Inhibition of hypoxia-induced proliferation of pulmonary arterial smooth muscle cells by a mTOR siRNA-loaded cyclodextrin nanovector

Role of lysine lactylation in neoplastic and inflammatory pulmonary diseases (Review)

Protein lysine lactylation is a ubiquitous and post‑translational modification of lysine residues that involves the addition of a lactyl group on both histone and non‑histone proteins. This process plays a pivotal role in human health and disease and was first discovered in 2019. This epigenetic modification regulates gene transcription from chromatin or directly influences non‑histone proteins by modulating protein‑DNA/protein interactions, activity and stability. The dual functions of lactylation in both histone and non‑histone proteins establish it as a crucial mechanism involved in various cellular processes, such as cell proliferation, differentiation, immune and inflammatory responses and metabolism. Specific enzymes, referred to as 'writers' and 'erasers', catalyze the addition or removal of lactyl groups at designated lysine sites, thereby dynamically modulating lactylation through alterations in their enzymatic activities. The respiratory system has a remarkably intricate metabolic profile. Numerous pulmonary diseases feature an atypical transition towards glycolytic metabolism, which is linked to an overproduction of lactate, a possible substrate for lactylation. However, there has yet to be a comprehensive review elucidating the full impact of lactylation on the onset, progression and potential treatment of neoplastic and inflammatory pulmonary diseases. In the present review, an extensive overview of the discovery of lactylation and advancements in research on the existing lactylation sites were discussed. Furthermore, the review particularly investigated the potential roles and mechanisms of histone and non‑histone lactylation in various neoplastic and inflammatory pulmonary diseases, including non‑small cell lung cancers, malignant pleural effusion, pulmonary fibrosis, acute lung injury and asthma, to excavate the new therapeutic effects of post‑translational modification on various pulmonary diseases.

Deciphering the inhibitory effects of trimetazidine on pulmonary hypertension development via decreasing fatty acid oxidation and promoting glucose oxidation

Pulmonary hypertension (PH) is a devastating disease characterized by vascular remodeling, resulting in right ventricular failure and death. Dysregulation of energy metabolism is linked to PH pathogenesis. Trimetazidine (TMZ), a selective long-chain 3-ketoacyl coenzyme A thiolase inhibitor, is critical in maintaining energy metabolism. Despite the indicated TMZ's inhibitory effect on pulmonary vascular remodeling in PH development, the integrated evaluation of the changes in biomolecules, such as metabolites and transcripts, that TMZ induces in the lung and heart tissues is largely unknown in vivo. For an improved understanding of the molecular mechanism involving the effects of TMZ on PH development, we performed a comprehensive analysis of the changes in cardiac metabolites and pulmonary transcripts of SU5416-Hypoxia (Su/Hx) rats treated with TMZ. Metabolomic analysis of the Su/Hx-induced PH hearts demonstrated that TMZ reduced the long-chain fatty acid concentration. Additionally, TMZ alleviated PH degree and excessive strain on the right heart functions in rats with Su/Hx-induced PH. We identified the candidate target genes for TMZ treatment during PH development. Interestingly, the mRNA levels of the fatty acid transporters were substantially downregulated by TMZ administration in the lungs with Su/Hx-induced PH. Notably, TMZ suppressed excessive proliferation of human pulmonary artery smooth muscle cells under hypoxic conditions. Our study suggests that TMZ ameliorates PH development by involving energy metabolism in the lungs and heart.

Diarylpentanoids and phenylpropanoids from the roots of Anthriscus sylvestris (L.) Hoffm

Three pairs of undescribed diarylpentanoid enantiomers (1-3) and five undescribed phenylpropanoids (4-8), along with seven known compounds, were isolated from the roots of Anthriscus sylvestris. The structures of compounds (1-8) were determined by analysis of their 1D and 2D NMR spectra, HRESIMS, and electronic circular dichroism. In addition, the inhibitory activities against hypoxia-stimulated pulmonary arterial smooth muscle cells abnormal proliferation were evaluated by MTT assay. The mRNA expression levels of Bcl-2, BAX, Caspase3, and IL-6 were detected by quantitative real-time PCR. The results showed that compounds (-)-1, (+)-1, (-)-2, (+)-3, 4, 8-10, 14, and 15 inhibited the abnormal proliferation of PASMCs by regulating the levels of apoptosis and inflammatory factors.

