siRNA takes a jab at hypertension.

Hypertension is a modifiable risk factor for cardiovascular disease, the leading cause of death worldwide, yet most US adults with hypertension do not meet goal blood pressure. KARDIA-1 demonstrates the efficacy of zilebesiran, a subcutaneously administered small interfering RNA, for lowering blood pressure, presenting a novel treatment option for this deadly disease.1.

[Study of metal organic framework with siRNA for overcoming matrix barrierin breast cancer].

Objective: This study aimed to develop a new delivery strategy that utilized metal organic framework (MOF) loaded with small-interfering RNA (siRNA) targeting ITGAV to overcome tumor matrix barrier, and thus enhance drug penetration and immune accessibility in breast cancer. Methods: MOF@siITGAV particles were constructed and characterized. The uptake of MOF@siITGAV in breast cancer cell line 4T1 was observed by the cellular uptake assay. The toxicity of MOF@siITGAV was detected by cell counting kit 8 (CCK-8). The blank control group, naked siITGAV group and MOF@siITGAV group were set. Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) and Western blot were used to detect the expressions of ITGAV. The level of transforming growth factor ß1 (TGF-ß1) in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA). The penetration of MOF@siITGAV in 4T1 cells was tested by constructing 3D spheroids. Mouse models of triple negative breast cancer were established. The effect of MOF@siITGAV on the growth of transplanted tumors and main organs was verified. Imminohistochemical (IHC) was used to test the expression of collagen and CD8. Results: MOF@siITGAV particles were constructed with sizes of (198.0±3.3) nm and zeta potential of -(20.2±0.4) mV. MOF@siITGAV could be engulfed by 4T1 cells and triggered to release siRNA. Compared to the blank control group, the expression of ITGAV in the MOF@siITGAV group [(46.5±11.3)%] and the naked siITGAV group [(109.9±19.0)%] was lower. TGF-ß1 in the cell culture medium of the blank control group, naked siITGAV group, and MOF@siITGAV group was (474.5±34.4) pg/ml, (437.2±16.5) pg/ml, and (388.4±14.4) pg/ml, respectively. MOF@siITGAV could better penetrate into 4T1 spheroids and exhibit no obvious toxicity. The cell viability was (99.7±3.5)%, (98.2±5.2)%, (97.3±6.6)%, (92.1±8.1)%, and (92.4±4.1)%, respectively, after MOF@siITGAV treatment with the concentration of 0, 10, 20, 40, 80, and 160 µg/ml, respectively, for 24 h. The tumor growth in the MOF@siITGAV group was suppressed significantly. After 15-day treatment, the tumor volume of the MOF@siITGAV group was (135.3±41.9) mm3, smaller than that of the blank control group [(691.1±193.0) mm3] (P=0.025). The expression of collagen and the number of CD8 positive cells of the MOF@siITGAV group were lower than those of the other two groups. No significant abnormalities were observed in the main organs of mice. Conclusions: Targeting the integrinαv on the surface of cancer cells could destroy extracellular matrix, improve drug delivery, and increase immune infiltration.

Effective delivery of anti-PD-L1 siRNA with human heavy chain ferritin (HFn) in acute myeloid leukemia cell lines.

Because of the high biocompatibility, self-assembly capability, and CD71-mediated endocytosis, using human heavy chain ferritin (HFn) as a nanocarrier would greatly increase therapeutic effectiveness and reduce possible adverse events. Anti-PD-L1 siRNA can downregulate the level of PD-L1 on tumor cells, resulting in the activation of effector T cells against leukemia. Therefore, this study aimed to produce the tumor-targeting siPD-L1/HFn nanocarrier. Briefly, the HFn coding sequence was cloned into a pET-28a, and the constructed expression plasmid was subsequently transformed into E. coli BL21. After induction of Isopropyl ß-D-1-thiogalactopyranoside (IPTG), HFn was purified with Ni-affinity chromatography and dialyzed against PBS. The protein characteristics were analyzed using SDS-PAGE, Western Blot, and Dynamic light scattering (DLS). The final concentration was assessed using the Bicinchoninic acid (BCA) assay. The encapsulation was performed using the standard pH system. The treatment effects of siPD-L1/HFn were carried out on HL-60 and K-562 cancer cell lines. The RT-PCR was used to determine the mRNA expression of PD-L1. The biocompatibility and excretion of siPD-L1/HFn have also been evaluated. The expression and purity of HFn were well verified through SDS-PAGE, WB, and DLS. RT-PCR analyses also showed significant siRNA-mediated PD-L1 silencing in both HL-60 and K-562 cells. Our study suggested a promising approach for siRNA delivery. This efficient delivery system can pave the way for the co-delivery of siRNAs and multiple chemotherapies to address the emerging needs of cancer combination therapy.

