Sustained superiority in KOOS subscores after matrix-associated chondrocyte implantation using spheroids compared to microfracture.

PURPOSE: To evaluate the safety and efficacy of matrix-associated autologous chondrocyte implantation (ACI) using spheroids in comparison to arthroscopic microfracture for the treatment of symptomatic cartilage defects of the knee. METHODS: In a prospective multicenter-controlled trial, patients aged between 18 and 50 years, with single symptomatic focal cartilage defects between 1 and 4 cm2 (mean 2.6 ± 0.8, median 2.75, range 1.44-5.00) in the knee were randomized to treatment with ACI with spheroids (n = 52) or microfracture (n = 50). Primary clinical outcome was assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS). Analyses were performed in a defined hierarchical manner where outcomes of ACI were first compared to baseline values followed by a comparison to the microfracture group with repeated-measures ANCOVA with a non-inferiority approach. Subgroup analyses were performed to investigate the influence of age and defect size on the overall KOOS. Secondary clinical outcomes were the magnetic resonance observation of cartilage repair tissue (MOCART), modified Lysholm score and International Knee Documentation Committee (IKDC) examination form. Safety data focused on adverse events. Here the 5 years results are presented at which there were 33 observed cases in the ACI group and 30 in the microfracture group. RESULTS: The overall KOOS and its five subscores were significantly improved compared to baseline for both the ACI and microfracture group. Non-inferiority of ACI to microfracture was confirmed for the overall KOOS and the subscores, while for the subscores activities of daily living, quality of life and sports and recreation of the threshold for superiority was passed. In the ACI group, a notably more rapid initial improvement of the KOOS was found at three months for the older age group compared to the younger age group and the microfracture group. No other differences were found based on age or defect size. In addition, clinical improvement was found for the MOCART, modified Lysholm and IKDC examination form both the ACI and microfracture group. No safety concern related to either treatment was observed. CONCLUSION: This study confirms the safety and efficacy of matrix-associated ACI with spheroids at a mid to long-term follow-up. Non-inferiority of ACI to microfracture was confirmed for the overall KOOS and all subscores, while superiority was reached for the subscores activities of daily living, quality of life and sports and recreation in the ACI group. This underlines the importance of ACI for the young and active patients. LEVEL OF EVIDENCE: I.

Forgivingness of an Anteromedially Positioned Small Locked Plate for High Tibial Osteotomy in Case of Overcorrection and Lateral Hinge Fracture.

High tibial osteotomy (HTO) represents a sensible treatment option for patients with moderate unicondylar osteoarthritis of the knee and extraarticular malalignment. The possibility of a continuously variable correction setting and a surgical approach low in complications has meant that the medial opening osteotomy has prevailed over the past decades. The objective of the present study was to determine whether anteromedially positioned small plates are nevertheless forgiving under biomechanically unfavourable conditions (overcorrection and lateral hinge fracture). In this study, a simulated HTO was performed on composite tibiae with a 10-mm wedge and fixed-angle anteromedial osteosynthesis with a small implant. Force was applied axially in a neutral mechanical axis, a slight and a marked overcorrection into valgus, with and without a lateral hinge fracture in each case. At the same time, a physiological gait with a dual-peak force profile and a peak load of 2.4 kN was simulated. Interfragmentary motion and rigidity were determined. The rigidity of the osteosynthesis increased over the cycles investigated. A slight overcorrection into valgus led to the lowest interfragmentary motion, compared with pronounced valgisation and neutral alignment. A lateral hinge fracture led to a significant decrease in rigidity and increase in interfragmentary motion. However, in no case was the limit of 1 mm interfragmentary motion critical for osteotomy healing exceeded. The degree of correction of the leg axis, and the presence of a lateral hinge fracture, have an influence on rigidity and interfragmentary motion. From a mechanically neutral axis ranging up to pronounced overcorrection, the implant investigated offers sufficient stability to allow healing of the osteotomy, even if a lateral hinge fracture is present.

