Theranostics最新文献

Rationale: Loss of histone deacetylase 5 (HDAC5) is frequently observed in multiple malignancies, including pancreatic ductal adenocarcinoma (PDAC), and is associated with poor patient survival. Although HDAC5 has been implicated in DNA damage repair, the molecular mechanisms by which it regulates DNA double-strand break (DSB) repair pathway choice remain unclear. Methods: Using PDAC cell lines, genetically engineered mouse models, patient-derived organoids, and biochemical assays, we investigated the role of HDAC5 in DNA end resection and homologous recombination (HR). Protein interactions, post-translational modifications, DNA repair pathway activity, and cellular responses to DNA damage and PARP inhibition were systematically analyzed. Results: We identify HDAC5 as a critical regulator of DNA end resection and HR through deacetylation of Ku70. DNA damage induces casein kinase 2 (CK2)-mediated phosphorylation of HDAC5, promoting its nuclear translocation. Nuclear HDAC5 directly deacetylates Ku70 at lysine 287, facilitating Ku70 dissociation from DSB sites, thereby enabling DNA end resection and HR repair. In contrast, HDAC5 loss or CK2 inhibition results in Ku70 K287 hyperacetylation, prolonged retention of the Ku heterodimer at DSBs, impaired DNA end resection, and suppression of HR. Consequently, HDAC5-deficient PDAC cells exhibit increased sensitivity to PARP inhibitors, while pharmacological CK2 inhibition sensitizes HDAC5-proficient tumors to PARP inhibition. Conclusions: These findings uncover a previously unrecognized CK2-HDAC5-Ku70 signaling axis that governs DNA repair pathway choice by regulating DNA end resection. Targeting this axis provides a mechanistic rationale for enhancing PARP inhibitor sensitivity in PDAC, including tumors without classical homologous recombination deficiency.

Background and Aim: Magnesium ion (Mg²⁺)-mediated metallo-immunotherapy effectively promotes the activation of memory T cells, thereby helping to mitigate tumor recurrence following traditional treatments such as radiotherapy (RT). However, factors such as the acidity of the tumor microenvironment, along with the upregulated expression of immune checkpoints induced by RT and Mg²⁺, may compromise its therapeutic efficacy. Material and Methods: In this work, we developed a T cell membrane-coated, hemin-loaded magnesium carbonate nanomedicine (designated as THM). Following intravenous injection, THM catalyzes the hydrogen peroxide generated during RT to induce a burst of reactive oxygen species (ROS), thereby producing a tumor vaccine that promotes dendritic cell maturation and T cell activation. Simultaneously, THM reacts with H⁺ to mitigate the acidic tumor microenvironment while releasing Mg²⁺, which further enhances the generation and activation of central memory T cells (Tcm) to confer long-term anti-tumor immunity following RT. Results: RT combined with Mg²⁺ treatment upregulates PD-L1 expression in tumor cells. Notably, the PD-1 protein on THM can competitively bind to PD-L1, thereby mitigating the side effects associated with the combined therapy. In vitro and in vivo data confirm that this combinatorial therapy boosts Tcm-mediated antitumor activity, mitigates treatment-induced immune suppression, and potently prevents tumor recurrence. Conclusions: This work provides critical insights for the clinical translation of antitumor immunotherapy.

Background: The switch to endothelial-to-mesenchymal transition (EndMT) in endothelial cells (ECs) induced by disturbed flow (d-flow) has been identified as the critical driver of the pathogenesis of inflammatory vascular disorders. We aimed to investigate the role of EndMT in abdominal aortic aneurysms (AAA) and the underlying mechanism. Methods: Immunoblotting, immunofluorescence and transmission electron microscope were used to assess d-flow-induced EndMT in human and mouse AAA models (Ang II/PPE). An Ibidi pump system was used to produce d-flow on human aortic endothelial cells (HAECs), and the expression of galectin-7 was enhanced and weakened using an adeno-associated virus. Furthermore, single-cell RNA sequencing was performed to explore the underlying mechanism of galectin-7-mediated EndMT. Results: EndMT induced by d-flow, which suppressed galectin-7 expression, was positively correlated with AAA. Enhanced galectin-7 expression inhibited d-flow-induced EndMT and AAA progression, whereas reduced galectin-7 expression resulted in the opposite effect. Mechanistically, we found a EndMT-related cluster in HAECs by single-cell RNA sequencing, and the SRGN gene in this cluster was considered the core gene. Galectin-7 bound competitively to the transcription factor CREB, resulting in the inhibition of SRGN transcription, which in turn prevented TGFβ/smad pathway activation, thereby restoring EndMT progression. Conclusions: EndMT transformation in ECs exposed to d-flow was the critical driver of AAA development. Furthermore, endothelium-enriched galectin-7 suppressed the EndMT process induced by d-flow and prevent AAA progression by transcriptionally inhibiting SRGN via competitive binding with CREB to restrict TGFβ/smad pathway.