Poly(ß-aminoester) Physicochemical Properties Govern the Delivery of siRNA from Electrostatically Assembled Coatings.

Localized short interfering RNA (siRNA) therapy has the potential to drive high-specificity molecular-level treatment of a variety of disease states. Unfortunately, effective siRNA therapy suffers from several barriers to its intracellular delivery. Thus, drug delivery systems that package and control the release of therapeutic siRNAs are necessary to overcome these obstacles to clinical translation. Layer-by-layer (LbL) electrostatic assembly of thin film coatings containing siRNA and protonatable, hydrolyzable poly(ß-aminoester) (PBAE) polymers is one such drug delivery strategy. However, the impact of PBAE physicochemical properties on the transfection efficacy of siRNA released from LbL thin film coatings has not been systematically characterized. In this study, we investigate the siRNA transfection efficacy of four structurally similar PBAEs in vitro. We demonstrate that small changes in structure yield large changes in physicochemical properties, such as hydrophobicity, pKa, and amine chemical structure, driving differences in the interactions between PBAEs and siRNA in polyplexes and in LbL thin film coatings for wound dressings. In our polymer set, Poly3 forms the most stable interactions with siRNA (Keff,w/w = 0.298) to slow release kinetics and enhance transfection of reporter cells in both colloidal and thin film coating approaches. This is due to its unique physiochemical properties: high hydrophobicity (clog P = 7.86), effective pKa closest to endosomal pH (pKa = 6.21), and high cooperativity in buffering (nhill = 7.2). These properties bestow Poly3 with enhanced endosomal buffering and escape properties. Taken together, this work elucidates the connections between small changes in polymer structure, emergent properties, and polyelectrolyte theory to better understand PBAE transfection efficacy.

Single Ascending and Multiple-Dose Trial of Zerlasiran, a Short Interfering RNA Targeting Lipoprotein(a): A Randomized Clinical Trial.

Importance: Lipoprotein(a) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic stenosis, with no pharmacological treatments approved by regulatory authorities. Objectives: To assess the safety and tolerability of zerlasiran, a short interfering RNA targeting hepatic synthesis of apolipoprotein(a), and effects on serum concentrations of lipoprotein(a). Design, Setting, and Participants: Single- and multiple-dose study in healthy participants and patients with stable ASCVD, respectively, with lipoprotein(a) serum concentrations greater than 150 nmol/L, conducted at 7 research sites in the US, the Netherlands, UK, and Australia between November 18, 2020, and February 8, 2023, with last follow-up on August 23, 2023. Interventions: Participants were randomized to receive (1) a single subcutaneous dose of placebo (n = 8), zerlasiran 300 mg (n = 6) or 600 mg (n = 6); or (2) 2 doses of placebo (n = 9), zerlasiran 200 mg (n = 9) at a 4-week interval or 300 mg (n = 9) or 450 mg (n = 9) at an 8-week interval. Main Outcomes Measures: The primary outcome was safety and tolerability. Secondary outcomes included serum levels of zerlasiran and effects on lipoprotein(a) serum concentrations. Results: Among 37 patients in the multiple-dose group (mean age, 56 [SD, 10.4] years; 15 [42%] women), 36 completed the trial. Among 14 participants with extended follow-up after single doses, 13 completed the trial. There were no serious adverse events. Median baseline lipoprotein(a) concentrations in the multiple-dose group were 288 (IQR, 199-352) nmol/L. Median changes in lipoprotein(a) concentration at 365 days after single doses were 14% (IQR, 13% to 15%) for the placebo group, -30% (IQR, -51% to -18%) for the 300 mg of zerlasiran group, and -29% (IQR, -39% to -7%) for the 600-mg dose group. After 2 doses, maximal median changes in lipoprotein(a) concentration were 19 (IQR, -17 to 28) nmol/L for the placebo group, -258 (IQR, -289 to -188) nmol/L for the 200 mg of zerlasiran group, -310 (IQR, -368 to -274) nmol/L for the 300-mg dose group, and -242 (IQR, -343 to -182) nmol/L for the 450-mg dose group, with maximal median percent change of 7% (IQR, -4% to 21%), -97% (IQR, -98% to -95%), -98% (IQR, -99% to -97%), and -99% (IQR, -99% to -98%), respectively, attenuating to 0.3% (IQR, -2% to 21%), -60% (IQR, -71% to -40%), -90% (IQR, -91% to -74%), and -89% (IQR, -91% to -76%) 201 days after administration. Conclusions: Zerlasiran was well tolerated and reduced lipoprotein(a) concentrations with infrequent administration. Trial Registration: ClinicalTrials.gov Identifier: NCT04606602.

