Monitoring the Response of Hyperbilirubinemia in the Mouse Brain by In Vivo Bioluminescence Imaging

Hepatic BMAL1 and HIF1α regulate a time-dependent hypoxic response and prevent hepatopulmonary-like syndrome

The transcriptional response to hypoxia is temporally regulated, yet the molecular underpinnings and physiological implications are unknown. We examined the roles of hepatic Bmal1 and Hif1α in the circadian response to hypoxia in mice. We found that the majority of the transcriptional response to hypoxia is dependent on either Bmal1 or Hif1α, through shared and distinct roles that are daytime determined. We further show that hypoxia-inducible factor (HIF)1α accumulation upon hypoxia is temporally regulated and Bmal1 dependent. Unexpectedly, mice lacking both hepatic Bmal1 and Hif1α are hypoxemic and exhibit increased mortality upon hypoxic exposure in a daytime-dependent manner. These mice display mild liver dysfunction with pulmonary vasodilation likely due to extracellular signaling regulated kinase (ERK) activation, endothelial nitric oxide synthase, and nitric oxide accumulation in lungs, suggestive of hepatopulmonary syndrome. Our findings indicate that hepatic BMAL1 and HIF1α are key time-dependent regulators of the hypoxic response and can provide molecular insights into the pathophysiology of hepatopulmonary syndrome.

Development of two mouse strains conditionally expressing bright luciferases with distinct emission spectra as new tools for in vivo imaging

In vivo bioluminescence imaging (BLI) has been an invaluable noninvasive method to visualize molecular and cellular behaviors in laboratory animals. Bioluminescent reporter mice harboring luciferases for general use have been limited to a classical luciferase, Luc2, from Photinus pyralis, and have been extremely powerful for various in vivo studies. However, applicability of reporter mice for in vivo BLI could be further accelerated by increasing light intensity through the use of other luciferases and/or by improving the biodistribution of their substrates in the animal body. Here we created two Cre-dependent reporter mice incorporating luciferases oFluc derived from Pyrocoeli matsumurai and Akaluc, both of which had been reported previously to be brighter than Luc2 when using appropriate substrates; we then tested their bioluminescence in neural tissues and other organs in living mice. When expressed throughout the body, both luciferases emitted an intense yellow (oFluc) or far-red (Akaluc) light easily visible to the naked eye. oFluc and Akaluc were similarly bright in the pancreas for in vivo BLI; however, Akaluc was superior to oFluc for brain imaging, because its substrate, AkaLumine-HCl, was distributed to the brain more efficiently than the oFluc substrate, D-luciferin. We also demonstrated that the lights produced by oFluc and Akaluc were sufficiently spectrally distinct from each other for dual-color imaging in a single living mouse. Taken together, these novel bioluminescent reporter mice are an ideal source of cells with bright bioluminescence and may facilitate in vivo BLI of various tissues/organs for preclinical and biomedical research in combination with a wide variety of Cre-driver mice.

Pathogenic factors of cognitive dysfunction after liver transplantation: an observational study

OBJECTIVES

Neurocognitive complications significantly reduce long-term health-related quality of life in patients undergoing liver transplantation; however, few studies have focused on their perioperative cognitive status. The authors designed a prospective observational study to determine the incidence and risk factors of posttransplant cognitive dysfunction.

METHODS

This study included patients with end-stage liver disease who were on the liver transplantation waiting list. We performed an investigation with a neuropsychological battery before and 1 week after the successful transplant, analyzed the changes, and further explored the complicated perioperative factors that contribute to cognitive dysfunction.

RESULTS

A total of 132 patients completed all the investigations. Compared with healthy controls and preoperative cognitive performance, 54 patients experienced deterioration, 50 patients remained unchanged, and 28 patients showed rapid improvement. Logistic regression analysis showed that age [odds ratio (OR) = 1.15, 95% confidence interval (CI, 1.07-1.22), P  < 0.001], the model for end-stage liver disease (MELD) score [OR = 1.07, 95% CI (1.03-1.13), P  = 0.038], systemic circulation pressure [OR = 0.95, 95% CI (0.91-0.99), P  = 0.026] within the first 30 min after portal vein opening, and total bilirubin concentration [OR = 1.02, 95% CI (1.01-1.03), P  = 0.036] on the seventh day post-transplant were closely related to the deterioration of cognitive function.