Rationale: Current gastrointestinal endoscopy mainly depends on morphological changes for lesion diagnosis, thus often failing to detect early colorectal cancers (CRCs) with subtle morphological alterations. Optical molecular imaging via endoscopy may provide a unique means to identify early CRCs that precede the morphological changes observed via conventional endoscopy. In addition, optical imaging methods are utilized for intraoperative navigation when imaging tumors. However, the primary challenge in applying optical molecular imaging clinically is the restricted kinds of clinically endorsed targeted probes. Cerenkov luminescence (CL) can be observed with almost all clinically validated radiotracers. Therefore, Cerenkov luminescence imaging (CLI) does not require the development of new probes and can directly utilize clinically validated radiotracers. This study aimed to use Cerenkov luminescence endoscopy (CLE) for diagnosing early CRC effectively. Methods: In a prospective observational study, we use a self-produced CLE to diagnose colorectal lesions (mainly CRC). The CL images of the lesions were recorded and analyzed in comparison with PET/CT scans and histopathology. Results: A total of 20 colorectal lesions from 15 patients were included in the study. The agreement between CLE and PET/CT in diagnosing early CRC (stage Ⅰ CRC and advanced adenoma) was 100%. The level of agreement of CLE images with histopathology was 88.9% acceptable to high for early CRC. Compared with that of colorectal hyperplastic polyps, the signal-to-background ratio of CLE from early CRCs was significantly greater (1.33 ± 0.17 vs 0.99 ± 0.03, P < 0.001). In phantoms, tumor-bearing nude mice, and rectal pseudotumor model dogs, CLE detected CL at the corresponding lesion locations. Conclusions: This study demonstrated for the first time that CLE could utilize Cerenkov luminescence molecular imaging to diagnose early CRCs, overcoming the limitations of current endoscopic diagnosis based on morphological changes. (ClinicalTrials.gov, NCT05575765).

Rationale: Bone metastases - common in metastatic castration-resistant prostate cancer (mCRPC) - lead to severe complications and currently suffer from limited therapeutic options. Poor solubility, systemic toxicity, and therapeutic resistance hamper conventional approaches, such as docetaxel (Dtx) treatment. Nanomedicine-based strategies - including polymer-drug conjugates - can help overcome said limitations through enhanced tumor targeting and reduced unwanted side effects in healthy tissues. Methods: An intratibial bone mCRPC mouse model - used to recapitulate tumor growth and microenvironmental dynamics - was developed and characterized. A poly-L-glutamic acid (PGA)-Dtx) conjugate synthesized to enhance Dtx delivery and efficacy was also characterized in terms of size, zeta potential, drug loading, and pH-dependent release. In vivo evaluations included tumor growth monitoring by bioluminescence imaging, cathepsin K activity from tumor by fluorescence imaging, bone damage evaluation by micro-computed tomography, tumor vasculature by light-sheet fluorescent microscopy, cell population at tumor site by histology, modulation of blood cell populations by tumor and treatment by hematology, and biodistribution of PGA-Dtx using fluorescent imaging and intravital microscopy. Results: Our intratibial bone mCRPC model supported reliable tumor establishment, progressive osteolytic damage and vascularization, and systemic inflammation. PGA-Dtx displayed optimal properties (6.6 nm size, -24.1 mV zeta potential, 3.3 mol % drug loading) and supported lower but sustained Dtx release at acidic pH. The enhanced tumor accumulation following PGA-Dtx administration significantly suppressed tumor growth in vivo, normalized cathepsin K activity levels, and reduced bone damage while avoiding the systemic toxicity associated with free Dtx. Conclusions: Our intratibial bone mCRPC mouse model provides a robust platform for studying PCa bone metastases and evaluating nanomedicine efficacy. PGA-Dtx displays promise as a safe and effective therapy for mCRPC, offering improved drug delivery and reduced systemic side effects, which supports the translational potential of polymer-drug conjugates in mCRPC management.