Ordered Mesoporous Silica Delivering siRNA as Cancer Nanotherapeutics: A Comprehensive Review.

Nanosized mesoporous silica has emerged as a promising flexible platform delivering siRNA for cancer treatment. This ordered mesoporous nanosized silica provides attractive features of well-defined and tunable porosity, structure, high payload, and multiple functionalizations for targeted delivery and increasing biocompatibility over other polymeric nanocarriers. Moreover, it also overcomes the lacunae associated with traditional administration of drugs. Chemically modified porous silica matrix efficiently entraps siRNA molecules and prevents their enzymatic degradation and premature release. This Review discusses the synthesis of silica using the sol-gel approach and the advantages with different silica mesostructure. Herein, the factors affecting the synthesis of silica at nanometer scale, shape, porosity and nanoparticle surface modification are also highlighted to attain the desired nanostructured silica carriers. Additional emphasis is given to chemically modified silica delivering siRNA, where the silica nanoparticle surface was modified with different chemical moieties such as amine modified with (3-aminoropyl) triethoxysilane, polyethylenimine, chitosan, poly(ethylene glycol), and cyclodextrin polymer modification to attain high therapeutic loading, improved dispersibility and biocompatibility. Upon systemic administration, ordered mesoporous nanosized silica encounters blood cells, immune cells, and organs mainly of the reticuloendothelial system (RES). Thereby, biocompatibility and biodistribution of silica based nanocarriers are deliberated to design principles for smart and efficacious nanostructured silica-siRNA carriers and their clinical trial status. This Review further reports the future scopes and challenges for developing silica nanomaterial as a promising siRNA delivery vehicle demanding FDA approval.

Lipid nanoparticle encapsulated large peritoneal macrophages migrate to the lungs via the systemic circulation in a model of clodronate-mediated lung-resident macrophage depletion.

Rationale: A mature tissue resident macrophage (TRM) population residing in the peritoneal cavity has been known for its unique ability to migrate to peritoneally located injured tissues and impart wound healing properties. Here, we sought to expand on this unique ability of large peritoneal macrophages (LPMs) by investigating whether these GATA6+ LPMs could also intravasate into systemic circulation and migrate to extra-peritoneally located lungs upon ablating lung-resident alveolar macrophages (AMs) by intranasally administered clodronate liposomes in mice. Methods: C12-200 cationic lipidoid-based nanoparticles were employed to selectively deliver a small interfering RNA (siRNA)-targeting CD-45 labeled with a cyanine 5.5 (Cy5.5) dye to LPMs in vivo via intraperitoneal injection. We utilized a non-invasive optical technique called Diffuse In Vivo Flow Cytometry (DiFC) to then systemically track these LPMs in real time and paired it with more conventional techniques like flow cytometry and immunocytochemistry to initially confirm uptake of C12-200 encapsulated siRNA-Cy5.5 (siRNA-Cy5.5 (C12-200)) into LPMs, and further track them from the peritoneal cavity to the lungs in a mouse model of AM depletion incited by intranasally administered clodronate liposomes. Also, we stained for LPM-specific marker zinc-finger transcription factor GATA6 in harvested cells from biofluids like broncho-alveolar lavage as well as whole blood to probe for Cy5.5-labeled LPMs in the lungs as well as in systemic circulation. Results: siRNA-Cy5.5 (C12-200) was robustly taken up by LPMs. Upon depletion of lung-resident AMs, these siRNA-Cy5.5 (C12-200) labeled LPMs rapidly migrated to the lungs via systemic circulation within 12-24 h. DiFC results showed that these LPMs intravasated from the peritoneal cavity and utilized a systemic route of migration. Moreover, immunocytochemical staining of zinc-finger transcription factor GATA6 further confirmed results from DiFC and flow cytometry, confirming the presence of siRNA-Cy5.5 (C12-200)-labeled LPMs in the peritoneum, whole blood and BALF only upon clodronate-administration. Conclusion: Our results indicate for the very first time that selective tropism, migration, and infiltration of LPMs into extra-peritoneally located lungs was dependent on clodronate-mediated AM depletion. These results further open the possibility of therapeutically utilizing LPMs as delivery vehicles to carry nanoparticle-encapsulated oligonucleotide modalities to potentially address inflammatory diseases, infectious diseases and even cancer.

RNAi-based drug design: considerations and future directions.