Inhibition of murine colorectal cancer metastasis by targeting M2-TAM through STAT3/NF-kB/AKT signaling using macrophage 1-derived extracellular vesicles loaded with oxaliplatin, retinoic acid, and Libidibia ferrea

Colorectal cancer is still unmanageable despite advances in target therapy. However, extracellular vesicles (EVs) have shown potential in nanomedicine as drug delivery systems, especially for modulating the immune cells in the tumor microenvironment (TME). In this study, M1 Macrophage EVs (M1EVs) were used as nanocarriers of oxaliplatin (M1EV1) associated with retinoic acid (M1EV2) and Libidibia ferrea (M1EV3), alone or in combination (M1EV4) to evaluate their antiproliferative and immunomodulatory potential on CT-26 and MC-38 colorectal cancer cell lines and prevent metastasis in mice of allograft and peritoneal colorectal cancer models. Tumors were evaluated by qRT-PCR and immunohistochemistry. The cell death profile and epithelial-mesenchymal transition process (EMT) were analyzed in vitro in colorectal cancer cell lines. Polarization of murine macrophages (RAW264.7 cells) was also carried out. M1EV2 and M1EV3 used alone or particularly M1EV4 downregulated the tumor progression by TME immunomodulation, leading to a decrease in primary tumor size and metastasis in the peritoneum, liver, and lungs. STAT3, NF-kB, and AKT were the major genes downregulated by of M1EV systems. Tumor-associated macrophages (TAMs) shifted from an M2 phenotype (CD163) to an M1 phenotype (CD68) reducing levels of IL-10, TGF-β and CCL22. Furthermore, malignant cells showed overexpression of FADD, APAF-1, caspase-3, and E-cadherin, and decreased expression of MDR1, survivin, vimentin, and PD-L1 after treatment with systems of M1EVs. The study shows that EVs from M1 antitumor macrophages can transport drugs and enhance their immunomodulatory and antitumor activity by modulating pathways associated with cell proliferation, migration, survival, and drug resistance.

Inhibitory Effect of PPARδ Agonist GW501516 on Proliferation of Hypoxia-induced Pulmonary Arterial Smooth Muscle Cells by Regulating the mTOR Pathway

OBJECTIVE

This study aimed to investigate the effects of the peroxisome proliferator-activated receptor δ (PPARδ) agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells (PASMCs) induced by hypoxia, in order to search for new drugs for the treatment and prevention of pulmonary vascular remodeling.

METHODS

PASMCs were incubated with different concentrations of GW501516 (10, 30, 100 nmol/L) under the hypoxic condition. The proliferation was determined by a CCK-8 assay. The cell cycle progression was analyzed by flow cytometry. The expression of PPARδ, S phase kinase-associated protein 2 (Skp2), and cell cycle-dependent kinase inhibitor p27 was detected by Western blotting. Then PASMCs were treated with 100 nmol/ L GW501516, 100 nmol/L mammalian target of rapamycin (mTOR) inhibitor rapamycin and/or 2 µmol/L mTOR activator MHY1485 to explore the molecular mechanisms by which GW501516 reduces the proliferation of PASMCs.

RESULTS

The presented data demonstrated that hypoxia reduced the expression of PPARδ in an oxygen concentration- and time-dependent manner, and GW501516 decreased the proliferation of PASMCs induced by hypoxia by blocking the progression through the G0/G1 to S phase of the cell cycle. In accordance with these findings, GW501516 downregulated Skp2 and upregulated p27 in hypoxia-exposed PASMCs. Further experiments showed that rapamycin had similar effects as GW501516 in inhibiting cell proliferation, arresting the cell cycle, regulating the expression of Skp2 and p27, and inactivating mTOR in hypoxia-exposed PASMCs. Moreover, MHY1485 reversed all the beneficial effects of GW501516 on hypoxia-stimulated PASMCs.

