Mechanisms Of Reprogramming Research Articles

Control of cell fate upon transcription factor-driven cardiac reprogramming.

Adult mammals are susceptible to substantial cardiomyocyte (CM) loss following various cardiac diseases due to the limited capacity of CM proliferation and regeneration. Recently, direct cardiac reprogramming, converting fibroblasts into induced CMs, has been achieved both in vitro and in vivo through forced expression of transcription factors (TFs). This review encapsulates the advancements made in enhancing reprogramming efficiency and underlying molecular mechanisms. It covers the optimization of TF-based reprogramming cocktails and in vivo delivery platform and recently identified regulators in enhancing reprogramming efficiency. In addition, we discuss recent insights into the molecular mechanisms of direct cardiac reprogramming from single-cell omics analyses. Finally, we briefly touch on remaining challenges and prospective direction of this field.

Spontaneously Immortalised Nonhuman Primate Müller Glia Cell Lines as Source to Explore Retinal Reprogramming Mechanisms for Cell Therapies.

Cell replacement therapies for ocular diseases characterised by photoreceptors degeneration are challenging due to poor primary cell survival in culture. A stable retinal cell source to replace lost photoreceptors holds promise. Müller glia cells play a pivotal role in retinal homoeostasis by providing metabolic and structural support to retinal neurons, preventing aberrant photoreceptors migration, and facilitating safe glutamate uptake. In fish and amphibians, injured retinas regenerate due to Müller-like glial stem cells, a phenomenon absent in the mammalian retina for unknown reasons. Research on Müller cells has been complex due to difficulties in obtaining pure cell population and their rapid de-differentiation in culture. While various Müller glia cell lines from human and rats are described, no nonhuman primate Müller glia cell line is currently available. Here, we report spontaneously immortalised Müller glia cell lines derived from macaque neural retinas that respond to growth factors and expand indefinitely in culture. They exhibit Müller cells morphology, such as an elongated shape and cytoplasmic projections, express Müller glia markers (VIMENTIN, GLUTAMINE SYNTHASE, glutamate-aspartate transporter, and CD44), and express stem cell markers such as PAX6 and SOX2. In the presence of factors that induce photoreceptor differentiation, these cells show a shift in gene expression patterns suggesting a state of de-differentiation, a phenomenon known in reprogrammed mammalian Müller cells. The concept of self-renewing retina might seem unfeasible, but not unprecedented. While vertebrate Müller glia have a regeneration potential absent in mammals, understanding the mechanisms behind reprogramming of Müller glia in mammals could unlock their potential for treating retinal degenerative diseases.

Increased translation driven by non-canonical EZH2 creates a synthetic vulnerability in enzalutamide-resistant prostate cancer

Overcoming resistance to therapy is a major challenge in castration-resistant prostate cancer (CRPC). Lineage plasticity towards a neuroendocrine phenotype enables CRPC to adapt and survive targeted therapies. However, the molecular mechanisms of epigenetic reprogramming during this process are still poorly understood. Here we show that the protein kinase PKCλ/ι-mediated phosphorylation of enhancer of zeste homolog 2 (EZH2) regulates its proteasomal degradation and maintains EZH2 as part of the canonical polycomb repressive complex (PRC2). Loss of PKCλ/ι promotes a switch during enzalutamide treatment to a non-canonical EZH2 cistrome that triggers the transcriptional activation of the translational machinery to induce a transforming growth factor β (TGFβ) resistance program. The increased reliance on protein synthesis creates a synthetic vulnerability in PKCλ/ι-deficient CRPC.