More than 25 years after its discovery, the post-transcriptional gene regulation mechanism termed RNAi is now transforming pharmaceutical development, proved by the recent FDA approval of multiple small interfering RNA (siRNA) drugs that target the liver. Synthetic siRNAs that trigger RNAi have the potential to specifically silence virtually any therapeutic target with unprecedented potency and durability. Bringing this innovative class of medicines to patients, however, has been riddled with substantial challenges, with delivery issues at the forefront. Several classes of siRNA drug are under clinical evaluation, but their utility in treating extrahepatic diseases remains limited, demanding continued innovation. In this Review, we discuss principal considerations and future directions in the design of therapeutic siRNAs, with a particular emphasis on chemistry, the application of informatics, delivery strategies and the importance of careful target selection, which together influence therapeutic success.

Recent Progress of Small Interfering RNA Delivery on the Market and Clinical Stage.

Small interfering RNAs (siRNAs) are promising therapeutic strategies, and five siRNA drugs have been approved by the Food and Drug Administration (FDA) and the European Commission (EC). This marks a significant milestone in the development of siRNA for clinical applications. The approved siRNA agents can effectively deliver siRNAs to the liver and treat liver-related diseases. Currently, researchers have developed diverse delivery platforms for transporting siRNAs to different tissues such as the brain, lung, muscle, and others, and a large number of siRNA drugs are undergoing clinical trials. Here, these delivery technologies and the latest advancements in clinical applications are summarized, and this Review provides a concise overview of the strategies employed for siRNA delivery to both hepatic and extrahepatic tissues.

SiRNA-HIF-1α delivered by attenuated Salmonella enhances the efficacy of Lenvatinib against hepatocellular carcinoma.

The treatment of hepatocellular carcinoma (HCC) remains a major challenge in the medical field. Lenvatinib, a multi-target tyrosine kinase inhibitor, has demonstrated anti-HCC effects by targeting and inhibiting pathways such as vascular endothelial growth factor receptor 1-3 (VEGFR1-3). However, the therapeutic efficacy of Lenvatinib is subject to various influences, with the hypoxic microenvironment of the tumor being a pivotal factor. Consequently, altering the hypoxic milieu of the tumor emerges as a viable strategy to augment the efficacy of Lenvatinib. Hypoxia-inducible factor-1α (HIF-1α), synthesized by tumor cells in response to oxygen-deprived conditions, regulates the expression of resistance genes, promotes tumor angiogenesis and cell proliferation, enhances tumor cell invasion, and confers resistance to radiotherapy and chemotherapy. Thus, we constructed a self-designed siRNA targeting HIF-1α to suppress its expression and improve the efficacy of Lenvatinib in treating HCC. The therapeutic efficacy of siRNA-HIF-1α in combination with Lenvatinib on HCC were evaluated through in vivo and in vitro experiments. The results showed that the recombinant Salmonella delivering siRNA-HIF-1α in combination with Lenvatinib effectively inhibited tumor growth and prolonged the survival of tumor-bearing mice. This treatment approach reduced cell proliferation and angiogenesis in HCC tissues while promoting tumor cell apoptosis. Additionally, this combined therapy significantly increased the infiltration of T lymphocytes and M1 macrophages within the tumor microenvironment, as well as elevated the proportion of immune cells in the spleen, thereby potentiating the host's immune response against the tumor.

An anti-GD2 aptamer-based bifunctional spherical nucleic acid nanoplatform for synergistic therapy targeting MDM2 for retinoblastoma.

Retinoblastoma (RB) is a type of pediatric solid tumor in the fundus. The lack of precision therapies combined with the difficulty of delivering small interfering RNA (siRNA) into the eyes means that there is currently no nucleic acid-based therapy for RB in clinical practice. Here, we reported on anti-GD2 and glutathione-responsive spherical nucleic acids (SNAs), loaded with siRNA and the inhibitor NVP-CGM097, which jointly blocked the oncogenic factor n in RB cells (Y79 and WERI-RB-1). The SNAs were formed through the self-assembly of bifunctional cholesterol amphiphiles containing aptamers that specifically targeted GD2-positive RB cells, allowing for the formation of an SNA with a dense DNA shell. The aptamer/siRNA component functioned both as a carrier and a payload, enhancing the specific recognition and delivery of both components and constituting an active agent for MDM2 regulation. Following SNA endocytosis by RB cells, siRNA and NVP-CGM097 were released from the SNA particles by glutathione, which synergistically blocked the MDM2-p53 pathway, increasing p53 protein content and inducing cell apoptosis. This study showed a potent antitumor effect following intravitreal injection of SNAs in Y79 tumor-bearing mice through clinical manifestation and tumor pathological analysis. In hematological analysis and hepatotoxicity assays, SNAs were safer for mice than melphalan, the favored drug for treating RB in clinical practice. Our results illustrated the potential of intravitreally injected SNAs as a precision medicine for treating RB.