CONCLUSION

GW501516 inhibited the proliferation of PASMCs induced by hypoxia through blocking the mTOR/Skp2/p27 signaling pathway.

Genome editing mRNA nanotherapies inhibit cervical cancer progression and regulate the immunosuppressive microenvironment for adoptive T-cell therapy

CRISPR/Cas9-based genome editing is promising for therapy of cervical cancer by precisely targeting human papillomavirus (HPV). To develop CRISPR/Cas9-based genome editing nanotherapies, a pH-responsive hybrid nonviral nanovector was constructed for co-delivering Cas9 mRNA and guide RNAs (gRNAs) targeting E6 or E7 oncogenes. The pH-responsive nanovector was fabricated using an acetalated cyclic oligosaccharide (ACD), in combination with low molecular weight polyethyleneimine. Thus obtained hybrid ACD nanoparticles (defined as ACD NP) showed efficient loading for both Cas9 mRNA and E6 or E7 gRNA, giving rise to two pH-responsive genome editing nanotherapies E6/ACD NP and E7/ACD NP, respectively. Cellularly, ACD NP exhibited high transfection but low cytotoxicity in HeLa cervical carcinoma cells. Also, efficient genome editing of target genes was achieved in HeLa cells, with minimal off-target effects. In mice bearing HeLa xenografts, treatment with E6/ACD NP or E7/ACD NP afforded effective editing of target oncogenes and considerable antitumor activities. More importantly, treatment with E6/ACD NP or E7/ACD NP notably promoted CD8+ T cell survival by reversing the immunosuppressive microenvironment, thereby leading to synergistic antitumor effects by combination therapy using the gene editing nanotherapies and adoptive T-cell transfer. Consequently, our pH-responsive genome editing nanotherapies deserve further development for the treatment of HPV-associated cervical cancer, and they can also serve as promising nanotherapies to improve efficacies of other immune therapies against different advanced cancers by regulating the immunosuppressive tumor microenvironment.

Self-Assembled DNA Nanostructure as a Carrier for Targeted siRNA Delivery in Glioma Cells

INTRODUCTION

RNA interference is a promising therapy in glioma treatment. However, the application of RNA interference has been limited in glioma therapy by RNA instability and the lack of tumor targeting. Here, we report a novel DNA tetrahedron, which can effectively deliver small interfering RNA to glioma cells and induce apoptosis.

METHODS

siRNA, a small interfering RNA that can suppress the expression of survivin in glioma, was loaded into the DNA tetrahedron (TDN). To enhance the ability of active targeting of this nanoparticle, we modified one side of the DNA nanostructure with aptamer as1411 (As-TDN-R), which can selectively recognize the nucleolin in the cytomembrane of tumor cells. The modified nanoparticles were characterized by agarose gel electrophoresis, dynamic light scattering, and transmission electron microscopy. The serum stability was evaluated by agarose gel electrophoresis. Nucleolin was detected by Western blot and immunofluorescence, and targeted cellular uptake was examined by flow cytometry. The TUNEL assay, flow cytometry, and Western Blot were used to detect apoptosis in U87 cells. The gene silencing of survivin was examined by qPCR, Western Blot, and immunofluorescence.

RESULTS

As-TDN-R alone showed better stability towards siRNA, indicating that TDN was a good siRNA protector. Compared with TDN alone, there was increased intercellular uptake of As-TDN-R by U87 cells, evidenced by overexpressed nucleolin in glioma cell lines. TUNEL assay, flow cytometry, and Western Blot revealed increased apoptosis in the As-TDN-R group. The downregulation of survivin protein and mRNA expression levels indicated that As-TDN-R effectively silenced the target gene.

