Retinoic Acid Research Articles

Vitamin A mediates FABP4 to regulate intramuscular fat production: a new target and strategy for optimizing beef quality

Beef quality is critically determined by intramuscular fat (IMF) deposition. Retinoic acid (RA), the active metabolite of vitamin A, plays an essential regulatory role in IMF development. To systematically investigate RA-mediated regulation of IMF formation in cattle, we established a concentration gradient of RA supplementation and employed a systematic screening approach to identify the optimal dosage for modulating bovine intramuscular adipocytes (IMAs) proliferation and differentiation. Subsequently, leveraging integrated multi-omics approaches, we screened the key downstream molecular targets through which RA governs IMF biosynthesis, and clarified the potential regulatory mechanism of this target. Our experimental data establish that RA promotes the proliferation of IMAs through modulation of G1/S phase progression. Concurrently, RA enhances triglyceride biosynthesis in IMAs by activating PPARγ-mediated cell differentiation and LPL-mediated intracellular lipid accumulation. Integrated transcriptomics and metabonomics analyses identified FABP4, CD36, EBF2, LRP1 and CAV1 as key candidate genes involved in RA-mediated IMF production. Functional interrogation revealed that FABP4 knockdown markedly attenuated lipid accumulation in IMAs, a phenotype rescued through RA supplementation, confirming FABP4 as the critical effector mediating vitamin A’s regulation of bovine IMF deposition. These results provide a new understanding of how nutritional factors affect beef quality at the molecular level.

Fast pH-Driven Solubilization Method of Realgar (As4S4) to Reduce the Toxicity of Arsenic [As(III)] for Medicinal Purposes.

Acute promyelocytic leukemia (APL) accounts for 5-15% of acute myeloid leukemia cases. It is typically characterized by the (15;17) chromosomal translocation, producing the pathogenic retinoic acid receptor (RAR) alpha/promyelocytic leukemia (PML) fusion protein. Recently, remission of APL has been achieved using the first chemotherapy-independent oral drug regimen in anticancer therapy, consisting of all-trans retinoic acid (targeting RARalpha) and the arsenic sulfide realgar (targeting PML). However, clinical adoption of realgar and the characterization of its active breakdown products have been hampered by its poor solubility. Here, a scalable pH/temperature-based process is described that partially mimics gut transition, achieving fast and reproducible solubilization of realgar. Six different spectroscopic and spectrometric techniques are employed to investigate solubilized realgar. Furthermore, it is shown that solubilized realgar targets PML, displaying wider in vitro therapeutic indices and lower off-target effects than arsenic trioxide, the current APL standard of care. Moreover, in line with evidence of an interplay between PML and HIV persistence, solubilized realgar can disrupt HIV latency, the main barrier to an HIV/AIDS cure, in CD4 T cells of people living with HIV. These findings may open avenues for streamlining realgar solubilization and designing less toxic, orally administrable arsenic-based therapies.

Abstract 5399: Placental gene PEG10 promotes onco-fetal metabolic reprogramming in hepatocellular carcinoma

Abstract Tumorigenesis is a complex biological process, accompanied by cellular dedifferentiation and metabolic reprogramming, which similarities to the metabolic characteristics of embryonic development stages. In our research, we focused particularly on the RNA-binding protein PEG10, which is highly expressed in the placenta and found to be similarly overexpressed in liver cancer cells, playing a key role in the process of aerobic glycolysis in tumor cells. This discovery suggests that there may be a phenomenon of fetal-like metabolic reprogramming in hepatocellular carcinoma (HCC), which is of significant importance for understanding the pathogenesis of HCC and for seeking new therapeutic strategies. In hepatocellular carcinoma (HCC) cells, we found that PEG10 enhances the stability of mRNA for key glycolytic genes hexokinase2 (HK2) and Glucose transporter 1 (GLUT1) by inhibiting the STAU1-mediated RNA degradation pathway, thereby promoting aerobic glycolysis in tumor cells. This process not only promotes the proliferation of tumor cells but also reduces the sensitivity of tumor cells to sorafenib. Furthermore, we observed in clinical samples that high expression of PEG10 is closely associated with poor prognosis in HCC patients, further confirming the important role of PEG10 in the development of HCC. Our research also found that retinoic acid can effectively inhibit aerobic glycolysis in tumor cells by suppressing the transcriptional expression of PEG10, thereby inhibiting the growth of tumor cells. In animal models, mice with liver-specific PEG10 gene knockout showed significant resistance to oncogene-induced liver cancer occurrence and development, providing strong evidence for PEG10 as a therapeutic target. These findings not only reveal the biological link between PEG10 and onco-fetal metabolic reprogramming at the molecular level but also indicate from a clinical perspective that PEG10 may be a potential biomarker and therapeutic target for HCC. The high expression of PEG10 is associated with poor prognosis in HCC patients, and the inhibitory effect of retinoic acid on PEG10 expression provides a new strategy for the treatment of HCC. These results provide new ideas for the future diagnosis and treatment of HCC, especially in the development of targeted therapeutic drugs against PEG10, which has important application prospects. Our research has laid a solid foundation for a deeper understanding of the metabolic reprogramming mechanisms of HCC and the development of new therapeutic methods. Citation Format: Dong Yin, Xinyi Yao, Jingyuan Zhang, Yin Zhang, Jianyou Liao, Kaishun Hu, Jiehua He, Daning Lu. Placental gene PEG10 promotes onco-fetal metabolic reprogramming in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5399.