Construction of aptamer-siRNA chimera and glutamine modified carboxymethyl-ß-cyclodextrin nanoparticles for the combination therapy against lung squamous cell carcinoma.

Combination therapy has become the most important treatment for advanced non-small cell lung cancer (NSCLC), which can significantly improve the prognosis of patients. However, poor targeting and adverse reactions limited its clinical application. Here, we constructed an AS1411 aptamer-programmed cell death ligand-1 (PD-L1) siRNA chimera/polyethylenimine/glutamine/ß-cyclodextrin/doxorubicin (Chimera/ PEI/Gln/ß-CD/DOX) nanoparticle for the combination therapy (chemotherapy combined with immunotherapy). Scanning electron microscopy showed that PEI/Gln/ß-CD/DOX nanoparticle was conical, with a diameter of about 250-500 nm. AS1411 aptamer-PD-L1 siRNA chimera can effectively bind NSCLC cells and inhibit PD-L1 expression, further activating T cells and CD8+T cells. Glutamine modification effectively promoted the doxorubicin uptake by cancer cells and induced their apoptosis. Animal experiments showed that our nanoparticles effectively treated the transplanted tumor, and the adverse reactions were reduced. Compared with the Aptamer/ß-CD/DOX group, the volume and ki-67 index of transplanted tumors in the Chimera/ß-CD/DOX group were significantly decreased, while the apoptosis ratio was increased. Immunohistochemical results showed that Compared with the Aptamer/ß-CD/DOX group, the number of T cells and CD8+T cells in the Chimera/ß-CD/DOX group was increased by 1.34 and 1.41 times. Glutamine modification enhanced the chemotherapeutic efficacy and anti-tumor immune response in vivo. Our study provided a new method for the combination therapy of lung squamous cell carcinoma.

Lepodisiran, an Extended-Duration Short Interfering RNA Targeting Lipoprotein(a): A Randomized Dose-Ascending Clinical Trial.

Importance: Epidemiological and genetic data have implicated lipoprotein(a) as a potentially modifiable risk factor for atherosclerotic disease and aortic stenosis, but there are no approved pharmacological treatments. Objectives: To assess the safety, tolerability, pharmacokinetics, and effects of lepodisiran on lipoprotein(a) concentrations after single doses of the drug; lepodisiran is a short interfering RNA directed at hepatic synthesis of apolipoprotein(a), an essential component necessary for assembly of lipoprotein(a) particles. Design, Setting, and Participants: A single ascending-dose trial conducted at 5 clinical research sites in the US and Singapore that enrolled 48 adults without cardiovascular disease and with lipoprotein(a) serum concentrations of 75 nmol/L or greater (or ≥30 mg/dL) between November 18, 2020, and December 7, 2021; the last follow-up visit occurred on November 9, 2022. Interventions: Participants were randomized to receive placebo or a single dose of lepodisiran (4 mg, 12 mg, 32 mg, 96 mg, 304 mg, or 608 mg) administered subcutaneously. Main Outcomes and Measures: The primary outcome was the safety and tolerability of the single ascending doses of lepodisiran. The secondary outcomes included plasma levels of lepodisiran for 168 days after dose administration and changes in fasting lipoprotein(a) serum concentrations through a maximum follow-up of 336 days (48 weeks). Results: Of the 48 participants enrolled (mean age, 46.8 [SD, 11.6] years; 35% were women), 1 serious adverse event occurred. The plasma concentrations of lepodisiran reached peak levels within 10.5 hours and were undetectable by 48 hours. The median baseline lipoprotein(a) concentration was 111 nmol/L (IQR, 78 to 134 nmol/L) in the placebo group, 78 nmol/L (IQR, 50 to 152 nmol/L) in the 4 mg of lepodisiran group, 97 nmol/L (IQR, 86 to 107 nmol/L) in the 12-mg dose group, 120 nmol/L (IQR, 110 to 188 nmol/L) in the 32-mg dose group, 167 nmol/L (IQR, 124 to 189 nmol/L) in the 96-mg dose group, 96 nmol/L (IQR, 72 to 132 nmol/L) in the 304-mg dose group, and 130 nmol/L (IQR, 87 to 151 nmol/L) in the 608-mg dose group. The maximal median change in lipoprotein(a) concentration was -5% (IQR, -16% to 11%) in the placebo group, -41% (IQR, -47% to -20%) in the 4 mg of lepodisiran group, -59% (IQR, -66% to -53%) in the 12-mg dose group, -76% (IQR, -76% to -75%) in the 32-mg dose group, -90% (IQR, -94% to -85%) in the 96-mg dose group, -96% (IQR, -98% to -95%) in the 304-mg dose group, and -97% (IQR, -98% to -96%) in the 608-mg dose group. At day 337, the median change in lipoprotein(a) concentration was -94% (IQR, -94% to -85%) in the 608 mg of lepodisiran group. Conclusions and Relevance: In this phase 1 study of 48 participants with elevated lipoprotein(a) levels, lepodisiran was well tolerated and produced dose-dependent, long-duration reductions in serum lipoprotein(a) concentrations. The findings support further study of lepodisiran. Trial Registration: ClinicalTrials.gov Identifier: NCT04914546.

