Cellular communication network factor 1 promotes retinal leakage in diabetic retinopathy via inducing neutrophil stasis and neutrophil extracellular traps extrusion.

BACKGROUND: Diabetic retinopathy (DR) is a major cause of blindness and is characterized by dysfunction of the retinal microvasculature. Neutrophil stasis, resulting in retinal inflammation and the occlusion of retinal microvessels, is a key mechanism driving DR. These plugging neutrophils subsequently release neutrophil extracellular traps (NETs), which further disrupts the retinal vasculature. Nevertheless, the primary catalyst for NETs extrusion in the retinal microenvironment under diabetic conditions remains unidentified. In recent studies, cellular communication network factor 1 (CCN1) has emerged as a central molecule modulating inflammation in pathological settings. Additionally, our previous research has shed light on the pathogenic role of CCN1 in maintaining endothelial integrity. However, the precise role of CCN1 in microvascular occlusion and its potential interaction with neutrophils in diabetic retinopathy have not yet been investigated. METHODS: We first examined the circulating level of CCN1 and NETs in our study cohort and analyzed related clinical parameters. To further evaluate the effects of CCN1 in vivo, we used recombinant CCN1 protein and CCN1 overexpression for gain-of-function, and CCN1 knockdown for loss-of-function by intravitreal injection in diabetic mice. The underlying mechanisms were further validated on human and mouse primary neutrophils and dHL60 cells. RESULTS: We detected increases in CCN1 and neutrophil elastase in the plasma of DR patients and the retinas of diabetic mice. CCN1 gain-of-function in the retina resulted in neutrophil stasis, NETs extrusion, capillary degeneration, and retinal leakage. Pre-treatment with DNase I to reduce NETs effectively eliminated CCN1-induced retinal leakage. Notably, both CCN1 knockdown and DNase I treatment rescued the retinal leakage in the context of diabetes. In vitro, CCN1 promoted adherence, migration, and NETs extrusion of neutrophils. CONCLUSION: In this study, we uncover that CCN1 contributed to retinal inflammation, vessel occlusion and leakage by recruiting neutrophils and triggering NETs extrusion under diabetic conditions. Notably, manipulating CCN1 was able to hold therapeutic promise for the treatment of diabetic retinopathy.

A Totipotent "All-In-One" Peptide Sequentially Blocks Immune Checkpoint and Reverses the Immunosuppressive Tumor Microenvironment.

Immune checkpoint blockade combined with reversal of the immunosuppressive tumor microenvironment (TME) can dramatically enhance anti-tumor immunity, which can be achieved by using multiple-agent therapy. However, the optimal dose and order of administration of different agents remain elusive. To address this dilemma, multiple agents are often grafted together to construct "all-in-one" totipotent drugs, but this usually comes at the cost of a lack of synergy between the agents. Herein, by comprehensively analyzing the conserved sites of the immune checkpoint and TME drug targets, peptide secondary structures, assembly properties, and other physicochemical properties, a high-content peptide library is designed. By using the "3D-molecular-evolution" screening strategy, an efficient and totipotent "all-in-one" peptide (TAP) is obtained, which possesses the abilities of self-assembling, blocking the PD-1/PD-L1 axis, inhibiting Rbm38-eIF4E complex formation, and activating p53. It is shown that in mice treated with TAP, with either subcutaneous tumors or patient-derived xenografts, PD-L1 is blocked, with increased activation of both T and NK cells whilst reversing the immunosuppressive TME. Moreover, TAP can mitigate tumor activity and suppress tumor growth, showing superior therapeutic effect over antibody-based drugs.

Synergetic Tumor Probes for Facilitating Therapeutic Delivery by Combined-Functionalized Peptide Ligands.

Both targeting and penetrating ability are the key characteristics for tissue probing and precise delivery. To construct an efficient nano probing and delivery system toward human epidermal growth factor receptor 2 (HER2) positive cancer, we established a nano liposomal system functionalized with a newly screened HER2 targeting peptide (HP2, YDLKEPEH) and the cell-penetrating peptide TAT simultaneously. Compared with the monofunctionalized liposomal probes, the dual-functional ones demonstrated a synergetic effect in cell uptake, drug delivery, and in vivo imaging. The improved efficacy of the synergetic system provides a prospective strategy for cancer diagnosis and therapy.

A Novel Peptide Probe for Identification of PLS3-Expressed Cancer Cells.

The T-plastin (PLS3) has a significant implication in epithelial-mesenchymal transition (EMT) and breast cancer prognosis. Using one-bead-one-compound library strategy, a novel peptide TP1 (KVKSDRVC) toward PLS3 was screened and exhibited the specificity for identifying PLS3-expressed cancer cells. Moreover, we found Fluorescein isothiocyanate-labeled TP1 (FITC-TP1) could act as a novel probe for EMT-induced cancer cells, preferentially in the leading edge. It also has satisfactory specificity for PLS3-expressed cancer cells spiked in the blood. FITC-TP1 was expected to become a diagnostic tool to identify PLS3-expressed circulating tumor cells and predict prognosis for patients with breast cancer in the future.

