Global Deletion of Pannexin 3 Resulting in Accelerated Development of Aging-Induced Osteoarthritis in Mice.

OBJECTIVE: Osteoarthritis (OA) results in pathologic changes in the joint tissue. The mechanisms driving disease progression remain largely unclear, and thus disease-modifying treatments are lacking. Pannexin 3 (Panx3) was identified as a potential mediator of cartilage degeneration in OA, and our previous study in mice indicated that deletion of the Panx3 gene delayed surgically induced cartilage degeneration. This study was undertaken to examine the role of Panx3 in other OA subtypes, particularly primary OA during aging, in a mouse model of aging-induced OA. METHODS: Wild-type (WT) and Panx3-/- C57BL/6J (Black-6) mice, ages 18-24 months, were analyzed by micro-computed tomography to investigate bone mineral density and body composition. Joints were harvested from the mice, and histopathologic analysis of the joint tissue for OA development was conducted with a specific focus on changes in articular cartilage, subchondral bone, and synovial tissue. RESULTS: Global loss of Panx3 in aging mice was not associated with increased mortality or changes in body composition. Mice lacking Panx3 had shorter appendicular skeletons than WT mice, but overall the body compositions appeared quite similar. Panx3 deletion dramatically accelerated cartilage degeneration and subchondral bone thickening with aging in both 18-month-old and 24-month-old mice, while promoting synovitis in 18-month-old mice. CONCLUSION: These observations in a mouse model of OA suggest that Panx3 has a protective role against the development of primary aging-associated OA. It appears that Panx3 has opposing context-specific roles in joint health following traumatic injury versus that associated with aging. These data strongly suggest that there are differences in the molecular pathways driving different subtypes of OA, and therefore a detailed understanding of these pathways could directly improve strategies for OA diagnosis, therapy, and research.

Double deletion of Panx1 and Panx3 affects skin and bone but not hearing.

Pannexins (Panxs), large-pore channel forming glycoproteins, are expressed in a wide variety of tissues including the skin, bone, and cochlea. To date, the use of single knock-out mouse models of both Panx1 and Panx3 have demonstrated their roles in skin development, bone formation, and auditory phenotypes. Due to sequence homology between Panx1 and Panx3, when one Panx is ablated from germline, the other may be upregulated in a compensatory mechanism to maintain tissue homeostasis and function. To evaluate the roles of Panx1 and Panx3 in the skin, bone, and cochlea, we created the first Panx1/Panx3 double knock-out mouse model (dKO). These mice had smaller litters and reduced body weight compared to wildtype controls. The dKO dorsal skin had decreased epidermal and dermal area as well as decreased hypodermal area in neonatal but not in older mice. In addition, mouse skull shape and size were altered, and long bone length was decreased in neonatal dKO mice. Finally, auditory tests revealed that dKO mice did not exhibit hearing loss and were even slightly protected against noise-induced hearing damage at mid-frequency regions. Taken together, our findings suggest that Panx1 and Panx3 are important at early stages of development in the skin and bone but may be redundant in the auditory system. KEY MESSAGES: Panx double KO mice had smaller litters and reduced body weight. dKO skin had decreased epidermal and dermal area in neonatal mice. Skull shape and size changed plus long bone length decreased in neonatal dKO mice. dKO had no hearing loss and were slightly protected against noise-induced damage.

Functional role of a polymorphism in the Pannexin1 gene in collagen-induced platelet aggregation.

Pannexin1 (Panx1) forms ATP channels that play a critical role in the immune response by reinforcing purinergic signal amplification in the immune synapse. Platelets express Panx1 and given the importance of ATP release in platelets, we investigated Panx1 function in platelet aggregation and the potential impact of genetic polymorphisms on Panx1 channels. We show here that Panx1 forms ATP release channels in human platelets and that inhibiting Panx1 channel function with probenecid, mefloquine or specific (10)Panx1 peptides reduces collagen-induced platelet aggregation but not the response induced by arachidonic acid or ADP. These results were confirmed using Panx1-/- platelets. Natural variations have been described in the human Panx1 gene, which are predicted to induce non-conservative amino acid substitutions in its coding sequence. Healthy subjects homozygous for Panx1-400C, display enhanced platelet reactivity in response to collagen compared with those bearing the Panx1-400A allele. Conversely, the frequency of Panx1-400C homozygotes was increased among cardiovascular patients with hyper-reactive platelets compared with patients with hypo-reactive platelets. Exogenous expression of polymorphic Panx1 channels in a Panx-deficient cell line revealed increased basal and stimulated ATP release from cells transfected with Panx1-400C channels compared with Panx1-400A expressing transfectants. In conclusion, we demonstrate a specific role for Panx1 channels in the signalling pathway leading to collagen-induced platelet aggregation. Our study further identifies for the first time an association between a Panx1-400A>C genetic polymorphism and collagen-induced platelet reactivity. The Panx1-400C variant encodes for a gain-of-function channel that may adversely affect atherothrombosis by specifically enhancing collagen-induced ATP release and platelet aggregation.

Targeted isolation, sequence analysis, and physical mapping of nonTIR NBS-LRR genes in soybean.