Abstract 7306: Selective and novel ALDH1 inhibitor enhances immune checkpoint blockade therapy in preclinical models of MSS colorectal cancer

Abstract Colorectal cancer (CRC) is the second leading cause of cancer-related deaths globally and the third most frequently diagnosed cancer type, according to the Global Cancer Observatory. While the emergence of immune-checkpoint inhibitors (ICI) in the past decade has transformed cancer treatment paradigms, their efficacy in CRC is limited, particularly in the microsatellite-stable (MSS) subtype, which constitutes 85% of cases. MSS CRC is characterized by a low mutation burden and an immunosuppressive tumor microenvironment (TME), resulting in poor responsiveness to ICIs. Recent studies have identified elevated ALDH1 expression and its enzymatic products in MSS tumors, with retinoic acid (RA) produced by ALDH1 playing a pivotal role in fostering an immunosuppressive TME. This RA-mediated immunosuppression arises not only from tumor cells but also from tumor-associated immune cells, such as M2 macrophages and myeloid-derived suppressor cells (MDSCs), both of which exhibit high ALDH1 activity. Using syngeneic mouse models of MSS CRC, including MC38-CEA and CT26 cell lines, we evaluated the therapeutic potential of combining ABD0171, a selective ALDH1 inhibitor (ALDH1i), with anti-PD-1 therapy. Our findings reveal that ABD0171 significantly enhances the efficacy of anti-PD-1 therapy, leading to improved survival outcomes in MSS CRC models. This synergistic effect is associated with substantial alterations in the TME immune landscape, including an increase in pro-inflammatory M1 macrophages and reductions in both M2 macrophages and regulatory T cells (Tregs). Mechanistically, ALDH1 inhibition significantly reduces intratumoral RA levels, disrupting a key pathway responsible for the differentiation of immunosuppressive macrophages from monocytes. Ongoing studies are exploring the molecular mechanisms underlying these effects. Overall, our work underscores the potential of selective ALDH1 targeting as a strategy to overcome immunotherapy resistance in MSS CRC, offering new therapeutic opportunities for patients with this challenging cancer subtype. Citation Format: Akinchan Kumar, Andrada Constantinescu, Ismail Ceylan, Mileidys Perez-Alea, Bassam Janji. Selective and novel ALDH1 inhibitor enhances immune checkpoint blockade therapy in preclinical models of MSS colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7306.

Abstract 5432: Restoring mitochondrial quantity and quality to reverse Warburg effect and drive tumor differentiation