CONCLUSION

The incidences of deterioration, maintenance, and improvement in cognitive function were 40.9%, 37.9%, and 21.2%, respectively. Increasing age, higher MELD score, lower perfusion pressure in the early stage of the new liver, and higher total bilirubin concentration postoperatively may be independent pathogenic factors.

Macrophage CD5L is a target for cancer immunotherapy

BACKGROUND

Reprogramming of immunosuppressive tumor-associated macrophages (TAMs) presents an attractive therapeutic strategy in cancer. The aim of this study was to explore the role of macrophage CD5L protein in TAM activity and assess its potential as a therapeutic target.

METHODS

Monoclonal antibodies (mAbs) against recombinant CD5L were raised by subcutaneous immunization of BALB/c mice. Peripheral blood monocytes were isolated from healthy donors and stimulated with IFN/LPS, IL4, IL10, and conditioned medium (CM) from different cancer cell lines in the presence of anti-CD5L mAb or controls. Subsequently, phenotypic markers, including CD5L, were quantified by flow cytometry, IF and RT-qPCR. Macrophage CD5L protein expression was studied in 55 human papillary lung adenocarcinoma (PAC) samples by IHC and IF. Anti-CD5L mAb and isotype control were administered intraperitoneally into a syngeneic Lewis Lung Carcinoma mouse model and tumor growth was measured. Tumor microenvironment (TME) changes were determined by flow cytometry, IHC, IF, Luminex, RNAseq and RT-qPCR.

FINDINGS

Cancer cell lines CM induced an immunosuppressive phenotype (increase in CD163, CD206, MERTK, VEGF and CD5L) in cultured macrophages. Accordingly, high TAM expression of CD5L in PAC was associated with poor patient outcome (Log-rank (Mantel-Cox) test p = 0.02). We raised a new anti-CD5L mAb that blocked the immunosuppressive phenotype of macrophages in vitro. Its administration in vivo inhibited tumor progression of lung cancer by altering the intratumoral myeloid cell population profile and CD4⁺ T-cell exhaustion phenotype, thereby significantly modifying the TME and increasing the inflammatory milieu.

INTERPRETATION

CD5L protein plays a key function in modulating the activity of macrophages and their interactions within the TME, which supports its role as a therapeutic target in cancer immunotherapy.

FUNDING

For a full list of funding bodies, please see the Acknowledgements.

The Activation of PPARγ by (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic Acid Counteracts the Epithelial–Mesenchymal Transition Process in Skin Carcinogenesis

Cutaneous squamous cell carcinoma (cSCC) is the most common UV-induced keratinocyte-derived cancer, and its progression is characterized by the epithelial–mesenchymal transition (EMT) process. We previously demonstrated that PPARγ activation by 2,4,6-octatrienoic acid (Octa) prevents cutaneous UV damage. We investigated the possible role of the PPARγ activators Octa and the new compound (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic acid (A02) in targeting keratinocyte-derived skin cancer. Like Octa, A02 exerted a protective effect against UVB-induced oxidative stress and DNA damage in NHKs. In the squamous cell carcinoma A431 cells, A02 inhibited cell proliferation and increased differentiation markers’ expression. Moreover, Octa and even more A02 counteracted the TGF-β1-dependent increase in mesenchymal markers, intracellular ROS, the activation of EMT-related signal transduction pathways, and cells’ migratory capacity. Both compounds, especially A02, counterbalanced the TGF-β1-induced cell membrane lipid remodeling and the release of bioactive lipids involved in EMT. In vivo experiments on a murine model useful to study cell proliferation in adult animals showed the reduction of areas characterized by active cell proliferation in response to A02 topical treatment. In conclusion, targeting PPARγ may be useful for the prevention and treatment of keratinocyte-derived skin cancer.