RTM reprograms macrophages via the HIF-1α/METTL3/PFKM axis to protect mice against sepsis

The metabolic reprogramming of macrophages is a potential therapeutic strategy for sepsis treatment, but the mechanism underlying this reprogramming remains unclear. Since glycolysis can drive macrophage phenotype switching, the rate-limiting enzymes in glycolysis may be key to treating sepsis. Here, we found that, compared with other isoenzymes, the expression of 6-phosphofructokinase, muscle type (PFKM) was the most upregulated in monocytes from septic patients. Recombinant thrombomodulin (rTM) treatment downregulated the protein expression of PFKM in macrophages. Both rTM treatment and Pfkm knockout protected mice from sepsis and reduced the production of the proinflammatory cytokines IL-1β, IL-6, TNF-α, and IL-27, whereas PFKM overexpression increased the production of these cytokines. Mechanistically, rTM treatment inhibited glycolysis in macrophages by decreasing PFKM expression in a hypoxia-inducible factor-1α (HIF-1α)-dependent manner. HIF-1α overexpression increased methyltransferase-like 3 (METTL3) expression, elevated the m6A level on Pfkm, and upregulated the protein expression of PFKM. METTL3 silence attenuated HIF-1α-mediated PFKM expression. These findings provide insight into the underlying mechanism of macrophage reprogramming for the treatment of sepsis.

Regulatory mechanisms of steroid hormone receptors on gene transcription through chromatin interaction and enhancer reprogramming.

Regulation of steroid hormone receptors (SHRs) on transcriptional reprogramming is crucial for breast cancer progression. SHRs, including estrogen receptor (ER), androgen receptor (AR), progesterone receptor (PR), and glucocorticoid receptor (GR) play key roles in remodeling the transcriptome of breast cancer cells. However, the molecular mechanisms by which SHRs regulate chromatin landscape in enhancer regions and transcription factor interactions remain largely unknown. In this review, we summarized the regulatory effects of 3 types of SHRs (AR, PR, and GR) on gene transcription through chromatin interactions and enhancer reprogramming. Specifically, AR and PR exhibit bi-directional regulatory effects (both inhibitory and promoting) on ER-mediated gene transcription, while GR modulates the transcription of pro-proliferation genes in ER-positive breast cancer cells. In addition, we have presented four enhancer reprogramming mechanisms (transcription factor cooperation, pioneer factor binding, dynamic assisted loading, and tethering) and the multiple enhancer-promoter contact models. Based on these mechanisms and models, this review proposes that the combination of multiple therapy strategies such as agonists/antagonists of SHRs plus endocrine therapy and the adoption of the latest sequencing technologies are expected to improve the efficacy of ER positive breast cancer treatment.

Iron-loaded cancer-associated fibroblasts induce immunosuppression in prostate cancer.

Iron is an essential biomineral in the human body. Here, we describe a subset of iron-loaded cancer-associated fibroblasts, termed as FerroCAFs, that utilize iron to induce immunosuppression in prostate cancer and predict an unfavorable clinical outcome. FerroCAFs secrete myeloid cell-associated proteins, including CCL2, CSF1 and CXCL1, to recruit immunosuppressive myeloid cells. We report the presence of FerroCAFs in prostate cancer from both mice and human, as well as in human lung and ovarian cancers, and identify a conserved cell surface marker, the poliovirus receptor. Mechanistically, the accumulated iron in FerroCAFs is caused by Hmox1-mediated iron release from heme degradation. The intracellular iron activates the Kdm6b, an iron-dependent epigenetic enzyme, to induce an accessible chromatin state and transcription of myeloid cell-associated protein genes. Targeting the FerroCAFs by inhibiting the Hmox1/iron/Kdm6b signaling axis incurs anti-tumor immunity and tumor suppression. Collectively, we report an iron-loaded FerroCAF cluster that drives immunosuppression through an iron-dependent epigenetic reprogramming mechanism and reveal promising therapeutic targets to boost anti-tumor immunity.

Mechanisms of neural infiltration-mediated tumor metabolic reprogramming impacting immunotherapy efficacy in non-small cell lung cancer

