Visualizing myocardial inflammation in a rat model of type 4 cardiorenal syndrome by dual-modality molecular imaging

Ultrahigh-Resolution Visualization of Vascular Heterogeneity in Brain Tumors via Magnetic Nanoparticles-Enhanced Susceptibility-Weighted Imaging

The precise assessment of vascular heterogeneity in brain tumors is vital for diagnosing, grading, predicting progression, and guiding treatment decisions. However, currently, there is a significant shortage of high-resolution imaging approaches. Herein, we propose a contrast-enhanced susceptibility-weighted imaging (CE-SWI) utilizing the minimalist dextran-modified Fe3O4 nanoparticles (Dextran@Fe3O4 NPs) for ultrahigh-resolution mapping of vasculature in brain tumors. The Dextran@Fe3O4 NPs are prepared via a facile coprecipitation method under room temperature, and exhibit small hydrodynamic size (28 nm), good solubility, excellent biocompatibility, and high transverse relaxivity (r2*, 159.7 mM-1 s-1) under 9.4 T magnetic field. The Dextran@Fe3O4 NPs-enhanced SWI can increase the contrast-to-noise ratio (CNR) of cerebral vessels to 2.5 times that before injection and achieves ultrahigh-spatial-resolution visualization of microvessels as small as 0.1 mm in diameter. This advanced imaging capability not only allows for the detailed mapping of both enlarged peritumoral drainage vessels and the intratumoral microvessels, but also facilitates the sensitive imaging detection of vascular permeability deterioration in a C6 cells-bearing rat glioblastoma model. Our proposed Dextran@Fe3O4 NPs-enhanced SWI provides a powerful imaging technique with great clinical translation potential for the precise theranostics of brain tumors.

A Minimalist Iron Oxide Nanoprobe for the High-Resolution Depiction of Stroke by Susceptibility-Weighted Imaging

The precise mapping of collateral circulation and ischemic penumbra is crucial for diagnosing and treating acute ischemic stroke (AIS). Unfortunately, there exists a significant shortage of high-sensitivity and high-resolution in vivo imaging techniques to fulfill this requirement. Herein, a contrast enhanced susceptibility-weighted imaging (CE-SWI) using the minimalist dextran-modified Fe3O4 nanoparticles (Fe3O4@Dextran NPs) are introduced for the highly sensitive and high-resolution AIS depiction under 9.4 T for the first time. The Fe3O4@Dextran NPs are synthesized via a simple one-pot coprecipitation method using commercial reagents under room temperature. It shows merits of small size (hydrodynamic size 25.8 nm), good solubility, high transverse relaxivity (r2) of 51.3 mM-1s-1 at 9.4 T, and superior biocompatibility. The Fe3O4@Dextran NPs-enhanced SWI can highlight the cerebral vessels readily with significantly improved contrast and ultrahigh resolution of 0.1 mm under 9.4 T MR scanner, enabling the clear spatial identification of collateral circulation in the middle cerebral artery occlusion (MCAO) rat model. Furthermore, Fe3O4@Dextran NPs-enhanced SWI facilitates the precise depiction of ischemia core, collaterals, and ischemic penumbra post AIS through matching analysis with other multimodal MR sequences. The proposed Fe3O4@Dextran NPs-enhanced SWI offers a high-sensitivity and high-resolution imaging tool for individualized characterization and personally precise theranostics of stroke patients.

Iron oxide nanoparticles for treatment and diagnosis of chronic inflammatory diseases: A systematic review

Chronic inflammatory conditions are among the most prevalent diseases worldwide. Several debilitating diseases such as atherosclerosis, inflammatory bowel disease, rheumatoid arthritis, and Alzheimer's are linked to chronic inflammation. These conditions often develop into complex and fatal conditions, making early detection and treatment of chronic inflammation crucial. Current diagnostic methods show high variability and do not account for disease heterogeneity and disease-specific proinflammatory markers, often delaying the disease detection until later stages. Furthermore, existing treatment strategies, including high-dose anti-inflammatory and immunosuppressive drugs, have significant side effects and an increased risk of infections. In recent years, superparamagnetic iron oxide nanoparticles (SPIONs) have shown tremendous biomedical potential. SPIONs can function as imaging modalities for magnetic resonance imaging, and as therapeutic agents due to their magnetic hyperthermia capability. Furthermore, the surface functionalization of SPIONs allows the detection of specific disease biomarkers and targeted drug delivery. This systematic review explores the utility of SPIONs against chronic inflammatory disorders, focusing on their dual role as diagnostic and therapeutic agents. We extracted studies indexed in the Web of Science database from the last 10 years (2013-2023), and applied systematic inclusion criteria. This resulted in a final selection of 38 articles, which were analyzed for nanoparticle characteristics, targeted diseases, in vivo and in vitro models used, and the efficacy of the therapeutic or diagnostic modalities. The results revealed that ultrasmall SPIONs are excellent for imaging arterial and neuronal inflammation. Furthermore, novel therapies using SPIONs loaded with chemotherapeutic drugs show promise in the treatment of inflammatory diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Panax notoginseng saponins inhibits NLRP3 inflammasome-mediated pyroptosis by downregulating lncRNA-ANRIL in cardiorenal syndrome type 4

