Ciliary abnormalities due to defects in the retrograde transport protein DYNC2H1 in short-rib polydactyly syndrome.

The short-rib polydactyly (SRP) syndromes are a heterogeneous group of perinatal lethal skeletal disorders with polydactyly and multisystem organ abnormalities. Homozygosity by descent mapping in a consanguineous SRP family identified a genomic region that contained DYNC2H1, a cytoplasmic dynein involved in retrograde transport in the cilium. Affected individuals in the family were homozygous for an exon 12 missense mutation that predicted the amino acid substitution R587C. Compound heterozygosity for one missense and one null mutation was identified in two additional nonconsanguineous SRP families. Cultured chondrocytes from affected individuals showed morphologically abnormal, shortened cilia. In addition, the chondrocytes showed abnormal cytoskeletal microtubule architecture, implicating an altered microtubule network as part of the disease process. These findings establish SRP as a cilia disorder and demonstrate that DYNC2H1 is essential for skeletogenesis and growth.

Understanding dietary carbohydrates in black soldier fly larvae treatment of organic waste in the circular economy.

Black soldier fly larvae (BSFL) treatment is promising for organic waste valorisation in the circular economy; however, waste variability impacts the process performance and quality of produced larvae. Specifically, variation in the carbohydrate profile of treated wastes has been suggested to have a significant impact on BSFL treatment performance and quality of produced larvae, with particular carbohydrates either positively or negatively influencing these variables. This study examines the hypothesis that the types of carbohydrates within the substrate can have significant influence on larval survival, waste reduction, bioconversion, and waste conversion efficiency, as well as the crude lipid content and fatty acid profiles of the produced larvae. The carbohydrates explored were D glucose, sucrose, D (-) fructose, corn and wheat starch, D (+) galactose, D (+) mannose, D (+) xylose, D (-) arabinose and xylan from beechwood. Young larvae were grown for 9 days on chicken feed-based diets containing various carbohydrate additives each at 20 dry mass %. Treatments containing hemicellulose constituents galactose and arabinose produced the most adverse effects on process performance relative to the benchmark. Xylan was significantly detrimental to bioconversion (-14.7 ± 3.8%) and waste conversion efficiencies (-19.0 ± 4.4%). There were minimal significant effects on performance from mono- and di-saccharides and starch additives. Larvae crude lipid contents were significantly increased by wheat starch (+12.6 ± 3.0%) and decreased by galactose (-15.0 ± 1.4%) and xylan additives (-27.5 ± 3.4%), however fatty acid profiles were largely unaffected and were dominated by lauric acid. These results indicate that despite an otherwise balanced and nutritious substrate, the carbohydrate profile of organic waste should be an important consideration in BSFL treatment when ensuring process performance and larval lipid contents. The consequences of these results for BSFL treatment of real wastes are discussed. Large scale treatment facilities should formulate substrates accordingly and identify methods to mitigate the anti-nutritional effects of poor carbohydrate profiles, particularly those high in hemicelluloses and their constituents.

Lipopolysaccharide-induced inflammation attenuates taste progenitor cell proliferation and shortens the life span of taste bud cells.

BACKGROUND: The mammalian taste bud, a complex collection of taste sensory cells, supporting cells, and immature basal cells, is the structural unit for detecting taste stimuli in the oral cavity. Even though the cells of the taste bud undergo constant turnover, the structural homeostasis of the bud is maintained by balancing cell proliferation and cell death. Compared with nongustatory lingual epithelial cells, taste cells express higher levels of several inflammatory receptors and signalling proteins. Whether inflammation, an underlying condition in some diseases associated with taste disorders, interferes with taste cell renewal and turnover is unknown. Here we report the effects of lipopolysaccharide (LPS)-induced inflammation on taste progenitor cell proliferation and taste bud cell turnover in mouse taste tissues. RESULTS: Intraperitoneal injection of LPS rapidly induced expression of several inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and interleukin (IL)-6, in mouse circumvallate and foliate papillae. TNF-alpha and IFN-gamma immunoreactivities were preferentially localized to subsets of cells in taste buds. LPS-induced inflammation significantly reduced the number of 5-bromo-2'-deoxyuridine (BrdU)-labeled newborn taste bud cells 1-3 days after LPS injection, suggesting an inhibition of taste bud cell renewal. BrdU pulse-chase experiments showed that BrdU-labeled taste cells had a shorter average life span in LPS-treated mice than in controls. To investigate whether LPS inhibits taste cell renewal by suppressing taste progenitor cell proliferation, we studied the expression of Ki67, a cell proliferation marker. Quantitative real-time RT-PCR revealed that LPS markedly reduced Ki67 mRNA levels in circumvallate and foliate epithelia. Immunofluorescent staining using anti-Ki67 antibodies showed that LPS decreased the number of Ki67-positive cells in the basal regions surrounding circumvallate taste buds, the niche for taste progenitor cells. PCR array experiments showed that the expression of cyclin B2 and E2F1, two key cell cycle regulators, was markedly downregulated by LPS in the circumvallate and foliate epithelia. CONCLUSIONS: Our results show that LPS-induced inflammation inhibits taste progenitor cell proliferation and interferes with taste cell renewal. LPS accelerates cell turnover and modestly shortens the average life span of taste cells. These effects of inflammation may contribute to the development of taste disorders associated with infections.