BackgroundCurrent evidence underlines the active role of neural infiltration and axonogenesis within the tumor microenvironment (TME), with implications for tumor progression. Infiltrating nerves stimulate tumor growth and dissemination by secreting neurotransmitters, whereas tumor cells influence nerve growth and differentiation through complex interactions, promoting tumor progression. However, the role of neural infiltration in the progression of non-small cell lung cancer (NSCLC) remains unclear.MethodsThis study employs the techniques of immunohistochemistry, immunofluorescence, RNA sequencing, molecular biology experiments, and a murine orthotopic lung cancer model to deeply analyze the specific mechanisms behind the differential efficacy of NSCLC immunotherapy from the perspectives of neuro-tumor signal transduction, tumor metabolism, and tumor immunity.ResultsThis study demonstrates that nerve growth factor (NGF) drives neural infiltration in NSCLC, and 5-hydroxytryptamine (5-HT), which is secreted by nerves, is significantly elevated in tumors with extensive neural infiltration. Transcriptome sequencing revealed that 5-HT enhanced glycolysis in NSCLC cells. Pathway analysis indicated that 5-HT activated the PI3K/Akt/mTOR pathway, promoting tumor metabolic reprogramming. This reprogramming exacerbated immunosuppression in the TME. Neutralizing 5-HT-mediated metabolic reprogramming in tumor immunity enhanced the efficacy of PD-1 monoclonal antibody treatment in mice.ConclusionsThe findings of this study provide a novel perspective on the crosstalk between nerves and lung cancer cells and provide insights into further investigations into the role of nerve infiltration in NSCLC progression.

CALB2 drives pancreatic cancer metastasis through inflammatory reprogramming of the tumor microenvironment

BackgroundEarly dissemination to distant organs accounts for the dismal prognosis of patients with pancreatic ductal adenocarcinoma (PDAC). Chronic, dysregulated, persistent and unresolved inflammation provides a preferred tumor microenvironment (TME) for tumorigenesis, development, and metastasis. A better understanding of the key regulators that maintain inflammatory TME and the development of predictive biomarkers to identify patients who are most likely to benefit from specific inflammatory-targeted therapies is crucial for advancing personalized cancer treatment.MethodsThis study identified cell-specific expression of CALB2 in human PDAC through single-cell RNA sequencing analysis and assessed its clinicopathological correlations in tissue microarray using multi-color immunofluorescence. Co-culture systems containing cancer-associated fibroblasts (CAFs) and patient-derived organoids (PDOs) in vitro and in vivo were employed to elucidate the effects of CALB2-activated CAFs on PDAC malignancy. Furthermore, CUT&RUN assays, luciferase reporter assays, RNA sequencing, and gain- or loss-of-function assays were used to unravel the molecular mechanisms of CALB2-mediated inflammatory reprogramming and metastasis. Additionally, immunocompetent KPC organoid allograft models were constructed to evaluate CALB2-induced immunosuppression and PDAC metastasis, as well as the efficacy of inflammation-targeted therapy.ResultsCALB2 was highly expressed both in CAFs and cancer cells and correlated with an unfavorable prognosis and immunosuppressive TME in PDAC patients. CALB2 collaborated with hypoxia to activate an inflammatory fibroblast phenotype, which promoted PDAC cell migration and PDO growth in vitro and in vivo. In turn, CALB2-activated CAFs upregulated CALB2 expression in cancer cells through IL6-STAT3 signaling-mediated direct transcription. In cancer cells, CALB2 further activated Ca2+-CXCL14 inflammatory axis to facilitate PDAC metastatic outgrowth and immunosuppression. Genetic or pharmaceutical inhibition of CXCL14 significantly suppressed CALB2-mediated metastatic colonization of PDAC cells in vivo and extended mouse survival.ConclusionsThese findings identify CALB2 as a key regulator of inflammatory reprogramming to promote PDAC metastatic progression. Combination therapy with αCXCL14 monoclonal antibody and gemcitabine emerges as a promising strategy to suppress distant metastasis and improve survival outcomes in PDAC with CALB2 overexpression.

Potential mechanisms of metabolic reprogramming induced by ischemia-reperfusion injury in diabetic myocardium.