Small Interfering RNA to Reduce Lipoprotein(a) in Cardiovascular Disease.

BACKGROUND: Lipoprotein(a) is a presumed risk factor for atherosclerotic cardiovascular disease. Olpasiran is a small interfering RNA that reduces lipoprotein(a) synthesis in the liver. METHODS: We conducted a randomized, double-blind, placebo-controlled, dose-finding trial involving patients with established atherosclerotic cardiovascular disease and a lipoprotein(a) concentration of more than 150 nmol per liter. Patients were randomly assigned to receive one of four doses of olpasiran (10 mg every 12 weeks, 75 mg every 12 weeks, 225 mg every 12 weeks, or 225 mg every 24 weeks) or matching placebo, administered subcutaneously. The primary end point was the percent change in the lipoprotein(a) concentration from baseline to week 36 (reported as the placebo-adjusted mean percent change). Safety was also assessed. RESULTS: Among the 281 enrolled patients, the median concentration of lipoprotein(a) at baseline was 260.3 nmol per liter, and the median concentration of low-density lipoprotein cholesterol was 67.5 mg per deciliter. At baseline, 88% of the patients were taking statin therapy, 52% were taking ezetimibe, and 23% were taking a proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor. At 36 weeks, the lipoprotein(a) concentration had increased by a mean of 3.6% in the placebo group, whereas olpasiran therapy had significantly and substantially reduced the lipoprotein(a) concentration in a dose-dependent manner, resulting in placebo-adjusted mean percent changes of -70.5% with the 10-mg dose, -97.4% with the 75-mg dose, -101.1% with the 225-mg dose administered every 12 weeks, and -100.5% with the 225-mg dose administered every 24 weeks (P<0.001 for all comparisons with baseline). The overall incidence of adverse events was similar across the trial groups. The most common olpasiran-related adverse events were injection-site reactions, primarily pain. CONCLUSIONS: Olpasiran therapy significantly reduced lipoprotein(a) concentrations in patients with established atherosclerotic cardiovascular disease. Longer and larger trials will be necessary to determine the effect of olpasiran therapy on cardiovascular disease. (Funded by Amgen; OCEAN[a]-DOSE ClinicalTrials.gov number, NCT04270760.).

IGT mediated Nanog siRNA delivery in prostate cancer cells improves chemosensitization of Epirubicin in vitro.

Despite the enormous potential of siRNAs to transcriptionally downregulate disease causing proteins in many genetic diseases, efficient delivery and endosomal escape are the two bottlenecks that have resulted in only a handful of FDA approved drugs. In this report, we have successfully delivered siRNA against Nanog with the help of pentafluorobenzyl modified Internal Oligo-guanidinium transporter (IGT) that has previously shown promising results in peptide and antisense morpholino delivery. Nanog downregulation in prostate cancer cell line DU145 in serum containing media led to suppression of associated proteins such as KLF4, FAK and cMyc and also enhanced the chemosensitivity of Epirubicin, an anthracycline based drug, in DU145 cells by associated MDR-1 downregulation in vitro. These results show that IGT is a promising candidate for siRNA delivery and its conjugation with stable siRNAs could enhance the chemotherapeutic efficiency of siRNAs alone and in combination with small molecule-based drugs.

A single-administration therapeutic interfering particle reduces SARS-CoV-2 viral shedding and pathogenesis in hamsters.