Most cloned plant disease resistance genes (R-genes) code for proteins belonging to the nucleotide binding site (NBS) leucine-rich repeat (LRR) superfamily. NBS-LRRs can be divided into two classes based on the presence of a TIR domain ( Toll and interleukin receptor-like sequence) or a coiled coil motif (nonTIR) in their N-terminus. We used conserved motifs specific to nonTIR-NBS-LRR sequences in a targeted PCR approach to generate nearly 50 genomic soybean sequences with strong homology to known resistance gene analogs (RGAs) of the nonTIR class. Phylogenetic analysis classified these sequences into four main subclasses. A representative clone from each subclass was used for genetic mapping, bacterial artificial chromosome (BAC) library screening, and construction of RGA-containing BAC contigs. Of the 14 RGAs that could be mapped genetically, 12 localized to a 25-cM region of soybean linkage group F already known to contain several classical disease resistance loci. A majority of the genomic region encompassing the RGAs was physically isolated in eight BAC contigs, together spanning more than 1 Mb of genomic sequence with at least 12 RGA copies. Phylogenetic and sequence analysis, together with genetic and physical mapping, provided insights into the genome organization and evolution of this large cluster of soybean RGAs.

Characterization of embryonic mortality in broilers / Caracterización de mortalidad embrionaria en pollos de engorde

ABSTRACT Objective. The purpose of this study was to characterize the incidence of EM in Ross 308 strain eggs. Materials and methods. A prospective cohort study was performed, through candling and embryodiagnosis, in 4 groups of eggs coming from 4 different age breeders. Other data such as percentage of infertility, malformation, malposition, cracked and contaminated eggs were reported. Results. General EM reached 16.08% IC95% (14.69; 17.60) and was different among the different age-groups (p<0.001), being higher for eggs from 64 week-old breeders with 27.66% IC95%(23.92; 31.99) and lower for the 47 weeks old ones (8.84% IC95%) (6.97; 11.22). In the first week of incubation 57.53% of the embryos died and mortality was at its highiest during days 1 and 3; in the second week EM was 38.42% died, with a maximum of deaths between days 19 and 21. Conclusions. This study allowed confirmation on the biphasic behaviour of EM, although there are variations in the peaks of mortality possibly attributed to differences in production conditions for each enterprise.

RESUMEN Objetivo. El propósito de este estudio fue caracterizar la incidencia de mortalidad embrionaria (ME) en huevos de estirpes Ross 308 en una empresa de Santander, Colombia. Materiales y métodos. Se realizó un estudio de cohorte prospectivo en el cual se siguieron durante la incubación, por medio de ovoscopía y embriodiagnóstico, 4 grupos de huevos provenientes de reproductoras de 4 edades diferentes. Se reporta el porcentaje de infertilidad, de malformaciones, malposición, huevos fisurados y contaminados. Resultados. La ME general alcanzó 16.08% IC95%(14.69; 17.60) y fue diferente entre los grupos de edad (p<0.001); esta fue mayor para los huevos de reproductoras de 64 semanas con 27.66% IC95% (23.92; 31.99) y menor para las de 47 semanas con 8.84% IC95% (6.97; 11.22). En la primera semana de incubación murió el 57.53% de los embriones y se presentó el pico de muerte entre los días 1 y 3; la segunda semana murió el 38.42%, con un máximo de muertes entre el día 19 y 21. Conclusiones. Este estudio, es el primero de su naturaleza para la zona y la estirpe y permitió confirmar el comportamiento bifásico de la ME aunque existen variaciones en los picos de mortalidad atribuidas posiblemente a las diferencias de las condiciones de producción propias de las empresas.

Disección anatómica de la musculatura mímica facial: revisión iconográfica de apoyo a los tratamientos complementarios en rejuvenecimiento facial / Anatomical dissection of the mimic facial musculature: iconographic review as a support to the complementary treatments in facial rejuvenation

A la hora de valorar las múltiples técnicas empleadas en el rejuvenecimiento facial y centrándonos de manera particular en aquellos procedimientos mínimamente invasivos complementarios a las intervenciones habituales en Cirugía Plástica-Estética, cobra especial relevancia el conocimiento exhaustivo de las estructuras musculares implicadas en la mímica facial. A tal efecto, se ha realizado un estudio anatómico en cadáveres frescos, en los que se han disecado las principales estructuras referidas. Se presenta un resumen iconográfico de los músculos faciales implicados, haciendo hincapié en su anatomía descriptiva y funcional, así como un recuerdo de las principales áreas problemáticas por alguna circunstancia especial (presencia de un nervio sensitivo o motor) (AU)

To value the multiple technologies involved in facial rejuvenation and focusing in those minimally invasive complementary procedures to the usual Plastic and Aesthetic Surgeries, it´s very important the exhaustive knowledge of the muscular structures involved in the facial movements. To such an effect, an anatomical study has been realized in fresh corpses, dissecting the principal above-mentioned structures. We present an iconographic summary of the facial implied muscles, emphasizing in his descriptive and functional anatomy, as well as a recollection of the principal problematic areas for some special circumstance (presence of a sensory or motornerve) (AU)