This study aimed to explore metabolic reprogramming in diabetic myocardium subjected to ischemia-reperfusion injury (I/RI) and potential mechanisms. Increased vulnerability after I/RI in diabetic myocardium is a major cause of the high prevalence of perioperative adverse cardiac events, and the specific alterations in energy metabolism after I/RI in diabetic myocardium and the impact on increased vulnerability are not fully understood. Metabolomic methods were used to explore the differences and characteristics of metabolites in the heart tissues of four groups, and then, single-cell RNA sequencing (ScRNA-seq) was used to explore the potential mechanism of metabolic reprogramming. It was found that the fatty acid metabolism of db/db mouse I/RI (DMI) showed a significant upward trend, especially the metabolites of ultra-long and medium-long-chain fatty acids; the metabolic flow analysis found that the U-13C glucose M + 6 was significantly higher in the C57BL mouse sham operation (NM) group than in the db/db mouse sham operation (DM) group, and in the C57BL mouse I/RI (NMI) than in the DMI group. Compared with the NMI group, the intermediate metabolites of glycolysis and tricarboxylic acid (TCA) cycle were significantly reduced in the DMI group; all comparisons were statistically significant (p < 0.05), indicating that the glucose uptake of diabetic myocardetis, the ability of glucose glycolysis after I/RI, and the contribution of glucose to TCA were significantly reduced. The results of ScRNA-seq revealed that the number of Cluster 0 myocardial isoforms was significantly increased in diabetic myocardium, and the differential genes were mainly enriched in fatty acid metabolism, and the PPARA signaling pathway was found to be over-activated and involved in the regulation of metabolic reprogramming of diabetic myocardial I/RI. Metabolic reprogramming of diabetic myocardial I/RI may be the main cause of increased myocardial vulnerability. The number of myocardial subtype Cluster 0 increased significantly, and PPARA PPARA is a ligand-activated receptor of the nuclear hormone receptor family that plays a central regulatory role in lipid metabolism.signaling pathway activation may be a potential mechanism for reprogramming metabolism in diabetic myocardium.

Sperm miR-142-3p Reprogramming Mediates Paternal Pre-Pregnancy Caffeine Exposure-Induced Non-Alcoholic Steatohepatitis in Male Offspring Rats.

Numerous studies have suggested a strong association between paternal adverse environmental exposure and increased disease susceptibility in offspring. However, the impact of paternal pre-pregnant caffeine exposure (PPCE) on offspring health remains unexplored. This study elucidates the sperm reprogramming mechanism and potential intervention targets for PPCE-induced non-alcoholic steatohepatitis (NASH) in offspring. Here, male rats are administrated caffeine (15-60mgkg-1/d) by gavage for 8 weeks and then mated with females to produce offspring. This study finds that NASH with transgenerational inheritance occurred in PPCE adult offspring. Mechanistically, a reduction of miR-142-3p is implicated in the occurrence of NASH, characterized by hepatic lipid metabolism dysfunction and chronic inflammation through an increase in ACSL4. Conversely, overexpression of miR-142-3p mitigated these manifestations. The origin of reduced miR-142-3p levels is traced to hypermethylation in the miR-142-3p promoter region of parental sperm, induced by elevated corticosterone levels rather than by caffeine per se. Similar outcomes are confirmed in offspring conceived via in vitro fertilization using miR-142-3pKO sperm. Overall, this study provides the first evidence of transgenerational inheritance of NASH in PPCE offspring and identifies miR-142-3p as a potential therapeutic target for NASH induced by paternal environmental adversities.

Abstract A063: The role of JAK/STAT3 signaling in lung premetastatic niche formation and progression