Abstract Reduced mitochondrial quality and quantity in tumors is associated with dedifferentiation and increased malignancy. However, it remains unclear how to restore mitochondrial quantity and quality in tumors, and whether mitochondrial restoration can drive tumor differentiation. Our study shows that restoring mitochondrial function using retinoic acid (RA) to boost mitochondrial biogenesis and a mitochondrial uncoupler to enhance respiration synergistically drives neuroblastoma differentiation and inhibits proliferation. U-13C-glucose/glutamine isotope tracing revealed a metabolic shift from the pentose phosphate pathway to oxidative phosphorylation, accelerating the TCA cycle and switching substrate preference from glutamine to glucose. These effects were reversed by ETC inhibitors or in ρ0 cells lacking mtDNA, emphasizing the necessity of mitochondrial function for differentiation. Dietary RA and uncoupler treatment promoted tumor differentiation in an orthotopic neuroblastoma xenograft model, evidenced by neuropil production and Schwann cell recruitment. Single-cell RNA sequencing analysis of the orthotopic xenografts revealed that this strategy effectively eliminated the stem cell population, promoted differentiation, and increased mitochondrial gene signatures along the differentiation trajectory, which could potentially significantly improve patient outcomes. Collectively, our findings establish a mitochondria-centric therapeutic strategy for inducing tumor differentiation, suggesting that maintaining/driving differentiation in tumor requires not only ATP production but also continuous ATP consumption and sustained ETC activity. Citation Format: Haowen Jiang, Sarah Jane Tiche, Clifford JiaJun He, Junyan Liu, Fuyun Bian, Mohamed Jedoui, Balint Forgo, Md Tauhidul Islam, Meng Zhao, Pamela O. Emengo, Bo He, Yang Li, Albert M. Li, Anh T. Truong, Jestine Ho, Cathyrin Simmermaker, Yanan Yang, Meng-Ning Zhou, Zhen Hu, Katrin J. Svensson, Daniel J. Cuthbertson, Florette K. Hazard, Lei Xing, Hiroyuki Shimada, Bill Chiu, Jiangbin Ye. Restoring mitochondrial quantity and quality to reverse Warburg effect and drive tumor differentiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5432.

Abstract 4435: PRAME-mediated retinoid resistance is overcome by EZH2 inhibition in keratinocyte carcinoma

Abstract Retinoids have exhibited efficacy as treatments and prophylactics for both types of keratinocyte carcinoma (KC): basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). However, the practical efficacy of these compounds is limited by retinoid resistance mechanisms. Preferentially Expressed Antigen in Melanoma (PRAME) is a cancer-testis antigen ectopically expressed in a subset of BCC and cSCC tumors. In gametes, PRAME binds Enhancer of Zeste Homologue 2 (EZH2), an epigenetic silencer, selectively targeting transcriptional repression to retinoic acid response elements (RARE) in gene promoters. The functions and therapeutic relevance of PRAME expression in KC tumors have not been investigated. A combination of transcriptomic analyses, 2D and 3D cell culture approaches were undertaken to evaluate the contributions of PRAME to KC pathogenesis and treatment response. Pharmacological retinoid sensitization strategies were also investigated. Epidermal differentiation and cytokine signaling pathways were downregulated in high PRAME-expressing tumors and in PRAME overexpressing (OE) cell lines. Conversely, low-PRAME tumors and PRAME depleted cell lines exhibited an enrichment of epidermal differentiation and cytokine signaling gene signatures. PRAME OE impaired epidermal differentiation in 3D organotypic skin culture models. Additionally, PRAME OE impaired RARE activation and conferred resistance to retinoid-induced growth suppression. PRAME depletion restored RARE activation and restored retinoid-induced growth suppression. Mechanistically, PRAME was determined to abrogate the anti-keratinization effect of retinoid treatment in SCC cells and organoid models. PRAME also abrogated the cell death promoting effect of retinoid treatment in BCC cells. Targeting of EZH2, using pharmacological or genetic strategies, in combination with retinoid treatment, resulted in a selective repression of cell growth in KC cell lines. Similar effects were observed when performing co-treatments using cell lines representative of cutaneous melanoma and lung squamous cell carcinoma. This study illustrates potential roles for PRAME in modulating differentiation programs and demonstrates a role for PRAME in conferring resistance to retinoid-based therapeutics. Furthermore, this study offers a preclinical demonstration of a drug repurposing strategy including retinoid compounds and EZH2 inhibitors to suppress the growth of PRAME-expressing cells. Citation Format: Brandon Liam Ramchatesingh, Ivan V. Litvinov. PRAME-mediated retinoid resistance is overcome by EZH2 inhibition in keratinocyte carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4435.

