Angiotensin II-induced infiltration of monocytes in the heart is largely mediated by CXCL1-CXCR2 signalling which initiates and aggravates cardiac remodelling. Inhibition of CXCL1 and/or CXCR2 may represent new therapeutic targets for treating hypertensive heart diseases.

Angiotensin II (Ang II) and inflammation are associated with pathogenesis of atrial fibrillation (AF), but the underlying molecular mechanisms of these events remain unknown. The immunoproteasome has emerged as a critical regulator of inflammatory responses. Here, we investigated its role in Ang II-induced AF in immunosubunit PSMB10 (also known as β2i or LMP10) knockout (KO) mice. AF was induced by Ang II infusion (2000 ng/min per kg). PSMB10 expression and trypsin-like activity were increased in atrial tissues and serum from Ang II-treated mice or serum from patients with AF. Moreover, Ang II-infused wild-type (WT) mice had a higher AF and increased atrial fibrosis, reactive oxygen species production, and inflammation compared with saline-treated WT animals. These effects were attenuated in PSMB10 KO mice but were aggravated in recombinant adeno-associated virus serotype 9-PSMB10-treated mice. Administration of IKKβ-specific inhibitor IMD 0354 reduced Ang II-induced AF, reactive oxygen species production, inflammation, and NF-kB (nuclear factor-kB) activation. Mechanistically, Ang II infusion upregulated PSMB10 expression to promote PTEN (phosphatase and tensin homolog deleted on chromosome ten) degradation and AKT1 activation, which not only activated TGF-β-Smad2/3 signaling leading to cardiac fibrosis but also induced IKKβ activation and ubiquitin-mediated degradation of IkBα ultimately resulting in activation of NF-kB target genes (IL [interleukin]-1β, IL-6, NOX [NADPH oxidase] 2, NOX4, and CX43 [connexin 43]). Overall, our study identifies immunosubunit PSMB10 as a novel regulator that contributes to Ang II-induced AF and suggests that inhibition of PSMB10 may represent a potential therapeutic target for treating hypertensive AF.

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A sound theoretical rationale for the design of a magnetic nanocarrier capable of magnetic capture in vivo after intravenous administration could help elucidate the parameters necessary for in vivo magnetic tumor targeting. In this work, we utilized our long-circulating polymeric magnetic nanocarriers, encapsulating increasing amounts of superparamagnetic iron oxide nanoparticles (SPIONs) in a biocompatible oil carrier, to study the effects of SPION loading and of applied magnetic field strength on magnetic tumor targeting in CT26 tumor-bearing mice. Under controlled conditions, the in vivo magnetic targeting was quantified and found to be directly proportional to SPION loading and magnetic field strength. Highest SPION loading, however, resulted in a reduced blood circulation time and a plateauing of the magnetic targeting. Mathematical modeling was undertaken to compute the in vivo magnetic, viscoelastic, convective, and diffusive forces acting on the nanocapsules (NCs) in accordance with the Nacev-Shapiro construct, and this was then used to extrapolate to the expected behavior in humans. The model predicted that in the latter case, the NCs and magnetic forces applied here would have been sufficient to achieve successful targeting in humans. Lastly, an in vivo murine tumor growth delay study was performed using docetaxel (DTX)-encapsulated NCs. Magnetic targeting was found to offer enhanced therapeutic efficacy and improve mice survival compared to passive targeting at drug doses of ca. 5-8 mg of DTX/kg. This is, to our knowledge, the first study that truly bridges the gap between preclinical experiments and clinical translation in the field of magnetic drug targeting.

Clinical applications of curcumin for the treatment of cancer and other chronic diseases have been mainly hindered by its short biological half-life and poor water solubility. Nanotechnology-based drug delivery systems have the potential to enhance the efficacy of poorly soluble drugs for systemic delivery. This study proposes the use of poly(lactic-co-glycolic acid) (PLGA)-based polymeric oil-cored nanocapsules (NCs) for curcumin loading and delivery to colon cancer in mice after systemic injection. Formulations of different oil compositions are prepared and characterized for their curcumin loading, physico-chemical properties, and shelf-life stability. The results indicate that castor oil-cored PLGA-based NC achieves high drug loading efficiency (≈18% w(drug)/w(polymer)%) compared to previously reported NCs. Curcumin-loaded NCs internalize more efficiently in CT26 cells than the free drug, and exert therapeutic activity in vitro, leading to apoptosis and blocking the cell cycle. In addition, the formulated NC exhibits an extended blood circulation profile compared to the non-PEGylated NC, and accumulates in the subcutaneous CT26-tumors in mice, after systemic administration. The results are confirmed by optical and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. In vivo growth delay studies are performed, and significantly smaller tumor volumes are achieved compared to empty NC injected animals. This study shows the great potential of the formulated NC for treating colon cancer.

Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8–19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI2 microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression analysis, were evaluated in hippocampal pyramidal neurons excised by laser capture microdissection. Following maternal cocaine exposure, global DNA methylation was significantly decreased at P3 and increased at P30. Among the 492 CGIs whose methylation was significantly altered by cocaine at P3, 34% were hypermethylated while 66% were hypomethylated. Several of these CGIs contained promoter regions for genes implicated in crucial cellular functions. Endogenous expression of selected genes linked to the abnormally methylated CGIs was correspondingly decreased or increased by as much as 4–19-fold. By P30, some of the cocaine-associated effects at P3 endured, reversed to opposite directions, or disappeared. Further, additional sets of abnormally methylated targets emerged at P30 that were not observed at P3. Taken together, these observations indicate that maternal cocaine exposure during the second and third trimesters of gestation could produce potentially profound structural and functional modifications in the epigenomic programs of neonatal and prepubertal mice.

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and increases the risk of stroke, heart failure, and death. Ang II (angiotensin II) triggers AF, mainly through stimulation of the AT1R (Ang II type I receptor). The immunoproteasome is a highly efficient proteolytic machine derived from the constitutive proteasome, but the role it plays in regulating AT1R activation and triggering AF remains unknown. Here, we show that among the catalytic subunits, β5i (PSMB8) expression, and chymotrypsin-like activity were the most significantly upregulated in atrial tissue of Ang II–infused mice or serum from patients with AF. β5i KO (β5i knockout) in mice markedly attenuated Ang II-induced AF incidence, atrial fibrosis, inflammatory response, and oxidative stress compared with WT (wild type) animals, but injection with recombinant adeno-associated virus serotype 9–β5i increased these effects. Moreover, we found that ATRAP (AT1R-associated protein) was a target of β5i. Overexpression of ATRAP significantly attenuated Ang II-induced atrial remodeling and AF in recombinant adeno-associated virus serotype 9–β5i-injected mice. Mechanistically, Ang II upregulated β5i expression to promote ATRAP degradation, which resulted in activation of AT1R-mediated NF-κB signaling, increased NADPH oxidase activity, increased TGF (transforming growth factor)-β1/Smad signaling, and altered the expression of Kir2.1 and CX43 (connexin 43) in the atria, thereby affecting atrial remodeling and AF. In summary, this study identifies β5i as a negative regulator of ATRAP stability that contributes to AT1R activation and to AF, highlighting that targeting β5i activity may represent a potential therapeutic approach for the treatment of hypertensive AF.

Arsenic exposure causes nonalcoholic steatohepatitis (NASH). Inflammation is a key contributor to the pathology of nonalcoholic fatty liver disease (NAFLD), including NASH. However, it is unclear how arsenic induces inflammation. In mouse livers, we show that arsenic trioxide (As2O3) induced NASH, increased autophagy and NLRP3 inflammasome activation, increased lipid accumulation, and resulted in dysregulation of lipid-related genes. Supplemented with taurine (Tau) attenuated the inflammation and autophagy caused by As2O3. In HepG2 cells, we found that As2O3-induced pyroptotic cell death was dependent upon the activation of NLRP3 inflammasome, which was CTSB-dependent. In addition, inhibiting autophagy alleviated the As2O3-induced increase of cytosolic CTSB expression and subsequent release of LDH, activation of the NLRP3 inflammasome, and pyroptosis. Moreover, we found that Tau alleviated As2O3-induced elevation of autophagy, CTSB expression, and activation of the NLRP3 inflammasome, and reduced the release of LDH, pyroptotic cell death, and inflammation. Interestingly, As2O3-induced lipid accumulation could not be alleviated by either inhibition of autophagy nor by inhibition of CTSB. Additionally, neither inhibition of the NLRP3 inflammasome or Tau treatment could alleviate lipid accumulation. These results demonstrated that As2O3-induced pyroptosis involves autophagy, CTSB, and the NLRP3 inflammasome cascade, and that Tau alleviates As2O3-induced liver inflammation by inhibiting the autophagic-CTSB-NLRP3 inflammasomal pathway rather than decreasing lipid accumulation. These findings give insight into the association of autophagy, inflammation, pyroptosis, and NASH induced by As2O3.