity-cancer link. Obesity is also associated with a structural remodeling of the adipose tissue, including increased localized fibrosis and disrupted angiogenesis that contribute to the development and progression of cancers. Furthermore, tumor cells feed off the adipose tissue, where increased lipolysis within adipocytes leads to the release of fatty acids and stromal cell aerobic glycolysis leading to the increased production of lactate. Both have been hypothesized to support the higher energetic demands of cancer cells. Here, we aim to provide an update on the state of the literature revolving around the role of the adipose tissue in cancer initiation and progression.

Tissue-resident memory CAR T cells with stem-like characteristics display enhanced efficacy against solid and liquid tumors

Chimeric antigen receptor (CAR) Tcells demonstrate remarkable success in treating hematological malignancies, but their effectiveness in non-hematopoietic cancers remains limited. This study proposes enhancing CAR Tcell function and localization in solid tumors by modifying the epigenome governing tissue-residency adaptation and early memory differentiation. We identify that a key factor in human tissue-resident memory CAR Tcell (CAR-TRM) formation is activation in the presence of the pleotropic cytokine, transforming growth factor β (TGF-β), which enforces a core program of both "stemness" and sustained tissue residency by mediating chromatin remodeling and concurrent transcriptional changes. This approach leads to a practical and clinically actionable invitro production method for engineering peripheral blood Tcells into a large number of "stem-like" CAR-TRM cells resistant to tumor-associated dysfunction, possessing an enhanced ability to accumulate in situ and rapidly eliminate cancer cells for more effective immunotherapy.

Cardiovascular Interactions of Renin-Angiotensin-Aldosterone System Assessed by Cardiac Magnetic Resonance: The Multi-Ethnic Study of Atherosclerosis.

The effects of the renin-angiotensin-aldosterone system in cardiovascular system have been described based on small studies. The aim of this study was to evaluate the relationship between aldosterone and plasma renin activity (PRA) and cardiovascular structure and function. We studied a random sample of Multi-Ethnic Study of Atherosclerosis participants who had aldosterone and PRA blood assays at 2003-2005 and underwent cardiac magnetic resonance at 2010. Participants taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers were excluded. The aldosterone group was composed by 615 participants, mean age 61.6 ± 8.9 years, while the renin group was 580 participants, mean age 61.5 ± 8.8 years and both groups had roughly 50% females. In multivariable analysis, 1 SD increment of log-transformed aldosterone level was associated with 0.07 g/m2 higher left ventricle (LV) mass index (P = 0.04) and 0.11 ml/m2 higher left atrium (LA) minimal volume index (P < 0.01). Additionally, higher log-transformed aldosterone was associated with lower LA maximum strain and LA emptying fraction (P < 0.01). Aldosterone levels were not significantly associated with aortic measures. Log-transformed PRA was associated with lower LV end diastolic volume index (β standardized = 0.08, P = 0.05). PRA levels were not significantly associated with LA and aortic structural or functional differences. Higher levels of aldosterone and PRA are associated with concentric LV remodeling changes. Moreover, aldosterone was related to deleterious LA remodeling changes.

Cardiovascular interactions of renin angiotensin aldosterone system assessed by cardiac magnetic resonance: The Multi-Ethnic Study of Atherosclerosis.

The effects of the Renin Angiotensin Aldosterone System in cardiovascular system has been described based on small studies. The aim of this study was to evaluate the relationship between aldosterone and plasma renin activity and cardiovascular structure and function. We studied a random sample of Multi-Ethnic Study of Atherosclerosis participants who had aldosterone and plasma renin activity blood assays at 2003-2005 and underwent cardiac magnetic resonance at 2010. Participants taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers were excluded. The aldosterone group was composed by 615 participants, mean age 61.6 ± 8.9 years, while the renin group was 580 participants, mean age 61.5 ± 8.8 years and both groups had roughly 50% females. In multivariable analysis, 1 SD increment of log-transformed aldosterone level was associated with 0.07g/m 2 higher left ventricle mass index (p=0.04) and 0.11ml/m 2 higher left atrium minimal volume index (p < 0.01). Additionally, higher log-transformed aldosterone was associated with lower left atrium maximum strain and left atrium emptying fraction (βstandardized = -0.12, p < 0.01 and - 0.15, p < 0.01, respectively). Aldosterone levels were not significantly associated with aortic measures. Log-transformed plasma renin activity was associated with lower left ventricle end diastolic volume index (βstandardized = 0.08, p=0.05). Plasma renin activity levels were not significantly associated with left atrium and aortic structural or functional differences. Higher levels of aldosterone and plasma renin activity are associated with concentric left ventricle remodeling changes. Moreover, aldosterone was related to deleterious left atrium remodeling changes.