OBJECTIVE

Cardiorenal syndrome type 4 (CRS4) is a complication of chronic kidney disease. Panax notoginseng saponins (PNS) have been confirmed to be efficient in cardiovascular diseases. Our study aimed to explore the therapeutic role and mechanism of PNS in CRS4.

METHODS

CRS4 model rats and hypoxia-induced cardiomyocytes were treated with PNS, with and without pyroptosis inhibitor VX765 and ANRIL overexpression plasmids. Cardiac function and cardiorenal function biomarkers levels were measured by echocardiography and ELISA, respectively. Cardiac fibrosis was detected by Masson staining. Cell viability was determined by cell counting kit-8 and flow cytometry. Expression of fibrosis-related genes (COL-I, COL-III, TGF-β, α-SMA) and ANRIL was examined using RT-qPCR. Pyroptosis-related protein levels of NLRP3, ASC, IL-1β, TGF-β1, GSDMD-N, and caspase-1 were measured by western blotting or immunofluorescence staining.

RESULTS

PNS improved cardiac function, and inhibited cardiac fibrosis and pyroptosis in a dose-dependent manner in model rats and injured H9c2 cells (p < 0.01). The expression of fibrosis-related genes (COL-I, COL-III, TGF-β, α-SMA) and pyroptosis-related proteins (NLRP3, ASC, IL-1β, TGF-β1, GSDMD-N, and caspase-1) was inhibited by PNS in injured cardiac tissues and cells (p < 0.01). Additionally, ANRIL was upregulated in model rats and injured cells, but PNS reduced its expression in a dose-dependent manner (p < 0.05). Additionally, the inhibitory effect of PNS on pyroptosis in injured H9c2 cells was enhanced by VX765 and reversed by ANRIL overexpression, respectively (p < 0.05).

CONCLUSION

PNS inhibits pyroptosis by downregulating lncRNA-ANRIL in CRS4.

18F-FDG PET/MRI Imaging in a Preclinical Rat Model of Cardiorenal Syndrome-An Exploratory Study

Cardiorenal syndrome (CRS) denotes the bidirectional interaction of chronic kidney disease and heart failure with an adverse prognosis but with a limited understanding of its pathogenesis. This study correlates biochemical blood markers, histopathological and immunohistochemistry features, and 2-deoxy-2-fluoro-D-glucose positron emission tomography (¹⁸F-FDG PET) metabolic data in low-dose doxorubicin-induced heart failure, cardiorenal syndrome, and renocardiac syndrome induced on Wistar male rats. To our knowledge, this is the first study that investigates the underlying mechanisms for CRS progression in rats using ¹⁸F-FDG PET. Clinical, metabolic cage monitoring, biochemistry, histopathology, and immunohistochemistry combined with PET/MRI (magnetic resonance imaging) data acquisition at distinct points in the disease progression were employed for this study in order to elucidate the available evidence of organ crosstalk between the heart and kidneys. In our CRS model, we found that chronic treatment with low-dose doxorubicin followed by acute 5/6 nephrectomy incurred the highest mortality among the study groups, while the model for renocardiac syndrome resulted in moderate-to-high mortality. ¹⁸F-FDG PET imaging evidenced the doxorubicin cardiotoxicity with vascular alterations, normal kidney development damage, and impaired function. Given the fact that standard clinical markers were insensitive to early renal injury, we believe that the decreasing values of the ¹⁸F-FDG PET-derived renal marker across the groups and, compared with their age-matched controls, along with the uniform distribution seen in healthy developing rats, could have a potential diagnostic and prognostic yield in cardiorenal syndrome.

LINC00936 exacerbated myocardial infarction progression via miR-4795-3p/Wnt3a signaling pathway based on biological and imaging methods

OBJECTIVE

LncRNAs show great potential in diagnosing and treating myocardial infarction (MI). Clarifying the mechanism of lncRNAs on MI is of great significance for the application of MI biomarkers. Therefore, this report intended to determine the role and mechanism of LINC00936 on MI by biological and imaging methods.

