Combined treatment of lactic acid-ultrasound-papain on yak meat and its tenderization mechanism.

The combined effects of lactic acid-ultrasound-papain on yak meat tenderization were investigated, and its tenderization mechanism elucidated. The optimal condition for combined tenderization was obtained with 0.03% lactic acid, ultrasound for 30 mins, and 200 U/g of papain. When compared with the untreated yak meat, the cutting force and the cooking loss of the tenderized yak meat were decreased by 62.16% and 31.25%, respectively, while the myofibrillar fragmentation index increasing 4.3 times. After the combined tenderization, it was observed a loose arrangement of muscle with larger gaps and cavities. The random-coil content of myofibrillar protein increased to 48.3%, while α-helix decreased to 14.4%, indicating that the myofibrillar protein underwent some unfolding and stretching. These results demonstrated that this combined treatment improved the tenderization of yak meat by disrupting muscle integrity, increasing its water-holding capacity, denaturing myofibrillar protein, and changing its spatial structure. The combined process using lactic acid-ultrasound-papain showed some potential to improve meat texture.

Gut microbiota of Anabas testudineus (Bloch, 1792) in the e-waste dismantling region: In situ status and relationship with internal metal burden.

Due to the production of large quantities of electronic waste (e-waste), unsafe dismantling has caused serious pollution as well as toxicological impacts on both wildlife and humans. As an important aspect of physiology and health, the wildlife's gut microbiota and its changes induced by pollution have been recruiting increasing concerns. To reveal the gut microbiota-related ecotoxicology induced by e-waste dismantling, this study resolves the gut microbiota profile of Anabas testudineus, a native highly adapted nonmodel fish under the in situ exposure, and reveals whether and how the microbiota was altered. The comparisons are made by collecting samples from different e-waste polluted sites in Guiyu (a town in South China) and a nearby reference (nonpolluted) site. The overall gut microbiota landscape of A. testudineus is similar to that of other reported fishes, with an average of ∼300 OTUs, and constituted by Firmicutes (34.51%), Fusobacteria (29.16%) as the major phyla. Obviously different liver metal burdens/fingerprints were observed between the e-waste and reference sites. Accordingly, although the alpha-diversity (ACE, Simpson, and Shannon) of the gut microbiota did not significantly vary, a detailed exploration of the microbiota constitution indicated significant differences at various taxonomic levels, including a series of significantly different species and biomarkers, and showing site-specific beta-diversity clustering patterns. Interestingly, a few bacteria with greater abundance in the fish gut of e-waste polluted sites were also reported to present in other contaminated environments, have a role in wastewater treatment, be capable to transform metal, etc. Redundancy analysis (RDA) and Pearson association analyses indicated significant associations between Mn and Cetobacterium somerae (Pearson r = 0.3612, p = 0.0008) and between Pb and Clostridium colicanis (Pearson r = 0.5151, p < 0.0001). In summary, pollution from e-waste dismantling may have a role in altering the fish gut microbiota, and this research provides insights for better understanding e-waste ecotoxicology and improving future conservation.

A dynamic clamp protocol to artificially modify cell capacitance.

Dynamics of excitable cells and networks depend on the membrane time constant, set by membrane resistance and capacitance. Whereas pharmacological and genetic manipulations of ionic conductances of excitable membranes are routine in electrophysiology, experimental control over capacitance remains a challenge. Here, we present capacitance clamp, an approach that allows electrophysiologists to mimic a modified capacitance in biological neurons via an unconventional application of the dynamic clamp technique. We first demonstrate the feasibility to quantitatively modulate capacitance in a mathematical neuron model and then confirm the functionality of capacitance clamp in in vitro experiments in granule cells of rodent dentate gyrus with up to threefold virtual capacitance changes. Clamping of capacitance thus constitutes a novel technique to probe and decipher mechanisms of neuronal signaling in ways that were so far inaccessible to experimental electrophysiology.

The Guide to Dendritic Spikes of the Mammalian Cortex In Vitro and In Vivo.

Half a century since their discovery by Llinás and colleagues, dendritic spikes have been observed in various neurons in different brain regions, from the neocortex and cerebellum to the basal ganglia. Dendrites exhibit a terrifically diverse but stereotypical repertoire of spikes, sometimes specific to subregions of the dendrite. Despite their prevalence, we only have a glimpse into their role in the behaving animal. This article aims to survey the full range of dendritic spikes found in excitatory and inhibitory neurons, compare themin vivoversusin vitro, and discuss new studies describing dendritic spikes in the human cortex. We focus on neocortical and hippocampal neurons and present a roadmap to identify and understand the broader role of dendritic spikes in single-cell computation.

