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Spheroids provide a 3D environment with intensive cell–cell contacts. As a result of their excellent regenerative properties and rapid progress in their high-throughput production, spheroids are increasingly suggested as building blocks for tissue engineering. In this review, we focus on innovative biotechnological approaches that increase the quality of spheroids for this specific type of application. These include in particular the fabrication of coculture spheroids, mimicking the complex morphology and physiological tasks of natural tissues. In vitro preconditioning under different culture conditions and incorporation of biomaterials improve the function of spheroids and their directed fusion into macrotissues of desired shapes. The continuous development of these sophisticated approaches may markedly contribute to a broad implementation of spheroid-based tissue engineering in future regenerative medicine. Spheroids are increasingly used as building blocks in tissue engineering, because they ideally mimic the physiological 3D environment of tissues. Automatized large-scale production of spheroids is technically feasible. Compared to 2D cell systems, spheroids exhibit an enhanced regenerative capacity, which can be improved during the production process by adjusting the culture conditions and incorporation of biomaterials. The complexity of tissues can be mimicked by incorporation of multiple cell types in coculture spheroids. Macrotissues can be generated by seeding spheroids on scaffolds or by scaffold-free fusion of spheroids.

Somatostatin is a peptide hormone, which most commonly is produced by endocrine cells and the central nervous system. In mammals, somatostatin originates from pre-prosomatostatin and is processed to a shorter form, i.e., somatostatin-14, and a longer form, i.e., somatostatin-28. The two peptides repress growth hormone secretion and are involved in the regulation of glucagon and insulin synthesis in the pancreas. In recent years, the processing and secretion of somatostatin have been studied intensively. However, little attention has been paid to the regulatory mechanisms that control its expression. This review provides an up-to-date overview of these mechanisms. In particular, it focuses on the role of enhancers and silencers within the promoter region as well as on the binding of modulatory transcription factors to these elements. Moreover, it addresses extracellular factors, which trigger key signaling pathways, leading to an enhanced somatostatin expression in health and disease.

Accumulating evidence indicates that there is an interaction between the gut microbiota and endometriotic lesions. The new formation of these lesions is associated with stem cell recruitment, angiogenesis and inflammation, which may affect the composition of the gut microbiota. To test this hypothesis, we herein induced endometriotic lesions by transplantation of uterine tissue fragments from green fluorescent protein (GFP)+ donor mice into the peritoneal cavity of GFP- C57BL/6 wild-type mice. Sham-transplanted animals served as controls. Fecal pellets of the animals were collected 3 days before as well as 7 and 21 days after the induction of endometriosis to analyze the composition of the gut microbiota by means of 16S ribosomal RNA gene sequencing. The transplantation of uterine tissue fragments resulted in the establishment of endometriotic lesions in all analyzed mice. These lesions exhibited a typical histomorphology with endometrial glands surrounded by a vascularized stroma. Due to their bright GFP signal, they could be easily differentiated from the surrounding GFP- host tissue. Bacterial 16S rRNA genes were successfully PCR-amplified from the DNA extracts of all obtained mice fecal samples. However, no significant effect of endometriosis induction on the composition of the bacterial microbiota was detected with our experimental setup. Our findings allow careful speculation that endometriosis in mice does not induce pronounced dysbiosis during the acute phase of lesion formation.

The NADPH/NADP + redox couple is central to metabolism and redox signalling. NADP redox state is differentially regulated by distinct enzymatic machineries at the subcellular compartment level. Nonetheless, a detailed understanding of subcellular NADP redox dynamics is limited by the availability of appropriate tools. Here, we introduce NAPstars, a family of genetically encoded, fluorescent protein-based NADP redox state biosensors. NAPstars offer real-time, specific measurements, across a broad-range of NADP redox states, with subcellular resolution. NAPstar measurements in yeast, plants, and mammalian cell models, reveal a conserved robustness of cytosolic NADP redox homoeostasis. NAPstars uncover cell cycle-linked NADP redox oscillations in yeast and illumination- and hypoxia-dependent NADP redox changes in plant leaves. By applying NAPstars in combination with selective impairment of the glutathione and thioredoxin antioxidative pathways under acute oxidative challenge, we find an unexpected and conserved role for the glutathione system as the primary mediator of antioxidative electron flux. This article presents NAPstars, a family of genetically-encoded biosensors that enable real-time monitoring of NADP redox dynamics across species. The sensors reveal robust NADP redox regulation, cell-cycle-linked NADP oscillations, and glutathione as the major conduit for anti-oxidative electron flux.