Regeneration in starved planarians depends on TRiC/CCT subunits modulating the unfolded protein response.

Planarians are able to stand long periods of starvation by maintaining adult stem cell pools and regenerative capacity. The molecular pathways that are needed for the maintenance of regeneration during starvation are not known. Here, we show that down-regulation of chaperonin TRiC/CCT subunits abrogates the regeneration capacity of planarians during starvation, but TRiC/CCT subunits are dispensable for regeneration in fed planarians. Under starvation, they are required to maintain mitotic fidelity and for blastema formation. We show that TRiC subunits modulate the unfolded protein response (UPR) and are required to maintain ATP levels in starved planarians. Regenerative defects in starved CCT-depleted planarians can be rescued by either chemical induction of mild endoplasmic reticulum stress, which leads to induction of the UPR, or by the supplementation of fatty acids. Together, these results indicate that CCT-dependent UPR induction promotes regeneration of planarians under food restriction.

[Knee realignment osteotomy in adults]. / Kniegelenksnahe Umstellungsosteotomien des Erwachsenen.

BACKGROUND: Nowadays, osteotomy near the knee joint for axial deformities has become an indispensable surgical procedure for joint preservation in the orthopaedic-surgical spectrum. The exact localization and analysis of the deformity are crucial to restoring physiological loading conditions of the entire leg by means of a suitable osteotomy. PROCEDURES: Thus, above all, the medial "open-wedge" osteotomy has established itself as a standard procedure for the treatment of gonarthrosis caused by varus malalignment. Furthermore, the varus closed-wedge osteotomy of the distal femur also shows very good long-term results. Basically, osteotomies close to the knee are causal corrections in which biological and mechanical aspects must be taken into account. Thus, the correct indication, attention to risk factors, and surgical technique determine the long-term success of the procedure. The doctrine of femoral valgus deformity and the resulting lateral arthrosis, on the other hand, must be reconsidered according to the latest knowledge.

Matrix-Associated Autologous Chondrocyte Implantation with Spheroid Technology Is Superior to Arthroscopic Microfracture at 36 Months Regarding Activities of Daily Living and Sporting Activities after Treatment.

OBJECTIVE: Matrix-associated autologous chondrocyte implantation (ACI) and microfracture (MF) are well-established treatments for cartilage defects of the knee. However, high-level evidence comparing microfracture and spheroid technology ACI is limited. DESIGN: Prospective, phase III clinical trial with patients randomized to ACI (N = 52) or MF (N = 50). Level of evidence: 1, randomized controlled trial. Both procedures followed standard protocols. For ACI 10 to 70 spheroids/cm2 were administered. Primary outcome measure was the Knee Injury and Osteoarthritis Outcome Score (KOOS). This report presents results for 36 months after treatment. RESULTS: Both ACI and MF showed significant improvement over the entire 3-year observation period. For the overall KOOS, noninferiority of ACI (the intended primary goal of the study) was formally confirmed; additionally, for the subscores "Activities of Daily Living" and "Sport and Recreation," superiority of ACI over MF was shown at descriptive level. Occurrence of adverse events were not different between both treatments (ACI 77%; MF 74%). Four patients in the MF group required reoperation which was defined as treatment failure. No treatment failure was reported for the ACI group. CONCLUSIONS: Patients treated with matrix-associated ACI with spheroid technology showed substantial improvement in various clinical outcomes after 36 months. The advantages of ACI compared with microfracture was underlined by demonstrating noninferiority, in overall KOOS and superiority in the KOOS subscores "Activities of Daily Living" and "Sport and Recreation." In the present study, subgroups comparing different age groups and defect sizes showed comparable clinical outcomes.

Tnfaip2/exoc3-driven lipid metabolism is essential for stem cell differentiation and organ homeostasis.