Abstract 7298: DUSP11 is an intracellular innate immune checkpoint in lung adenocarcinoma

Abstract The major success of immune checkpoint inhibitors (ICIs) to treat cancer highlights both the efficacy of inhibiting immunosuppressive proteins as a means of re-activating the anti-tumor immune response and the generalizability of targeting such proteins (i.e., therapies are clinically useful across many cancer types). While the major focus in immuno-oncology has been to manipulate the adaptive immune system, recent attention has been given to manipulating the innate immune system to treat cancer and/or enhance adaptive responses. In this work we detail the intracellular protein, Dual Specificity Phosphatase 11 (DUSP11), as an innate immune checkpoint (iIC) in lung adenocarcinoma (LUAD), among other cancers. LUAD remains a leading cause of death worldwide, largely due to mutant oncogene acquired therapeutic resistance and a lack of effective alternative therapeutic options, including ICIs. There is a clear unmet need for new methods to treat refractory LUAD. In this work we targeted DUSP11, a phosphatase with high affinity for 5’ triphosphate RNA (3pRNA) that has readily been reported as a host factor that aids viruses escape of immune detection. As many cancers show dysregulated RNA transcript processing, we hypothesized that DUSP11 knockdown would increase the presence and detection of immunostimulatory RNA by pattern recognition receptors (PRRs) and activate anti-cancer immune mechanisms. To do this, we engineered multiple Dicer substrate small interfering RNAs targeting DUSP11 and showed that decreased expression at the mRNA and protein levels had significant impacts on cell viability for multiple cancer cell types, including LUAD. The decrease in LUAD cell viability was due to induction of apoptosis, and innate immune responses were significantly upregulated, evidenced by increased expression of interferon-stimulated genes (ISGs), release of type I IFN, and paracrine stimulation of cells expressing IFNAR1. As retinoic acid inducible gene I (RIG-I) was an ISG that was upregulated upon DUSP11 knockdown, we speculated that, as in viral studies, RIG-I was responsible for the anti-cancer phenotype. Indeed, the knockdown of RIG-I, but not other intracellular PRRs, recovered the cell viability and innate immune response phenotypes. To corroborate this, we showed that knocking down DUSP11 enhances the effect of RIG-I agonizing 3pRNA, and we showed that LUAD cells engineered to be deficient in RIG-I do not respond to DUSP11 knockdown. Ongoing studies in mice appear to show that the anti-cancer effect of modulating DUSP11 activity is conserved in vivo. Overall, our preclinical studies suggest that DUSP11 is an excellent target to modulate innate immunity and induce LUAD cell death. Early studies suggest that this target and mechanism is generalizable to other cancer types; however, understanding which cancers respond and why, as well as assessing the safety and toxicity of targeting this protein warrant further investigation. Citation Format: Brian J. Thomas, Xue Bai, Benjamin J. Cryer, Mark A. Daniels, Margaret J. Lange, Donald H. Burke. DUSP11 is an intracellular innate immune checkpoint in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7298.

Abstract 4: Vitamin D blocks platinum-induced ovarian cancer stem cell plasticity

Most women diagnosed with late-stage high grade serous ovarian cancer (HGSOC) develop recurrent, platinum-resistant tumors. Ovarian cancer stem cells (OCSCs) are hypothesized to contribute to the emergence of these tumors. CSCs reside in a plastic state, with the ability to convert between non-CSC to CSC. This process of dedifferentiation is thought to continue during tumor development and chemotherapeutic agents such as platinum can exaggerate CSC plasticity. However, the underlying mechanism has not been established. Furthermore, how platinum transforms non-OCSCs into OCSCs to contribute to this subpopulation of cells remains unclear. To examine OCSC plasticity, aldehyde dehydrogenase (ALDH; functional marker) and fluorescence activated cell sorting were used to isolate OCSCs (ALDH+) and non-OCSCs (ALDH-) from HGSOC cell lines, OVCAR5 and OVCAR3. To determine if platinum induced conversion of non-OCSC to OCSC, ALDH- cells were cultured for 3-10 days after sorting. At timepoints examined, ALDH- cells remained ALDH-, (>99% were ALDH- after 10 days). ALDH- cells were then treated with cisplatin (OVCAR5: 12μM,16h, OVCAR3: 15μM 16h), and the percent of ALDH+ cells was measured using flow cytometry. Treatment of cisplatin resulted in conversion of approximately 4% and 10% of ALDH- cells into ALDH+ cells (p<0.05) in OVCAR5 and OVCAR3 cells, respectively. Furthermore, converted OCSCs displayed increased (p<0.05) expression of stemness genes (BMI1, NANOG, OCT4, SOX2) and spheroid formation compared to parental ALDH+, demonstrating that platinum induced the observed differences in the stemness phenotype. With the goal of targeting key genes and pathways to inhibit platinum-induced OCSC conversion, RNA-sequencing was performed on ALDH- and ALDH+ cells before and after cisplatin treatment. Vitamin D receptor (VDR)/retinoid x receptor (RXR) activation was a major pathway in the platinum-induced converted OCSC transcriptome, which was of interest because VDR signaling plays a role in differentiation, and its key binding partner, RXR and retinoic acid receptor (RAR) are linked to stemness. To determine the effect of vitamin D on OCSC conversion, ALDH- cells were treated with vitamin D for 24h (OVCAR5: 34nM, OVCAR3: 56nM) and/or cisplatin and the ALDH activity was measured with flow cytometry. Vitamin D treatment in combination with cisplatin significantly decreased the platinum-induced percent of converting cells (p<0.05). Additionally, vitamin D treatment decreased expression of stemness genes and spheroid formation in both whole cell and sorted cell populations. Currently, we are further investigating the relationship between cisplatin, RAR/RXR signaling and stemness. Collectively, these results demonstrate a role for VDR signaling in platinum-induced OCSC conversionproviding further support for the development targeted therapies to block the persistence of OCSCs and ultimately reduce patient mortality. Citation Format: Tara X. Metcalfe, Sophie Xanders, Shu Zhang, Christiane Hassel, Heather M. O'Hagan, Kenneth P. Nephew. Vitamin D blocks platinum-induced ovarian cancer stem cell plasticity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4.

