Ultralow radiant exposure of a short-pulsed laser to disrupt melanosomes with localized thermal damage through a turbid medium

Shimojo Y., Nishimura T., Tsuruta D., et al. Ultralow radiant exposure of a short-pulsed laser to disrupt melanosomes with localized thermal damage through a turbid medium. Scientific Reports 14, 20112 (2024); https://doi.org/10.1038/s41598-024-70807-7.Short-pulsed lasers can treat dermal pigmented lesions through selective photothermolysis. The irradiated light experiences multiple scattering by the skin and is absorbed by abnormal melanosomes as well as by normal blood vessels above the target. Because the fluence is extremely high, the absorbed light can cause thermal damage to the adjacent tissue components, leading to complications. To minimize radiant exposure and reduce the risk of burns, a model of the melanosome-disruption threshold fluence (MDTF) has been developed that accounts for the light-propagation efficiency in the skin. However, the light-propagation efficiency is attenuated because of multiple scattering, which limits the extent to which the radiant exposure required for treatment can be reduced. Here, this study demonstrates the principle of melanosome disruption with localized thermal damage through a turbid medium by ultralow radiant exposure of a short-pulsed laser. The MDTF model was combined with a wavefront-shaping technique to design an irradiation condition that can increase the light-propagation efficiency to the target. Under this irradiation condition, melanosomes were disrupted at a radiant exposure 25 times lower than the minimal value used in conventional laser treatments. Furthermore, almost no thermal damage to the skin was confirmed through a numerical simulation. These experimental and numerical results show the potential for noninvasive melanosome disruption and may lead to the improvement of the safety of short-pulsed laser treatment

Immunohistochemical Localization of the Aquaporins AQP1, AQP3, AQP4, and AQP5 in the Mouse Respiratory System

Aquaporins are membrane water channel proteins that function mainly in water transfer across cellular membranes. In our present study, we investigated the immunohistochemical distribution of aquaporin 1 (AQP1), AQP3, AQP4, and AQP5 in the mouse respiratory system by immunofluorescence, immunoperoxidase, and immunoelectron microscopy. AQP3, AQP4, and AQP5 are expressed in epithelial cells, whereas AQP1 is expressed in subepithelial connective tissues and capillaries. In the airway surface epithelia from the nasal cavity to the intrapulmonary bronchioles, AQP5 was found to be mainly localized to the luminal side and both AQP3 and AQP4 to the abluminal side. In the alveolar epithelium, AQP5 is localized to the apical membranes of both type I and type II alveolar cells. Compared with the previous studies on the rat respiratory system, in which AQP5 is restricted to the alveolar type I cells and absent from the airway surface epithelia, we found that AQP5 in the mouse is much more widely distributed throughout the surface epithelia. These results suggest that AQP5 has a critical role in water-handling, such as the maintenance of airway surface liquid and clearance of alveolar fluid in the mouse respiratory system

The Role of Apelin on the Alleviative Effect of Angiotensin Receptor Blocker in Unilateral Ureteral Obstruction-Induced Renal Fibrosis

Background: Apelin is a selective endogenous ligand of the APJ receptor, which genetically has closest identity to the angiotensin II type 1 receptor (AT-1). The effects of the apelin/APJ system on renal fibrosis still remain unclear. Methods: We examined the effects of the apelin/APJ system on renal fibrosis during AT-1 blockade in a mouse unilateral ureteral obstruction (UUO) model. Results: We obtained the following results: (1) At UUO day 7, mRNA expressions of apelin/APJ and phosphorylations of Akt/endothelial nitric oxide synthase (eNOS) in the UUO kidney were increased compared to those in the nonobstructed kidney. (2) AT-1 blockade by the treatment with losartan resulted in a further increase of apelin mRNA as well as phosphorylations of Akt/eNOS proteins, and this was accompanied by alleviated renal interstitial fibrosis, decreased myofibroblast accumulation, and a decreased number of interstitial macrophages. (3) Blockade of the APJ receptor by the treatment with F13A during losartan administration completely abrogated the effects of losartan in the activation of the Akt/eNOS pathway and the amelioration of renal fibrosis. (4) Inhibition of NOS by the treatment with L-NAME also resulted in a further increase in renal fibrosis compared to the control group. Conclusion: These results suggest that increased nitric oxide production through the apelin/APJ/Akt/eNOS pathway may, at least in part, contribute to the alleviative effect of losartan in UUO-induced renal fibrosis

Immunohistochemical Localization of the Water Channels AQP4 and AQP5 in the Rat Pituitary Gland