Lipid metabolism influences stem cell maintenance and differentiation but genetic factors that control these processes remain to be delineated. Here, we identify Tnfaip2 as an inhibitor of reprogramming of mouse fibroblasts into induced pluripotent stem cells. Tnfaip2 knockout impairs differentiation of embryonic stem cells (ESCs), and knockdown of the planarian para-ortholog, Smed-exoc3, abrogates in vivo tissue homeostasis and regeneration-processes that are driven by somatic stem cells. When stimulated to differentiate, Tnfaip2-deficient ESCs fail to induce synthesis of cellular triacylglycerol (TAG) and lipid droplets (LD) coinciding with reduced expression of vimentin (Vim)-a known inducer of LD formation. Smed-exoc3 depletion also causes a strong reduction of TAGs in planarians. The study shows that Tnfaip2 acts epistatically with and upstream of Vim in impairing cellular reprogramming. Supplementing palmitic acid (PA) and palmitoyl-L-carnitine (the mobilized form of PA) restores the differentiation capacity of Tnfaip2-deficient ESCs and organ maintenance in Smed-exoc3-depleted planarians. Together, these results identify a novel role of Tnfaip2 and exoc3 in controlling lipid metabolism, which is essential for ESC differentiation and planarian organ maintenance.

A Prospective, Randomized, Open-Label, Multicenter, Phase III Noninferiority Trial to Compare the Clinical Efficacy of Matrix-Associated Autologous Chondrocyte Implantation With Spheroid Technology Versus Arthroscopic Microfracture for Cartilage Defects of the Knee.

BACKGROUND: Autologous chondrocyte implantation (ACI) and microfracture are established treatments for large, full-thickness cartilage defects, but there is still a need to expand the clinical and health economic knowledge of these procedures. PURPOSE: To confirm the noninferiority of ACI compared with microfracture. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: Patients were randomized to be treated with matrix-associated ACI using spheroid technology (n = 52) or microfracture (n = 50). Both procedures followed standard methods. Patients were assessed by the Knee injury and Osteoarthritis Outcome Score (KOOS), MOCART (magnetic resonance observation of cartilage repair tissue) scoring system, Bern score, modified Lysholm score, International Cartilage Repair Society (ICRS) rating (histological and immunochemical scoring after rebiopsy 24 months after implantation), and International Knee Documentation Committee (IKDC) examination form. The main assessments were conducted 24 months after study treatment. RESULTS: In the primary intention-to-treat analysis, the overall KOOS score for both ACI and microfracture yielded a statistically significant improvement relative to baseline. According to the between-group analysis, ACI passed the test of noninferiority compared with microfracture; thus, the primary goal of the study was achieved. The KOOS subscores yielded the same qualitative results as the overall KOOS score (ie, for each of these, noninferiority was demonstrated), and in 1 case (Activities of Daily Living subscore), the threshold for superiority was passed. The subgroup analyses did not yield any clear evidence of an association between treatment effect and any of the categories investigated (age, diagnosis, defect localization, sex). A histological analysis of biopsies from 16 patients (ACI: n = 9; microfracture: n = 7) suggested a better quality of repair in the patients treated with ACI. CONCLUSION: The efficacy of both ACI and microfracture was demonstrated with respect to both functional outcomes and morphological repair. The primary analysis confirmed the statistical hypothesis of the noninferiority of ACI, even for relatively small cartilage defects (1-4 cm2) treated in this study, the indication for which microfracture is generally accepted as the standard of care. ACI showed significant superiority in the KOOS subscores of Activities of Daily Living at 24 months and Knee-related Quality of Life at 12 months. REGISTRATION: NCT01222559 (ClinicalTrials.gov identifier).

Effects on proprioception by Kinesio taping of the knee after anterior cruciate ligament rupture.