Kisspeptin regulates airway hyperresponsiveness and remodeling in a mouse model of asthma.

Asthma is a multifactorial disease of origin characterized by airway hyperresponsiveness (AHR) and airway remodeling. Several pieces of evidence from other pathologies suggest that Kisspeptins (Kp) regulate cell proliferation, migration, and invasion, mechanisms that are highly relevant to asthma. Our recent in vitro studies show Kp-10 (active peptide of Kp), via its receptor, KISS1R, inhibits human airway smooth muscle cell proliferation. Here, we hypothesize a crucial role for Kp-10 in regulating AHR and airway remodeling in vivo. Utilizing C57BL/6J mice, we assessed the effect of chronic intranasal Kp-10 exposure on mixed allergen (MA)-induced mouse model of asthma. MA-challenged mice showed significant deterioration of lung function compared to those exposed to vehicle (DPBS); Kp-10 treatment significantly improved the MA-altered lung functions. Mice treated with Kp-10 alone did not show any notable changes in lung functions. MA-exposed mice showed a significant reduction in KISS1R expression as compared to vehicle alone. MA-challenged mice showed significant alterations in immune cell infiltration in the airways and remodeling changes. Proinflammatory cytokines were significantly increased upon MA exposure, an effect abrogated by Kp-10 treatment. Furthermore, biochemical and histological studies showed Kp-10 exposure significantly reduced MA-induced smooth muscle mass and soluble collagen in the lung. Overall, our findings highlight the effect of chronic Kp-10 exposure in regulating MA-induced AHR and remodeling. © 2023 The Pathological Society of Great Britain and Ireland.

Combined Epimedii Folium and Ligustri Lucidi Fructus with dexamethasone alleviate the proliferation of airway smooth muscle cells by regulating apoptosis/autophagy

Ethnopharmacological relevanceTraditional Chinese medicine (TCM) theory believes kidney deficiency is the root cause of chronic refractory asthma with pathological changes of airway remodeling. Our previous experiments confirmed that the combination of Epimedii Folium and Ligustri Lucidi Fructus (ELL) with the effect of nourishing Yin and Yang of the kidney could improve the pathological changes of airway remodeling in asthmatic rats, but the specific mechanism remains unclear. Aim of the studyThis research was designed to reveal the synergy of ELL and dexamethasone (Dex) in the proliferation, apoptosis, and autophagy of airway smooth muscle cells (ASMCs). Materials and methodsPrimary cultures of ASMCs from rats were prepared and induced with histamine (Hist), Z-DEVD-FMK (ZDF), rapamycin (Rap), or 3-Methyladenine (3-MA) at generation 3–7 for 24 or 48 h. Subsequently, the cells were treated with Dex, ELL, and ELL&Dex for 24 or 48 h. The effect of various concentrations of inducers and drugs on cell viability was detected by Methyl Thiazolyl Tetrazolium (MTT) assay, cell proliferation was tested using immunocytochemistry (ICC) by detecting Ki67 protein, cell apoptosis was measured by Annexin V-FITC/PI assay and Hoechst nuclear staining, cell ultrastructure was observed by transmission electron microscopy (TEM), and immunofluorescence (IF), Western blot (WB) combined with quantitative real-time PCR (qPCR) were used for measuring autophagy and apoptosis-related genes including protein 53 (P53), cysteinyl aspartate-specific proteinase (Caspase)-3, microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, mammalian target of rapamycin (mTOR) and p-mTOR. ResultsIn ASMCs, Hist and ZDF promoted cell proliferation, significantly decreased Caspase-3 protein expression, and up-regulated Beclin-1 levels; Dex alone and in combination with ELL promoted Beclin-1, Caspase-3, and P53 expression, enhancing autophagy activity and apoptosis in Hist and ZDF-induced AMSCs. In contrast, Rap inhibited cell viability, increased Caspase-3, P53, Beclin-1, and LC3-II/I and decreased the levels of mTOR and p-mTOR with promoting apoptosis and autophagy; ELL or ELL&Dex reduced P53, Beclin-1, and LC3-II/I to down-regulate apoptosis and the excessive autophagic state of ASMCs induced by Rap. In the 3-MA model, cell viability and autophagy were reduced; ELL&Dex significantly upgraded the expression of Beclin-1, P53, and Caspase-3 and promoted apoptosis and autophagy of ASMCs. ConclusionsThese results suggest that ELL combined with Dex may regulate the proliferation of ASMCs by promoting apoptosis and autophagy and be a potential medicine for the treatment of asthma.