Abstract Pancreatic ductal adenocarcinoma (PDA) is a highly deadly disease with a five-year survival rate of only 13%. Oncogenic KRAS (Kras) is a near-universal driver of PDA, and its activity is required for the formation of PDA precursor lesions, pancreatic intraepithelial neoplasia (PanIN). PanIN formation is accompanied by fibrosis and immune cell infiltration, creating a precursor tumor microenvironment that is maintained and evolves through disease progression. Our previous work has demonstrated that Kras in epithelial cells drives fibroblast activation during very early stages of pancreatic tumorigenesis and that fibroblast reprogramming occurs in a JAK/STAT3 signaling-dependent manner. Other groups have described that pancreatic cancer cells secrete specific factors to prime the liver and lung through immunomodulation and extracellular matrix remodeling, forming the premetastatic niche (PMN). Additionally, recent papers in the field have suggested a role for JAK/STAT3-reprogramming in the formation of the PMN during pancreatic tumorigenesis. Presently, it remains to be elucidated at what stage of PDA tumorigenesis the PMN is initiated, as well as the mechanisms underlying formation. In a pilot experiment, we induced pancreas specific Kras until mice had PanIN lesions but no overt malignancy. We then harvest the pancreas and lung for single cell RNA sequencing. Here, results showed that when Kras is expressed within the pancreas of a mouse, fibroblasts are reprogrammed within the lung, prior to pancreatic tumor formation. Additionally, data indicates JAK/STAT3 signaling activation present within these fibroblasts. We also used multiple lung metastasis models, both spontaneous and tail vein injection, to show persistence of this reprogramming. This suggests that pancreatic Kras expression can systemically reprogram fibroblasts to form a PMN more capable of seeding cancer cells. Our in vitro studies have showed similar results as lung fibroblasts treated with Kras ON conditioned media show increased pSTAT3. Furthermore, using multiplex ELISA on iKras conditioned media, we have identified multiple promising secreted factor hits that may play a role in lung fibroblast reprogramming. Ongoing studies aim to define the mechanism of pulmonary fibroblast reprogramming in the context of the PMN and to assess the role of pSTAT3+ fibroblast reprogramming on establishment of pulmonary metastases. Citation Format: Emily Lasse Opsahl, Carlos E Espinoza, Katelyn L Donahue, Ahmed M Elhossiny, Padma Kadiyala, Allison C Bischoff, Mary Poggi, Yaqing Zhang, Jiaqi Shi, Timothy Frankel, Marina Pasca di Magliano. The role of JAK/STAT3 signaling in lung premetastatic niche formation and progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A063.

Upregulated expression of ubiquitin ligase TRIM21 promotes PKM2 nuclear translocation and astrocyte activation in experimental autoimmune encephalomyelitis.

Reactive astrocytes play critical roles in the occurrence of various neurological diseases such as multiple sclerosis. Activation of astrocytes is often accompanied by a glycolysis-dominant metabolic switch. However, the role and molecular mechanism of metabolic reprogramming in activation of astrocytes have not been clarified. Here, we found that PKM2, a rate-limiting enzyme of glycolysis, displayed nuclear translocation in astrocytes of EAE (experimental autoimmune encephalomyelitis) mice, an animal model of multiple sclerosis. Prevention of PKM2 nuclear import by DASA-58 significantly reduced the activation of mice primary astrocytes, which was observed by decreased proliferation, glycolysis and secretion of inflammatory cytokines. Most importantly, we identified the ubiquitination-mediated regulation of PKM2 nuclear import by ubiquitin ligase TRIM21. TRIM21 interacted with PKM2, promoted its nuclear translocation and stimulated its nuclear activity to phosphorylate STAT3, NF-κB and interact with c-myc. Further single-cell RNA sequencing and immunofluorescence staining demonstrated that TRIM21 expression was upregulated in astrocytes of EAE. TRIM21 overexpressing in mice primary astrocytes enhanced PKM2-dependent glycolysis and proliferation, which could be reversed by DASA-58. Moreover, intracerebroventricular injection of a lentiviral vector to knockdown TRIM21 in astrocytes or intraperitoneal injection of TEPP-46, which inhibit the nuclear translocation of PKM2, effectively decreased disease severity, CNS inflammation and demyelination in EAE. Collectively, our study provides novel insights into the pathological function of nuclear glycolytic enzyme PKM2 and ubiquitination-mediated regulatory mechanism that are involved in astrocyte activation. Targeting this axis may be a potential therapeutic strategy for the treatment of astrocyte-involved neurological disease.

Glycolytic reprogramming governs crystalline silica-induced pyroptosis and inflammation through promoting lactylation modification