INTRODUCTION: The use of Kinesio tape (KT) to improve proprioception is a matter of considerable debate. In comparison, the rupture of the anterior cruciate ligament is a sufficiently well-investigated injury with a proven compromise of proprioception. The objective of the present study was to assess a supportive effect on proprioception after KT application, taking the anterior cruciate ligament (ACL) rupture as an example. MATERIALS AND METHODS: Forty-eight patients who had suffered an ACL rupture, confirmed clinically and by magnetic resonance imaging, and who were treated conservatively or were awaiting surgery were included in this study. In all patients, a gait analysis was performed on the affected leg before and after KT application. In addition, the IKDC score, the Lysholm score, stability using the Rolimeter, and the angle reproduction test were determined. RESULTS: Thirty-nine men and nine women who had had an ACL rupture for at least 3 weeks were included in the study. Significant improvements were achieved on the affected knee joint for the gait analysis parameters touchdown and unrolling, cadence, stability and stance phase as well as an extension of the hip joint. The Lysholm score improved from 79.3 to 85.8 (p < 0.001) and the IKDC score from 60.2 to 71.3 points (p < 0.001). Significant improvements were achieved in the Rolimeter and angle reproduction test. CONCLUSIONS: The use of KT has a positive effect on proprioception in patients with an anterior cruciate ligament rupture. Therefore, the application may improve gait pattern as well as the subjective function of the affected knee joint.

Insights into Sex Chromosome Evolution and Aging from the Genome of a Short-Lived Fish.

The killifish Nothobranchius furzeri is the shortest-lived vertebrate that can be bred in the laboratory. Its rapid growth, early sexual maturation, fast aging, and arrested embryonic development (diapause) make it an attractive model organism in biomedical research. Here, we report a draft sequence of its genome that allowed us to uncover an intra-species Y chromosome polymorphism representing-in real time-different stages of sex chromosome formation that display features of early mammalian XY evolution "in action." Our data suggest that gdf6Y, encoding a TGF-ß family growth factor, is the master sex-determining gene in N. furzeri. Moreover, we observed genomic clustering of aging-related genes, identified genes under positive selection, and revealed significant similarities of gene expression profiles between diapause and aging, particularly for genes controlling cell cycle and translation. The annotated genome sequence is provided as an online resource (http://www.nothobranchius.info/NFINgb).

MiR-21 is required for efficient kidney regeneration in fish.

BACKGROUND: Acute kidney injury in mammals, which is caused by cardiovascular diseases or the administration of antibiotics with nephrotoxic side-effects is a life-threatening disease, since loss of nephrons is irreversible in mammals. In contrast, fish are able to generate new nephrons even in adulthood and thus provide a good model to study renal tubular regeneration. RESULTS: Here, we investigated the early response after gentamicin-induced renal injury, using the short-lived killifish Nothobranchius furzeri. A set of microRNAs was differentially expressed after renal damage, among them miR-21, which was up-regulated. A locked nucleic acid-modified antimiR-21 efficiently knocked down miR-21 activity and caused a lag in the proliferative response, enhanced apoptosis and an overall delay in regeneration. Transcriptome profiling identified apoptosis as a process that was significantly affected upon antimiR-21 administration. Together with functional data this suggests that miR-21 acts as a pro-proliferative and anti-apoptotic factor in the context of kidney regeneration in fish. Possible downstream candidate genes that mediate its effect on proliferation and apoptosis include igfbp3 and fosl1, among other genes. CONCLUSION: In summary, our findings extend the role of miR-21 in the kidney. For the first time we show its functional involvement in regeneration indicating that fast proliferation and reduced apoptosis are important for efficient renal tubular regeneration.

Towards an understanding of kidney diseases associated with WT1 mutations.