Role of hypoxia inducible factor HIF-1α in heart valves.

The 2016 Albert Lasker Basic Medical Research Award and subsequently the 2019 Nobel Prize in Physiology or Medicine were awarded to William Kaelin, Jr., Sir Peter Ratcliffe, and Gregg Semenza for their work on how cells sense and adapt to hypoxic conditions. Their work showed that the changes in gene expression, cell metabolism, and tissue remodelling that occur in response to low oxygen concentrations are orchestrated by the transcription factor, hypoxia inducible factor-1α (HIF-1α). While the effects mediated by HIF-1α have been widely studied, its role in heart valves has only recently been investigated. These studies have shown that HIF-1α expression is evident in mechanisms that regulate the structure and function of heart valves. These include embryonic development, the regulation of the extracellular matrix, angiogenesis and the initiation of the calcification process. This review provides a background on the role and function of HIF-1α in response to hypoxia and a discussion of the available evidence of its involvement in the regulation of heart valves in health and disease.

Vascular adaptation to cancer beyond angiogenesis: The role of PTEN.

Cancer is a public health problem, and it needs blood vessels to grow. Knowing more about the processes of vascular adaptation to cancer improves our chances of attacking it, since the tumor for its extension needs such adaptation to satisfy its progressive demand for nutrients. The main objective of this review is to present the reader with some fundamental molecular pathways for vascular adaptation to cancer, highlighting within them the regulatory role of homologous tensin and phosphatase protein (PTEN). Hence the review describes vascular adaptation to cancer through somewhat known processes, such as angiogenesis, but emphasizes others that are much less explored, namely the changes in vascular reactivity and remodeling of the vascular wall -intima-media thickness and adjustments in the extracellular matrix- The role of PTEN in physiological and pathological vascular mechanisms in different types of cancer is deepened, as a crucial mediator in vascular adaptation to cancer, and points pending further exploration in cancer vascularization are suggested.

Angiogenic genes and proteins are differentially expressed in left and right ventricular tissue in perinatal sheep hearts

