OBJECTIVE: Autoimmunity refers to the presence of autoantibodies and autoreactive lymphocytes against the structural molecules of an individual\'s cells or tissues, known as self-antigens or autoantigens. It might exist in the absence of autoimmune disease. However, how autoimmunity develops remains a mystery, despite the discovery of autoantibodies in human cord blood.
METHODS: Murine fetuses on day 14 of gestation were subjected to intraperitoneal injection of murine thyroid peroxidase (TPO) peptides or collagen type II (CII) at graded doses via transuterine approach. Postnatally, the recipients were examined for autoantibodies by ELISA and autoreactive lymphocytes by in vitro incorporation of tritium and for the development of autoimmune thyroiditis or arthritis.
RESULTS: At one month of age, the recipients did not secrete significant levels of anti-TPO or CII IgG2a in sera until a dose of 0.5 µg TPO or 5.0 µg CII was injected in utero. Serum anti-TPO or CII IgG2a persisted for at least two to four months postnatally. In recipients with elevated autoantibodies, their lymphocytes also showed proliferative responses specifically to TPO or CII. However, the development of autoantibodies and autoreactive lymphocytes was not associated with inflammatory cell infiltration of thyroid glands or paw joints even though anti-TPO or CII IgG2a was enhanced by postnatal TPO or CII challenge.
CONCLUSIONS: Fetal exposure to free autoantigens could be immunogenic, shedding new light on the in utero origin of autoantibodies and autoreactive lymphocytes. The development of autoimmunity requires a threshold intensity of autoantigen exposure in the fetus.

Chondrocyte differentiation controls skeleton development and stature. Here we provide a comprehensive map of chondrocyte-specific enhancers and show that they provide a mechanistic framework through which non-coding genetic variants can influence skeletal development and human stature. Working with fetal chondrocytes isolated from mice bearing a Col2a1 fluorescent regulatory sensor, we identify 780 genes and 2\'704 putative enhancers specifically active in chondrocytes using a combination of RNA-seq, ATAC-seq and H3K27ac ChIP-seq. Most of these enhancers (74%) show pan-chondrogenic activity, with smaller populations being restricted to limb (18%) or trunk (8%) chondrocytes only. Notably, genetic variations overlapping these enhancers better explain height differences than those overlapping non-chondrogenic enhancers. Finally, targeted deletions of identified enhancers at the Fgfr3, Col2a1, Hhip and, Nkx3-2 loci confirm their role in regulating cognate genes. This enhancer map provides a framework for understanding how genes and non-coding variations influence bone development and diseases.