HEX-1 reduces colitis-driven colorectal cancer via inactivating the prolyl isomerase PIN1 sensitization and remodeling the gut microbiota

Metabolic reprogramming, a pivotal hallmark of cancer, plays a crucial role in both the initiation and progression of colorectal cancer (CRC). Despite the vast unknowns surrounding the identity and biological activities of most natural metabolites in diseases, our study, utilizing native metabolomics results through GC–MS/MS, identified a small molecule, 4,4-Dimethyl-2-cyclohexen-1-one, named HEX-1 in the serum of CRC patients. We have further explored and assessed its biological activities. HEX-1 suppressed the proliferation of cancer cells and tumorigenesis via the inactivation and sensitization of PIN1. Notably, HEX-1 exhibits similar functional effects as all-trans retinoic acid (atRA) but stands out by not inducing the degradation of PIN1 mRNA or protein expression, unlike biological compounds associated with atRA. HEX-1 demonstrated the ability to induce G1/S arrest in vitro and ameliorate the progression of inflammatory CRC in mice by remodeling the gut microbiota. As volatile organic compounds (VOCs), HEX-1 could be detected feasibly. Its unique ability to penetrate whole cell populations positions it as a promising approach for cancer therapy and as an enhancer for chemotherapy and immunotherapy. The findings suggest that HEX-1 holds the potential as a valuable addition to the armamentarium against CRC.Graphical

Acquired Reactive Perforating Collagenosis Complicated by Diabetes Mellitus and Hypertension: A Case Report

A 55-year-old male with a 15-year history of diabetes mellitus and hypertension presented with a two-month history of progressive pruritic papules and nodules on both lower limbs. Despite initial misdiagnosis and unsuccessful antifungal therapy, dermatoscopic and histopathological evaluations confirmed acquired reactive perforating collagenosis (ARPC), a rare condition often associated with systemic diseases. This case underscores the diagnostic challenges of ARPC and highlights the importance of integrating dermatoscopy and histopathology to differentiate it from other perforating or pruritic dermatoses. Notably, the coexistence of diabetes and hypertension in this patient aligns with the recognized association between ARPC and metabolic disorders, emphasizing the need for comprehensive systemic evaluation in similar presentations. Symptomatic treatment with topical retinoic acid cream led to significant improvement, demonstrating a practical therapeutic approach in resource-limited settings. This report contributes to the limited literature on ARPC by illustrating its clinical, dermatoscopic, and histopathological features in the context of common comorbidities, reinforcing its relevance for dermatologists and internists alike.

Effect of MiRNA 204-5P Mimics and Lipopolysaccharide-Induced Inflammation on Transcription Factor Levels, Cell Maintenance, and Retinoic Acid Signaling in Primary Limbal Epithelial Cells

Effect of MiRNA 204-5P Mimics and Lipopolysaccharide-Induced Inflammation on Transcription Factor Levels, Cell Maintenance, and Retinoic Acid Signaling in Primary Limbal Epithelial Cells

Perturbing LSD1 and WNT rewires transcription to synergistically induce AML differentiation.