CONCLUSION

The novel nanoparticle can serve as a good carrier for targeting siRNA delivery in glioma. Further exploration of the DNA nanostructure can greatly promote the application of DNA-based drug systems in glioma.

mTOR Signaling in Pulmonary Vascular Disease: Pathogenic Role and Therapeutic Target

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease without a cure. The exact pathogenic mechanisms of PAH are complex and poorly understood, yet a number of abnormally expressed genes and regulatory pathways contribute to sustained vasoconstriction and vascular remodeling of the distal pulmonary arteries. Mammalian target of rapamycin (mTOR) is one of the major signaling pathways implicated in regulating cell proliferation, migration, differentiation, and protein synthesis. Here we will describe the canonical mTOR pathway, structural and functional differences between mTOR complexes 1 and 2, as well as the crosstalk with other important signaling cascades in the development of PAH. The pathogenic role of mTOR in pulmonary vascular remodeling and sustained vasoconstriction due to its contribution to proliferation, migration, phenotypic transition, and gene regulation in pulmonary artery smooth muscle and endothelial cells will be discussed. Despite the progress in our elucidation of the etiology and pathogenesis of PAH over the two last decades, there is a lack of effective therapeutic agents to treat PAH patients representing a significant unmet clinical need. In this review, we will explore the possibility and therapeutic potential to use inhibitors of mTOR signaling cascade to treat PAH.

Targeted Delivery of Sildenafil for Inhibiting Pulmonary Vascular Remodeling

Pulmonary arterial hypertension is a fatal lung disease caused by the progressive remodeling of small pulmonary arteries (PAs). Sildenafil can prevent the remodeling of PAs, but conventional sildenafil formulations have shown limited treatment efficacy for their poor accumulation in PAs. Here, glucuronic acid (GlcA)-modified liposomes (GlcA-Lips) were developed to improve the delivery of sildenafil to aberrant over-proliferative PA smooth muscle cells via targeting the GLUT-1 (glucose transport-1), and, therefore, inhibiting the remodeling of PAs in a monocrotaline-induced PA hypertension model. GlcA-Lips encapsulating sildenafil (GlcA-sildenafil-Lips) had a size of 90 nm and a pH-sensitive drug release pattern. Immunostaining assay indicated the overexpression of GLUT-1 in PA smooth muscle cells. Cellular uptake studies showed a 1-fold increase of GlcA-Lips uptake by PA smooth muscle cells and pharmacokinetics and biodistribution experiments indicated longer blood circulation time of GlcA-Lips and increased ability to target PAs by 1-fold after 8 hours administration. Two-week treatment indicated GlcA-sildenafil-Lips significantly inhibited the remodeling of PAs, with a 32% reduction in the PA pressure, a 41% decrease in the medial thickening, and a 44% reduction of the right ventricle cardiomyocyte hypertrophy, and improved survival rate. Immunohistochemical analysis showed enhanced expression of caspase-3, after administration of GlcA-sildenafil-Lips, and reduced expression of P-ERK1/2 (phosphorylated ERK1/2) and HK-2 (hexokinase-2), and increased level of eNOS (endothelial nitric oxide synthase) and cyclic GMP (cGMP). In conclusion, targeted delivery of sildenafil to PA smooth muscle cells with GlcA-Lips could effectively inhibit the remodeling of PAs in the monocrotaline-induced PA hypertension.

Salidroside attenuates hypoxia-induced pulmonary arterial smooth muscle cell proliferation and apoptosis resistance by upregulating autophagy through the AMPK-mTOR-ULK1 pathway

BACKGROUND

Recent studies have shown that both adenosine monophosphate activated protein kinase (AMPK) and the mammalian target of rapamycin (mTOR) are energy sensors and are related to autophagy. Our recent reports have shown that salidroside can exert protective effects against hypoxia-induced pulmonary arterial smooth muscle cell (PASMC) proliferation and apoptosis resistance through the AMPK pathway. This study aims to explore the relationship among AMPK, mTOR and ULK1 in PASMCs under hypoxic conditions and to investigate whether the protective effects of salidroside are related to the autophagic cell death pathway.