BACKGROUND: Non-pharmacological treatments based on collagen as a dietary supplement are emerging as a new area of interest to support preventive or therapeutic effects in patients with osteoarthritis (OA).
OBJECTIVE: In a multicenter, prospective, double-blind, placebo-controlled, randomized study, to evaluate the effectiveness and safety of the use of the Artneo complex containing undenatured chicken collagen type II in patients with OA of the knee joints.
METHODS: The study enrolled 212 outpatients from 12 centers in the Russian Federation with knee OA, stages II and III according to the Kellgren-Lawrence classification. The participants included 171 women (80.7%) and 41 men (19.3%), with an average age of 60.2±9.0 years (range: 40 to 75 years). The study population was randomly allocated in equal proportions into two groups using an interactive web response system (IWRS). Group 1 (Artneo) consisted of 106 patients who took one capsule of the drug once daily for 180 days. Group 2 (Placebo) also had 106 patients, with the dosage form and regimen identical to Group 1. During the treatment period, the following outcomes were assessed: WOMAC index, KOOS, pain according to VAS, quality of life using the EQ-5D questionnaire, and the need for NSAIDs. All patients underwent a clinical blood test, general urine analysis, biochemical blood test, and ultrasound examination of the affected knee joint.
RESULTS: In a prospective, double-blind, placebo-controlled, randomized study, it was demonstrated that the Artneo combination, containing undenatured chicken collagen type II, has a positive effect on all clinical manifestations of OA: it effectively reduces pain, stiffness, and improves the functional state of joints and quality of life. It has a good safety profile and is superior to placebo in all parameters studied.
CONCLUSIONS: The results of the study confirm the good effectiveness and safety of the Artneo combination in patients with OA of the knee joints.
Обоснование. Немедикаментозные методы лечения, основанные на приеме коллагена в качестве биологически активной добавки, позиционируют как новый объект интереса для поддержки профилактического или терапевтического эффекта у пациентов с остеоартритом (ОА). Цель. В многоцентровом проспективном двойном слепом плацебо-контролируемом рандомизированном исследовании оценить эффективность и безопасность применения комплекса Артнео, содержащего неденатурированный куриный коллаген II типа, у пациентов с ОА коленных суставов (КС). Материалы и методы. В исследование включены 212 амбулаторных пациентов из 12 центров Российской Федерации с диагнозом ОА КС II и III стадии по Келлгрену–Лоуренсу: 171 (80,7%) женщина, 41 (19,3%) мужчина, средний возраст которых составил 60,2±9,0 года (40–75 лет). Исследуемую популяцию случайным образом с использованием интерактивной системы веб-ответа (IWRS) распределили в равном соотношении на 2 группы: группа «Aртнео» (основная группа) – 106 пациентов, принимавших препарат по 1 капсуле 1 раз в день на протяжении 180 дней; группа «Плацебо» (группа сравнения) – 106 больных, у которых форма выпуска и режим приема были идентичны. На фоне терапии проводили оценку индекса WOMAC, KOOS, боли по Визуальной аналоговой шкале, качества жизни по опроснику EQ-5D, потребности в нестероидных противовоспалительных препаратах. Всем пациентам выполнили клинический, общий и биохимический анализы крови, ультразвуковое исследование целевого КС. Результаты. Комбинация Артнео, содержащая неденатурированный куриный коллаген II типа, позитивно влияет на все клинические проявления ОА: эффективно уменьшает боль, скованность, улучшает функциональное состояние суставов и качество жизни. Кроме того, она обладает хорошим профилем безопасности и превосходит плацебо по всем исследуемым параметрам. Заключение. Результаты проведенного исследования подтверждают хорошую эффективность и безопасность комбинации Артнео у пациентов с ОА КС.

Osteoarthritis (OA) is a common joint disorder characterized by cartilage degeneration, often leading to pain and functional impairment. Minced cartilage implantation (MCI) has emerged as a promising one-step alternative for large cartilage defects. However, the source of chondrocytes for MCI remains a challenge, particularly in advanced OA, as normal cartilage is scarce. We performed in vitro studies to evaluate the feasibility of MCI using osteophyte cartilage, which is present in patients with advanced OA. Osteophyte and articular cartilage samples were obtained from 22 patients who underwent total knee arthroplasty. Chondrocyte migration and proliferation were assessed using cartilage fragment/atelocollagen composites to compare the characteristics and regenerative potential of osteophytes and articular cartilage. Histological analysis revealed differences in cartilage composition between osteophytes and articular cartilage, with higher expression of type X collagen and increased chondrocyte proliferation in the osteophyte cartilage. Gene expression analysis identified distinct gene expression profiles between osteophytes and articular cartilage; the expression levels of COL2A1, ACAN, and SOX9 were not significantly different. Chondrocytes derived from osteophyte cartilage exhibit enhanced proliferation, and glycosaminoglycan production is increased in both osteophytes and articular cartilage. Osteophyte cartilage may serve as a viable alternative source of MCI for treating large cartilage defects in OA.

