The creation of organisms with Cre-loxP conditional gene recombination systems often faces challenges, particularly when creating the initial (F0) generation with both a Cre recombinase and a DNA site flanked by loxP elements (floxed site). The primary reason is that it is difficult to synthesize a single plasmid with both the Cre gene and the floxed site, since Cre-mediated recombination spontaneously occurs when the plasmid is amplified in Escherichia coli bacterial cells. Here, we introduce an artificial nucleic acid sequence TATATATATATATATATA, named TAx9, that enables the integration of both the Cre gene and the floxed site into a single plasmid.
View Article and Find Full Text PDFAdult myogenic cell lines are useful to study muscle development, repair and regeneration. In newts, which are known for their high regenerative capacity, myogenic cell lines have not been established in species other than the Eastern newt Notophthalmus viridescens. In this study, we established another myogenic cell line, named CpM01, from the skeletal muscle of the forearm of the adult Japanese fire-bellied newt Cynops pyrrhogaster.
View Article and Find Full Text PDFBackground: Newts, a type of urodele amphibian, offer remarkable insights into regenerative medicine due to their extraordinary tissue regeneration capabilities-a challenging feat in humans. During limb regeneration of adult newts, fascinating cellular and molecular processes are revealed, including scarless healing, de-differentiation of mature cells, and regeneration of limbs and digits. Sonic hedgehog (Shh), crucial for vertebrate limb development, is regulated by the zone of polarizing activity regulatory sequence (ZRS) in the limb bud zone of polarizing activity (ZPA).
View Article and Find Full Text PDFRegeneration competent vertebrates such as newts and salamanders possess a weakened adaptive immune system characterized by multiple connections between the lymphatic system and the blood vascular system called lymphatic hearts. The role of lymphatic vasculature and these lymphaticovenous connections in regeneration is unknown. We used in-vivo near-infrared lymphangiography, ultra-high frequency ultrasonography, micro-CT lymphangiography, and histological serial section 3-dimentional computer reconstruction to evaluate the lymphatic territories of Cynops pyrrhogaster.
View Article and Find Full Text PDFIn adult newts, when a limb is amputated, a mesenchymal cell mass called the blastema is formed on the stump, where blood vessels filled with premature erythrocytes, named polychromatic normoblasts (PcNobs), elongate. We previously demonstrated that PcNobs in the blastema express an orphan gene, , and that they secrete growth factors such as BMP2 and TGFβ1 into the surrounding tissues. However, the relationship between Newtic1 expression and growth factor secretion was not clear since was thought to encode a membrane protein.
View Article and Find Full Text PDFNewts can regenerate their limbs throughout their life-span. Focusing on muscle, certain species of newts such as Cynops pyrrhogaster dedifferentiate muscle fibers in the limb stump and mobilize them for muscle creation in the regenerating limb, as they grow beyond metamorphosis. However, which developmental process is essential for muscle dedifferentiation, metamorphosis or body growth, is unknown.
View Article and Find Full Text PDFIn surgical and cosmetic studies, scarless regeneration is an ideal method to heal skin wounds. To study the technologies that enable scarless skin wound healing in medicine, animal models are useful. However, four-limbed vertebrates, including humans, generally lose their competency of scarless regeneration as they transit to their terrestrial life-stages through metamorphosis, hatching or birth.
View Article and Find Full Text PDFNewts are unique salamanders that can regenerate their limbs as postmetamorphic adults. In order to regenerate human limbs as newts do, it is necessary to determine whether the cells homologous to those contributing to the limb regeneration of adult newts also exist in humans. Previous skin manipulation studies in larval amphibians have suggested that stump skin plays a pivotal role in the axial patterning of regenerating limbs.
View Article and Find Full Text PDFBiopharmaceutical products are of great importance in the treatment or prevention of many diseases and represent a growing share of the global pharmaceutical market. The usual technology for protein synthesis (cell-based expression) faces certain obstacles, especially with 'difficult-to-express' proteins. Cell-free protein synthesis (CFPS) can overcome the main bottlenecks of cell-based expression.