Wearable Photomedicine for Neonatal Jaundice Treatment Using Blue Organic Light-Emitting Diodes (OLEDs): Toward Textile-Based Wearable Phototherapeutics

Neonatal jaundice is a very common disease in newborns and can lead to brain damage or death in severe cases. Phototherapy with light-emitting diode (LED) arrays is widely used as the easiest and fastest way to relieve jaundice in newborns, but it has distinct disadvantages such as loss of water in the patient, damage to the retina, and separation from parents. In this paper, a novel light source-based phototherapy for neonatal jaundice is proposed using a textile-based wearable organic light-emitting diode (OLED) platform that can move flexibly and conform to the curvature of the human body. The soft and flexible textile-based blue OLED platform is designed to have a peak wavelength of 470 nm, suitable for jaundice treatment, and shows performance (>20 µW cm-2 nm- 1 ) suitable for intensive jaundice treatment even at low voltage (<4.0 V). The textile-based OLEDs fabricated in this study exhibit an operating reliability of over 100 h and low-temperature operation (<35 °C). The results of an in vitro jaundice treatment test using a large-area blue OLED confirm that the bilirubin level decreases to 12 mg dL-1 with 3 h of OLED irradiation.

Reduction of Cell Proliferation by Acute C2H6O Exposure

Simple Summary

Alcoholic beverages and acetaldehyde formed during their metabolism are carcinogenic to humans. Alcohol drinking may affect bone marrow stem cell niche, suppressing physiological hematopoiesis and ultimately reducing the organism’s capacity to fight against cancer, infections, and to promote tissue regeneration. To elucidate in vivo the cellular mechanisms associated with alcohol intake toxicity, we used a mouse model in which proliferating cells produce the firefly’s light-emitting protein. In this animal, alcohol exposure transiently “turns off the light”, indicating a negative effect on cell proliferation in the bone marrow and spleen. Pharmacological treatment with substances interfering with ethanol metabolism, reducing acetaldehyde production, partially restores the physiological cell proliferation rate. Over 560 million people worldwide have increased susceptibility to acetaldehyde toxicity and 4% of cancer deaths are attributable to alcohol. Our model might provide a suitable tool to further investigate in vivo the effects of alcohol metabolism and aldehydes production on carcinogenesis.

Abstract

Endogenous acetaldehyde production from the metabolism of ingested alcohol exposes hematopoietic progenitor cells to increased genotoxic risk. To develop possible therapeutic strategies to prevent or reverse alcohol abuse effects, it would be critical to determine the temporal progression of acute ethanol toxicity on progenitor cell numbers and proliferative status. We followed the variation of the cell proliferation rate in bone marrow and spleen in response to acute ethanol intoxication in the MITO-Luc mouse, in which NF-Y-dependent cell proliferation can be assessed in vivo by non-invasive bioluminescent imaging. One week after ethanol administration, bioluminescent signals in bone marrow and spleen decreased below the level corresponding to physiological proliferation, and they progressively resumed to pre-treatment values in approximately 4 weeks. Boosting acetaldehyde catabolism by administration of an aldehyde dehydrogenase activity activator or administration of polyphenols with antioxidant activity partially restored bone marrow cells’ physiological proliferation. These results indicate that in this mouse model, bioluminescent alteration reflects the reduction of the physiological proliferation rate of bone marrow progenitor cells due to the toxic effect of aldehydes generated by alcohol oxidation. In summary, this study presents a novel view of the impact of acute alcohol intake on bone marrow cell proliferation in vivo.

Evaluation of Cell-Penetrating Peptides Using Microfluidic In Vitro 3D Brain Endothelial Barrier

In drug delivery to the human brain, blood vessels are a significant hurdle because they restrict the entry of most solutes to protect brain. To overcome this hurdle, an in vitro 3D model for brain endothelial barrier is developed using a microfluidic device with hydrogel providing a 3D extracellular matrix scaffold. Using the model, peptides known to utilize receptor-mediated transcytosis are verified, which has been one of the most promising mechanisms for brain-specific penetration. The cytotoxicity and cellular damage to the peptide are investigated and the receptor-mediated transcytosis and brain endothelial specific penetrating abilities of the peptides in a quantitative manner are demonstrated. As a preclinical test, applying the quantification assays conducted in this study are suggested, including the penetrating ability, cytotoxicity, endothelial damage, and receptor specificity. Using this microfluidic device as an in vitro platform for evaluating various brain targeting drugs and drug carrier candidates is also proposed.