Novel Molecule Nell-1 Promotes the Angiogenic Differentiation of Dental Pulp Stem Cells.

INTRODUCTION: This work aimed to reveal the crucial role of Nell-1 in the angiogenic differentiation of human dental pulp stem cells (DPSCs) alone or co-cultured with human umbilical vein endothelial cell (HUVECs) in vitro and whether this molecule is involved in the pulp exposure model in vivo. METHODS: Immunofluorescence was conducted to ascertain the location of Nell-1 on DPSCs, HUVECs, and normal rat dental tissues. RT-PCR, Western blot, and ELISA were performed to observe the expression levels of angiogenic markers and determine the angiogenic differentiation of Nell-1 on DPSCs alone or co-cultured with HUVECs, as well as in vitro tube formation assay. Blood vessel number for all groups was observed and compared using immunohistochemistry by establishing a rat pulp exposure model. RESULTS: Nell-1 is highly expressed in the nucleus of DPSCs and HUVECs and is co-expressed with angiogenic markers in normal rat pulp tissues. Hence, Nell-1 can promote the angiogenic marker expression in DPSCs alone and co-cultured with other cells and can enhance angiogenesis in vitro as well as in the pulp exposure model. CONCLUSION: Nell-1 may play a positive role in the angiogenic differentiation of DPSCs.

Nell-1 attenuates lipopolysaccharide-induced inflammation in human dental pulp cells.

Nel-like molecule type 1 (Nell-1) is a secreted protein that plays an important role in osteoinduction in multiple animal models. A previous study has suggested the anti-inflammatory effect of Nell-1 on bone inflammation inhibition. However, its role in pulpitis has not been investigated. The present study aims to explore the effect of human recombinant Nell-1 (Nell-1) on rat pulp inflammation response, and its effect on lipopolysaccharide-induced inflammation in human dental pulp cells and its related intracellular signaling pathways. 30 Wistar rats with healthy non-carious maxillary first molars were chosen, Nell-1 was absorbed onto a sterile collagen sponge and capped onto exposed pulps. The expression of IL-6 and IL-8 were detected by immunohistochemical staining. Human dental pulp cells (hDPCs) were isolated from healthy extracted premolars and third molars. hDPCs were co-cultured with Escherichia coli lipopolysaccharide (LPS), Nell-1 protein, and mitogen-activated protein kinase (MAPK) inhibitors. The expression of pro-inflammatory cytokines and chemokines, such as IL-6 and IL-8, was examined via quantitative real-time PCR and enzyme-linked immunosorbent assay. The results showed that Nell-1 inhibited the inflammatory response of rat pulp. LPS treatment contributed to the expression of inflammatory factors in hDPCs, whereas Nell-1 obviously suppressed the LPS-induced inflammation. p38 MAPK and extracellular signal-regulated kinase (ERK) MAPK inhibitors attenuated the anti-inflammatory effect of hrNell-1, whereas the c-Jun N-terminal kinases (JNK) MAPK inhibitor exerted minimal effect. Therefore Nell-1 could inhibit LPS-induced inflammation in human dental pulp cells, and this effect may be mediated by p38 and ERK MAPK signaling pathways, but not JNK MAPK signaling pathway.

Interaction of Nel-like molecule 1 with apoptosis related protein 3 with its influence on human dental pulp cells proliferation and differentiation into odontoblasts.

Nel-like molecule 1 (Nell-1) is an essential positive regulator of tooth development and odontoblast differentiation. However, its precise mechanism remains undetermined. This study aims to explore the possible receptor or binding protein of Nell-1. Results showed that Nell-1 and Apoptosis related protein 3(APR3) expression levels were high in odontoblasts and inversely correlated. Endogenous Nell-1 co-immunoprecipitated with APR3, and this co-IP was reciprocal. Double immunofluorescence staining revealed that Nell-1 and APR3 colocalized on the nuclear envelope of human dental pulp cells. Nell-1 inhibited the proliferation of these cells co-infected with APR3 through Cyclin D1 downregulation. The interaction of Nell-1 with APR3 stimulated alkaline phosphatase (ALP) activity and promoted the expression and mineralization of DSPP, ALP, OPN, and BSP. The shRNA of APR3 decreased cell differentiation and mineralization. Nell-1 could reciprocally interact with APR3 and stimulate the differentiation and mineralization of human dental pulp cells. Future studies should explore the potential functional connection and the molar mechanism of such interaction.