The pituitary gland is composed of the adenohypophysis and neurohypophysis. The adenohypophysis contains endocrine cells, folliculo-stellate (FS) cells, and marginal layer cells, whereas the neurohypophysis mainly comprises axons and pituicytes. To understand the molecular nature of water transfer in the pituitary gland, we examined the immunohistochemical localization of the membrane water channels aquaporin-4 (AQP4) and AQP5 in rat tissue. Double immunofluorescence analysis of AQP4 and S100 protein, a known marker for FS cells, marginal layer cells, and pituicytes, clearly revealed that FS cells and marginal layer cells in the adenohypophysis and the pituicytes in pars nervosa are positive for AQP4. AQP5 was found to be localized at the apical membrane in some marginal layer cells surrounding the Rathke’s residual pouch, in which AQP4 was observed to be localized on the basolateral membranes. These results suggest the following possibilities: 1) FS cells especially require water for their functions and 2) transepithelial water transfer could occur between the lumen of Rathke’s residual pouch and the interstitial fluid in the adenohypophysis through the AQP4 and AQP5 channels in the marginal layer cells

Differentiation of Human Adipose-Derived Mesenchymal Stromal/Stem Cells into Insulin-Producing Cells with A Single Tet-Off Lentiviral Vector System

Objective: Human adipose-derived mesenchymal stromal/stem cells (hASC) constitute an attractive source of stemcells for cell-based therapies in regenerative medicine and tissue engineering as they are easy to acquire fromlipoaspirate, expansion, and genetic modification ex vivo. The combination of Pdx-1, MafA, and NeuroD1 has beenindicated to possess the ability to reprogram various types of cells into insulin-producing cells. The aim of this study is toinvestigate whether MafA and NeuroD1 would cooperate with Pdx-1 in the differentiation of hASC into insulin-producingcells.Materials and Methods:In this experimental study, we generated polycistronic expression vectors expressing Pdx1and MafA/NeuroD1 with a reporter from a human EF-1α promoter using 2A peptides in a single tet-off lentiviral vectorsystem. Briefly, hASC were transduced with the lentiviral vectors and allowed to differentiate into insulin-producing cellsin vitro and in vivo. Thereafter, RNA expression, dithizone staining, and immunofluorescent analysis were conducted.Results: Cleaved transcriptional factors from a single tet-off lentiviral vector were functionally equivalent to their nativeproteins and strictly regulated by doxycycline (Dox). Insulin gene expression in hASC transduced with Pdx1, Pdx1/MafA, and Pdx1/NeuroD1 in differentiation medium were successfully increased by 1.89 ± 0.39, 4.81 ± 0.98, 5.51 ±0.63, respectively, compared to venus-transduced, control hASC. These cells could form dithizone-positive cell clustersin vitro and were found to express insulin in vivo.Conclusion: Using our single tet-off lentiviral vector system, Pdx-1 and MafA/NeuroD1 could be simultaneouslyexpressed in the absence of Dox. Further, this system allowed the differentiation of hASC into insulin-producing cells

Pulmonary thrombotic microangiopathy caused by gastric carcinoma.

Pulmonary tumour thrombotic microangiopathy (PTTM) is characterised by wide spread tumour emboli along with fibrocellular intimal proliferation and thrombus formation in small pulmonary arteries and arterioles. PTTM is a rare but fatal complication of carcinoma, but the pathogenesis remains to be clarified. An autopsy case of PTTM caused by gastric adenocarcinoma is described, in which tumour cells in the PTTM lesion had positive immunoreactivity for platelet-derived growth factor (PDGF) and PDGF receptor (PDGFR), and proliferating fibromuscular intimal cells also showed expression of PDGFR. In addition, the overexpression of PGDF was detected in the alveolar macrophages. These findings suggest that PDGF derived from alveolar macrophages and from tumour cells may act together in promoting fibrocellular intimal proliferation. To the best of the authors\u27 knowledge, the possible involvement of activated alveolar macrophages in PTTM has not been previously reported

Bullous Pemphigoid IgG Induces BP180 Internalization via a Macropinocytic Pathway

Bullous pemphigoid (BP) is an autoimmune blistering skin disease induced by pathogenic autoantibodies against a type II transmembrane protein (BP180, collagen type XVII, or BPAG2). In animal models, BP180 autoantibody-antigen interaction appears insufficient to develop blisters, but involvement of complement and neutrophils is required. However, cultured keratinocytes treated with BP-IgG exhibit a reduction in the adhesive strength and a loss of expression of BP180, suggesting that the autoantibodies directly affect epidermal cell–extracellular matrix integrity. In this study, we explored the consequences of two distinct epithelial cells treated with BP-IgG, particularly the fate of BP180. First, we followed the distribution of green fluorescent protein–tagged BP180 in an epithelial cell line, 804G, and normal human epidermal keratinocytes after autoantibody clustering. After BP-IgG treatment, the adhesive strength of the cells to their substrate was decreased, and BP180 was internalized in both cell types, together with the early endosomal antigen-1. By using various endocytosis inhibitors and a fluid-uptake assay, we demonstrated that BP-IgG–induced BP180 internalization is mediated via a macropinocytic pathway. Moreover, a macropinocytosis inhibitor rescued a BP-IgG–induced reduction in the adhesive strength of the cells from their substrate. The results of this study suggest that BP180 internalization induced by BP-IgG plays an important role in the initiation of disease pathogenesis