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Molecules (Basel, Switzerland) Oct 2020Previous non-viral gene therapy was directed towards two animal models of dwarfism: Immunodeficient (lit/scid) and immunocompetent (lit/lit) dwarf mice. The former,...
Previous non-viral gene therapy was directed towards two animal models of dwarfism: Immunodeficient (lit/scid) and immunocompetent (lit/lit) dwarf mice. The former, based on hGH DNA administration into muscle, performed better, while the latter, a homologous model based on mGH DNA, was less efficient, though recommended as useful for pre-clinical assays. We have now improved the growth parameters aiming at a complete recovery of the lit/lit phenotype. Electrotransfer was based on three pulses of 375 V/cm of 25 ms each, after mGH-DNA administration into two sites of each non-exposed tibialis cranialis muscle. A 36-day bioassay, performed using 60-day old lit/lit mice, provided the highest GH circulatory levels we have ever obtained for GH non-viral gene therapy: 14.7 ± 3.7 ng mGH/mL. These levels, at the end of the experiment, were 8.5 ± 2.3 ng/mL, i.e., significantly higher than those of the positive control (4.5 ± 1.5 ng/mL). The catch-up growth reached 40.9% for body weight, 38.2% for body length and 82.6%-76.9% for femur length. The catch-up in terms of the mIGF-1 levels remained low, increasing from the previous value of 5.9% to the actual 8.5%. Although a complete phenotypic recovery was not obtained, it should be possible starting with much younger animals and/or increasing the number of injection sites.
Topics: Animals; Electroporation; Gene Transfer Techniques; Genetic Therapy; Growth Hormone; Mice; Muscle, Skeletal; Plasmids
PubMed: 33142961
DOI: 10.3390/molecules25215034 -
American Journal of Physiology.... Jun 2020Myokines, such as irisin, have been purported to exert physiological effects on skeletal muscle in an autocrine/paracrine fashion. In this study, we aimed to investigate...
Myokines, such as irisin, have been purported to exert physiological effects on skeletal muscle in an autocrine/paracrine fashion. In this study, we aimed to investigate the mechanistic role of in vivo fibronectin type III domain-containing 5 (Fndc5)/irisin upregulation in muscle. Overexpression (OE) of Fndc5 in rat hindlimb muscle was achieved by in vivo electrotransfer, i.e., bilateral injections of Fndc5 harboring vectors for OE rats ( = 8) and empty vector for control rats ( = 8). Seven days later, a bolus of DO (7.2 mL/kg) was administered via oral gavage to quantify muscle protein synthesis. After an overnight fast, on , 2-deoxy-d-glucose-6-phosphate (2-DG6P; 6 mg/kg) was provided during an intraperitoneal glucose tolerance test (2 g/kg) to assess glucose handling. Animals were euthanized, musculus tibialis cranialis muscles and subcutaneous fat (inguinal) were harvested, and metabolic and molecular effects were evaluated. Muscle Fndc5 mRNA increased with OE (~2-fold; = 0.014), leading to increased circulating irisin (1.5 ± 0.9 to 3.5 ± 1.2 ng/mL; = 0.049). OE had no effect on protein anabolism or mitochondrial biogenesis; however, muscle glycogen was increased, along with glycogen synthase 1 gene expression ( = 0.04 and 0.02, respectively). In addition to an increase in glycogen synthase activation in OE ( = 0.03), there was a tendency toward increased glucose transporter 4 protein ( = 0.09). However, glucose uptake (accumulation of 2-DG6P) was identical. Irisin elicited no endocrine effect on mitochondrial biogenesis or uncoupling proteins in white adipose tissue. Hindlimb overexpression led to physiological increases in Fndc5/irisin. However, our data indicate limited short-term impacts of irisin in relation to muscle anabolism, mitochondrial biogenesis, glucose uptake, or adipose remodeling.
Topics: Animals; Deoxyglucose; Deuterium Oxide; Electroporation; Fibronectins; Gene Expression; Glucose; Glucose Tolerance Test; Glucose Transporter Type 4; Glucose-6-Phosphate; Glycogen; Glycogen Synthase; Hindlimb; Male; Mitochondrial Uncoupling Proteins; Muscle, Skeletal; Organelle Biogenesis; Protein Biosynthesis; RNA, Messenger; Rats; Subcutaneous Fat
PubMed: 32369414
DOI: 10.1152/ajpendo.00034.2020 -
Anatomical Record (Hoboken, N.J. : 2007) Jan 2022Hind foot drumming as a form of seismic signaling plays a pivotal role in the communication of various mammalian species including Bathyergidae (African mole-rats). The...
Hind foot drumming as a form of seismic signaling plays a pivotal role in the communication of various mammalian species including Bathyergidae (African mole-rats). The aim of the present study was to histologically determine if the action of hind foot drumming would influence the number of type II fibers present in the hind limb muscles of two drumming (Georychus capensis and Bathyergus suillus) and one non-drumming (Cryptomys hottentotus natalensis) bathyergid species. Twenty-one frozen muscles of each species were selected for the purpose of mid-belly cryostat sections. These sections were immunohistochemically labeled for myosin heavy chain slow muscle fibers (MHCs). In addition, oxidative capacity was determined by means of histochemical staining. A high percentage of fast type II muscle fibers was found in all the functional muscle groups, although there were no statistical differences between the drumming and non-drumming species. Bathyergus suillus had significantly fewer type II fibers in mm. semitendinosus, gluteofemoralis, tibialis cranialis, plantaris, and the medial head of m. gastrocnemius compared to the other two species. In all three species, the majority of the muscle fibers in all functional muscle groups demonstrated low oxidative capacity which correlated with the expression of type II muscle fibers. It therefore seems likely that the number of type II muscle fibers in the hind limb muscles of the Bathyergidae species studied here is more influenced by either body size or digging strategy rather than being an adaptation for hind foot drumming.