Background: Beige adipocytes play a critical role in thermoregulation by upregulating uncoupling protein 1 (UCP1) upon stimulation. While the transcriptional regulation of UCP1 in adipose tissue has been extensively investigated, the mechanisms governing its translational control remain largely elusive. Methods: A cold exposure protocol was employed to induce beige adipocyte biogenesis in mouse subcutaneous fat. The overall metabolic rate of mice was monitored by metabolic cage. Primary adipocyte precursors were isolated from the stromal vascular fraction (SVF) of inguinal white adipose tissue (iWAT) and differentiated into beige adipocytes using a standard adipogenic induction cocktail. Transmission electron microscopy (TEM) was utilized to examine mitochondrial morphology. Functional rescue experiments were performed via adenovirus-mediated gene overexpression. Potential binding partners were screened by LC-MS/MS, while RNA immunoprecipitation (RIP) and RNase protection assay (RPA) were applied to evaluate RNA-protein and RNA-RNA interactions, respectively. Additional mechanistic insights were obtained through qPCR, Western blotting, Immunohistochemistry and bioinformatics analyses. Results: In this study, we discovered that Hilnc, a long non-coding RNA (lncRNA), functions in beige adipocytes by suppressing UCP1 translation. Adipocyte-specific Hilnc-deficient mice display increased energy expenditure, elevated body temperature, smaller inguinal white adipose tissue volume and coupling efficiency, and elevated UCP1 protein level. Hilnc binds to the 3' untranslated region of Ucp1 mRNA and recruits insulin-like growth factor 2 binding protein 2 for translational suppression. The previously characterized human Hilnc functional homolog negatively correlates with UCP1 protein levels in human adipose tissues and suppresses UCP1 translation via similar mechanisms. Conclusion: Our findings highlight Hilnc's post-transcriptional role in thermoregulation in beige adipocytes and offer new insights into the variability of thermogenesis among individuals.

Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD) and multiple sclerosis (MS), are characterized by progressive neuronal dysfunction and limited therapeutic options, largely due to the restrictive nature of the blood-brain barrier (BBB). Exosomes, naturally occurring extracellular vesicles (EVs), have gained attention as innovative drug delivery vehicles owing to their intrinsic ability to cross the BBB, minimal immunogenicity, high biocompatibility, and capability to carry diverse therapeutic cargos such as proteins, nucleic acids, and small molecules. Furthermore, exosomes can be bioengineered to enhance drug-loading efficiency and targeting specificity, positioning them as a versatile and effective platform for treating NDDs. In this review, we summarize recent advances in exosome biogenesis, secretion, and engineering, with an emphasis on innovative strategies for exosome isolation, drug loading, and surface modification. We further explore their roles in modulating neuroinflammation, promoting neural regeneration, and enabling precise therapeutic delivery. Critical challenges associated with large-scale production, quality control, and regulatory compliance under Good Manufacturing Practices (GMP) are also discussed. Collectively, these developments underscore the transformative potential of engineered exosomes in advancing precision therapies for neurodegenerative disorders and offer strategic insights into their clinical translation.

Rationale: Although reperfusion has been established as the main strategy for stroke treatment, it frequently causes irreversible secondary injury with dynamic pathological changes. The ischemic microenvironment in the brain continues to deteriorate after reperfusion, resulting in progressive expansion of the injured area and subsequent neuronal death. Therefore, it is urgent to find a therapeutic strategy for long-term management of ischemic stroke at post-reperfusion stages. Methods: In this study, we designed an inflammation cascade-directed therapy using a biomimetic polydopamine nanosystem (MPP-B@MM). The synthesis of the nanosystem was confirmed by transmission electron microscopy, scanning electron microscopy, dynamic laser scattering, proton nuclear magnetic resonance, and so forth. The capability of blood-brain barrier crossing was investigated by cellular study with fluorescence imaging. Meanwhile, reactive oxygen species assay, apoptosis detection, and flow cytometry were employed to evaluate intracellular anti-apoptotic effects of the nanosystem. For in vivo evaluation, a middle cerebral artery occlusion model was established. Anti-stroke efficacy and mechanism of action of the nanosystem were assessed through multiple analytical methods, including behavioral tests, immunohistochemical staining, mRNA sequencing, and blood biochemical analysis. Results: In vitro experiments demonstrated that MPP-B@MM exhibited superior cellular uptake and blood-brain barrier crossing, significantly attenuated mitochondrial damage, and rescued injured neurons. Comprehensive in vivo studies, spanning both acute and chronic phases, confirmed the superior long-term therapeutic performance of the nanosystem. Importantly, mRNA sequencing and pharmacological intervention experiments demonstrated that Homx1 served as the predominant molecular target for acidosis-responsive drug release. Conclusions: This tailored nanosystem demonstrated acute neuroprotective effects during the initial phase of ischemic stroke. As inflammation progressed, the acidosis-responsive motif in the nanosystem could serve as an on-demand therapeutic method, spatiotemporally increasing neurotrophic factor expression at the stroke lesion, which significantly contributed to brain recovery.