Birth places a great stress on the fetal heart due to increased cardiac workload, following a disconnection from the low-resistance placenta and closure of fetal shunts. The mechanisms that regulate myocardial microvascular growth and development during the perinatal period are largely unknown. We hypothesized that birth stimulates an increase in angiogenic gene and protein expression in a ventricular dependent manner to reflect the changing roles for the left and right ventricles (LV, RV). Fetal (135 d gestation, dGA; term=147 dGA) and neonatal (1 and 5 postnatal days, PD) sheep LV and RV were snap frozen. Gene expression of key angiogenic regulators ( VEGFA, VEGFR1, VEGFR2, ANGPT1, ANGPT2, PGC1A), endothelial cell growth ( DDL4, NOTCH4, SPP1, PECAM1, NCL), nitric oxide synthesis ( NOS2, NOS3), and extracellular matrix (ECM) remodeling ( MMP2, MMP9, THBS1) were quantified using real-time qPCR (n=12/age group). Protein expression of VEGFA and VEGF-R2 were measured by Western blot (n=5/age group). Data were analyzed by two-way ANOVA with Tukey’s post-hoc test to determine effects of age, ventricle, and interaction. Significance was set at P&lt;0.05. At 135 dGA, all angiogenic, nitric oxide synthesis, ECM, DDL4, SPP1, and PECAM1 mRNA expression levels were higher in the RV vs. LV. At PD1, there were no differences between LV and RV. At PD5, VEGFA, VEGFR1, ANGPT1, ANGPT2, PGC1A, DDL4, SPP1, PECAM1, NCL, MMP2, and THBS1 mRNA expression levels were again higher in the RV vs. LV. At 135 dGA, VEGFA and VEGF-R2 protein expression levels were 76% and 72% lower, respectively, in the RV vs. LV. Within each ventricle, age related changes to mRNA expression patterns were unique. In the LV, mRNA expression of NOTCH4 and NCL increased stepwise from 135 dGA to PD5; however, in the RV, both were upregulated at PD1 but returned to fetal levels by PD5. In contrast, all angiogenic, ECM, DDL4, SPP1, PECAM1, and NOS2 genes were downregulated in the RV at PD1 but all returned to fetal levels by PD5. In the LV, VEGF-R2 protein expression was 56% and 73% lower at PD 1 and 5, respectively, vs. 135 dGA. In summary, gene and protein expression patterns involved in angiogenesis and vascular remodeling change over the perinatal period and are differentially expressed in the ventricles. Greater angiogenic gene expression levels in the RV vs. the LV at 135 dGA might be due to the RV serving as the main systemic pump in utero, thus requiring relatively increased microcirculation. However, reduced VEGFA and VEGF-R2 protein levels at 135 dGA contradict this hypothesis; histological studies to determine vascularity are ongoing. Likewise, the subsequent downregulation of angiogenic genes in the RV at PD1 might be due to the RV’s sudden decrease in cardiac output as the LV becomes the main pump. The underlying reasons for why LV angiogenic genes are not significantly upregulated in the early postnatal period, given its new role as the main systemic pump, are yet to be elucidated. NIH R21-HL152112 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Pregnenolone Inhibits Doxorubicin-Induced Cardiac Oxidative Stress, Inflammation, and Apoptosis-Role of Matrix Metalloproteinase 2 and NADPH Oxidase 1.

The clinical usefulness of doxorubicin (DOX) is limited by its serious adverse effects, such as cardiotoxicity. Pregnenolone demonstrated both anti-inflammatory and antioxidant activity in animal models. The current study aimed to investigate the cardioprotective potential of pregnenolone against DOX-induced cardiotoxicity. After acclimatization, male Wistar rats were randomly grouped into four groups: control (vehicle-treated), pregnenolone (35 mg/kg/d, p.o.), DOX (15 mg/kg, i.p, once), and pregnenolone + DOX. All treatments continued for seven consecutive days except DOX, which was administered once on day 5. The heart and serum samples were harvested one day after the last treatment for further assays. Pregnenolone ameliorated the DOX-induced increase in markers of cardiotoxicity, namely, histopathological changes and elevated serum levels of creatine kinase-MB and lactate dehydrogenase. Moreover, pregnenolone prevented DOX-induced oxidative changes (significantly lowered cardiac malondialdehyde, total nitrite/nitrate, and NADPH oxidase 1, and elevated reduced glutathione), tissue remodeling (significantly decreased matrix metalloproteinase 2), inflammation (significantly decreased tumor necrosis factor-α and interleukin 6), and proapoptotic changes (significantly lowered cleaved caspase-3). In conclusion, these findings show the cardioprotective effects of pregnenolone in DOX-treated rats. The cardioprotection achieved by pregnenolone treatment can be attributed to its antioxidant, anti-inflammatory, and antiapoptotic actions.

Cardiac magnetic resonance findings and prognosis in type 1 myotonic dystrophy.