Topics: Animals; Mole Rats; Muscle Fibers, Fast-Twitch; Muscle Fibers, Skeletal; Muscle, Skeletal; Myosin Heavy Chains
PubMed: 34240567
DOI: 10.1002/ar.24712 -
Scientific Reports Jan 2021Here we present the first record of a stem-Coracii outside the Holarctic region, found in the early Eocene of Patagonia at the Laguna del Hunco locality. Ueekenkcoracias...
Here we present the first record of a stem-Coracii outside the Holarctic region, found in the early Eocene of Patagonia at the Laguna del Hunco locality. Ueekenkcoracias tambussiae gen. et sp. nov. consists of an incomplete right hind limb that presents the following combination of characters, characteristic of Coracii: relatively short and stout tibiotarsus, poorly developed crista cnemialis cranialis, short and wide tarsometatarsus, with the tuberositas m. tibialis cranialis located medially on the shaft, and curved and stout ungual phalanges. Although the presence of a rounded and conspicuous foramen vasculare distale and the trochlea metatarsi II strongly deflected medially resemble Primobucconidae, a fossil group only found in the Eocene of Europe and North America, our phylogenetic analysis indicates the new taxon is the basalmost known Coracii. The unexpected presence of a stem-Coracii in the Eocene of South America indicates that this clade had a more widespread distribution than previously hypothesized, already extending into the Southern Hemisphere by the early Eocene. Ueekenkcoracias tambussiae represents new evidence of the increasing diversity of stem lineages of birds in the Eocene. The new material provides novel morphological data for understanding the evolutionary origin and radiation of rollers and important data for estimates of the divergence time of the group.
Topics: Animals; Argentina; Birds; Fossils
PubMed: 33446824
DOI: 10.1038/s41598-020-80479-8 -
Frontiers in Neuroscience 2024Medical imaging allows for the visualization of spinal cord compression sites; however, it is impossible to assess the impact of visible stenotic sites on neuronal...
UNLABELLED
Medical imaging allows for the visualization of spinal cord compression sites; however, it is impossible to assess the impact of visible stenotic sites on neuronal functioning, which is crucial information to formulate a correct prognosis and install targeted therapy. It is hypothesized that with the transcranial electrical stimulation (TES) technique, neurological impairment can be reliably diagnosed.
OBJECTIVE
To evaluate the ability of the TES technique to assess neuronal functional integrity in ataxic horses by recording TES-induced muscular evoked potentials (MEPs) in three different muscles and to structurally involve multiple ancillary diagnostic techniques, such as clinical neurological examination, plain radiography (RX) with ratio assessment, contrast myelography, and post-mortem gross and histopathological examination.
METHODS
Nine ataxic horses, showing combined fore and hindlimb ataxia (grades 2-4), were involved, together with 12 healthy horses. TES-induced MEPs were recorded bilaterally at the level of the trapezius (TR), the extensor carpi radialis (ECR), and tibialis cranialis (TC) muscles. Two Board-certified radiologists evaluated intra- and inter-sagittal diameter ratios on RX, reductions of dorsal contrast columns, and dural diameters (range skull-T1). Post-mortem gross pathological and segmental histopathological examination was also performed by a Board-certified pathologist.
RESULTS
TES-MEP latencies were significantly prolonged in both ECR and TC in all ataxic horses as opposed to the healthy horses. The TR showed a mixed pattern of normal and prolonged latency times. TES-MEP amplitudes were the least discriminative between healthy and ataxic horses. Youden's cutoff latencies for ataxic horses were 24.6 ms for the ECR and 45.5 ms for the TC (sensitivity and specificity of 100%). For healthy horses, maximum latency values were 22 and 37 ms, respectively. RX revealed spinal cord compression in 8 out of 9 involved ataxic horses with positive predictive values of 0-100%. All ataxic horses showed multi-segmental Wallerian degeneration. All pathological changes recorded in the white matter of the spinal cord were widely dispersed across all cervical segments, whereas gray matter damage was more localized at the specific segmental level.
CONCLUSION
TES-MEP latencies are highly sensitive to detect impairment of spinal cord motor functions for mild-to-severe ataxia (grades 2-4).
PubMed: 38665290
DOI: 10.3389/fnins.2024.1342803 -
Folia Morphologica Feb 2024That the peroneus tertius muscle (PT) is a separate entity has been debated. PT has been reported to be part of the extensor digitorum longus muscle, part of the...
BACKGROUND
That the peroneus tertius muscle (PT) is a separate entity has been debated. PT has been reported to be part of the extensor digitorum longus muscle, part of the extensor digitorum brevis, or a separate muscle. While pigs have a PT as well as primates, there are no reports of its association with the extensor digitorum longus muscle or extensor digitorum brevis.
MATERIALS AND METHODS
In this study, we used gross dissection and Sihler's staining to determine the origin, course, insertion, and innervation of the pig PT.
RESULTS
The PT and extensor digitorum longus muscles jointly originated from the femur and ran between the tibialis cranialis and peroneus longus muscles. The PT was inserted at the retinaculum of the metatarsal extensors, tarsal bone, and second metatarsal bone. The branches of the common fibular nerve to the extensor digitorum longus muscle were distributed to the PT.
CONCLUSIONS
The innervations suggest that the PT and extensor digitorum longus muscles of the pig were derived from the same muscle mass during development but were named separately due to differences in their morphology. Furthermore, morphological features suggest that pig PT and human PT are probably different muscles.
PubMed: 38299444
DOI: 10.5603/fm.98348