Citations

Large segmental osseous defects heal poorly. Recombinant, human bone morphogenetic protein-2 (rhBMP-2) is used clinically to promote bone healing, but it is applied at very high doses that cause adverse side effects and raise costs while providing only incremental benefit. We describe a previously unexplored, alternative approach to bone regeneration using chemically modified messenger RNA (cmRNA). An optimized cmRNA encoding BMP-2 was delivered to critical-sized femoral osteotomies in rats. The cmRNA remained orthotopically localized and generated BMP locally for several days. Defects healed at doses ≥25 μg of BMP-2 cmRNA. By 4 weeks, all animals treated with 50 μg of BMP-2 cmRNA had bridged bone defects without forming the massive callus seen with rhBMP-2. Moreover, such defects recovered normal mechanical strength quicker and initiated bone remodeling faster. cmRNA regenerated bone via endochondral ossification, whereas rhBMP-2 drove intramembranous osteogenesis; cmRNA provides an innovative, safe, and highly translatable technology for bone healing.

Abstract Increased mechanistic insight into the pathogenesis of knee osteoarthritis (KOA) is needed to develop efficacious disease-modifying treatments. Though age-related pathogenic mechanisms are most relevant to the majority of clinically presenting KOA, the bulk of our mechanistic understanding of KOA has been derived using surgically induced posttraumatic OA (PTOA) models. Here, we took an integrated approach of meta-analysis and multi-omics data analysis to elucidate pathogenic mechanisms of age-related KOA in mice. Protein-level data were integrated with transcriptomic profiling to reveal inflammation, autophagy, and cellular senescence as primary hallmarks of age-related KOA. Importantly, the molecular profiles of cartilage aging were unique from those observed following PTOA, with less than 3% overlap between the 2 models. At the nexus of the 3 aging hallmarks, advanced glycation end product (AGE)/receptor for AGE (RAGE) emerged as the most statistically robust pathway associated with age-related KOA. This pathway was further supported by analysis of mass spectrometry data. Notably, the change in AGE–RAGE signaling over time was exclusively observed in male mice, suggesting sexual dimorphism in the pathogenesis of age-induced KOA in murine models. Collectively, these findings implicate dysregulation of AGE–RAGE signaling as a sex-dependent driver of age-related KOA.

Abstract Objective To evaluate the content validity and psychometric properties of the Activity Impairment in Migraine Diary (AIM‐D). Background Measuring treatment effects on migraine impairment requires a psychometrically sound patient‐reported outcome (PRO) measure developed consistent with U.S. Food and Drug Administration guidance. Methods The AIM‐D was created from concepts that emerged during qualitative interviews with five clinicians experienced in treating migraine and concept elicitation (CE) interviews with 40 adults with episodic migraine (EM) or chronic migraine (CM). The initial version was refined based on three waves of cognitive interviews with 38 adults with EM or CM and input from a panel of clinical and measurement experts. The AIM‐D was psychometrically evaluated using data from 316 adults with EM or CM who participated in a 13‐week prospective observational study. Study participants completed PRO assessments including the AIM‐D and a daily headache diary. Exploratory and confirmatory factor analysis were used to determine the factor structure. The reliability, validity, and responsiveness of the AIM‐D were assessed. Additional PRO measures including the Patient Global Impression – Severity (PGI‐S), Migraine Specific Quality of Life Questionnaire, Version 2.1 Role Function‐Restrictive domain, and Headache Impact Test were used for psychometric evaluation of the AIM‐D. Results Based on CE interviews with adults with migraine and input from an expert panel, activity impairment was identified as the target in the preliminary conceptual framework, which had two domains: performance of daily activities (PDAs) and physical impairment (PI). Revision of the draft AIM‐D through multiple rounds of cognitive interviews and expert panel meetings resulted in a content valid 11‐item version. Exploratory factor analysis supported both one‐ and two‐domain structures for the AIM‐D, which were further supported by confirmatory factor analysis (factor loadings all >0.90). The AIM‐D domains (PDA and PI) and total score showed high internal consistency reliability (Cronbach's alpha 0.95–0.97), acceptable test–retest reliability for weekly average scores (intraclass correlation coefficient >0.60 for participants with no change in PGI‐S between baseline and week 2), and good convergent and known‐groups validity. There was evidence of responsiveness based on changes in PGI‐S score and monthly migraine days. Conclusion The AIM‐D is a content valid and psychometrically sound measure designed to evaluate activity impairment and is suitable for use in clinical trials of preventive treatments for EM or CM.