The high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a primary driver of the COVID-19 pandemic. While existing interventions prevent severe disease, they exhibit mixed efficacy in preventing transmission, presumably due to their limited antiviral effects in the respiratory mucosa, whereas interventions targeting the sites of viral replication might more effectively limit respiratory virus transmission. Recently, intranasally administered RNA-based therapeutic interfering particles (TIPs) were reported to suppress SARS-CoV-2 replication, exhibit a high barrier to resistance, and prevent serious disease in hamsters. Since TIPs intrinsically target the tissues with the highest viral replication burden (i.e., respiratory tissues for SARS-CoV-2), we tested the potential of TIP intervention to reduce SARS-CoV-2 shedding. Here, we report that a single, postexposure TIP dose lowers SARS-CoV-2 nasal shedding, and at 5 days postinfection, infectious virus shed is below detection limits in 4 out of 5 infected animals. Furthermore, TIPs reduce shedding of Delta variant or WA-1 from infected to uninfected hamsters. Cohoused "contact" animals exposed to infected, TIP-treated animals exhibited significantly lower viral loads, reduced inflammatory cytokines, no severe lung pathology, and shortened shedding duration compared to animals cohoused with untreated infected animals. TIPs may represent an effective countermeasure to limit SARS-CoV-2 transmission.

Blockade of Mbd2 by siRNA-loaded liposomes protects mice against OVA-induced allergic airway inflammation via repressing M2 macrophage production.

Objective: To address the role of methyl-CpG-binding domain 2 (MBD2) in the pathogenesis of asthma and its potential as a target for the asthmatic therapy. Methods: Studies were conducted in asthmatic patients and macrophage-specific Mbd2 knockout mice to dissect the role of MBD2 in asthma pathogenesis. Additionally, RNAi-based therapy with Mbd2 siRNA-loaded liposomes was conducted in an ovalbumin (OVA)-induced allergic airway inflammation mouse model. Results: Asthmatic patients and mice challenged with OVA exhibited upregulated MBD2 expression in macrophages, especially in alternatively activated (M2) macrophages. In particular, macrophage-specific knockout of Mbd2 protected mice from OVA-induced allergic airway inflammation and suppressed the M2 program. Notably, intratracheal administration of liposomes carrying Mbd2 siRNA decreased the expression of Mbd2 and prevented OVA-induced allergic airway inflammation in mice, as indicated by the attenuated airway inflammation and mucus production. Conclusions: The above data indicate that Mbd2 implicates in the pathogenesis of asthma predominantly by regulating the polarization of M2 macrophages, which supports that Mbd2 could be a viable target for treatment of asthma in clinical settings.

Development of siRNA Delivery System by Lipid Nanoparticles Modified with Functional Materials for Cancer Treatment.

Nucleic acid drugs can control gene expression and function in a manner different from that of conventional compounds. On the other hand, nucleic acids can be easily degraded in the in vivo circumstances. In addition, nucleic acids cannot penetrate cell membranes. Therefore, a drug delivery system (DDS) is essential to protect nucleic acid molecules until they reach the target cell and to release them efficiently inside the cell. In order to apply nucleic acid drugs to new cancer therapeutic strategies, the author has been developing a DDS that enables functional control of vascular endothelial cells that consist of the tumor microenvironment. The aim of my study is to develop lipid nanoparticles (LNPs) were modified with functional molecules that control their pharmacokinetics in vivo and intracellular fate to delivered small interfering RNA (siRNA) to tumor vasculature. By imparting pH-responsive membrane fusion properties to lipid nanoparticles, I have developed a system that responds to acidification in endosomes within cells and subsequently efficiently releases siRNA into the cytoplasm via membrane fusion, where siRNA molecules exhibit their function. In addition, by developing a method for presenting functional molecules, such as peptides, saccharides and so on, that recognize target cells on the surface of LNPs, I succeeded in establishing LNPs which internalize more efficiently into specific cells than off-target cells. Finally, by integrating these technologies, I developed an in vivo siRNA DDS that enables in vivo control of genes of interest in tumor vascular endothelial cells and succeeded in cancer therapy by regulating vascular function.

p63 silencing induces epigenetic modulation to enhance human cardiac fibroblast to cardiomyocyte-like differentiation.