Cardiac involvement is a major determinant of prognosis in type 1 myotonic dystrophy (DM1), but limited information is available about myocardial remodeling and tissue changes. The aim of the study was to investigate cardiac magnetic resonance (CMR) findings and their prognostic significance in DM1. We retrospectively identified all DM1 patients referred from a neurology unit to our CMR laboratory from 2009 to 2020. Thirty-four patients were included (aged 45 ± 12, 62% male individuals) and compared with 68 age-matched and gender-matched healthy volunteers (43 male individuals, age 48 ± 15 years). At CMR, biventricular and biatrial volumes were significantly smaller (all P < 0.05), as was left ventricular mass (P < 0.001); left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) were significantly lower (all P < 0.01). Five (15%) patients had a LVEF less than 50% and four (12%) a RVEF less than 50%. Nine patients (26%) showed mid-wall late gadolinium enhancement (LGE; 5 ± 2% of LVM), and 14 (41%) fatty infiltration. Native T1 in the interventricular septum (1041 ± 53 ms) was higher than for healthy controls (1017 ± 28 ms) and approached the upper reference limit (1089 ms); the extracellular volume was slightly increased (33 ± 2%, reference <30%). Over 3.7 years (2.0-5.0), 6 (18%) patients died of extracardiac causes, 5 (15%) underwent device implantation; 5 of 21 (24%) developed repetitive ventricular ectopic beats (VEBs) on Holter monitoring. LGE mass was associated with the occurrence of repetitive VEBs (P = 0.002). Lower LV stroke volume (P = 0.017), lower RVEF (P = 0.016), a higher LVMi/LVEDVI ratio (P = 0.016), fatty infiltration (P = 0.04), and LGE extent (P < 0.001) were associated with death. DM1 patients display structural and functional cardiac abnormalities, with variable degrees of cardiac muscle hypotrophy, fibrosis, and fatty infiltration. Such changes, as evaluated by CMR, seem to be associated with the development of ventricular arrhythmias and a worse outcome.

Effect of local application of bone morphogenetic protein -2 on experimental tooth movement and biological remodeling in rats.

Background: This study attempts to detect the potential effects of local bone morphogenetic protein -2 (BMP-2) on orthodontic tooth movement and periodontal tissue remodeling. Methods: Forty adult SD rats were randomly divided into four groups: blank control group, unilateral injection of BMP-2 on the pressure side or tension side of orthodontic teeth and bilateral injection of BMP-2. Their maxillary first molar was moved by a 30g constant force closed coil spring. 60μL of BMP-2 with a concentration of 0.5μg/mL was injected into each part at a time. In addition, three rats were selected as healthy control rats without any intervention. Fluorescent labeled BMP-2 was used to observe the distribution of exogenous BMP-2 in tissues. Micro-CT was used to measure the microscopic parameters of tooth displacement, trabecular bone and root absorption volume. Three different histological methods were used to observe the changes of tissue remodeling, and then the number of osteoclasts and the content of collagen fibers were calculated. Results: Compared with the blank control group, BMP-2 injection reduced the movement distance and increased the collagen fiber content and bone mass (p < 0.01). There was no significant difference in tooth movement distance, BV/TV ratio and BMD between injection sites in unilateral injection group (p > 0.05). In the case of bilateral injection of BMP-2, the osteogenesis is enhanced. Unilateral injection of BMP-2 did not promote root resorption, but double injection showed root resorption (p < 0.01). Conclusion: Our study does show that the osteogenesis of BMP-2 is dose-dependent rather than site-dependent when a certain amount of BMP-2 is applied around orthodontic teeth. Local application of BMP-2 around orthodontic teeth in an appropriate way can enhance bone mass and tooth anchorage without increasing the risk of root absorption volume. However, high levels of BMP-2 may cause aggressive root resorption. These findings are of great significance, that is, BMP-2 is an effective target for regulating orthodontic tooth movement.

Application of "Fabulous" stent system to improve aortic remodeling after TEVAR for type B aortic dissection.

Application of "Fabulous" stent system to improve aortic remodeling after TEVAR for type B aortic dissection.

Selective neuronal knockout of STAT3 function inhibits epilepsy progression, improves cognition, and restores dysregulated gene networks in a temporal lobe epilepsy model.