Collagen has a major role in the structural organization of tendons. Picrosirius red (PSR) staining viewed under polarized light microscopy is the standard method to evaluate the organization of collagen fibers in tissues. It is also used to distinguish between type I and type III collagen in tissue sections. However, accurate analysis and interpretation of PSR images are challenging because of technical factors and historical misconceptions. The aim of this study was to clarify whether collagen types I and III can be distinguished by PSR staining in rat Achilles tendons, using double immunohistochemistry as the positive control. Our findings showed that PSR staining viewed with polarized light microscopy was suitable for qualitative and quantitative assessment of total collagen but was not able to distinguish collagen types. We found it critical to use a polarizing microscope equipped with a rotating stage; tendon section orientation at 45° with respect to crossed polarizers was optimal for the qualitative and quantitative assessment of collagen organization. Immunohistochemistry was superior to PSR staining for detection of collagen type III. We also compared formalin and Bouin solution as fixatives. Both produced similar birefringence, but formalin-fixed tendons provided higher quality histological detail with both hematoxylin–eosin and immunostaining:

» Orthopaedics pioneered the expansion of gene therapy beyond its traditional scope of diseases that are caused by rare single-gene defects. Orthopaedic applications of gene therapy are most developed in the areas of arthritis and regenerative medicine, but several additional possibilities exist. » Invossa, an ex vivo gene therapeutic for osteoarthritis, was approved in South Korea in 2017, but its approval was retracted in 2019 and remains under appeal; a Phase-III clinical trial of Invossa has restarted in the U.S. » There are several additional clinical trials for osteoarthritis and rheumatoid arthritis that could lead to approved gene therapeutics for arthritis. » Bone-healing and cartilage repair are additional areas that are attracting considerable research; intervertebral disc degeneration and the healing of ligaments, tendons, and menisci are other applications of interest. Orthopaedic tumors, genetic diseases, and aseptic loosening are additional potential targets. » If successful, these endeavors will expand the scope of gene therapy from providing expensive medicines for a few patients to providing affordable medicines for many.

PURPOSE Radical prostatectomy (RP) alone is often inadequate in curing men with clinically localized, high-risk prostate cancer (PC). We hypothesized that chemohormonal therapy (CHT) with androgen-deprivation therapy plus docetaxel before RP would improve biochemical progression–free survival (BPFS) over RP alone. PATIENTS AND METHODS Men with clinically localized, high-risk PC were assigned to RP alone or neoadjuvant CHT with androgen deprivation plus docetaxel (75 mg/m 2 body surface area every 3 weeks for 6 cycles) and RP. The primary end point was 3-year BPFS. Biochemical failure was defined as a serum prostate-specific antigen level > 0.2 ng/mL that increased on 2 consecutive occasions that were at least 3 months apart. Secondary end points included 5-year BPFS, overall BPFS, local recurrence, metastasis-free survival (MFS), PC-specific mortality, and overall survival (OS). RESULTS In total, 788 men were randomly assigned. Median follow-up time was 6.1 years. The overall rates of grade 3 and 4 adverse events during chemotherapy were 26% and 19%, respectively. No difference was seen in 3-year BPFS between neoadjuvant CHT plus RP and RP alone (0.89 v 0.84, respectively; 95% CI for the difference, −0.01 to 0.11; P = .11). Neoadjuvant CHT was associated with improved overall BPFS (hazard ratio [HR], 0.69; 95% CI, 0.48 to 0.99), improved MFS (HR, 0.70; 95% CI, 0.51 to 0.95), and improved OS (HR, 0.61; 95% CI, 0.40 to 0.94) compared with RP alone. CONCLUSION The primary study end point, 3-year BPFS, was not met. Although some improvement was seen in secondary end points, any potential benefit must be weighed against toxicity. Our data do not support the routine use of neoadjuvant CHT and RP in patients with clinically localized, high-risk PC at this time.