A 6-month-old female infant with megalophthalmos was referred with the suspicion of congenital glaucoma. Refractive measurements obtained with handheld autorefractometry were -7.00 -2.00 × 90° in the right eye and -6.00 -2.00 × 100° in the left eye and ultrasonic axial lengths were 22.50 mm in both eyes. Intraocular pressures and vertical and horizontal corneal diameters of the proband were 11 mm Hg, 11 mm, and 11.50 mm in both eyes, respectively. She was diagnosed as having early-onset high myopia. Her father also had degenerative high myopia (-12.00 diopters) in the right eye, bilateral congenital lens opacities, and retinal detachment in the left eye. Her mother was emmetropic with normal eye examination results. Clinical exome sequencing analysis revealed a novel ENST00000380518.3 c.3528_3530 delins GACCATTAGCA (Chr12:48369813: GCA > TGCTAATGGTC) variant in the collagen type II alpha 1 chain (COL2A1) on chromosome 12q13 (OMIM 108300), consistent with the Stickler syndrome type 1. Subsequent segregation analysis revealed paternal inheritance. Although many pathogenic null variants have been described within the COL2A1 gene, there is currently no documented literature pertaining to this specific variant, making this the inaugural report of its manifestation in scientific discourse. [J Pediatr Ophthalmol Strabismus. 2024;61(3):e23-e27.].

The purpose was to investigate relationships of cumulative load and cartilage turnover biomarkers with 2-year changes in cartilage in knee osteoarthritis. From participants with Kellgren-Lawrence (KL) grades of 1 to 3, cartilage thickness and transverse relaxation time (T2) were computed from 24-month (baseline) and 48-month magnetic resonance images. Cumulative load was the interaction term of the Physical Activity Scale for the Elderly (PASE) and body mass index (BMI). Serum cartilage oligomeric matrix protein (COMP) and the nitrated form of type II collagen (Coll2-1 NO2) were collected at baseline. Multiple regressions (adjusted for baseline age, KL grade, cartilage measures, pain, comorbidity) evaluated the relationships of cumulative load and biomarkers with 2-year changes. In 406 participants (63.7 (8.7) years), interactions of biomarkers with cumulative load weakly predicted 2-year cartilage changes: (i) COMP × cumulative load explained medial tibia thickness change (R2 increased 0.062 to 0.087, p < 0.001); (ii) Coll2-1 NO2 × cumulative load explained central medial femoral T2 change (R2 increased 0.177 to 0.210, p < 0.001); and (iii) Coll2-1 NO2 × cumulative load explained lateral tibia T2 change (R2 increased 0.166 to 0.188, p < 0.001). Moderate COMP or Coll2-1 NO2 at baseline appeared protective. High COMP or Coll2-1 NO2, particularly with high BMI and low PASE, associated with worsening cartilage. Moderate serum concentrations of cartilage turnover biomarkers, at high and low physical activity, associated with maintained cartilage outcomes over 2 years. In conclusion, high concentrations of cartilage turnover biomarkers, particularly with high BMI and low physical activity, associated with knee cartilage thinning and increasing T2 over 2 years. Key Points • Higher quality cartilage may be better able to tolerate a larger cumulative load than poor quality cartilage. • Among participants enrolled in the Osteoarthritis Initiative Biomarkers Consortium Project, a representation of cumulative load exposure and its interaction with cartilage turnover biomarkers were weakly related with 2-year change in knee cartilage. • These findings suggest that cartilage turnover is a factor that modifies the relationship between loading exposure and cartilage loss in knee OA.