METHODS

Rat PASMCs were cultured and divided into five groups: the normoxia, hypoxia, hypoxia + MHY1485 (mTOR agonist), hypoxia + rapamycin (mTOR inhibitor) and hypoxia + salidroside groups. Hypoxic cells were treated as indicated for 24 h. Cell viability was evaluated by the CCK-8 assay. Cell apoptosis was measured by the TUNEL assay. The autophagy flux of PASMCs was evaluated with tandem mRFP-GFP fluorescence microscopy. Autophagosomes were detected by electron microscopy. Protein expression of LC3, p62, AMPK, P-AMPK (Thr 172), P-ULK1 (Ser 555 and Ser 317), mTOR, P-mTOR (Ser 2448), ULK1 and P-ULK1 (Ser 757) was detected by western blot assay.

RESULTS

PASMC proliferation and apoptosis resistance were observed under hypoxic conditions. Autophagy flux, the number of autophagosomes and the LC3II/LC3I ratio were increased in the hypoxia group compared with the normoxia group, whereas p62 expression was decreased. Treatment with rapamycin or salidroside reversed hypoxia-induced PASMC proliferation and apoptosis resistance and further increased autophagy flux, autophagosome levels and the LC3II/LC3I ratio but decreased p62 expression. Treatment with MHY1485 reversed hypoxia-induced PASMC apoptosis resistance and decreased autophagy flux as well as increased autophagosome levels, the LC3II/LC3I ratio and p62 expression. P-AMPK (Thr 172) and P-ULK1 (Ser 555) of the AMPK-ULK1 pathway were increased in the hypoxia group and were further increased in the salidroside group. Rapamycin and MHY1485 had no effect on either P-AMPK (Thr 172) or P-ULK1 (Ser 555). Phosphorylation of ULK1 at serine 317 did not significantly affect the five groups. Furthermore, P-mTOR (Ser 2448) and P-ULK1 (Ser 757) of the AMPK-mTOR-ULK1 pathway were decreased in the hypoxia group and were further decreased in the salidroside group. MHY1485 increased the expression of both P-mTOR(Ser 2448) and P-ULK1(Ser 757), whereas rapamycin had the opposite effect.

CONCLUSIONS

Salidroside might inhibit hypoxia-induced PASMC proliferation and reverse apoptosis resistance via the upregulation of autophagy through both the AMPKα1-ULK1 and AMPKα1-mTOR-ULK1 pathways.

Non-proinflammatory and responsive nanoplatforms for targeted treatment of atherosclerosis

Atherosclerosis is the leading cause of many fatal cardiovascular and cerebrovascular diseases. Whereas nanomedicines are promising for targeted therapy of atherosclerosis, great challenges remain in development of effective, safe, and translational nanotherapies for its treatment. Herein we hypothesize that non-proinflammatory nanomaterials sensitive to low pH or high reactive oxygen species (ROS) may serve as effective platforms for triggerable delivery of anti-atherosclerotic therapeutics in cellular and tissue microenvironments of inflammation. To demonstrate this hypothesis, an acid-labile material of acetalated β-cyclodextrin (β-CD) (Ac-bCD) and a ROS-sensitive β-CD material (Ox-bCD) were separately synthesized by chemical modification of β-CD, which were formed into responsive nanoparticles (NPs). Ac-bCD NP was rapidly hydrolyzed in mildly acidic buffers, while hydrolysis of Ox-bCD NP was selectively accelerated by H₂O₂. Using an anti-atherosclerotic drug rapamycin (RAP), we found stimuli-responsive release of therapeutic molecules from Ac-bCD and Ox-bCD nanotherapies. Compared with non-responsive poly(lactide-co-glycolide) (PLGA)-based NP, Ac-bCD and Ox-bCD NPs showed negligible inflammatory responses in vitro and in vivo. By endocytosis in cells and intracellularly releasing cargo molecules in macrophages, responsive nanotherapies effectively inhibited macrophage proliferation and suppressed foam cell formation. After intraperitoneal (i.p.) delivery in apolipoprotein E-deficient (ApoE^-/-) mice, fluorescence imaging showed accumulation of NPs in atherosclerotic plaques. Flow cytometry analysis indicated that the lymphatic translocation mediated by neutrophils and monocytes/macrophages may contribute to atherosclerosis targeting of i.p. administered NPs, in addition to targeting via the leaky blood vessels. Correspondingly, i.p. treatment with different nanotherapies afforded desirable efficacies. Particularly, both pH and ROS-responsive nanomedicines more remarkably delayed progression of atherosclerosis and significantly enhanced stability of atheromatous lesions, in comparison to non-responsive PLGA nanotherapy. Furthermore, responsive nanovehicles displayed good safety performance after long-term administration in mice. Consequently, for the first time our findings demonstrated the therapeutic advantages of nanomedicines responsive to mildly acidic or abnormally high ROS microenvironments for the treatment of atherosclerosis.