Rationale: Myocardial ischemia-reperfusion (MI/R) injury induces apoptosis, metabolic dysregulation, and ventricular remodeling through complex pathological mechanisms. Although nanozyme engineering has the potential for antioxidation, reoxygenation, and pro-vascularization, achieving responsive modulation of the pathological microenvironment remains significantly challenging. Methods: A layered double hydroxide (LDH)-based nanozyme (ZnSrMo-LDH/Cu) was synthesized via a low-temperature hydrothermal/isomorphic substitution method for MI/R treatment. The reactive oxygen species (ROS) scavenging ability and responsive ion release performance of ZnSrMo-LDH/Cu were evaluated through various spectroscopic characterization methods. The biosafety and therapeutic efficiency of ZnSrMo-LDH/Cu-BSA nanozymes were assessed by in vitro and in vivo experiments. Results: ZnSrMo-LDH/Cu demonstrated cascade superoxide dismutase (SOD) and catalase (CAT) activities, effectively overcoming acidic microenvironment limitations to maintain CAT activity rather than peroxidase (POD) activity while scavenging ROS to generate oxygen, with a ROS scavenging capacity 2.97 times that of Fe₃O₄. Moreover, the acid-triggered Sr²⁺ release promoted vascular regeneration and synergistically improved the ischemic-hypoxic microenvironment. Consequently, after bovine serum albumin (BSA) modification, ZnSrMo-LDH/Cu-BSA demonstrated excellent cytoprotective effects, reducing the cardiomyocyte apoptosis rates to 9.4% (in vitro) and 20.7% (in vivo) of the levels in the MI/R group. In vivo studies further validated that ZnSrMo-LDH/Cu-BSA enhanced cardiac function and attenuated ventricular remodeling by inhibiting oxidative stress and promoting angiogenesis. Mechanistically, ZnSrMo-LDH/Cu-BSA provided a cardioprotective effect by inhibiting the TGF-β signaling pathway, thereby alleviating cell damage caused by MI/R. Conclusions: The pathologically responsive LDH-based nanozyme represents a promising avenue for MI/R treatment.

Rationale: Sustained hypertension induces adverse cardiac remodeling. Platelet activation is instrumental in exacerbating inflammation by engaging with macrophages. C-C chemokine motif ligand 5 (CCL5) is contained within platelet α-granules, and released following platelet activation. This work delineated the specific contributions of CCL5 to platelet function, platelet-induced macrophage polarization, and hypertensive cardiac remodeling. Methods: CCL5 knockout (KO) mice infused with Angiotensin II (Ang II) were used to identify the role of CCL5 in vivo. CCL5 absence on platelet activation were evaluated on washed platelets. Two distinct models of platelet depletion and reconstitution were utilized to investigate the impact of platelets lacking CCL5. An in vitro co-culture system was established to explore the roles of CCL5-mediated platelet activation in M2 macrophage polarization. Results: CCL5 KO attenuated the adverse cardiac effects induced by Ang II, including fibrosis, hypertrophy, and functional impairment, accompanied by reduced platelet activation and M2 macrophage polarization in cardiac tissue. Platelet inhibitor administration and platelet depletion/reconstitution experiments revealed that the suppression of platelet activation by CCL5 KO contributed to the amelioration of Ang II-promoted cardiac M2 macrophage polarization and cardiac remodeling. CCL5 KO markedly suppressed the activation of TGF-β1 and NF-κB signaling, an effect observed both in cardiac tissue from Ang II-infused mice and in platelets following ADP stimulation in vitro. In in vitro co-culture systems, rmTGF-β1 reversed CCL5 KO platelet-impaired M2 macrophage polarization. NF-κB inhibition abolished recombinant CCL5 (rmCCL5)-induced platelet activation, while blocking antibodies against CCR1 and CCR3 inhibited rmCCL5-induced NF-κB signaling and platelet activation. Conclusions: These findings underscore the detrimental role of CCL5-mediated platelet activation in promoting M2 macrophage polarization during hypertensive cardiac remodeling and elucidate the molecular mechanism that CCL5 facilitates platelet-derived TGF-β1 signaling by promoting NF-κB activation via CCR1 and CCR3 receptors. These findings support CCL5 inhibition as a promising strategy against inflammation and cardiac damage.