View Article and Find Full Text PDFA 3-month alcoholism rehabilitation program at psychiatric hospitals is common in Japan for patients with alcohol use disorder (AUD). However, many AUD patients are often hospitalized for the treatment of digestive disorders due to alcohol-related liver diseases and pancreatitis. In this sense, AUD patients need to be better supported by professionals and departments in general hospitals.
View Article and Find Full Text PDFThe newt, a group of urodele amphibians, has outstanding ability to repeatedly regenerate various body parts, even in the terrestrial life-stage. In this animal, when the limb is amputated, a cell mass named the blastema appears on the stump and eventually gives rise to a new functional limb. Erythrocytes (red blood cells) in most non-mammalian vertebrates, including the newt, preserve their nucleus throughout their life-span, although physiological roles of such nucleated erythrocytes, other than oxygen delivery, are not known.
View Article and Find Full Text PDFThe origin of tetrodotoxin (TTX) in amphibians has long been disputed. In this study, TTX and its putative biosynthetic intermediates or shunt compounds (4,9-anhydro-10-hemiketal-5-deoxyTTX and Cep-242) were dietary administered to the captive-reared, non-toxic Japanese fire-bellied newt, Cynops pyrrhogaster. After 4 weeks, the ingested compounds were detected mainly in the newt body using liquid chromatography-mass spectrometry (LC-MS), while these compounds were not converted into other TTX analogues in newts.
View Article and Find Full Text PDFThe newt is an amazing four-limbed vertebrate that can regenerate various body parts including the retina. In this animal, when the neural retina (NR) is removed from the eye by surgery (retinectomy), both the NR and the retinal pigment epithelium (RPE) eventually regenerate through the process of reprogramming and proliferation of RPE cells. Thus far, we have pursued the onset mechanism of adult newt retinal regeneration.
View Article and Find Full Text PDFThe newt switches the cellular mechanism for limb regeneration from a stem/progenitor-based mechanism(larval mode)to a dedifferentiation-based one(adult mode)as it grows beyond metamorphosis. When it comes to muscle, larval newts regenerate muscle from muscle stem/progenitor cells such as satellite cells, but after metamorphosis the animals recruit muscle fibers for the same purpose by means of dedifferentiation in which muscle fibers(multinucleated cell)at the stump are fragmented to produce mononucleated cells, the primary cell source for new muscle. Dedifferentiation of muscle fibers may have been advantageous for the newt, during its evolution, to quickly regenerate the limbs by supplementing satellite cells whose number and potency become restricted by metamorphosis(transformation to adapt to terrestrial environments)or aging.
View Article and Find Full Text PDFThe newt, a urodele amphibian, has an outstanding ability- even as an adult -to regenerate a functional retina through reprogramming and proliferation of the retinal pigment epithelium (RPE) cells, even though the neural retina is completely removed from the eye by surgery. It remains unknown how the newt invented such a superior mechanism. Here we show that disability of RPE cells to regenerate the retina brings about a symptom of proliferative vitreoretinopathy (PVR), even in the newt.
View Article and Find Full Text PDFThe newt, a urodele amphibian, is able to repeatedly regenerate its limbs throughout its lifespan, whereas other amphibians deteriorate or lose their ability to regenerate limbs after metamorphosis. It remains to be determined whether such an exceptional ability of the newt is either attributed to a strategy, which controls regeneration in larvae, or on a novel one invented by the newt after metamorphosis. Here we report that the newt switches the cellular mechanism for limb regeneration from a stem/progenitor-based mechanism (larval mode) to a dedifferentiation-based one (adult mode) as it transits beyond metamorphosis.
View Article and Find Full Text PDFThe adult newt has the remarkable ability to regenerate a functional retina from retinal pigment epithelium (RPE) cells, even when the neural retina (NR) is completely lost from the eye. In this system, RPE cells are reprogrammed into a unique state of multipotent cells, named RPESCs, in an early phase of retinal regeneration. However, the signals that trigger reprogramming remain unknown.