Cartilage-selective genes identified in genome-scale analysis of non-cartilage and cartilage gene expression.

BACKGROUND: Cartilage plays a fundamental role in the development of the human skeleton. Early in embryogenesis, mesenchymal cells condense and differentiate into chondrocytes to shape the early skeleton. Subsequently, the cartilage anlagen differentiate to form the growth plates, which are responsible for linear bone growth, and the articular chondrocytes, which facilitate joint function. However, despite the multiplicity of roles of cartilage during human fetal life, surprisingly little is known about its transcriptome. To address this, a whole genome microarray expression profile was generated using RNA isolated from 18-22 week human distal femur fetal cartilage and compared with a database of control normal human tissues aggregated at UCLA, termed Celsius. RESULTS: 161 cartilage-selective genes were identified, defined as genes significantly expressed in cartilage with low expression and little variation across a panel of 34 non-cartilage tissues. Among these 161 genes were cartilage-specific genes such as cartilage collagen genes and 25 genes which have been associated with skeletal phenotypes in humans and/or mice. Many of the other cartilage-selective genes do not have established roles in cartilage or are novel, unannotated genes. Quantitative RT-PCR confirmed the unique pattern of gene expression observed by microarray analysis. CONCLUSION: Defining the gene expression pattern for cartilage has identified new genes that may contribute to human skeletogenesis as well as provided further candidate genes for skeletal dysplasias. The data suggest that fetal cartilage is a complex and transcriptionally active tissue and demonstrate that the set of genes selectively expressed in the tissue has been greatly underestimated.

Early-onset age-related changes in dendritic cell subsets can impair antigen-specific T helper 1 (Th1) CD4 T cell priming.

Decline in CD4 T cell immune responses is associated with aging. Although a number of immunological defects have been identified in elderly mice (>18 months old), a key early-onset immune defect at middle age could be a driver or contributor to defective CD4 T cell responses. Our studies demonstrate that age-related alterations in DC subsets within the priming environment of middle-aged mice (12 months old) correlate with and can directly contribute to decreases in antigen-specific CD4 T cell Th1 differentiation, which measured by T-bet and IFN-γ expression, was decreased significantly in T cells following VSV infection or s.c. immunization with a protein antigen in the context of immune stimulation via OX40. The deficient Th1 phenotype, observed following protein antigen challenge, was found to be the result of an age-related decrease in an inflammatory DC subset (CD11b+ Gr-1/Ly6C+) in the dLN that corresponded with T cell dysfunction. In the virus model, we observed significant changes in two DC subsets: mDCs and pDCs. Thus, different, early age-related changes in the DC profile in the priming environment can significantly contribute to impaired Th1 differentiation, depending on the type of immunological challenge.

Defects in the peripheral taste structure and function in the MRL/lpr mouse model of autoimmune disease.

While our understanding of the molecular and cellular aspects of taste reception and signaling continues to improve, the aberrations in these processes that lead to taste dysfunction remain largely unexplored. Abnormalities in taste can develop in a variety of diseases, including infections and autoimmune disorders. In this study, we used a mouse model of autoimmune disease to investigate the underlying mechanisms of taste disorders. MRL/MpJ-Fas(lpr)/J (MRL/lpr) mice develop a systemic autoimmunity with phenotypic similarities to human systemic lupus erythematosus and Sjögren's syndrome. Our results show that the taste tissues of MRL/lpr mice exhibit characteristics of inflammation, including infiltration of T lymphocytes and elevated levels of some inflammatory cytokines. Histological studies reveal that the taste buds of MRL/lpr mice are smaller than those of wild-type congenic control (MRL/+/+) mice. 5-Bromo-2'-deoxyuridine (BrdU) pulse-chase experiments show that fewer BrdU-labeled cells enter the taste buds of MRL/lpr mice, suggesting an inhibition of taste cell renewal. Real-time RT-PCR analyses show that mRNA levels of several type II taste cell markers are lower in MRL/lpr mice. Immunohistochemical analyses confirm a significant reduction in the number of gustducin-positive taste receptor cells in the taste buds of MRL/lpr mice. Furthermore, MRL/lpr mice exhibit reduced gustatory nerve responses to the bitter compound quinine and the sweet compound saccharin and reduced behavioral responses to bitter, sweet, and umami taste substances compared with controls. In contrast, their responses to salty and sour compounds are comparable to those of control mice in both nerve recording and behavioral experiments. Together, our results suggest that type II taste receptor cells, which are essential for bitter, sweet, and umami taste reception and signaling, are selectively affected in MRL/lpr mice, a model for autoimmune disease with chronic inflammation.