Development of anti-membrane type 1-matrix metalloproteinase nanobodies as immunoPET probes for triple negative breast cancer imaging.

Triple-negative breast cancer (TNBC) is characterized by aggressiveness and high rates of metastasis. The identification of relevant biomarkers is crucial to improve outcomes for TNBC patients. Membrane type 1-matrix metalloproteinase (MT1-MMP) could be a good candidate because its expression has been reported to correlate with tumor malignancy, progression and metastasis. Moreover, single-domain variable regions (VHHs or Nanobodies) derived from camelid heavy-chain-only antibodies have demonstrated improvements in tissue penetration and blood clearance, important characteristics for cancer imaging. Here, we have developed a nanobody-based PET imaging strategy for TNBC detection that targets MT1-MMP. A llama-derived library was screened against the catalytic domain of MT1-MMP and a panel of specific nanobodies were identified. After a deep characterization, two nanobodies were selected to be labeled with gallium-68 (68Ga). ImmunoPET imaging with both ([68Ga]Ga-NOTA-3TPA14 and [68Ga]Ga-NOTA-3CMP75) in a TNBC mouse model showed precise tumor-targeting capacity in vivo with high signal-to-background ratios. (68Ga)Ga-NOTA-3CMP75 exhibited higher tumor uptake compared to (68Ga)Ga-NOTA-3TPA14. Furthermore, imaging data correlated perfectly with the immunohistochemistry staining results. In conclusion, we found a promising candidate for nanobody-based PET imaging to be further investigated as a diagnostic tool in TNBC.

Improved Cardiovascular Function in Old Mice After N-Acetyl Cysteine and Glycine Supplemented Diet: Inflammation and Mitochondrial Factors.

Metabolic, inflammatory, and functional changes occur in cardiovascular aging which may stem from oxidative stress and be remediable with antioxidants. Glutathione, an intracellular antioxidant, declines with aging, and supplementation with glutathione precursors, N-acetyl cysteine (NAC) and glycine (Gly), increases tissue glutathione. Thirty-month old mice were fed diets supplemented with NAC or NAC+Gly and, after 7 weeks, cardiac function and molecular studies were performed. The NAC+Gly supplementation improved diastolic function, increasing peak early filling velocity, and reducing relaxation time, left atrial volume, and left ventricle end diastolic pressure. By contrast, cardiac function did not improve with NAC alone. Both diet supplementations decreased cardiac levels of inflammatory mediators; only NAC+Gly reduced leukocyte infiltration. Several mitochondrial genes reduced with aging were upregulated in hearts by NAC+Gly diet supplementation. These Krebs cycle and oxidative phosphorylation enzymes, suggesting improved mitochondrial function, and permeabilized cardiac fibers from NAC+Gly-fed mice produced ATP from carbohydrate and fatty acid sources, whereas fibers from control old mice were less able to utilize fatty acids. Our data indicate that NAC+Gly supplementation can improve diastolic function in the old mouse and may have potential to prevent important morbidities for older people.

TNF/Ang-II synergy is obligate for fibroinflammatory pathology, but not for changes in cardiorenal function.

Angiotensin-II (Ang-II) infusion is associated with the development of interstitial fibrosis in both heart and kidney as a result of chemokine-dependent uptake of monocytes and subsequent development of myeloid fibroblasts. This study emphasizes on the synergistic role of tumor necrosis factor (TNF) on the time course of Ang-II-induced fibrosis and inflammation in heart and kidney. In wild-type (WT) hearts, Ang-II-induced fibrosis peaked within 1 week of infusion and remained stable over a 6-week period, while the myeloid fibroblasts disappeared; TNF receptor-1-knockout (TNFR1-KO) hearts did not develop a myeloid response or cardiac fibrosis during this time. WT hearts developed more accelerated cardiac hypertrophy and remodeling than TNFR1-KO In the kidney, 1-week Ang-II infusion did not evoke a fibrotic response; however, after 6 weeks, WT kidneys displayed modest but significant tubulointerstitial collagen deposition associated with the appearance of myeloid cells and profibrotic gene activation. Renal fibrosis was not seen in Ang-II-infused TNFR1-KO By contrast, while hypertension increased and cardiac function decreased more slowly in TNFR1-KO than WT, they were equivalently abnormal at 6 weeks. Similarly, serum markers for renal dysfunction were not different after 6 weeks. In conclusion, Ang-II infusion initiated fibroinflammatory responses with different time courses in heart and kidney, both requiring TNFR1 signaling, and both associated with monocyte-derived myeloid fibroblasts. TNFR1 deletion obviated the fibroinflammatory effects of Ang-II, but did not alter changes in blood pressure and cardiorenal function after 6 weeks. Thus, the synergy of TNF with Ang-II targets the fibroinflammatory component of Ang-II signaling.

