Pseudogenes are mutated copies of protein-coding genes that cannot be translated into proteins, but a small subset of pseudogenes has been detected at the protein level. Although ubiquitin pseudogenes represent one of the most abundant pseudogene families in many organisms, little is known about their expression and signaling potential. By re-analyzing public RNA-sequencing and proteomics datasets, we here provide evidence for the expression of several ubiquitin pseudogenes including UBB pseudogene 4 (UBBP4), which encodes Ub KEKS (Q2K, K33E, Q49K, N60S). The functional consequences of Ub KEKS conjugation appear to differ from canonical ubiquitylation. Quantitative proteomics shows that Ub KEKS modifies specific proteins including lamins. Knockout of UBBP4 results in slower cell division, and accumulation of lamin A within the nucleolus. Our work suggests that a subset of proteins reported as ubiquitin targets may instead be modified by ubiquitin variants that are the products of wrongly annotated pseudogenes and induce different functional effects.

The purpose of this study was to investigate the potential of a novel recombinant human type II collagen/polylactide scaffold (rhCo-PLA) in the repair of full-thickness cartilage lesions with autologous chondrocyte implantation technique (ACI). The forming repair tissue was compared to spontaneous healing (spontaneous) and repair with a commercial porcine type I/III collagen membrane (pCo). Domestic pigs (4-month-old, n ¼ 20) were randomized into three study groups and a circular full-thickness chondral lesion with a diameter of 8 mm was created in the right medial femoral condyle. After 3 weeks, the chondral lesions were repaired with either rhCo-PLA or pCo together with autologous chondrocytes, or the lesion was only debrided and left untreated for spontaneous repair. The repair tissue was evaluated 4 months after the second operation. Hyaline cartilage formed most frequently in the rhCo-PLA treatment group. Biomechanically, there was a trend that both treatment groups resulted in better repair tissue than spontaneous healing. Adverse subchondral bone reactions developed less frequently in the spontaneous group (40%) and the rhCo-PLA treated group (50%) than in the pCo control group (100%). However, no statistically significant differences were found between the groups. The novel rhCo-PLA biomaterial showed promising results in this proof-of-concept study, but further studies will be needed in order to determine its effectiveness in articular cartilage repair. 2,3 However, the original ACI procedure where a periosteal flap covers the repair area has major intrinsic limitations, such as initial mechanical weakness of the repaired site and periosteal hypertrophy. 4A wide variety of biomaterials have been introduced for cartilage repair as periosteal flap substitutes in ACI.5-8 Our research group has developed a novel biomaterial scaffold rhCo-PLA, which is a biodegradable scaffold combining recombinant human type II collagen (rhCo) and polylactide 96/4 felt (PLA). Being free of animal products, rhCo-PLA scaffold eliminates the risk of undesirable immunological responses and transmission of animal-derived pathogens.9,10 We have demonstrated the biocompatibility and neocartilage forming ability of recombinant human type II collagen.11,12 Furthermore, the recombinant technology enables batch consistency and manufacture of high purity collagen. The synthetic polylactide can be fabricated into a 3D scaffold structure that provides the repair site with mechanical support while gradually degrading as neotissue forms. However, PLAs alone have limitations in bioactivity. This is typically seen as a dense connective tissue layer around the PLA. 13 The rhCo, in contrast, is incorporated in the synthetic PLA mesh to improve its physico-chemical and biomechanical characteristics. Collagen enhances hydrophilicity of a scaffold. 6,14 Mechanical loading pumps water out of cartilage tissue, and during unloading, the water is reabsorbed. Thus, the water reabsorbing ability is an essential characteristic of a scaffold. W...

Cage change is one of the unavoidable routines in laboratory rodent care. However, cage change disrupts the rodents' olfactory environment and can evoke stress reactions. In this study, the short-term cardiovascular responses to three different cage change procedures were compared with telemetric monitoring. These procedures were: placing the rats into a new, clean cage (NEW), transferring the old cage lid into the clean cage (LID) and transferring an enrichment object into the clean cage (ENR) with the animals. Seven outbred rats (four Hsd:Sprague-Dawley and three HsdBrlHan:WIST) were instrumented with telemetric transmitters. The reactions were recorded during the 24 h following the cage change procedures. All cage change procedures (and also simple handling) caused elevated heart rate and mean arterial pressure levels for up to 5 h after the procedure, with the largest effect seen during the first hour. The reactions observed after cage change were significantly (P , 0.05) greater than those observed after simple handling. The reactions after NEW were significantly higher than the reactions after ENR or LID, though the results were dependent on the stock. In Wistar rats the LID procedure resulted in smaller reactions than ENR. In Sprague-Dawley rats, the differences between ENR and LID were not so clear, but the transfer of scent-marked material into the new cage decreased the reactions compared with the NEW procedure also in this stock. Based on these results, using the old cage lid on the new cage could reduce the disturbance of cage change in rats.

Subthreshold retinal laser therapy (SLT) is a treatment modality where the temperature of the retinal pigment epithelium (RPE) is briefly elevated to trigger the therapeutic benefits of sublethal heat shock. However, the temperature elevation induced by a laser exposure varies between patients due to individual differences in RPE pigmentation and choroidal perfusion. This study describes an electroretinography (ERG)-based method for controlling the temperature elevation during SLT. Methods: The temperature dependence of the photopic ERG response kinetics were investigated both ex vivo with isolated pig retinas and in vivo with anesthetized pigs by altering the temperature of the subject and recording ERG in different temperatures. A model was created for ERG-based temperature estimation and the feasibility of the model for controlling SLT was assessed through computational simulations. Results: The kinetics of the photopic in vivo flash ERG signaling accelerated between 3.6 and 4.7%/°C, depending on the strength of the stimulus. The temperature dependence was 5.0%/°C in the entire investigated range of 33 to 44°C in ex vivo ERG. The simulations showed that the method is suitable for determining the steady-state temperature elevation in SLT treatments with a sufficiently long laser exposure and large spot size, e.g., during > 30 s laser exposures with > 3 mm stimulus spot diameter. Conclusions: The described ERG-based temperature estimation model could be used to control SLT treatments such as transpupillary thermotherapy. Significance: The introduced ERG-based method for controlling SLT could improve the repeatability, safety, and efficacy of the treatment of various retinal disorders.

This study aims to evaluate the impact of adding different items in individually ventilated rat cages on the animal's activity, cardiovascular parameters and faecal stress indicators. The following three cage items made of aspen were compared: a cross made of two intersecting boards, a similar cross where drilled holes were loaded with food pellets (restricted feeding) and a rectangular tube. Male rats of the strains BN and F344 (n ¼ 12) were housed in groups of three; one rat in each group was implanted with a telemetric transponder to measure mean arterial pressure (MAP) and heart rate (HR). In a crossover design, each group spent 14 days with each type of cage furniture, thereafter faecal pellets were collected for faecal analyses. The means of activity and means and coefficient of variation for MAP and HR were calculated for days 2, 6, 10 and 14. As a way of determining which of the statistically significant MAP and HR mean changes were biologically meaningful, the night -day differences of the controls on day 14 were used. Both board types lowered MAP of F344 rats; hence dividing walls seem beneficial for F344 welfare. None of the MAP or HR differences in BN rats were biologically significant. No statistically significant differences in faecal corticosterone or IgA excretion were detected. In conclusion, provision of general recommendations with respect to cage furniture for rat cages is complicated because there is a clear genetic component involved in how animals respond to these structures.