View Article and Find Full Text PDFNewts have the ability to repeatedly regenerate their lens even during ageing. However, it is unclear whether this regeneration reflects an undisturbed genetic activity. To answer this question, we compared the transcriptomes of lenses, irises and tails from aged newts that had undergone lens regeneration 19 times with the equivalent tissues from young newts that had never experienced lens regeneration.
View Article and Find Full Text PDFThe tetrodotoxin (TTX) contents of the Japanese fire-bellied newt, Cynops pyrrhogaster, captive-reared from eggs to metamorphosed juveniles with a non-toxic diet for 70 weeks, as well as wild-caught juvenile newts, were investigated using a high-resolution hydrophilic interaction chromatography-LC-MS. TTX was detected in 0- to 22-week-old captive-reared juvenile newts but was not detected (<15 ng/g) in the 36- to 70-week-old newts, while significant levels of TTX (1.3-14 μg/g) were detected in the wild-caught juveniles.
View Article and Find Full Text PDFThe adult newt has the ability to regenerate the neural retina following injury, a process achieved primarily by the retinal pigment epithelium (RPE). To deliver exogenous genes to the RPE for genetic manipulation of regenerative events, we isolated the newt RPE65 promoter region by genome walking. First, we cloned the 2.
View Article and Find Full Text PDFRetinal regeneration in the adult newt is a useful system to uncover essential mechanisms underlying the regeneration of body parts of this animal as well as to find clues to treat retinal disorders such as proliferative vitreoretinopathy. Here, to facilitate the study of early processes of retinal regeneration, we provide a de novo assembly transcriptome and inferred proteome of the Japanese fire bellied newt (Cynops pyrrhogaster), which was obtained from eyeball samples of day 0-14 after surgical removal of the lens and neural retina. This transcriptome (237,120 in silico transcripts) contains most information of cDNAs/ESTs which has been reported in newts (C.
View Article and Find Full Text PDFThe reprogramming of retinal pigment epithelium (RPE) cells in the adult newt immediately after retinal injury is an area of active research for the study of retinal disorders and regeneration. We demonstrate here that unlike embryonic/larval retinal regeneration, adult newt RPE cells are not directly reprogrammed into retinal stem/progenitor cells; instead, they are programmed into a unique state of multipotency that is similar to the early optic vesicle (embryo) but preserves certain adult characteristics. These cells then differentiate into two populations from which the prospective-neural retina and -RPE layers are formed with the correct polarity.
View Article and Find Full Text PDFThe retinal pigment epithelium (RPE) is a partner of the neural retina and is indispensable for vision. In humans, proliferation and transformation (cell-type switching) of RPE cells after a traumatic injury of the neural retina causes a retinal disorder leading to loss of vision. In contrast, in certain adult amphibians such as Xenopus laevis and the newt, a similar process in RPE cells leads to regeneration of the entire retina.
View Article and Find Full Text PDFAdult newt retinal pigment epithelium (RPE) cells are mitotically quiescent in the physiological condition, but upon a traumatic injury of the neural retina (NR) they re-enter the cell-cycle and eventually regenerate the missing NR. Here, to understand the mechanism underlying the cell-cycle re-entry of RPE cells following NR injury, we first investigated changes in MEK-ERK signaling activity in RPE cells upon removal of the NR (retinectomy) from the eye of living animals, and found that ERK-mediated signaling activity is elevated quickly (in 30 min) upon retinectomy. In addition, we found, in in vitro analyses, that immediate early activation of MEK-ERK signaling may occur in RPE cells upon NR injury, intensifying the MEK-ERK signaling itself through up-regulation of the expression of constituent molecules in the pathway, and that 1-h blockade of such early MEK-ERK signaling interferes with the cell-cycle re-entry, which occurs 5-10 days later.
View Article and Find Full Text PDFThe newt is an indispensable model animal, of particular utility for regeneration studies. Recently, a high-throughput transgenic protocol was established for the Japanese common newt, Cynops pyrrhogaster. For studies of regeneration, metamorphosed animals may be favorable; however, for this species, there is no efficient protocol for maintaining juveniles after metamorphosis in the laboratory.
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