Impaired differentiation is a hallmark of myeloid malignancies1,2. Therapies that enable cells to circumvent the differentiation block, such as all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), are by and large curative in acute promyelocytic leukaemia3, but whether 'differentiation therapy' is a generalizable therapeutic approach for acute myeloid leukaemia (AML) and beyond remains incompletely understood. Here we demonstrate that simultaneous inhibition of the histone demethylase LSD1 (LSD1i) and the WNT pathway antagonist GSK3 kinase4 (GSK3i) robustly promotes therapeutic differentiation of established AML cell lines and primary human AML cells, as well as reducing tumour burden and significantly extending survival in a patient-derived xenograft mouse model. Mechanistically, this combination promotes differentiation by activating genes in the type I interferon pathway via inducing expression of transcription factors such as IRF7 (LSD1i) and the co-activator β-catenin (GSK3i), and their selective co-occupancy at targets such as STAT1, which is necessary for combination-induced differentiation. Combination treatment also suppresses the canonical, pro-oncogenic WNT pathway and cell cycle genes. Analysis of datasets from patients with AML suggests a correlation between the combination-induced transcription signature and better prognosis, highlighting clinical potential of this strategy. Collectively, this combination strategy rewires transcriptional programs to suppress stemness and to promote differentiation, which may have important therapeutic implications for AML and WNT-driven cancers beyond AML.

Identification of JNJ-61803534, a RORγt Inverse Agonist for the Treatment of Psoriasis.

The retinoic acid receptor-related orphan receptor gamma t (RORγt) is a nuclear transcription factor expressed in both innate and adaptive immune cells, driving Th17 cell differentiation and IL-17 production. The IL-23/IL-17 pathway is implicated in autoimmune and inflammatory diseases, and biologics that target IL-23/IL-17 signaling are efficacious in the treatment of psoriasis and psoriatic arthritis. RORγt, at the core of this pathway, represents an attractive opportunity for small-molecule intervention; however, combining high potency, nuclear receptor selectivity, and good physicochemical properties remains a challenge for RORγt inverse agonists. Recently, thiazole amides have been identified as potent RORγt inverse agonists; however, they often suffer from CYP450 autoinduction in the rat, precluding further development. Herein, we describe the discovery and development of potent and selective thiazole bisamide RORγt inverse agonists that avoid autoinduction in the rat. This effort culminated in the discovery of JNJ-61803534, which advanced into phase 1 clinical trials.

PML mutants from arsenic-resistant patients reveal SUMO1-TOPORS and SUMO2/3-RNF4 degradation pathways.

Arsenic effectively treats acute promyelocytic leukemia by inducing SUMO and ubiquitin-dependent degradation of the promyelocytic leukemia (PML)-retinoic acid receptor alpha oncogenic fusion protein. However, some patients relapse with arsenic-resistant disease because of missense mutations in PML. To determine the mechanistic basis for arsenic resistance, PML-/- cells were reconstituted with YFP fusions of wild-type PML-V and two common patient mutants: A216T and L217F. Both mutants were resistant to degradation by arsenic but for different biochemical reasons. Arsenic did not trigger SUMOylation of A216T PML, which failed to recruit the SUMO-targeting ubiquitin ligases RNF4 and TOPORS. L217F PML did respond with increased SUMO2/3 conjugation that facilitated RNF4 engagement but failed to reach the threshold of SUMO1 conjugation required to recruit TOPORS. Thus, neither mutant accumulated the appropriate polyubiquitin signal required for p97 binding. These PML mutants have revealed a convergence of SUMO1, SUMO2/3, TOPORS, and RNF4 that facilitates the arsenic-induced degradation of PML.

Retinal Production by Precision Fermentation of Saccharomyces cerevisiae

Retinoids, including retinol, retinal, and retinoic acid, are a group of vitamin A derivatives with skin-improving effects. Retinoic acid is highly effective for skin anti-aging but can cause irritation, requiring a prescription. Retinol, a less irritating alternative, needs conversion to retinal and then retinoic acid in the skin, whereas direct absorption of retinal enhances efficacy by bypassing this conversion process. This study aimed to produce retinal through precision fermentation using metabolically engineered Saccharomyces cerevisiae. The introduction of heterologous retinal biosynthetic genes and overexpression of the truncated HMG-CoA reductase (tHMG1) and acetyl-CoA acetyltransferase (ERG10) genes in the mevalonate (MVA) pathway increased retinal production up to 10.2 mg/L. At the same time, ethanol was produced as a major byproduct in S. cerevisiae. To address this, a pyruvate decarboxylase (Pdc)-deficient S. cerevisiae strain, incapable of producing ethanol, was employed. Overexpression of ERG10 and tHMG1 in the Pdc-deficient S. cerevisiae harboring the retinal biosynthetic plasmids achieved a retinal production up to 117.4 mg/L in the dodecane layer without ethanol through a two-phase in situ fermentation and extraction. This study demonstrates that eliminating pyruvate decarboxylase activity effectively redirects carbon flux toward retinal biosynthesis in the recombinant S. cerevisiae, offering a promising approach for sustainable retinal production through precision fermentation.