MMP-2-Controlled Transforming Micelles for Heterogeneic Targeting and Programmable Cancer Therapy.

Herein, through the active-peptide-functionalization, we developed a nanoscale micelles system (named HEKM) which consists of tumor microenvironment-regulated shape-changing with specific recognition abilities for enhanced cellular targeting, internalization and therapy of heterogeneic tumors. As a result, HEKMs could recognize and bind the tumor heterogeneity marker EGFR-HER2 complex, which led to an enhanced tumor targeting effect. In particular, HEKMs could self-assemble into nanorods under normal physiological conditions while transform into nanospheres in the tumor extracellular microenvironment by a sensitive response to matrix metalloproteinase-2 (MMP-2). The nanorods could prolong the blood circulation time while the nanospheres could accelerate tissue penetration in tumors. In vivo dual-modal targeted imaging was realized by FRET-fluorophore conjugation and gadolinium loading in HEKMs. Tumor cell apoptosis was achieved by proapoptotic element integration. The in vitro and in vivo studies both demonstrated that these rationally designed, shape-changing and targeting micelles could achieve maximized drug efficacy and minimum side effects.

Boosting the Theranostic Effect of Liposomal Probes toward Prominin-1 through Optimized Dual-Site Targeting.

Ligand-targeting specific liposomal probes are increasingly used as imaging and delivery vehicles for in vivo diagnosis. Thereinto, the ligand variety and density profoundly affect the binding behaviors toward the target. The synergetic effect of different ligands could be achieved only when the optimized molecular-recognition configuration occurred. In this study, we construct a dual-peptides-targeting liposomal probe named BTLS that could synergistically bind two different sites of prominin-1, a cancer stem cell marker. At the distance of 11 Å between the two new peptides, ligands could insert into the hollow pocket of prominin-1 and BTLS could achieve the appropriate spatial structure, showing the strong binding affinity in both cellular and in vivo levels. It is indicated that the design of density-optimized peptide-targeted liposomes could be promising to maximize the multifunctional targeting effects on the cancer theranostics.

Synergetic estrogen receptor-targeting liposome nanocarriers with anti-phagocytic properties for enhanced tumor theranostics.

Multifunctional nanocarriers have been widely applied due to their enhanced effect on tumor therapeutics. Nevertheless, owing to the natural immune clearance mechanisms in living bodies, nanocarriers tend to be eliminated during blood circulation, thereby impeding their effective arrival at the tumor sites. Herein, we constructed a synergetic targeted liposome nanocarrier system named SELS functionalized with both a tumor identification ligand (anti-ER (Estrogen Receptor) antibody) and an immune targeting ligand (Self-Peptide (SP)). The anti-ER antibody could recognize and bind ER-positive breast cancer tissues in a specific way. SP could activate the CD47-SIRPα immune response, which reduced phagocytosis of the nanoparticles by macrophages. Both the enhanced targeting ability and anti-phagocytosis behavior could improve the tumor uptake of the nanocarriers and prevent their immune clearance in living systems. Therefore, drug-loaded SELS enabled improved tumor imaging and therapeutic performance in living systems.

Tumor-microenvironment controlled nanomicelles with AIE property for boosting cancer therapy and apoptosis monitoring.

Mild acidity matrix, rich blood vessels and special biomarkers constitute the primary tumor microenvironment. Nanoparticles could change their physicochemical characteristics by functionalizing a series of moieties which is responsive towards pH or specific markers. So precise regulation of nanocarrier-based drug delivery systems by the tumor microenvironment has showed great potential for theranostics. Herein, we developed a smart nano delivery system STD-NM, showing tumor microenvironment responsive targeting, efficient drug delivery and precise evaluation of therapeutic effect in vivo. STD-NM kept in 'stealth' state in normal environment while 'activated' in the tumor acidic environment, which could show stability in blood circulation while deeply penetrate into tumor tissues. Additionally, STD-NM was designed with aggregation-induced emission (AIE) characteristic, of which the fluorescence 'switch on' when apoptosis taken place. Gene analysis by RNA-seq also confirmed a superior therapeutic effect of drug loaded STD-NM treatment. We envisioned the well-designed smart nano materials for drug delivery could open a new avenue in precisely tumor imaging and specific cancer therapeutics.

Molecular Cancer Imaging in the Second Near-Infrared Window Using a Renal-Excreted NIR-II Fluorophore-Peptide Probe.