METHODS

Hypoxia H9C2 model was established by hypoxia treatment. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay detected the apoptosis of H9C2. H2DCFDA staining and enzyme-linked immunosorbent assay (ELISA) was used to detect the reactive oxygen species (ROS) accumulation and Lactate dehydrogenase (LDH) contents, respectively. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect LINC00936, Wnt3a and miR-4795-3p levels. Western blot detected Wnt3a protein expression. Dual luciferase reporter assays detected the relationship of miR-4795-3p to LINC00936 or Wnt3a. Echocardiography analysis detected cardiac function. 2,3,5-Triphenyltetrazolium chloride (TTC) detected the infarct size. Masson staining detected the pathological changes.

RESULTS

LINC00936 level was elevated in the MI patients compared with the controls. Overexpression of LINC00936 promoted apoptosis and ROS accumulation in hypoxia H9C2 model and exacerbated MI progression in vivo. miR-4795-3p bound with LINC00936 in H9C2 cells and miR-4795-3p mimics inhibited apoptosis and ROS accumulation in hypoxia H9C2 model regulated by LINC00936. Wnt3a was targeted by miR-4795-3p and Wnt3a elevation promoted apoptosis and ROS accumulation in hypoxia H9C2 model.

CONCLUSION

In this report, we illustrated that LINC00936 exacerbated MI progression via the miR-4795-3p/Wnt3a signaling pathway based on biological and imaging methods. These findings might provide potential molecular target for the diagnosis and treatment of MI.

Telmisartan ameliorates cardiac fibrosis and diastolic function in cardiorenal heart failure with preserved ejection fraction

Chronic kidney disease (CKD) is a major contributor to the development of heart failure with preserved ejection fraction (HFpEF), whereas the underlying mechanism of cardiorenal HFpEF is still elusive. The aim of this study was to investigate the role of cardiac fibrosis in a rat model of cardiorenal HFpEF and explore whether treatment with Telmisartan, an inhibitor of renin-angiotensin-aldosterone system (RAAS), can ameliorate cardiac fibrosis and preserve diastolic function in cardiorenal HFpEF. Male rats were subjected to 5/6 subtotal nephrectomy (SNX) or sham operation (Sham), and rats were allowed four weeks to recover and form a stable condition of CKD. Telmisartan or vehicle was then administered p.o. (8 mg/kg/d) for 12 weeks. Blood pressure, brain natriuretic peptide (BNP), echocardiography, and cardiac magnetic resonance imaging were acquired to evaluate cardiac structural and functional alterations. Histopathological staining, real-time polymerase chain reaction (PCR) and western blot were performed to evaluate cardiac remodeling. SNX rats showed an HFpEF phenotype with increased BNP, decreased early to late diastolic transmitral flow velocity (E/A) ratio, increased left ventricular (LV) hypertrophy and preserved ejection fraction (EF). Pathology revealed increased cardiac fibrosis in cardiorenal HFpEF rats compared with the Sham group, while chronic treatment with Telmisartan significantly decreased cardiac fibrosis, accompanied by reduced markers of fibrosis (collagen I and collagen III) and profibrotic cytokines (α-smooth muscle actin, transforming growth factor-β1, and connective tissue growth factor). In addition, myocardial inflammation was decreased after Telmisartan treatment, which was in a linear correlation with cardiac fibrosis. Telmisartan also reversed LV hypertrophy and E/A ratio, indicating that Telmisartan can improve LV remodeling and diastolic function in cardiorenal HFpEF. In conclusion, cardiac fibrosis is central to the pathology of cardiorenal HFpEF, and RAAS modulation with Telmisartan is capable of alleviating cardiac fibrosis and preserving diastolic dysfunction in this rat model.

Early inflammatory changes and CC chemokine ligand-8 upregulation in the heart contribute to uremic cardiomyopathy

Uremic cardiomyopathy is a common complication in chronic kidney disease (CKD) patients, accounting for a high mortality rate. Several mechanisms have been proposed to link CKD and cardiac alterations; however, the early cardiac modifications that occur in CKD that may trigger cardiac remodeling and dysfunction remain largely unexplored. Here, in a mouse model of CKD induced by 5/6 nephrectomy, we first analyzed the early transcriptional and inflammatory changes that occur in the heart. Five days after 5/6 nephrectomy, RNA-sequencing showed the upregulation of 54 genes in the cardiac tissue of CKD mice and the enrichment of biological processes related to immune system processes. Increased cardiac infiltration of T-CD4⁺ lymphocytes, myeloid cells, and macrophages during early CKD was observed. Next, since CC chemokine ligand-8 (CCL8) was one of the most upregulated genes in the heart of mice with early CKD, we investigated the effect of acute and transient CCL8 inhibition on uremic cardiomyopathy severity. An increase in CCL8 protein levels was confirmed in the heart of early CKD mice. CCL8 inhibition attenuated the early infiltration of T-CD4⁺ lymphocytes and macrophages to the cardiac tissue, leading to a protection against chronic cardiac fibrotic remodeling, inflammation and cardiac dysfunction induced by CKD. Altogether, our data show the occurrence of transcriptional and inflammatory changes in the heart during the early phases of CKD and identify CCL8 as a key contributor to the early cardiac inflammatory state that triggers further cardiac remodeling and dysfunction in uremic cardiomyopathy.