Mutations in Wilms' tumor 1 (WT1) cause a wide spectrum of renal manifestations, eventually leading to end-stage kidney failure. Insufficient understanding of WT1's molecular functions in kidney development has hampered efficient therapeutic applications for WT1-associated diseases. Recently, the generation and characterization of mouse models and application of multiple state-of-the-art approaches have significantly expanded our understanding of the molecular mechanisms of how WT1 mutations lead to kidney failure. Here, we discuss the WT1 binding consensus and illustrate the major roles of WT1 in different cell populations in kidney biology. WT1 controls metanephric mesenchyme (MM) self-renewal and proliferation mainly by regulating FGF and BMP-pSMAD signaling pathways as well as Sall1 and Pax2, encoding key transcription factors; WT1 drives MM differentiation and mesenchyme-epithelial transition by targeting Fgf8 and Wnt4; WT1 defines podocyte identity by activation of other podocyte-specific transcription factors, including Mafb, Lmx1b, FoxC2, and Tcf21. These factors potentially cooperate with WT1 regulating the expression of components and regulators of the cytoskeleton for establishing podocyte polarity, slit diaphragm structure, and focal adhesion to the glomerular basement membrane. Understanding of WT1's function in kidney biology including WT1-regulated pathways will give insights that will eventually help therapeutic applications.

Integration of Cistromic and Transcriptomic Analyses Identifies Nphs2, Mafb, and Magi2 as Wilms' Tumor 1 Target Genes in Podocyte Differentiation and Maintenance.

The Wilms' tumor suppressor gene 1 (WT1) encodes a zinc finger transcription factor. Mutation of WT1 in humans leads to Wilms' tumor, a pediatric kidney tumor, or other kidney diseases, such as Denys-Drash and Frasier syndromes. We showed previously that inactivation of WT1 in podocytes of adult mice results in proteinuria, foot process effacement, and glomerulosclerosis. However, the WT1-dependent transcriptional network regulating podocyte development and maintenance in vivo remains unknown. Here, we performed chromatin immunoprecipitation followed by high-throughput sequencing with glomeruli from wild-type mice. Additionally, we performed a cDNA microarray screen on an inducible podocyte-specific WT1 knockout mouse model. By integration of cistromic and transcriptomic analyses, we identified the WT1 targetome in mature podocytes. To further analyze the function and targets of WT1 in podocyte maturation, we used an Nphs2-Cre model, in which WT1 is deleted during podocyte differentiation. These mice display anuria and kidney hemorrhage and die within 24 hours after birth. To address the evolutionary conservation of WT1 targets, we performed functional assays using zebrafish as a model and identified Nphs2, Mafb, and Magi2 as novel WT1 target genes required for podocyte development. Our data also show that both Mafb and Magi2 are required for normal development of the embryonic zebrafish kidney. Collectively, our work provides insights into the transcriptional networks controlled by WT1 and identifies novel WT1 target genes that mediate the function of WT1 in podocyte differentiation and maintenance.

Alternative splicing of Wilms tumor suppressor 1 (Wt1) exon 4 results in protein isoforms with different functions.

The Wilms tumor suppressor gene Wt1 encodes a zinc finger transcription factor that is essential for development of multiple organs including kidneys, gonads, spleen and heart. In mammals Wt1 comprises 10 exons with two characteristic splicing events: inclusion or skipping of exon 5 and alternative usage of two splice donor sites between exons 9 and 10. Most fish including zebrafish and medaka possess two wt1 paralogs, wt1a and wt1b, both lacking exon 5. Here we have characterized wt1 in guppy, platyfish and the short-lived African killifish Nothobranchius furzeri. All fish except zebrafish show alternative splicing of exon 4 of wt1a but not of wt1b with the wt1a(-exon 4) isoform being the predominant splice variant. With regard to function, Wt1a(+exon 4) showed less dimerization but stimulated transcription more effectively than the Wt1a(-exon 4) isoform. A specific knockdown of wt1a exon 4 in zebrafish was associated with anomalies in kidney development demonstrating a physiological function for Wt1a exon 4. Interestingly, alternative splicing of exon 4 seems to be an early evolutionary event as it is observed in the single wt1 gene of the sturgeon, a species that has not gone through teleost-specific genome duplication.