Temporal lobe epilepsy (TLE) is a progressive disorder mediated by pathological changes in molecular cascades and hippocampal neural circuit remodeling that results in spontaneous seizures and cognitive dysfunction. Targeting these cascades may provide disease-modifying treatments for TLE patients. Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) inhibitors have emerged as potential disease-modifying therapies; a more detailed understanding of JAK/STAT participation in epileptogenic responses is required, however, to increase the therapeutic efficacy and reduce adverse effects associated with global inhibition. We developed a mouse line in which tamoxifen treatment conditionally abolishes STAT3 signaling from forebrain excitatory neurons (nSTAT3KO). Seizure frequency (continuous in vivo electroencephalography) and memory (contextual fear conditioning and motor learning) were analyzed in wild-type and nSTAT3KO mice after intrahippocampal kainate (IHKA) injection as a model of TLE. Hippocampal RNA was obtained 24 h after IHKA and subjected to deep sequencing. Selective STAT3 KO in excitatory neurons reduced seizure progression and hippocampal memory deficits without reducing the extent of cell death or mossy fiber sprouting induced by IHKA injection. Gene expression was rescued in major networks associated with response to brain injury, neuronal plasticity, and learning and memory. We also provide the first evidence that neuronal STAT3 may directly influence brain inflammation. Inhibiting neuronal STAT3 signaling improved outcomes in an animal model of TLE, prevented progression of seizures and cognitive co-morbidities while rescuing pathogenic changes in gene expression of major networks associated with epileptogenesis. Specifically targeting neuronal STAT3 may be an effective disease-modifying strategy for TLE. This article is protected by copyright. All rights reserved.

Characterization and Advancement of an Evaluation Method for the Treatment of Spontaneous Osteoarthritis in STR/ort Mice: GRGDS Peptides as a Potential Treatment for Osteoarthritis

STR/ort mice spontaneously exhibit the typical osteoarthritis (OA) phenotype. However, studies describing the relationship between cartilage histology, epiphyseal trabecular bone, and age are lacking. We aimed to evaluate the typical OA markers and quantify the subchondral bone trabecular parameters in STR/ort male mice at different weeks of age. We then developed an evaluation model for OA treatment. We graded the knee cartilage damage using the Osteoarthritis Research Society International (OARSI) score in STR/ort male mice with or without GRGDS treatment. We measured the levels of typical OA markers, including aggrecan fragments, matrix metallopeptidase-13 (MMP-13), collagen type X alpha 1 chain (COL10A1), and SRY-box transcription factor 9 (Sox9), and quantified epiphyseal trabecular parameters. Compared to the young age group, elderly mice showed an increased OARSI score, decreased chondrocyte columns of the growth plate, elevated expression of OA markers (aggrecan fragments, MMP13, and COL10A1), and decreased expression of Sox9 at the articular cartilage region in elderly STR/ort mice. Aging also significantly enhanced the subchondral bone remodeling and microstructure change in the tibial plateau. Moreover, GRGDS treatment mitigated these subchondral abnormalities. Our study presents suitable evaluation methods to characterize and measure the efficacy of cartilage damage treatments in STR/ort mice with spontaneous OA.

Abstract 3268: Biomarkers of drug-tolerant persistent melanoma cells in human, correlation with tumor microenvironment and response to treatment