Prolonged inhalation of environmental crystalline silica (CS) can cause silicosis, characterized by persistent pulmonary inflammation and irreversible fibrosis, but the mechanism has not been elucidated. To uncover the role and underlying mechanism of glycolytic reprogramming in CS-induced pulmonary inflammation, the mouse silicosis models and glycolysis inhibition models were established in vivo. And the CS-induced macrophage activation models were utilized to further explore the underlying mechanism in vitro. The results showed that CS induced lung inflammation accompanied by glycolytic reprogramming and pyroptosis. The application of glycolysis inhibitor (2-DG) suppressed CS-induced pyroptosis and alleviated lung inflammation. In vitro, 2-DG effectively impeded CS-induced macrophage pyroptosis and inflammatory response. Mechanistically, 2-DG suppressed pyroptosis by inhibiting NLRP3 inflammasome activation both in vivo and in vitro. Furtherly, metabolite lactate facilitated NLRP3-dependent pyroptosis synergistically with CS particles, while blocking the source of lactate largely alleviated NLRP3 inflammasome activation and subsequent pyroptosis triggered by CS. More profoundly, the increment of lactate induced by CS might drive NLRP3-dependent pyroptosis by increasing histone lactylation levels. In conclusion, our findings demonstrated inhibiting glycolytic reprogramming could alleviate CS-induced inflammatory response through suppressing NLRP3 -dependent pyroptosis. Increased glycolytic metabolite lactate and protein lactylation modifications might represent significant mechanisms during CS-induced NLRP3 activation and macrophage pyroptosis.

Abstract We141: Leveraging Cardiac Gene Reprogramming at Single-Cell Resolution to Understand Heart Failure

Background: A defining characteristic of heart failure is cardiac gene reprogramming. Heart failure-induced pathological stressors activate transcription factors, including Gata4 , Tbx5 , and Mef2, required for cardiogenesis. These transcription factors activate fetal cardiac genes in the failing adult heart. The mechanism and role of such cardiac gene reprogramming in response to heart failure remain not fully characterized. Here, we leverage transcriptional reprogramming induced by thyroid hormone deficiency as a model system to understand adult heart failure at the single-cell level. Methods: We engineered a novel Myh6 / Myh7 reporter mouse line. Hypothyroidism was induced in mice with propylthiouracil (PTU). PTU treatment led to global cardiac gene reprogramming. To profile gene expression and chromatin accessibility during cardiac gene reprogramming, single nuclei multiomic sequencing was conducted. Echocardiographs on control and PTU-treated mice evaluated cardiac function changes associated with reprogramming. Cardiac tissues were collected to validate both known and newly identified candidates involved in cardiac gene reprogramming. Results: Characterization of hypothyroidic mice as a model for cardiac reprogramming revealed that the ventricles of PTU-treated hearts significantly switch from Myh6 to dominantly express Myh7 . Evaluation of echocardiographs showed that PTU-treated hearts are significantly atrophic, have chamber dilatation, and reduced cardiac function. Analysis of multiome datasets revealed a unique gene set that is differentially expressed and accessible during cardiac gene reprogramming. Upregulated and more accessible genes in PTU-treated cardiomyocytes (CM) are involved in muscle cell differentiation, muscle hypertrophy, and mitochondrion disassembly ( Tbx5 , Sox4 , Wnt2 , Rgs2 , Hey2 , Mfn2 ). Downregulated and less accessible genes in PTU-treated CMs are related to heart contraction, regulation of heart rate, and ion membrane transport ( Kcnd3 , Jarid2 , Epas1, Atp2a2 , Scn5a , Slc25a4 ). Conclusion: Induction of cardiac gene reprogramming by thyroid inhibition can be applied to understand adult heart failure mechanisms. Hypothyroidism effectively induces global remodeling in the adult heart. Single nuclei multiomic analysis reveals new mechanistic insights into cardiac gene reprogramming that alters the expression and accessibility of genes essential for heart development and maturation.

Abstract We028: Decoding m6a RNA methylomes identifies Igf2bp1 as a common barrier to direct reprogramming

Direct reprogramming has revolutionized the fields of stem cell biology and regenerative medicine. Targeted transdifferentiation of cells in situ holds significant promise in treating a large swathe of illness and injury including cardiovascular disease. However, much remains unknown about the molecular mechanisms of direct reprogramming, particularly its post-transcriptional regulation, including the role of m6a RNA modification. Here, by characterizing early changes in the m6a RNA methylome during reprogramming of fibroblasts toward three distinct lineages—cardiac, hepatic and neuronal—we identify lineage-specific features as well as common regulatory patterns. Our data reveal extensive changes in m6a methylome of direct reprogramming with clear impacts on cell fate decisions. Through loss-of-function screening of m6a readers, we uncovered Igf2bp1(insulin-like growth factor 2 mRNA binding protein 1) as a shared barrier to direct reprogramming. Further mechanistic studies will show how Igf2bp1 influences the reprogramming process mediated via m6a modifications. Collectively, our results present a fascinating portrait of m6a RNA methylome during direct reprogramming and reveal a key role of Igf2bp1 in maintaining cell fate, enhancing our mechanistic understanding of the reprogramming process.