Direct cell reprogramming represents a promising new myocardial regeneration strategy involving in situ transdifferentiation of cardiac fibroblasts into induced cardiomyocytes. Adult human cells are relatively resistant to reprogramming, however, likely because of epigenetic restraints on reprogramming gene activation. We hypothesized that modulation of the epigenetic regulator gene p63 could improve the efficiency of human cell cardio-differentiation. qRT-PCR analysis demonstrated significantly increased expression of a panel of cardiomyocyte marker genes in neonatal rat and adult rat and human cardiac fibroblasts treated with p63 shRNA (shp63) and the cardio-differentiation factors Hand2/Myocardin (H/M) versus treatment with Gata4, Mef2c and Tbx5 (GMT) with or without shp63 (p < 0.001). FACS analysis demonstrated that shp63+ H/M treatment of human cardiac fibroblasts significantly increased the percentage of cells expressing the cardiomyocyte marker cTnT compared to GMT treatment with or without shp63 (14.8% ± 1.4% versus 4.3% ± 1.1% and 3.1% ± 0.98%, respectively; p < 0.001). We further demonstrated that overexpression of the p63-transactivation inhibitory domain (TID) interferes with the physical interaction of p63 with the epigenetic regulator HDAC1 and that human cardiac fibroblasts treated with p63-TID+ H/M demonstrate increased cardiomyocyte marker gene expression compared to cells treated with shp63+ H/M (p < 0.05). Whereas human cardiac fibroblasts treated with GMT alone failed to contract in co-culture experiments, human cardiac fibroblasts treated with shp63+ HM or p63-TID+ H/M demonstrated calcium transients upon electrical stimulation and contractility synchronous with surrounding neonatal cardiomyocytes. These findings demonstrate that p63 silencing provides enhanced rat and human cardiac fibroblast transdifferentiation into induced cardiomyocytes compared to a standard reprogramming strategy. p63-TID overexpression may be a useful reprogramming strategy for overcoming epigenetic barriers to human fibroblast cardio-differentiation.

Single Ascending Dose Study of a Short Interfering RNA Targeting Lipoprotein(a) Production in Individuals With Elevated Plasma Lipoprotein(a) Levels.

Importance: Lipoprotein(a) (Lp[a]) is an important risk factor for atherothrombotic cardiovascular disease and aortic stenosis, for which there are no treatments approved by regulatory authorities. Objectives: To assess adverse events and tolerability of a short interfering RNA (siRNA) designed to reduce hepatic production of apolipoprotein(a) and to assess associated changes in plasma concentrations of Lp(a) at different doses. Design, Setting, and Participants: A single ascending dose study of SLN360, an siRNA targeting apolipoprotein(a) synthesis conducted at 5 clinical research unit sites located in the US, United Kingdom, and Australia. The study enrolled adults with Lp(a) plasma concentrations of 150 nmol/L or greater at screening and no known clinically overt cardiovascular disease. Participants were enrolled between November 18, 2020, and July 21, 2021, with last follow-up on December 29, 2021. Interventions: Participants were randomized to receive placebo (n = 8) or single doses of SLN360 at 30 mg (n = 6), 100 mg (n = 6), 300 mg (n = 6), or 600 mg (n = 6), administered subcutaneously. Main Outcomes and Measures: The primary outcome was evaluation of safety and tolerability. Secondary outcomes included change in plasma concentrations of Lp(a) to a maximum follow-up of 150 days. Results: Among 32 participants who were randomized and received the study intervention (mean age, 50 [SD, 13.5] years; 17 women [53%]), 32 (100%) completed the trial. One participant experienced 2 serious adverse event episodes: admission to the hospital for headache following SARS-CoV-2 vaccination and later for complications of cholecystitis, both of which were judged to be unrelated to study drug. Median baseline Lp(a) concentrations were as follows: placebo, 238 (IQR, 203-308) nmol/L; 30-mg SLN360, 171 (IQR, 142-219) nmol/L; 100-mg SLN360, 217 (IQR, 202-274) nmol/L; 300-mg SLN360, 285 (IQR, 195-338) nmol/L; and 600-mg SLN360, 231 (IQR, 179-276) nmol/L. Maximal median changes in Lp(a) were -20 (IQR, -61 to 3) nmol/L, -89 (IQR, -119 to -61) nmol/L, -185 (IQR, -226 to -163) nmol/L, -268 (IQR, -292 to -189) nmol/L, and -227 (IQR, -270 to -174) nmol/L, with maximal median percentage changes of -10% (IQR, -16% to 1%), -46% (IQR, -64% to -40%), -86% (IQR, -92% to -82%), -96% (IQR, -98% to -89%), and -98% (IQR, -98% to -97%), for the placebo group and the 30-mg, 100-mg, 300-mg, and 600-mg SLN360 groups, respectively. The duration of Lp(a) lowering was dose dependent, persisting for at least 150 days after administration. Conclusions and Relevance: In this phase 1 study of 32 participants with elevated Lp(a) levels and no known cardiovascular disease, the siRNA SLN360 was well tolerated, and a dose-dependent lowering of plasma Lp(a) concentrations was observed. The findings support further study to determine the safety and efficacy of this siRNA. Trial Registration: ClinicalTrials.gov Identifier: NCT04606602; EudraCT Identifier: 2020-002471-35.