Small molecules direct the generation of ameloblast-like cells from human embryonic stem cells

BackgroundAmeloblasts present a promising avenue for the investigation of enamel and tooth regeneration. Previous protocols for directing the differentiation of human embryonic stem cells (hESCs) into dental epithelial (DE) cells involving the need for additional cells, conditional medium, and the use of costly cytokines. Importantly, ameloblasts have not been generated from hESCs in previous studies. Hence, we aimed to identify defined differentiation conditions that would solely utilize small molecules to achieve the production of ameloblasts.MethodsWe developed a three-step strategy entailing the progression of hESCs through non-neural ectoderm (NNE) and DE to generate functional ameloblasts in vitro. Initially, the NNE fate was induced from hESCs using a 6-day differentiation protocol with 1 µmol/L Retinoic acid (RA). Subsequently, the NNE lineage was differentiated into DE by employing a combination of 1 µmol/L LDN193189 (a BMP signaling inhibitor) and 1 µmol/L XAV939 (a WNT signaling inhibitor). In the final phase, 3 µmol/L CHIR99021 (a WNT signaling activator) and 2 µmol/L DAPT (a NOTCH signaling inhibitor) were utilized to achieve the fate of ameloblasts from DE cells. Three-dimensional cultures were investigated to enhance the ameloblast differentiation ability of the induced DE cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunofluorescence were conducted to assess the expression of lineage-specific markers. Alizarin Red S (ARS) staining was performed to evaluate the formation of mineralization nodules.ResultsThe application of RA facilitated the efficient generation of NNE within a six-day period. Subsequently, upon stimulation with LDN193189 and XAV939, a notable emergence of DE cells was observed on the eighth days. By the tenth day, ameloblast-like cells derived from hESCs were generated. Upon cultivation in spheroids, these cells exhibited elevated levels of ameloblast markers AMBN and AMELX expression, suggesting that spheroid culture augments the differentiation of ameloblasts.ConclusionWe established an efficient small molecule-based method to differentiate hESCs into ameloblast-like cells through the concerted modulation of RA, BMP, WNT, and NOTCH signaling pathways, potentially advancing research in enamel and tooth regeneration.

Facial skin rejuvenation through plasma radiofrequency ablation combined with 5% resorcinol cream: clinical and LC-OCT evaluation.

Skin aging is characterized by loss of elasticity, wrinkles, and textural changes. Treatments range from non-invasive options, such as alpha-hydroxy acids and retinoic acid, to invasive procedures like chemical peels and laser therapies. Plasma radiofrequency (PRF) offers a minimally invasive solution with a favorable balance of efficacy and tolerability. This study assessed the clinical and microscopic outcomes of combining PRF ablation with a galenic cream containing 5% resorcinol in Nourivan™ Antiox for facial skin aging. Forty-one patients with visible signs of aging underwent a single PRF session followed by weekly applications of a 5% resorcinol cream for six weeks. Outcomes were evaluated using digital photography and line-field confocal optical coherence tomography (LC-OCT) at baseline, three months, and six months. Primary endpoints included wrinkle reduction and texture improvement; secondary endpoints included adverse effects and patient satisfaction. At six months, 92% of patients showed significant wrinkle reduction and improved collagen organization in LC-OCT images. Skin texture improvements were reported by 85% of patients. Adverse effects, such as mild erythema and peeling, were transient and resolved without discontinuation. PRF ablation combined with 5% resorcinol cream is an effective and well-tolerated treatment for facial skin aging, offering significant improvements in skin texture and appearance. Further research is needed to confirm these findings and explore long-term effects.

Transcriptomics as an Early Warning of Domoic Acid Exposure in Pacific Razor Clams (Siliqua patula).