In a pilot trial, we used the laser-Doppler device ‘Oxygen to see’ (O2C, LEA Medizintechnik, Winchesterstr. 2, D-35394 Gießen, Germany) to measure SO2, haemoglobin (Hb), and blood flow (BF) in 3, 10, and 14/16 mm depth in four tibial and clavicle fractures of three patients with multiple injuries who received NE. In 3 mm, up to 14.7% of the variability could be explained by MAP alone, and in 14/16 mm, up to 13.5% by NE alone. [...]only NE and not MAP had an effect on SO2 in 14/16 mm depth inside the fractures. Effect of early use of noradrenaline on in-hospital mortality in haemorrhagic shock after major trauma: a propensity-score analysis.

Cilostazol has previously been shown to reduce liver steatosis and enhance hepatic perfusion. We investigated the effects of cilostazol after major hepatectomy in a steatotic rat model. Six weeks prior to surgery, Sprague–Dawley rats were fed with a high-fructose diet. The treatment group received daily 5 mg/kg cilostazol. Seven days following the cilostazol treatment, all animals underwent 70% liver resection (PHX). Analysis of hepatic blood flow and microcirculation and immunohistochemical examinations were conducted 30 min after PHX (postoperative day [POD] 0) as well as on POD 1, POD 3 and POD 7. The weight of cilostazol-treated animals was significantly reduced compared to untreated controls after completion of the 6-week high-FRC diet. Furthermore, 41% macrovesicular steatosis was found in the control group compared to 8% in the cilostazol group. Hepatic arterial and portal venous perfusion were increased in the cilostazol group on POD 7. Lower liver enzyme release was found postoperatively in cilostazol-treated animals. Moreover, apoptosis and neutrophil infiltration were reduced after cilostazol treatment. Proliferation of hepatocytes and liver regeneration after PHX were significantly increased in the cilostazol group. Consequently, cilostazol should be evaluated as a novel strategy to reduce the rate of liver failure after PHX in steatotic liver.

Pancreatic islet transplantation still represents a promising therapeutic strategy for curative treatment of type 1 diabetes mellitus. However, a limited number of organ donors and insufficient vascularization with islet engraftment failure restrict the successful transfer of this approach into clinical practice. To overcome these problems, we herein introduce a novel strategy for the generation of prevascularized islet organoids by the fusion of pancreatic islet cells with functional native microvessels. These insulin‐secreting organoids exhibit a significantly higher angiogenic activity compared to freshly isolated islets, cultured islets, and non‐prevascularized islet organoids. This is caused by paracrine signaling between the β‐cells and the microvessels, mediated by insulin binding to its corresponding receptor on endothelial cells. In vivo , the prevascularized islet organoids are rapidly blood‐perfused after transplantation by the interconnection of their autochthonous microvasculature with surrounding blood vessels. As a consequence, a lower number of islet grafts are required to restore normoglycemia in diabetic mice. Thus, prevascularized islet organoids may be used to improve the success rates of clinical islet transplantation. Synopsis This study introduces a novel strategy to accelerate the revascularization of transplanted islets by the fusion of microvascular fragments (MVF) with pancreatic islet cells. These prevascularized islet organoids may be used to improve the success rate of clinical islet transplantation. The fusion of islet cells with MVF resulted in compact prevascularized islet organoids. Prevascularized islet organoids exhibited a highly angiogenic activity, mediated by a paracrine signaling between β‐cells and endothelial cells. The transplantation of prevascularized islet organoids restored normoglycemia in diabetic animals immediately after transplantation. Graphical Abstract This study introduces a novel strategy to accelerate the revascularization of transplanted islets by the fusion of microvascular fragments (MVF) with pancreatic islet cells. These prevascularized islet organoids may be used to improve the success rate of clinical islet transplantation.