Metabolic Reprogramming in Gliocyte Post-cerebral Ischemia/ Reperfusion: From Pathophysiology to Therapeutic Potential.

Ischemic stroke is a leading cause of disability and death worldwide. However, the clinical efficacy of recanalization therapy as a preferred option is significantly hindered by reperfusion injury. The transformation between different phenotypes of gliocytes is closely associated with cerebral ischemia/ reperfusion injury (CI/RI). Moreover, gliocyte polarization induces metabolic reprogramming, which refers to the shift in gliocyte phenotype and the overall transformation of the metabolic network to compensate for energy demand and building block requirements during CI/RI caused by hypoxia, energy deficiency, and oxidative stress. Within microglia, the pro-inflammatory phenotype exhibits upregulated glycolysis, pentose phosphate pathway, fatty acid synthesis, and glutamine synthesis, whereas the anti-inflammatory phenotype demonstrates enhanced mitochondrial oxidative phosphorylation and fatty acid oxidation. Reactive astrocytes display increased glycolysis but impaired glycogenolysis and reduced glutamate uptake after CI/RI. There is mounting evidence suggesting that manipulation of energy metabolism homeostasis can induce microglial cells and astrocytes to switch from neurotoxic to neuroprotective phenotypes. A comprehensive understanding of underlying mechanisms and manipulation strategies targeting metabolic pathways could potentially enable gliocytes to be reprogrammed toward beneficial functions while opening new therapeutic avenues for CI/RI treatment. This review provides an overview of current insights into metabolic reprogramming mechanisms in microglia and astrocytes within the pathophysiological context of CI/RI, along with potential pharmacological targets. Herein, we emphasize the potential of metabolic reprogramming of gliocytes as a therapeutic target for CI/RI and aim to offer a novel perspective in the treatment of CI/RI.

Decoding single-cell molecular mechanisms in astrocyte-to-iN reprogramming via Ngn2- and Pax6-mediated direct lineage switching

BackgroundThe limited regenerative capacity of damaged neurons in adult mammals severely restricts neural repair. Although stem cell transplantation is promising, its clinical application remains challenging. Direct reprogramming, which utilizes cell plasticity to regenerate neurons, is an emerging alternative approach.MethodsWe utilized primary postnatal cortical astrocytes for reprogramming induced neurons (iNs) through the viral-mediated overexpression of the transcription factors Ngn2 and Pax6 (NP). Fluorescence-activated cell sorting (FACS) was used to enrich successfully transfected cells, followed by single-cell RNA sequencing (scRNA-seq) using the 10 × Genomics platform for comprehensive transcriptomic analysis.ResultsThe scRNA-seq revealed that NP overexpression led to the differentiation of astrocytes into iNs, with percentages of 36% and 39.3% on days 4 and 7 posttransduction, respectively. CytoTRACE predicted the developmental sequence, identifying astrocytes as the reprogramming starting point. Trajectory analysis depicted the dynamic changes in gene expression during the astrocyte-to-iN transition.ConclusionsThis study elucidates the molecular dynamics underlying astrocyte reprogramming into iNs, revealing key genes and pathways involved in this process. Our research contributes novel insights into the molecular mechanisms of NP-mediated reprogramming, suggesting avenues for optimizing the efficiency of the reprogramming process.

Liquorilactobacillus: A Context of the Evolutionary History and Metabolic Adaptation of a Bacterial Genus from Fermentation Liquid Environments.