Abstract Introduction: Drug tolerant cancer persister cells can be silent for years but constitute a reservoir of genetic resistance and can eventually result in tumor relapse. We showed that targeted therapy (TT)-tolerant BRAFV600 melanoma persister cells (MPC) have a reduced global mRNA translation activity but an increased translation efficiency of a subset of mRNAs encoding proteins involved in transcription, chromatin remodeling and epigenetic changes. Here, we identify protein markers of MPC in patient biopsies treated either with TT or with immune checkpoint inhibitors (ICI). Since persister cells are not destroyed by the immune system, we explored the interactions of MPC with their immune microenvironment. Single cell expression of these candidate MPC markers, as well markers of the tumor microenvironment (31 lymphoid and myeloid markers), were studied in sequential biopsies from melanoma patients treated with TT or ICI by CyTOF. Spatial localization of MPC markers and various types of immune cells were studied by multiplex immunohistochemistry (Akoya Codex). In addition, the in vitro effect of the cell supernatants of MPC or naïve parental cells on immune cells was studied. Results: Biomarkers of persistence included 7 protein markers that are regulated at the translational level (MLL3, HDAC6, CCSER2, MT-ND5, ANK2, HIPK2, CBP) and 4 that are transcriptionally regulated (MITF, NGFR, CD36 and SLIT2). Some MPC markers were expressed at baseline in melanoma patients’ biopsies (n = 27) and their baseline expression tended to be associated with progressive disease (to TT or ICI). Paired biopsies from 18 patients showed that an increase in HDAC6, ANK2, HIPK2, CBP5 and MITF was statistically correlated with a short survival regardless of the type of treatment. Baseline lymphocytic infiltrate, especially CD4+ T cells, was associated with favorable clinical outcome. In addition, we found that the supernatants derived from naïve parental and persister cells have distinct effects on human CD4+, CD8+ T cells and macrophages. MPC supernatant had a significant inhibitory effect on the proliferation and activation of CD4+, CD8+ T cells as well as the expression of immune checkpoint markers (PD-1, PD-L1, CTLA4, LAG3, Tim3) compared to supernatant of naïve parental cells. We also found that supernatants of MPC induced M2-like polarization of macrophages. One major candidate to convey this effect is MIF (Macrophage migration inhibitory factor) that is specifically increased in MPC supernatant. Conclusion: Melanoma persister cells can be identified in patients’ biopsies during TT as well as ICI therapy. The expression of MPC protein markers is associated with poor clinical outcome regardless of the type of treatment. Their expression is inversely correlated with a hot immune environment that could result from the effect of immunosuppressive cytokines secreted by persister cells. Citation Format: Hongxu Chen, Shensi Shen, Sara Faouzi, Alexia Alfaro, Dorothee Baille, Séverine Roy, Naima Benannoune, Hugues Hermann, Samad Muhammadnejad, Stephan Vagner, Caroline Robert. Biomarkers of drug-tolerant persistent melanoma cells in human, correlation with tumor microenvironment and response to treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3268.

Distinct transcriptomic and epigenomic modalities underpin human memory T cell subsets and their activation potential

Human memory T cells (MTC) are poised to rapidly respond to antigen re-exposure. Here, we derived the transcriptional and epigenetic programs of resting and ex vivo activated, circulating CD4+ and CD8+ MTC subsets. A progressive gradient of gene expression from naïve to TCM to TEM is observed, which is accompanied by corresponding changes in chromatin accessibility. Transcriptional changes suggest adaptations of metabolism that are reflected in altered metabolic capacity. Other differences involve regulatory modalities comprised of discrete accessible chromatin patterns, transcription factor binding motif enrichment, and evidence of epigenetic priming. Basic-helix-loop-helix factor motifs for AHR and HIF1A distinguish subsets and predict transcription networks to sense environmental changes. Following stimulation, primed accessible chromatin correlate with an augmentation of MTC gene expression as well as effector transcription factor gene expression. These results identify coordinated epigenetic remodeling, metabolic, and transcriptional changes that enable MTC subsets to ultimately respond to antigen re-encounters more efficiently.

Dendritic effects of genetically encoded actin-labeling probes in cultured hippocampal neurons.

Actin cytoskeleton predominantly regulates the formation and maintenance of synapses by controlling dendritic spine morphology and motility. To visualize actin dynamics, actin molecules can be labeled by genetically fusing fluorescent proteins to actin monomers, actin-binding proteins, or single-chain anti-actin antibodies. In the present study, we compared the dendritic effect of EGFP-actin, LifeAct-TagGFP2 (LifeAct-GFP), and Actin-Chromobody-TagGFP2 (AC-GFP) in mouse cultured hippocampal neurons using unbiased quantitative methods. The actin-binding probes LifeAct-GFP and AC-GFP showed similar affinity to F-actin, but in contrast to EGFP-actin, they did not reveal subtle changes in actin remodeling between mushroom-shaped spines and filopodia. All tested actin probes colocalized with phalloidin similarly; however, the enrichment of LifeAct-GFP in dendritic spines was remarkably lower compared with the other constructs. LifeAct-GFP expression was tolerated at a higher expression level compared with EGFP-actin and AC-GFP with only subtle differences identified in dendritic spine morphology and protrusion density. While EGFP-actin and LifeAct-GFP expression did not alter dendritic arborization, AC-GFP-expressing neurons displayed a reduced dendritic tree. Thus, although all tested actin probes may be suitable for actin imaging studies, certain limitations should be considered before performing experiments with a particular actin-labeling probe in primary neurons.