Measurement of BAT activity by targeted molecular magnetic resonance imaging

OBJECTIVE

The aim of this study was to measure brown adipose tissue (BAT) activity by targeted peptide (CKGGRAKDC-NH2)-coupled, polyethylene glycol (PEG)-coated ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles with magnetic resonance imaging (MRI).

METHODS

The peptide was conjugated with PEG-coated USPIO to obtain targeted probes. Male C57BL/6 J mice were randomly divided into cold exposing and control group (n = 5 per group). T2*-weighted images were obtained pre- and post-contrast probes. Histological and gene expression analyses were carried out.

RESULTS

T2* relaxation time of BAT in the cold exposing group decreased more significantly compared to the control group. The calculated R2* increased with the reduction of T2* value. The ΔR2* (26.68 s^-1) of BAT in the cold exposing group was significantly higher (P < 0.05) than the control group. Iron particle sediments in BAT of the cold exposing group were revealed more than the control group with Prussian blue staining. The UCP1 expression level was up-regulated after cold activation.

CONCLUSIONS

BAT activity could be measured in vivo by the targeted peptide-coupled, PEG-coated USPIOs with MRI.

CMR publications from China of the last more than 30 years

Cardiovascular magnetic resonance (CMR) is a non-invasive imaging technology, gradually playing an irreplaceable role in the diagnosis and treatment of cardiovascular diseases. This review demonstrates the progress and research highlights of Chinese CMR publications of the last more than 30 years. At initial stage (1988 to 1997), CMR was introduced to evaluate cardiac anatomy, blood flow and ventricular function roughly in China. In the development stage (1998-2007), CMR began to play an important role in the diagnosis of cardiovascular and pericardial disease with the emergence of new techniques, such as myocardial perfusion imaging and magnetic resonance angiography. Since 2008, the development of CMR in China has reached a prosperous period. Cardiovascular disease can be both qualitatively and quantitatively assessment by CMR "one-stop" multi-parameter imaging, including the morphology, function, myocardial perfusion, tissue characteristics, metabolism and even the microstructure of myocardial fibers, which provides comprehensive assessment of the severity, risk stratification and prognosis of cardiovascular disease. Although CMR in China developed very rapidly in recent years, China still needs to put more efforts in CMR research and make greater contributions to the development of CMR in the world.

Protective effects of naringenin in cardiorenal syndrome

BACKGROUND

Cardiorenal syndrome is a complicated and bidirectional interrelationship between the heart and kidneys. Naringenin (NG) is a naturally occurring flavonoid possessing various biological and pharmacological properties.

MATERIALS AND METHODS

We tested whether NG could improve cardiac and renal function in a rat model of cardiorenal syndrome.

RESULTS

The results showed that NG-attenuated cardiac remodeling and cardiac dysfunction in rats with cardiorenal syndrome, as evidenced by decrease of left ventricle weight (LVW), increase of body weight (BW), decrease of LVW/BW, decrease of concentrations of serum creatinine, blood urea nitrogen, type-B natriuretic peptide, aldosterone, angiotensin (Ang) II, C-reactive protein, and urine protein, increase of left ventricular systolic pressure and falling rates of left ventricular pressure (dp/dtmax), and decrease of left ventricular diastolic pressure, left ventricular end-diastolic pressure, and -dp/dtmax. NG significantly inhibited the increase of lipid profiles including low-density lipoprotein, TC, and TG in rats. In addition, NG significantly inhibited the increase of cardiac expression of IL-1β, IL-6, and interferon γ. Moreover, NG decreased malonaldehyde level, increased superoxide dismutase activity and glutathione content in rats, and increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunit of γ-glutamylcysteine ligase (GCLc) in rats and Ang II-treated cardiac fibroblasts. Inhibition of Nrf2 and glutathione synthesis significantly suppressed NG-induced decrease of ROS level. Inhibition of Nrf2 markedly suppressed NG-induced increase of GCLc expression in Ang II-treated cardiac fibroblasts.

CONCLUSIONS

The data provide novel options for therapy of patients and new insights into the cardioprotective effects of NG in cardiorenal syndrome.