OBJECTIVE: To evaluate the efficacy of Artneo (AN) in comparison with a combination of glucosamine hydrochloride and chondroitin sulfate (GC) in patients with osteoarthritis (OA) of the knee joint (KJ).
METHODS: 70 patients with stages I-III of primary knee OA were randomized into 2 groups. Participants in the 1st (n=35) took AN 1 caps/day, in the 2nd (n=35) GC according to the standard regimen. After 7, 30, 90, 180 days, the Lequesne index (severity of OA), pain when moving according to VAS, WOMAC score were assessed, after 1, 3, 6 months - quality of life SF-36 and morning stiffness, after 6 months - MRI with T2 mapping, laboratory safety indicators.
RESULTS: Over the course of 6 months of use, an improvement in the WOMAC index and a decrease in pain were observed without intergroup differences, and a greater decrease in stiffness in the AN group. After 3 months, the severity of OA decreased from moderate to mild in the AN group and was significantly lower compared to the GC group; quality of life (physical component of SF-36) was higher in the AN group. After 6 months, there was an improvement in cartilage ultrastructure (T2 relaxation time) in both groups and a more pronounced reduction of the synovitis area (MRI) in the AN group (2.95 and 1.37 times in the AN and GC group, respectively). There were no clinically significant adverse reactions observed in both groups.
CONCLUSIONS: The use of AN in patients with stage I-III primary knee OA was not inferior in efficacy to the combination of GC. Further studies with greater statistical power (sample size) and follow-up period are warranted including in real clinical practice.
Цель. Оценить эффективность Артнео (АН) в сравнении с комбинацией глюкозамина гидрохлорида и хондроитина сульфата (ГХ) у больных остеоартритом (ОА) коленного сустава (КС). Материалы и методы. В исследовании 70 пациентов с I–III стадиями первичного ОА КС рандомизированы на 2 группы. В 1-й (n=35) группе участники принимали АН по 1 капсуле в сутки, во 2-й (n=35) – ГХ по стандартной схеме. Через 7, 30, 90, 180 дней оценивали индекс Лекена (тяжесть ОА), боль при движении по Визуальной аналоговой шкале, индекс WOMAC, через 1, 3, 6 мес – качество жизни по физическому компоненту SF-36 и утреннюю скованность, через 6 мес проводили магнитно-резонансную томографию с T2-картированием, оценивали лабораторные показатели безопасности. Результаты. На протяжении 6 мес в обеих группах наблюдали улучшение индекса WOMAC и уменьшение боли. Большее снижение утренней скованности отмечали в группе АН. Через 3 мес тяжесть ОА уменьшилась с умеренной до слабой в группе АН и оказалась значимо ниже по сравнению с группой ГХ, а качество жизни по SF-36 было выше в группе АН. Через 6 мес отмечены улучшение ультраструктуры хряща (время T2-релаксации) в обеих группах и более выраженное снижение площади синовита в группе АН (в 2,95 и 1,37 раза в группах АН и ГХ соответственно). Клинически значимых нежелательных реакций не отмечено ни в одной из групп. Заключение. Применение АН у пациентов с первичным ОА КС I–III стадии не уступало по эффективности комбинации ГХ. Целесообразно проведение дальнейших исследований с большей статистической мощностью (размером выборки) и более длительным периодом наблюдения, в том числе в условиях реальной клинической практики.

Inflammation and loss of articular cartilage are considered the major cause of temporomandibular joint osteoarthritis (TMJOA), a painful condition of the temporomandibular joint (TMJ). To determine the cause of TMJ osteoarthritis in these patients, synovial fluid of TMJOA patients was compared prior to and after hyaluronic lavage, revealing substantially elevated levels of interleukin (IL) 1β, reactive oxidative stress (ROS), and an overload of Fe3+ and Fe2+ prior to lavage, indicative of ferroptosis as a mode of chondrocyte cell death. To ask whether prolonged inflammatory conditions resulted in ferroptosis-like transformation in vitro, we subjected TMJ chondrocytes to IL-1β treatment, resulting in a shift in messenger RNA sequencing gene ontologies related to iron homeostasis and oxidative stress-related cell death. Exposure to rat unilateral anterior crossbite conditions resulted in reduced COL2A1 expression, fewer chondrocytes, glutathione peroxidase 4 (GPX4) downregulation, and 4-hydroxynonenal (4-HNE) upregulation, an effect that was reversed after intra-articular injections of the ferroptosis inhibitor ferrostatin 1 (Fer-1). Our study demonstrated that ferroptosis conditions affected mitochondrial structure and function, while the inhibitor Fer-1 restored mitochondrial structure and the inhibition of hypoxia-inducible factor 1α (HIF-1α) or the transferrin receptor 1 (TFRC) rescued IL-1β-induced loss of mitochondrial membrane potential. Inhibition of HIF-1α downregulated IL-1β-induced TFRC expression, while inhibition of TFRC did not downregulate IL-1β-induced HIF-1α expression in chondrocytes. Moreover, inhibition of HIF-1α or TFRC downregulated the IL-1β-induced MMP13 expression in chondrocytes, while inhibition of HIF-1α or TFRC rescued IL-1β-inhibited COL2A1 expression in chondrocytes. Furthermore, upregulation of TFRC promoted Fe2+ entry into chondrocytes, inducing the Fenton reaction and lipid peroxidation, which in turn caused ferroptosis, a disruption in chondrocyte functions, and an exacerbation of condylar cartilage degeneration. Together, these findings illustrate the far-reaching effects of chondrocyte ferroptosis in TMJOA as a mechanism causing chondrocyte death through iron overload, oxidative stress, and articular cartilage degeneration and a potential major cause of TMJOA.