Nell-1 promotes the neural-like differentiation of dental pulp cells.

Previous studies showed that Nel-like molecule-1 (Nell-1) can positively regulate odontoblastic differentiation and dentin formation. Intriguingly, our group found that Nell-1 is co-expressed with neural markers. The purpose of this study was to investigate whether Nell-1 protein plays a regulatory role in the differentiation of dental pulp cells into neural-like cells by in vivo and in vitro studies. The expression patterns of Nell-1 and dental pulp neural markers were observed by double immunofluorescence staining in normal dental pulp tissue sections of Wistar rat. Collagen sponge containing Nell-1 protein was added into the pulp cavity of rat molars in order to observe the expression patterns of neural markers in rat dental pulp repair and regeneration model by immunohistochemical staining. Moreover, human dental pulp stem cells (hDPSCs) were cultured, and different concentrations of Nell-1 protein were added for 12 h, 24 h, and 72h. The expression of neural markers was detected by using quantitative real-time polymerase chain reaction and Western blot. Nell-1 was co-expressed with neural markers including substance P (SP) and Nestin in rat dental pulp tissue. The expression of neural markers including SP, neuron-specific enolase (NSE), and Nestin was increased obviously in rat dental pulp tissues stimulated with Nell-1 protein. In cultured hDPSCs induced by Nell-1 protein, the expression of neural markers including glial fibrillary acidic protein (GFAP), Nestin, and ß-III tubulin was increased. Nell-1 plays a positive role in inducing the differentiation of DPSCs into neural-like cells.

Effects of Nel-like molecule-1 and bone morphogenetic protein 2 combination on rat pulp repair.

Nel-like molecule-1 (NELL-1) is a novel highly specific growth factor that can induce osteoblast differentiation and bone formation as well as odontoblast differentiation. Recent studies have suggested that NELL-1 can synergistically increase bone formation and regeneration with bone morphogenetic protein 2 (BMP2) and inhibit adverse effects induced by BMP2. This study aimed to evaluate the combined effects of NELL-1 and BMP2 on rat pulp repair. The experiment used healthy non-carious maxillary first molars from 60 Wistar rats. Exposed pulps were capped with NELL-1 plus BMP2, NELL-1 alone, and BMP2 alone, and each was absorbed onto a sterile collagen sponge. In the control samples, the collagen sponge alone and Dycal were used as capping agents. After l, 2 and 4 weeks, the rats were sacrificed. The formation of reparative dentin, as well the situation of pulp repair, was detected by hematoxylin-eosin (HE) staining; moreover, the expression of dentin specific protein-dentin sialophosphoprotein (DSPP) and the pro-inflammatory cytokines interleukin-6 (IL6) and interleukin-8 (IL8) was detected by immunohistochemical staining. Quantitative real-time PCR experiment was used to investigate the mRNA levels of IL6 and IL8. The results showed that pulp capping with NELL-1 plus BMP2 in rats had superior ability in inducing reparative dentin formation with dentin tubules and in reducing the inflammatory cell response compared with the other groups. These findings suggested that combined use of NELL-1 and BMP2 could positively regulate pulp repair.

Characterization of 19 polymorphic SSR markers in Spirodela polyrhiza (Lemnaceae) and cross-amplification in Lemna perpusilla.

PREMISE OF THE STUDY: Polymorphic microsatellite primers were developed for greater duckweed, Spirodela polyrhiza (Lemnaceae), to investigate genetic diversity and structure for application in a bioremediation program. METHODS AND RESULTS: A total of 401 publicly available S. polyrhiza whole-genome shotgun sequences were searched for simple sequence repeat loci of two or more nucleotides. Of these, 60 primer pairs were selected to analyze 68 individuals of S. polyrhiza from three populations. Nineteen polymorphic microsatellite loci were developed. A total of 108 alleles were detected with an average of 5.7 alleles per locus. The levels of expected and observed heterozygosity were 0.0511-0.8669 and 0-0.8750, respectively. Ten loci also successfully amplified in 16 individuals of Lemna perpusilla. CONCLUSIONS: The results demonstrate the broad utility of these microsatellite loci for studying population genetics in S. polyrhiza.