Long-term survival of transplanted induced pluripotent stem cell-derived neurospheres with nerve conduit into sciatic nerve defects in immunosuppressed mice

Since the advent of induced pluripotent stem cells (iPSCs), clinical trials using iPSC-based cell transplantation therapy have been performed in various fields of regenerative medicine. We previously demonstrated that the transplantation of mouse iPSC-derived neurospheres containing neural stem/progenitor cells with bioabsorbable nerve conduits promoted nerve regeneration in the long term in murine sciatic nerve defect models. However, it remains unclear how long the grafted iPSC-derived neurospheres survived and worked after implantation. In this study, the long-term survival of the transplanted mouse iPSC-derived neurospheres with nerve conduits was evaluated in high-immunosuppressed or non-immunosuppressed mice using in vivo imaging for the development of iPSC-based cell therapy for peripheral nerve injury. Complete 5-mm long defects were created in the sciatic nerves of immunosuppressed and non-immunosuppressed mice and reconstructed using nerve conduits coated with iPSC-derived neurospheres labeled with ffLuc. The survival of mouse iPSC-derived neurospheres on nerve conduits was monitored using in vivo imaging. The transplanted iPSC-derived neurospheres with nerve conduits survived for 365 days after transplantation in the immunosuppressed allograft models, but only survived for at least 14 days in non-immunosuppressed allograft models. This is the first study to find the longest survival rate of stem cells with nerve conduits transplanted into the peripheral nerve defects using in vivo imaging and demonstrates the differences in graft survival rate between the immunosuppressed allograft model and immune responsive allograft model. In the future, if iPSC-derived neurospheres are successfully transplanted into peripheral nerve defects with nerve conduits using iPSC stock cells without eliciting an immune response, axonal regeneration will be induced due to the longstanding supportive effect of grafted cells on direct remyelination and/or secretion of trophic factors.     

Validation of the organic electrochemical transistor for in vitro toxicology

Background

The gastrointestinal epithelium provides a physical and biochemical barrier to the passage of ions and small molecules; however this barrier may be breached by pathogens and toxins. The effect of individual pathogens/toxins on the intestinal epithelium has been well characterized: they disrupt barrier tissue in a variety of ways, such as by targeting tight junction proteins, or other elements of the junctions between adjacent cells. A variety of methods have been used to characterize disruption in barrier tissue, such as immunofluorescence, permeability assays and electrical measurements of epithelia resistance, but these methods remain time consuming, costly and ill-suited to diagnostics or high throughput toxicology.

Methods

The advent of organic electronics has created a unique opportunity to interface the worlds of electronics and biology, using devices such as the organic electrochemical transistor (OECT), whose low cost materials and potential for easy fabrication in high throughput formats represent a novel solution for assessing epithelial tissue integrity.

Results

In this study, OECTs were integrated with gastro-intestinal cell monolayers to study the integrity of the gastrointestinal epithelium, providing a very sensitive way to detect minute changes in ion flow across the cell layer due to inherent amplification by the transistor.

Major conclusions

We validate the OECT against traditional methods by monitoring the effect of toxic compounds on epithelial tissue. We show a systematic characterization of this novel method, alongside existing methods used to assess barrier tissue function.

General significance

The toxic compounds induce a dramatic disruption of barrier tissue, and the OECT measures this disruption with increased temporal resolution and greater or equal sensitivity when compared with existing methods. This article is part of a Special Issue entitled Organic Bioelectronics — Novel Applications in Biomedicine.     

A retinoic acid receptor agonist tamibarotene suppresses iron accumulation in the liver

Objective:

Hepatic iron overload (HIO) and iron‐induced oxidative stress have recently emerged as an important factor for the development and progression of insulin resistance. The aim of this study was to evaluate the effect of tamibarotene, a selective retinoic acid receptor α/β agonist, on hepatic iron metabolism, based on our previous findings that retinoids suppress hepatic iron accumulation by increasing hepatic iron efflux through the regulation of hemojuvelin and ferroportin expression.

Design and Methods:

We quantitated the non‐heme iron content and iron metabolism‐related gene expression in the liver, and serum lipid and blood glucose levels in KK‐A^y mice after dietary administration of tamibarotene.