In vivo molecular imaging of tumors targeting a specific cancer cell marker is a promising strategy for cancer diagnosis and imaging guided surgery and therapy. While targeted imaging often relies on antibody-modified probes, peptides can afford targeting probes with small sizes, high penetrating ability, and rapid excretion. Recently, in vivo fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) shows promise in reaching sub-centimeter depth with microscale resolution. Here, a novel peptide (named CP) conjugated NIR-II fluorescent probe is reported for molecular tumor imaging targeting a tumor stem cell biomarker CD133. The click chemistry derived peptide-dye (CP-IRT dye) probe afforded efficient in vivo tumor targeting in mice with a high tumor-to-normal tissue signal ratio (T/NT > 8). Importantly, the CP-IRT probes are rapidly renal excreted (≈87% excretion within 6 h), in stark contrast to accumulation in the liver for typical antibody-dye probes. Further, with NIR-II emitting CP-IRT probes, urethra of mice can be imaged fluorescently for the first time noninvasively through intact tissue. The NIR-II fluorescent, CD133 targeting imaging probes are potentially useful for human use in the clinic for cancer diagnosis and therapy.

pH-Triggered Peptide Self-Assembly for Targeting Imaging and Therapy toward Angiogenesis with Enhanced Signals.

Mild acidic environment and angiogenesis are two typical characteristics of tumor. The specific response toward both lower pH and angiogenesis may enhance the targeting ability both for drug and diagnostic probe delivery. Herein, we present a kind of dual responding self-assembled nanotransformation material that is tumor angiogenesis targeting and pH triggered based on amphiphilic conjugation between peptides (STP) and aromatic molecules (tetraphenylethylene (TPE)). The morphology of the self-assembled peptide conjugates is responsibly changed from nanoparticles in neutral condition to nanofibers in acidic condition, which "turn on" the in vivo targeting imaging and accelerate the efficient drug delivery and in vivo therapy. On the basis of the well-controlled nanotransformation both in vitro and in vivo, we envisioned the successful demonstration of the responding materials would open a new avenue in turn on targeting imaging diagnostics and specific cancer therapeutics.

Targeting peptide functionalized liposomes towards aminopeptidase N for precise tumor diagnosis and therapy.

Aminopeptidase N (APN/CD13) is closely related to the growth of cancers and is suggested as a suitable target for anti-cancer therapy. Based on the "one-bead-one-compound" (OBOC) approach on a microarray device, we screened out a novel affinity peptide LN (YEVGHRC). It was determined that LN could specifically recognize and bind to APN. Moreover, LN-functionalized liposomes (LN-LS) could achieve efficient nano-encapsulated drug delivery under APN-overexpressing tumor conditions in vitro and in vivo. We expect that LN-LS could provide a new strategy for APN-positive tumor diagnosis and therapy.

Switchable Liposomes: Targeting-Peptide-Functionalized and pH-Triggered Cytoplasmic Delivery.

One switchable nanodelivery system was constructed. Liposomes were functionalized by a novel dual-recognition peptide STP, which is pH-responsive as well as the affinity ligand of tumor marker VEGFR2 (the angiogenesis marker vascular endothelial growth factor receptor 2). Efficient drug delivery and in vivo therapy could be "turned on" and accelerated only in the conditions of VEGFR2 overexpression and a mild acidic environment. We envisioned that the successful demonstration of this switchable nanocarrier system would open a new avenue on rapid cytoplasmic delivery for specific cancer diagnostics and therapeutics.

Switchable probes: pH-triggered and VEGFR2 targeted peptides screening through imprinting microarray.

One switchable affinity peptide, STP, is screened out from a high-throughput library by an integrated imprinting microarray. STP is pH triggered and also the ligand of the marker VEGFR2. Efficient cell recognition and penetration as well as an in vivo image could be "turned on" and accelerated only in the condition of VEGFR2 overexpression and a mild acidic environment.

Peptide functionalized targeting liposomes: for nanoscale drug delivery towards angiogenesis.

A novel affinity peptide S1 (LIDHEWKENYFPLSF) was screened out via a "one bead one compound" (OBOC) approach on a microarray device. It was identified that S1 could specifically recognize and bind to vascular endothelial growth factor receptor 2 (VEGFR2), which is an angiogenesis biomarker. Moreover, S1-functionalized liposomes (S1-LS) could achieve efficient nanoscale drug delivery under the conditions of VEGFR2-overexpression in vitro and in vivo. It was demonstrated that S1-LS would be a promising VEGFR2-targeting drug delivery system.

Removal of anionic azo dyes from aqueous solution by functional ionic liquid cross-linked polymer.

A novel functional ionic liquid based cross-linked polymer (PDVB-IL) was synthesized from 1-aminoethyl-3-vinylimidazolium chloride and divinylbenzene for use as an adsorbent. The physicochemical properties of PDVB-IL were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The adsorptive capacity was investigated using anionic azo dyes of orange II, sunset yellow FCF, and amaranth as adsorbates. The maximum adsorption capacity could reach 925.09, 734.62, and 547.17 mg/g for orange II, sunset yellow FCF and amaranth at 25°C, respectively, which are much better than most of the other adsorbents reported earlier. The effect of pH value was investigated in the range of 1-8. The result shows that a low pH value is found to favor the adsorption of those anionic azo dyes. The adsorption kinetics and isotherms are well fitted by a pseudo second-order model and Langmuir model, respectively. The adsorption process is found to be dominated by physisorption. The introduction of functional ionic liquid moieties into cross-linked poly(divinylbenzene) polymer constitutes a new and efficient kind of adsorbent.