RNAi therapy to the wall of arteries and veins: anatomical, physiologic, and pharmacological considerations

Background

Cardiovascular disease remains a major health care challenge. The knowledge about the underlying mechanisms of the respective vascular disease etiologies has greatly expanded over the last decades. This includes the contribution of microRNAs, endogenous non-coding RNA molecules, known to vastly influence gene expression. In addition, short interference RNA has been established as a mechanism to temporarily affect gene expression. This review discusses challenges relating to the design of a RNA interference therapy strategy for the modulation of vascular disease. Despite advances in medical and surgical therapies, atherosclerosis (ATH), aortic aneurysms (AA) are still associated with high morbidity and mortality. In addition, intimal hyperplasia (IH) remains a leading cause of late vein and prosthetic bypass graft failure. Pathomechanisms of all three entities include activation of endothelial cells (EC) and dedifferentiation of vascular smooth muscle cells (VSMC). RNA interference represents a promising technology that may be utilized to silence genes contributing to ATH, AA or IH. Successful RNAi delivery to the vessel wall faces multiple obstacles. These include the challenge of cell specific, targeted delivery of RNAi, anatomical barriers such as basal membrane, elastic laminae in arterial walls, multiple layers of VSMC, as well as adventitial tissues. Another major decision point is the route of delivery and potential methods of transfection. A plethora of transfection reagents and adjuncts have been described with varying efficacies and side effects. Timing and duration of RNAi therapy as well as target gene choice are further relevant aspects that need to be addressed in a temporo-spatial fashion.

Conclusions

While multiple preclinical studies reported encouraging results of RNAi delivery to the vascular wall, it remains to be seen if a single target can be sufficient to the achieve clinically desirable changes in the injured vascular wall in humans. It might be necessary to achieve simultaneous and/or sequential silencing of multiple, synergistically acting target genes. Some advances in cell specific RNAi delivery have been made, but a reliable vascular cell specific transfection strategy is still missing. Also, off-target effects of RNAi and unwanted effects of transfection agents on gene expression are challenges to be addressed. Close collaborative efforts between clinicians, geneticists, biologists, and chemical and medical engineers will be needed to provide tailored therapeutics for the various types of vascular diseases.

Regulation on Toll-like Receptor 4 and Cell Barrier Function by Rab26 siRNA-loaded DNA Nanovector in Pulmonary Microvascular Endothelial Cells

The small GTPase Rab26 is involved in multiple processes, such as vesicle-mediated secretion and autophagy. However, the mechanisms and functions of Rab26 in the human pulmonary microvascular endothelial cells (HPMVECs) are not clear. In this study, we thoroughly investigated the role and novel mechanism of Rab26 in permeability and apoptosis of HPMVECs using a self-assembled Rab26 siRNA loaded DNA Y-motif nanoparticle (siRab26-DYM) and Rab26 adenovirus. We found that siRab26-DYM could be efficiently transfected into HPMVECs in a time- and dose-dependent manner. Importantly, the siRab26-DYM nanovector markedly aggravated the LPS-induced apoptosis and hyper-permeability of HPMVECs by promoting the nuclear translocation of Foxo1, and subsequent activation of Toll-like receptor 4 (TLR4) signal pathway. Overexpression of Rab26 by Rab26 adenoviruses partially inactivated LPS-induced TLR4 signaling pathway, suppressed the cell apoptosis and attenuated the hyperpermeability of HPMVECs. These results suggest that the permeability and apoptosis of HPMVECs can be modulated by manipulating Rab26 derived TLR4 signaling pathway, and that Rab26 can be potential therapeutic target for the treatment of vascular diseases related to endothelial barrier functions.