As oceans warm, harmful algal blooms (HABs) are expected to increase, including blooms of Pseudo-nitzschia, a diatom that produces domoic acid (DA), which is a potent neurotoxin. Regulatory limits for human consumption (0.075-0.1 mg/kg/day; acute exposure) exist for the Pacific razor clam; however, fisheries currently do not have regulatory limits for chronic low-level exposure to DA even though razor clams can retain DA for over a year after an algal bloom. For bivalves, exposure to marine toxins may disrupt important cellular processes, leading to concerns about effects on their overall health and potential population- and ecosystem-level impacts. Transcriptomics was used to identify differentially expressed genes in razor clams (N = 30) from Long Beach, WA, collected prior to, during, and after a DA-producing bloom. Differentially expressed genes were identified that may indicate exposure of razor clams to DA, including clams with tissue DA concentrations that fall below regulatory limits for human consumption. Targeting these genes in real-time PCR assays may provide an early warning system for routine monitoring of DA in clams. Our results suggest DA exposure is associated with physiological responses ranging from decreased immune function to the potential disruption of cell communication, including retinoic acid catabolic processes, cell adhesion, collagen fibril organization, and immune effector processes. This work may also allow us to examine potential drivers of population-level change and whether chronic lower-level exposure to DA negatively impacts razor clam function, consequently affecting individual and population health.

Genetic targets related to aging for the treatment of coronary artery disease

BackgroundCoronary Artery Disease (CAD) is the most common cardiovascular disease worldwide, threatening human health, quality of life and longevity. Aging is a dominant risk factor for CAD. This study aims to investigate the potential mechanisms of aging-related genes and CAD, and to make molecular drug predictions that will contribute to the diagnosis and treatment.MethodsWe downloaded the gene expression profile of circulating leukocytes in CAD patients (GSE12288) from Gene Expression Omnibus database, obtained differentially expressed aging genes through “limma” package and GenaCards database, and tested their biological functions. Further screening of aging related characteristic genes (ARCGs) using least absolute shrinkage and selection operator and random forest, generating nomogram charts and ROC curves for evaluating diagnostic efficacy. Immune cells were estimated by ssGSEA, and then combine ARCGs with immune cells and clinical indicators based on Pearson correlation analysis. Unsupervised cluster analysis was used to construct molecular clusters based on ARCGs and to assess functional characteristics between clusters. The DSigDB database was employed to explore the potential targeted drugs of ARCGs, and the molecular docking was carried out through Autodock Vina. Finally, single-cell data (GSE159677) of arterial intima was used to further explore the expression of aging signature genes in different cell subpopulations.ResultsWe identified 8 ARCGs associated with CAD, in which HIF1A and FGFR3 were up while NOX4, TCF7L2, HK3, CDK18, TFAP4, and ITPK1 were down in CAD patients. Based on this, CAD patients can be divided into two molecular clusters, among which cluster A mainly involves functional pathways such as ECM receptor interaction and focal adhesion; cluster B mainly involves functional pathways such as amimo sugar and nucleotide sugar metabolism and pyrimidine metabolism. In addition, the molecular docking results showed that retinoic acid and resveratrol had good binding affinity with targets genes. Further single-cell analysis results showed that NOX4, TCF7L2, ITPK1, and HIF1A were specifically expressed in different types of cells in atherosclerotic tissues.ConclusionOur study identified several ARCGs that may be involved in the pathogenesis and progression of CAD. Further, retinoic acid and resveratrol were potential candidate molecule drugs for inhibiting these targets.

Translational genomics of osteoarthritis in 1,962,069 individuals.

Osteoarthritis is the third most rapidly growing health condition associated with disability, after dementia and diabetes1. By 2050, the total number of patients with osteoarthritis is estimated to reach 1 billion worldwide2. As no disease-modifying treatments exist for osteoarthritis, a better understanding of disease aetiopathology is urgently needed. Here we perform a genome-wide association study meta-analyses across up to 489,975 cases and 1,472,094 controls, establishing 962 independent associations, 513 of which have not been previously reported. Using single-cell multiomics data, we identify signal enrichment in embryonic skeletal development pathways. We integrate orthogonal lines of evidence, including transcriptome, proteome and epigenome profiles of primary joint tissues, and implicate 700 effector genes. Within these, we find rare coding-variant burden associations with effect sizes that are consistently higher than common frequency variant associations. We highlight eight biological processes in which we find convergent involvement of multiple effector genes, including the circadian clock, glial-cell-related processes and pathways with an established role in osteoarthritis (TGFβ, FGF, WNT, BMP and retinoic acid signalling, and extracellular matrix organization). We find that 10% of the effector genes express a protein that is the target of approved drugs, offering repurposing opportunities, which can accelerate translation.