Left Atrial Volume and Pulmonary Artery Diameter Are Noninvasive Measures of Age-Related Diastolic Dysfunction in Mice.

Impaired cardiac diastolic function occurs with aging in many species and may be difficult to measure noninvasively. In humans, left atrial (LA) volume is a robust measure of chronic diastolic function as the LA is exposed to increased left ventricular filling pressures. We hypothesized that LA volume would be a useful indicator of diastolic function in aging mice. Further, we asked whether pressures were propagated backwards affecting pulmonary arteries (PAs) and right ventricle (RV). We measured LA, PA, and RV infundibulum dimensions with echocardiography and used mouse-specific Doppler systems and pressure catheters for noninvasive and invasive measures. As C57BL/6 mice aged from 3 to 29-31 months, LA volume almost tripled. LA volume increases correlated with traditional diastolic function measures. Within groups of 14- and 31-month-old mice, LA volume correlated with diastolic function measured invasively. In serial studies, mice evaluated at 20 and 24 months showed monotonic increases in LA volume; other parameters changed less predictably. PA diameters, larger in 30-month-old mice than 6-month-old mice, correlated with LA volumes. Noninvasive LA volume and PA diameter assessments are useful and state independent measures of diastolic function in mice, correlating with other measures of diastolic dysfunction in aging. Furthermore, serial measurements over 4 months demonstrated consistent increases in LA volume suitable for longitudinal cardiac aging studies.

A novel bioimpedance technique to monitor fluid volume state during hemodialysis treatment.

Bioimpedance spectroscopy is a potential candidate for monitoring of body fluids during dialysis. In this article, the suitability of knee-to-knee (KK) as an alternative to wrist-to-ankle (WA) bioimpedance spectroscopy measurements during dialysis is evaluated. Measurements on eight patients (22 dialysis sessions) showed a good correlation between the change in extracellular resistance (Re) in KK and WA measurements. A deeper analysis indicated that the change in Re normalized for ultrafiltrated volume [DeltaRe/UFV (%/L)] depends on the characteristics of the patient: clinically stable patients [with a presumed lower extracellular fluid - total body volume (VB) relationship] show a higher DeltaRe/UFV (%/L) mean +/- standard deviation (WA: 8.90 +/- 1.9 and KK: 8.29 +/- 2.2) than clinically unstable patients with pitting peripheral edema (WA: 2.10 +/- 0.8 and KK: 2.07 +/- 0.2). Simulations based on bioimpedance equations considering Hanai theory confirm the results. The KK method, especially in combination with proper use of the introduced DeltaRe/UFV (%/L) normalization could possibly offer new options for comfortable online monitoring and the evaluation of fluid volume state during dialysis.

Model-based correction of the influence of body position on continuous segmental and hand-to-foot bioimpedance measurements.

Bioimpedance spectroscopy (BIS) is suitable for continuous monitoring of body water content. The combination of body posture and time is a well-known source of error, which limits the accuracy and therapeutic validity of BIS measurements. This study evaluates a model-based correction as a possible solution. For this purpose, an 11-cylinder model representing body impedance distribution is used. Each cylinder contains a nonlinear two-pool model to describe fluid redistribution due to changing body position and its influence on segmental and hand-to-foot (HF) bioimpedance measurements. A model-based correction of segmental (thigh) and HF measurements (Xitron Hydra 4200) in nine healthy human subjects (following a sequence of 7 min supine, 20 min standing, 40 min supine) has been evaluated. The model-based compensation algorithm represents a compromise between accuracy and simplicity, and reduces the influence of changes in body position on the measured extracellular resistance and extracellular fluid by up to 75 and 70%, respectively.