Thyroid Hormone and Heart Failure: Charting Known Pathways for Cardiac Repair/Regeneration.

Heart failure affects more than 64 million people worldwide, having a serious impact on their survival and quality of life. Exploring its pathophysiology and molecular bases is an urgent need in order to develop new therapeutic approaches. Thyroid hormone signaling, evolutionarily conserved, controls fundamental biological processes and has a crucial role in development and metabolism. Its active form is L-triiodothyronine, which not only regulates important gene expression by binding to its nuclear receptors, but also has nongenomic actions, controlling crucial intracellular signalings. Stressful stimuli, such as acute myocardial infarction, lead to changes in thyroid hormone signaling, and especially in the relation of the thyroid hormone and its nuclear receptor, which are associated with the reactivation of fetal development programmes, with structural remodeling and phenotypical changes in the cardiomyocytes. The recapitulation of fetal-like features of the signaling may be partially an incomplete effort of the myocardium to recapitulate its developmental program and enable cardiomyocytes to proliferate and finally to regenerate. In this review, we will discuss the experimental and clinical evidence about the role of the thyroid hormone in the recovery of the myocardium in the setting of heart failure with reduced and preserved ejection fraction and its future therapeutic implications.

Analysis of the activity of c-kit immunopositive alpha-cells of the pancreas in exogenous infusions and endogenously formed pathology

There are a number of factors and agents that change the population of endocrinocytes and their secretory activity depending on various conditions and experimentally formed pathologies. These include the impact of intermittent hypoxic hypoxia; experimentally formed pathology (diabetes); genetically formed pathology (arterial hypertension), direct effect on endocrinocytes of the pancreas with their own pathophysiological mechanism. In this context, it is interesting to analyze the state of the progenitor potential of alpha cells depending on the living conditions of the organism, its effects, and developing pathological conditions in it. The aim of the work is to determine the activity of the proliferative factor c-kit in alpha cells under exogenous factors – intermittent hypoxic hypoxia and endogenously formed pathology – arterial hypertension and diabetes. Materials and methods. The study was conducted on the pancreas of SHR and Wistar rats. Glucagon and c-kit in pancreatic islets were determined by the immunofluorescence method. The immunofluorescence reaction was studied with an AxioImager-M2 fluorescence microscope. Results. Analysis of the c-kit positive alpha-cell index in rats with diabetes showed a 5-fold increase. This was explained by the fact, that the development of hyperglycemia in diabetes mellitus was characterized not only by an increased level of glucose in the blood due to insufficient insulin production but also due to an increase in the number of alpha cells, their active proliferation and possible transdifferentiation from beta cells. The number of c-kit positive alpha cells in SHR rats decreased. This may indicate that these changes were not so related to a violation of the modulation of the transcription factor, but to the participation of neurogenic mechanisms. The decrease in c-kit positive alpha cells in animals with hypoxic hypoxia can be explained by transdifferentiation (remodeling) changes, aimed at suppressing proliferative processes in alpha endocrinocytes. Conclusions. The increase in the number of c-kit positive alpha cells in rats with diabetes is explained by the fact, that the development of hyperglycemia in diabetes is characterized not only by an increased level of glucose in the blood due to insufficient insulin production but also by an increase in the number of alpha cells, their active proliferation and possible transdifferentiation from beta cells. A decrease in the number of c-kit positive alpha cells in SHR rats may indicate that these changes are not so much related to a violation of the modulation of the transcription factor, but to the participation of neurogenic mechanisms. The decrease in c-kit positive alpha cells in animals with hypoxic hypoxia can be explained by transdifferentiation (remodeling) changes, aimed at suppressing proliferative processes in alpha endocrinocytes.