Osteoarthritis is the most prevalent type of degenerative arthritis. It is characterized by persistent pain, joint dysfunction, and physical disability. Pain relief and inflammation control are prioritised during osteoarthritis treatment Mume Fructus (Omae), a fumigated product of the Prunus mume fruit, is used as a traditional medicine in several Asian countries. However, its therapeutic mechanism of action and effects on osteoarthritis and articular chondrocytes remain unknown. In this study, we analyzed the anti-osteoarthritis and articular regenerative effects of Mume Fructus extract on rat chondrocytes. Mume Fructus treatment reduced the interleukin-1β-induced expression of matrix metalloproteinase 3, matrix metalloproteinase 13, and a disintegrin and metalloproteinase with thrombospondin type 1 motifs 5. Additionally, it enhanced collagen type II alpha 1 chain and aggrecan accumulation in rat chondrocytes. Furthermore, Mume Fructus treatment regulated the inflammatory cytokine levels, mitogen-activated protein kinase phosphorylation, and nuclear factor-kappa B activation. Overall, our results demonstrated that Mume Fructus inhibits osteoarthritis progression by inhibiting the nuclear factor-kappa B and mitogen-activated protein kinase pathways to reduce the levels of inflammatory cytokines and prevent cartilage degeneration. Therefore, Mume Fructus may be a potential therapeutic option for osteoarthritis.

The knee joint has long been considered a closed system. The pathological effects of joint diseases on distant organs have not been investigated. Herein, our clinical data showed that post-traumatic joint damage, combined with joint bleeding (hemarthrosis), exhibits a worse liver function compared with healthy control. With mouse model, hemarthrosis induces both cartilage degeneration and remote liver damage. Next, we found that hemarthrosis induces the upregulation in ratio and differentiation towards Th17 cells of CD4+ T cells in peripheral blood and spleen. Deletion of CD4+ T cells reverses hemarthrosis-induced liver damage. Degeneration of cartilage matrix induced by hemarthrosis upregulates serological type II collagen (COL II), which activates CD4+ T cells. Systemic application of a COL II antibody blocks the activation. Furthermore, bulk RNAseq and single-cell qPCR analysis revealed that the cartilage Akt pathway is inhibited by blood treatment. Intra-articular application of Akt activator blocks the cartilage degeneration and thus protects against the liver impairment in mouse and pig models. Taken together, our study revealed a pathological joint-liver axis mediated by matrikine-activated CD4+ T cells, which refreshes the organ-crosstalk axis and provides a new treatment target for hemarthrosis-related disease. Intra-articular bleeding induces cartilage degradation through down-reulation of cartilage Akt pathway. During this process, the soluble COL II released from the damaged cartilage can activate peripheral CD4+ T cells, differention into Th17 cells and secretion of IL-17, which consequently induces liver impairment. Intra-articular application of sc79 (inhibitor of Akt pathway) can prevent the cartilage damage as well as its peripheral influences.