Geraniol exerts several direct pharmacological effects on tumor cells and, thus, has been suggested as a promising anti-cancer compound. Because vascularization is a major precondition for tumor growth, we analyzed in this study the anti-angiogenic action of geraniol. In vitro, geraniol reduced the migratory activity of endothelial-like eEND2 cells. Western blot analyses further revealed that geraniol downregulates proliferating cell nuclear antigen (PCNA) and upregulates cleaved caspase-3 (Casp-3) expression in eEND2 cells. Moreover, geraniol blocked vascular endothelial growth factor (VEGF)/VEGFR-2 signal transduction, resulting in a suppression of downstream AKT and ERK signaling pathways. In addition, geraniol significantly reduced vascular sprout formation in a rat aortic ring assay. In vivo, geraniol inhibited the vascularization of CT26 tumors in dorsal skinfold chambers of BALB/c mice, which was associated with a smaller tumor size when compared to vehicle-treated controls. Immunohistochemical analyses confirmed a decreased number of Ki67-positive cells and CD31-positive microvessels with reduced VEGFR-2 expression within geraniol-treated tumors. Taken together, these findings indicate that geraniol targets multiple angiogenic mechanisms and, therefore, is an attractive candidate for the anti-angiogenic treatment of tumors.

Electrochemotherapy (ECT) combines the reversible electroporation (rEP) with intravenous (i.v.) or intratumoral (i.t.) administration of chemotherapeutic drugs. We conducted this study to compare the efficacy of i.v., i.t., and i.v. + i.t. injection of bleomycin (BLM) in ECT treatment of colorectal hepatic metastases in a rat model. WAG/Rij rats were randomized into three groups and underwent ECT with i.v., i.t., or i.v. + i.t. injection of BLM. Tumor volumes and oxygenation were measured by means of ultrasound and photoacoustic imaging. Moreover, liver and tumor tissue were analyzed by histology and immunohistochemistry. The i.v. and i.v. + i.t. groups exhibited a 44.0% and 46.6% reduction in oxygen saturation of the tumor tissue when compared to pretreatment values, whereas the i.t. group only showed a reduction of 35.2%. The extent of tumor tissue necrosis did not statistically differ between the groups. However, the i.t. group showed a tendency towards a lower necrosis rate. Cell proliferation, apoptotic cell death, vascularization, and immune cell infiltration were comparable in the treated tumors of the three groups. ECT with i.v. administration of BLM should be preferred in clinical practice, as the combined i.v. + i.t. therapy did not show superior oncological outcomes in the present study.

Radiotherapy, while effective in cancer treatment, can lead to side effects, such as radiodermatitis with potential long-term consequences including telangiectasias, ulceration and fibrosis of the skin, eventually resulting in impaired wound healing. In this study, we analyzed whether the healing of such challenging wounds can be improved by nanofat (NF). NF is generated by mechanical emulsification and filtration of fat samples and, thus, is a random mixture of adipose-derived stem cells, microvascular fragments, extracellular matrix components and growth factors. Two months after localized ionizing radiation of the skin with a total dose of 20 Gy, full-thickness wounds were created in dorsal skinfold chambers of mice, which were filled with platelet-rich plasma (PRP; control, n  = 8) or NF fixed in PRP (PRP + NF, n  = 8). The healing process was assessed by means of stereomicroscopy, intravital fluorescence microscopy, histology and immunohistochemistry over 14 days. The closure of PRP + NF-treated wounds was accelerated, as indicated by significantly smaller wound areas on day 14 when compared to controls. This was associated with a higher density of blood-perfused microvessels inside the wounds. Moreover, PRP + NF-treated wounds showed a tendency towards an improved granulation tissue formation, lymphatic drainage and M2/M1 macrophage ratio. Taken together, these findings suggest that the application of NF represents a promising therapeutic strategy for the management of complex wounds in irradiated skin.