Recent advances in siRNA delivery

In the 1990s an unexpected gene-silencing phenomena in plants, the later called RNA interference (RNAi), perplexed scientists. Following the proof of activity in mammalian cells, small interfering RNAs (siRNAs) have quickly crept into biomedical research as a new powerful tool for the potential treatment of different human diseases based on altered gene expression. In the past decades, several promising data from ongoing clinical trials have been reported. However, despite surprising successes in many pre-clinical studies, concrete obstacles still need to be overcome to translate therapeutic siRNAs into clinical reality. Here, we provide an update on the recent advances of RNAi-based therapeutics and highlight novel synthetic platforms for the intracellular delivery of siRNAs.

Nanomaterial-dependent immunoregulation of dendritic cells and its effects on biological activities of contraceptive nanovaccines

Nanovehicles are promising delivery systems for various vaccines. Nevertheless, different biophysicochemical properties of nanoparticles (NPs), dominating their in vitro and in vivo performances for vaccination, remain unclear. We attempted to elucidate the effects of NPs and their pH-sensitivity on in vitro and in vivo efficacy of resulting prophylactic nanovaccines containing a contraceptive peptide (FSHR). To this end, pH-responsive and non-responsive nanovaccines were produced using acetalated β-cyclodextrin (Ac-bCD) and poly(lactic-co-glycolic acid) (PLGA), respectively. Meanwhile, FSHR derived from an epitope of the follicle-stimulating hormone receptor was used as the model antigen. FSHR-containing Ac-bCD and PLGA NPs were successfully prepared by a nanoemulsion technique, leading to well-shaped nanovaccines with high loading efficiency. The pH-sensitivity of Ac-bCD and PLGA nanovaccines was examined by in vitro hydrolysis and antigen release studies. Nanovaccines could be effectively engulfed by dendritic cells (DCs) via endocytosis in both dose and time dependent manners, and their intracellular trafficking was closely related to the pH-sensitivity of the carrier materials. Furthermore, nanovaccines could induce the secretion of inflammatory cytokines by DCs and T cells co-cultured with the stimulated DCs. In vivo evaluations demonstrated that nanovaccines were more potent than that based on the complete Freund's adjuvant, with respect to inducing anti-FSHR antibody, reducing the sperm count, inhibiting the sperm motility, and increasing the teratosperm rate. Immunization of male mice with nanovaccines notably decreased the parturition incidence of the mated females. Consequently, both in vitro and in vivo activities of FSHR could be considerably augmented by NPs. More importantly, our studies indicated that the pH-responsive nanovaccine was not superior over the non-responsive counterpart for the examined peptide antigen.

Regulation of vascular smooth muscle cell autophagy by DNA nanotube-conjugated mTOR siRNA

The efficient delivery of short interfering RNA (siRNA) is an enormous challenge in the field of gene therapy. Herein, we report a delivery nanosystem based on programmed DNA self-assembly mammalian target of rapamycin (mTOR) siRNA-loaded DNA nanotubes (DNA-NTs). We demonstrate that these siRNA-DNA-NTs can be effectively transfected into pulmonary arterial smooth muscle cells (PASMCs) via endocytosis; and that the loaded mTOR siRNA can induce obvious autophagy and inhibit cell growth under both normal and hypoxic conditions. Moreover, we found that mTOR siRNA can control the autophagy and proliferation of PASMCs under hypoxic condition, suggesting a potential therapeutic application for mTOR siRNA in diseases involving abnormal autophagy in PASMCs.