In the present work, we carried out a comparative genomic analysis to trace the evolutionary trajectory of the bacterial species that make up the Liquorilactobacillus genus, from the identification of genes and speciation/adaptation mechanisms in their unique characteristics to the identification of the pattern grouping these species. We present phylogenetic relationships between Liquorilactobacillus and related taxa such as Bacillus, basal lactobacilli and Ligilactobacillus, highlighting evolutionary divergences and lifestyle transitions across different taxa. The species of this genus share a core genome of 1023 genes, distributed in all COGs, which made it possible to characterize it as Liquorilactobacillus sensu lato: few amino acid auxotrophy, low genes number for resistance to antibiotics and general and specific cellular reprogramming mechanisms for environmental responses. These species were divided into four clades, with diversity being enhanced mainly by the diversity of genes involved in sugar metabolism. Clade 1 presented lower (< 70%) average amino acid identity with the other clades, with exclusive or absent genes, and greater distance in the genome compared to clades 2, 3 and 4. The data pointed to an ancestor of clades 2, 3 and 4 as being the origin of the genus Ligilactobacillus, while the species of clade 1 being closer to the ancestral Bacillus. All these traits indicated that the species of clade 1 could be soon separated in a distinct genus.

Chirality-Dependent Reprogramming of Macrophages.

The chirality of materials directly influences their transport and biological effects in physiological conditions. However, the impact of chiral materials on cellular metabolic reprogramming remains incompletely elucidated. In this study, we have synthesized chiral gold particles through a light-driven particle growth approach and demonstrated that d-Au particles exhibited superior macrophage activation ability compared to l-Au particles. An inflammatory creatine-phosphocreatine shunt was induced following d-Au stimulation. This shunt, facilitated by the upregulated expression of creatine kinase muscle-type (CKM), also resulted in a reduction in cytosolic levels of creatine. Pharmacological inhibition and genetic ablation of CKM further suppressed the secretion of pro-inflammatory cytokines, without compromising mitochondrial respiration. Moreover, the activation of macrophages induced by d-Au was mediated through the activation of the NF-κB and NLRP3 inflammasome pathways. Inhibition of CKM expression not only decreased the secretion of CXCL2 but also attenuated IL-1β by suppressing the NLRP3 inflammasome pathways. Our investigation into the metabolic reprogramming mechanism of chiral materials on macrophage activation is pivotal for the application of chiral-based anticancer therapies.

The combination of SHP099 inhibits the malignant biological behavior of L-OHP/5-FU-resistant colorectal cancer cells by regulating energy metabolism reprogramming

Background and objectiveColorectal cancer (CRC) is one of the most common malignancies in China. At present, there is a problem that the CRC treatment drugs SHP099, L-OHP and 5-FU are insensitive to tumor cells. Combination medication is an important means to solve the insensitivity of medication alone. The purpose of this project was to explore the effect and molecular mechanism of SHP099 combination on the malignant biological behavior of L-OHP/5-FU resistant strains of CRC. MethodsHT29 and SW480 cells were cultured in media supplemented with L-OHP or 5-FU to establish drug-resistant strains. HT29 and SW480 drug-resistant cells were subcutaneously injected into the ventral nerves of nude mice at a dose of 5 × 106 to establish CRC drug-resistant animal models. CCK-8, Western blot, flow cytometry, Transwell and kit detection were used to detect the regulatory mechanism of energy metabolism reprogramming in drug-resistant CRC cells. ResultsCompared with nonresistant strains, L-OHP/5-FU-resistant strains exhibited greater metabolic reprogramming. Functionally, SHP099 can restrain the metabolic reprogramming of L-OHP/5-FU-resistant strains and subsequently restrain the proliferation, colony formation, migration and spheroid formation of L-OHP/5-FU-resistant strains. Downstream mechanistic studies have shown that SHP099 interferes with the metabolic reprogramming of L-OHP/5-FU drug-resistant strains by suppressing the PI3K/AKT pathway, thereby restraining the malignant biological behavior of L-OHP/5-FU drug-resistant strains and alleviating CRC. ConclusionThe combination of SHP099 can restrain the malignant biological behavior of L-OHP/5-FU-resistant CRC cells and alleviate the progression of CRC by interfering with the reprogramming of energy metabolism. This study explored the effect of SHP099 combination on dual-resistant CRC cells for the first time, and provided a new therapeutic idea for solving the problem of SHP099 insensitivity to CRC cells.