Results:

It was demonstrated that tamibarotene significantly reduced blood glucose and hepatic iron, but not serum lipids, and that hemojuvelin expression significantly decreased while ferroportin increased, as observed previously.

Conclusions:

These results suggest that tamibarotene is a promising alternative for the treatment of insulin resistance associated with HIO.     

Development of a Serial Order in Speech Constrained by Articulatory Coordination

Universal linguistic constraints seem to govern the organization of sound sequences in words. However, our understanding of the origin and development of these constraints is incomplete. One possibility is that the development of neuromuscular control of articulators acts as a constraint for the emergence of sequences in words. Repetitions of the same consonant observed in early infancy and an increase in variation of consonantal sequences over months of age have been interpreted as a consequence of the development of neuromuscular control. Yet, it is not clear how sequential coordination of articulators such as lips, tongue apex and tongue dorsum constrains sequences of labial, coronal and dorsal consonants in words over the course of development. We examined longitudinal development of consonant-vowel-consonant(-vowel) sequences produced by Japanese children between 7 and 60 months of age. The sequences were classified according to places of articulation for corresponding consonants. The analyses of individual and group data show that infants prefer repetitive and fronting articulations, as shown in previous studies. Furthermore, we reveal that serial order of different places of articulations within the same organ appears earlier and then gradually develops, whereas serial order of different articulatory organs appears later and then rapidly develops. In the same way, we also analyzed the sequences produced by English children and obtained similar developmental trends. These results suggest that the development of intra- and inter-articulator coordination constrains the acquisition of serial orders in speech with the complexity that characterizes adult language.     

An X-linked haplotype of Neandertal origin is present among all non-African populations

Recent work on the Neandertal genome has raised the possibility of admixture between Neandertals and the expanding population of Homo sapiens who left Africa between 80 and 50 Kya (thousand years ago) to colonize the rest of the world. Here, we provide evidence of a notable presence (9% overall) of a Neandertal-derived X chromosome segment among all contemporary human populations outside Africa. Our analysis of 6,092 X-chromosomes from all inhabited continents supports earlier contentions that a mosaic of lineages of different time depths and different geographic provenance could have contributed to the genetic constitution of modern humans. It indicates a very early admixture between expanding African migrants and Neandertals prior to or very early on the route of the out-of-Africa expansion that led to the successful colonization of the planet.     

Process engineering and optimization of glycerol separation in a packed-bed reactor for enzymatic biodiesel production

A process model for efficient glycerol separation during methanolysis in an enzymatic packed-bed reactor (PBR) was developed. A theoretical glycerol removal efficiency from the reaction mixture containing over 30% methyl esters was achieved at a high flow rate of 540 ml/h. To facilitate a stable operation of the PBR system, a batch reaction prior to continuous methanolysis was conducted using oils with different acid values and immobilized lipases pretreated with methyl esters. The reaction system successfully attained the methyl ester content of over 30% along with reduced viscosity and water content. Furthermore, to obtain a high methyl ester content above 96% continuously, long-term lipase stability was confirmed by operating a bench-scale PBR system for 550 h, in which the intermediates containing methyl esters and residual glycerides were fed into the enzyme-packed columns connected in series. Therefore, the developed process model is considered useful for industrial biodiesel production.     

Cyclooxygenase-2 is required for activated pancreatic stellate cells to respond to proinflammatory cytokines

Cyclooxygenase-2 (COX-2) mediates various inflammatory responses and is expressed in pancreatic tissue from patients with chronic pancreatitis. To examine the role of COX-2 in chronic pancreatitis, we investigated its participation in regulating functions of pancreatic stellate cells (PSCs), using isolated rat PSCs. COX-2 was expressed in culture-activated PSCs but not in freshly isolated quiescent PSCs. TGF-1, IL-1, and IL-6 enhanced COX-2 expression in activated PSCs, concomitantly increasing the expression of -smooth muscle actin (-SMA), a parameter of PSC activation. The COX-2 inhibitor NS-398 blocked culture activation of freshly isolated quiescent PSCs. NS-398 also inhibited the enhancement of -SMA expression by TGF-1, IL-1, and IL-6 in activated PSCs. These data indicate that COX-2 is required for the initiation and promotion of PSC activation. We further investigated the mechanism by which cytokines enhance COX-2 expression in PSCs. Adenovirus-mediated expression of dominant negative Smad2/3 inhibited the increase in expression of COX-2, -SMA, and collagen-1 mediated by TGF-1 in activated PSCs. Moreover, dominant negative Smad2/3 expression attenuated the expression of COX-2 and -SMA enhanced by IL-1 and IL-6. Anti-TGF- neutralizing antibody also attenuated the increase in COX-2 and -SMA expression caused by IL-1 and IL-6. IL-6 as well as IL-1 enhanced TGF-1 secretion from PSCs. These data indicate that Smad2/3-dependent pathway plays a central role in COX-2 induction by TGF-1, IL-1, and IL-6. Furthermore, IL-1 and IL-6 promote PSC activation by enhancing COX-2 expression indirectly through Smad2/3-dependent pathway by increasing TGF-1 secretion from PSCs. transforming growth factor-; interleukin; Smad; autocrine; pancreatic fibrosis     

Occurrence of a nonsulfated chondroitin proteoglycan in the dried saliva of Collocalia swiftlets (edible bird's-nest)

Despite their wide occurrence, proteoglycans (PGs) have never been isolated from the saliva of higher animals. We found that the Collocalia glycoproteins isolated from edible birds'-nests (the dried forms of regurgitated saliva of male Collocalia swiftlets) were rich in a PG containing nonsulfated chondroitin glycosaminoglycans (GAGs). We have devised a method to isolate a PG from the water extract of the white nest built by Aerodramus fuciphagus (white nest swiftlets) with a yield of 2-mg PG per gram nest. This PG contained 83% of carbohydrates, of which 79% were GalNAc and GlcUA (D-glucuronic acid) in an equimolar ratio. By using chondroitin AC lyase, the structure of GAGs in this PG was established to be chondroitin ( --> 4GlcUAbeta1 --> 3GalNAcbeta1 --> )(n) chains. The average molecular mass of the chondroitin chain was estimated to be 49 kDa by gel filtration. We have isolated a linkage region hexasaccharide, DeltaHexUAalpha1 --> 3GalNAcbeta1 --> 4GlcUAbeta1 --> 3Galbeta1 --> 3Galbeta1 --> 4Xyl, from this PG by chondroitinase ABC digestion to show that the GAGs in this PG are also linked to the core protein through the common tetrasaccharide linker, GlcUAbeta1 --> 3Galbeta1 --> 3Galbeta1 --> 4Xyl, found in various PGs. As water was not effective in extracting uronic acid-containing glycoconjugates from the black nest built by black nest swiftlets (A. maximus), we used 4 M guanidium chloride and anion-exchange chromatography in the presence of urea to extract and isolate about 30 mg of a chondroitin PG preparation from 10 g of the desialylated black nest. As the biological significance of chondroitin is still not well understood, bird's nest should become a convenient source for preparing this unique GAG to study its biological functions.     

Epithelial Na+ channel and ion transport in human nasal polyp and paranasal sinus mucosa

The purpose of the present study is to characterize the ENaC-mediated Na+ absorption in human upper airway epithelia, nasal cavity, and paranasal sinus. To perform the purpose, we obtained epithelial cells from human nasal polyp (NP) and paranasal sinus mucosa (PSM) by endoscopic surgery. We measured the short-circuit current (I(sc)) sensitive to benzamil (a specific ENaC blocker). The benzamil-sensitive I(sc) (Na+ absorption) in NP was larger than that in PSM. The mRNA expression of three subunits of ENaC was as follows: alpha>beta>gamma in both tissue, NP and MS. The mRNA expression of gamma subunit of ENaC in NP was larger than that in PSM, but no difference of mRNA expression of alpha or beta ENaC subunit between NP and PSM was detected. We found correlation of the Na+ absorption to mRNA expression of gamma ENaC in NP and PSM. Forskolin diminished the Na+ absorption associated with an increase in Cl- secretion. These observations suggest that: (1) human NP absorbs more ENaC-mediated Na+ than PSM, (2) expression of gamma ENaC in plays a key role in the ENaC-mediated Na+ absorption in NP and PSM, and (3) cAMP diminishes the ENaC-mediated Na+ absorption by stimulating Cl- secretion (diminution of driving force for Na+ absorption) in NP and PSM.