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Introduction The study evaluates the levels of matrix metalloprotease-8 (MMP-8), and Cathepsin-K (CatK) in peri-implant crevicular fluid (PICF) among patients with immediate loaded (IL) and delayed-loaded (DL) implants at different time points to know the inflammation and osteogenic status. Methods The study population consisted of two groups (n = 25, each group) with a mean age of 28.7 ± 3.5 years, and PICF was collected. MMP-8 and CatK levels were quantified through ELISA. Results We observed the concentrations of inflammatory markers (MMP-8 and CatK) at three time points in the IL and DL groups. The mean concentration of MMP-8 in the IL group was 9468 ± 1230 pg/mL, 5547 ± 1088 pg/mL, and 7248 ± 1396 pg/mL at 2 weeks, 3 months, and 12 months, respectively; while in the DL group was 10 816 ± 779.7 pg/mL, 9531 ± 1245 pg/mL, and 9132 ± 1265 pg/mL at 2 weeks, 3 and 12 months, respectively. The mean concentration of Cat-K in the IL group was observed at 422.1 ± 36.46 pg/mL, 242.9 ± 25.87 pg/mL, and 469 ± 75.38 pg/mL at 2 weeks, 3, and 12 months, whereas in the DL group was 654.6 ± 152.9 pg/mL, 314.7 ± 28.29 pg/mL, and 539.8 ± 115.1 pg/mL at 2 weeks, 3 months and 12 months, respectively. Conclusion In this study, the levels of CatK and MMP-8 levels decline at 12 months in both groups, and the IL group shows lower values compared to the DL group; however, no significant changes were observed after analyses were adjusted for multiple comparisons (p > 0.025). Therefore, there is not much difference observed in the inflammation process between immediate and delayed loading. (Clinical trial identifier: CTRI/2017/09/009668)., Validerad;2023;Nivå 2;2023-06-29 (sofila);Funder: All-India Institute of Medical Sciences

Introduction The study evaluates the levels of matrix metalloprotease-8 (MMP-8), and Cathepsin-K (CatK) in peri-implant crevicular fluid (PICF) among patients with immediate loaded (IL) and delayed-loaded (DL) implants at different time points to know the inflammation and osteogenic status. Methods The study population consisted of two groups (n = 25, each group) with a mean age of 28.7 ± 3.5 years, and PICF was collected. MMP-8 and CatK levels were quantified through ELISA. Results We observed the concentrations of inflammatory markers (MMP-8 and CatK) at three time points in the IL and DL groups. The mean concentration of MMP-8 in the IL group was 9468 ± 1230 pg/mL, 5547 ± 1088 pg/mL, and 7248 ± 1396 pg/mL at 2 weeks, 3 months, and 12 months, respectively; while in the DL group was 10 816 ± 779.7 pg/mL, 9531 ± 1245 pg/mL, and 9132 ± 1265 pg/mL at 2 weeks, 3 and 12 months, respectively. The mean concentration of Cat-K in the IL group was observed at 422.1 ± 36.46 pg/mL, 242.9 ± 25.87 pg/mL, and 469 ± 75.38 pg/mL at 2 weeks, 3, and 12 months, whereas in the DL group was 654.6 ± 152.9 pg/mL, 314.7 ± 28.29 pg/mL, and 539.8 ± 115.1 pg/mL at 2 weeks, 3 months and 12 months, respectively. Conclusion In this study, the levels of CatK and MMP-8 levels decline at 12 months in both groups, and the IL group shows lower values compared to the DL group; however, no significant changes were observed after analyses were adjusted for multiple comparisons (p > 0.025). Therefore, there is not much difference observed in the inflammation process between immediate and delayed loading. (Clinical trial identifier: CTRI/2017/09/009668)., Validerad;2023;Nivå 2;2023-06-29 (sofila);Funder: All-India Institute of Medical Sciences

Periodontitis is a highly prevalent disease leading to uncontrolled osteoclastic jawbone resorption and ultimately edentulism; however, the disease onset mechanism has not been fully elucidated. Here we propose a mechanism for initial pathology based on results obtained using a recently developed Osteoadsorptive Fluogenic Sentinel (OFS) probe that emits a fluorescent signal triggered by cathepsin K (Ctsk) activity. In a ligature-induced mouse model of periodontitis, a strong OFS signal is observed before the establishment of chronic inflammation and bone resorption. Single cell RNA sequencing shows gingival fibroblasts to be the primary cellular source of early Ctsk. The in vivo OFS signal is activated when Toll-Like Receptor 9 (TLR9) ligand or oral biofilm extracellular DNA (eDNA) is topically applied to the mouse palatal gingiva. This previously unrecognized interaction between oral microbial eDNA and Ctsk of gingival fibroblasts provides a pathological mechanism for disease initiation and a strategic basis for early diagnosis and treatment of periodontitis.

Osteoclast (OC) abnormalities represent osteoporosis's critical mechanism (OP). OCs undergo multiple processes that range from monocytic to functional. Different drugs target OCs at different developmental stages; however, almost no Suitable drug-targeted delivery systems exist. Therefore, we designed two dual-targeting nanoparticles to target OCs at different functional stages. Using the calcitonin gene-related peptide receptor (CGRPR), which OC precursors highly express, and specific TRAPpeptides screened in the bone resorption lacuna, where mature OCs function, respectively, two types of dual-targeted nanoparticles were constructed. Afterwards, nanoparticles were grafted with hyaluronic acid (HA), which specifically binds to CD44 on the surface of the OCs. In vivo and in vitro experiments show that both nanoparticles have noticeable targeting effects on OCs. This suggests that dual-targeting nanoparticles designed for different functional periods of OC can be well targeted to the corresponding OC, and further promote the more precise delivery of drugs used to treat OP., QC 20221214

Case summaryA 9-month-old entire male domestic longhair cat presented with a history of pathological fractures, chronic musculoskeletal pain and poor growth. Multiple facial and skeletal abnormalities were identified on physical examination and advanced imaging (CT and radiographs). A variant in CTSK was identified in the affected cat following whole-exome sequencing (WES). The cat was managed symptomatically with diet, environmental modifications and analgesia.Relevance and novel informationThis is the first report of a cat with a similar clinical presentation and genetic variant to the hereditary human genetic disorder pyknodysostosis. In this case, WES was performed, which often facilitates the diagnosis of various hereditary disorders (ie, a conceptual framework for practicing feline genomic medicine). Despite the severe skeletal and appendicular abnormalities described, the cat was alive more than 2 years after its initial presentation.

We describe the design and synthesis of OFS-1, an Osteoadsorptive Fluorogenic Sentinel imaging probe that is adsorbed by hydroxyapatite (HAp) and bone mineral surfaces, where it generates an external fluorescent signal in response to osteoclast-secreted cathepsin K (Ctsk). The probe consists of a bone-anchoring bisphosphonate moiety connected to a Förster resonance energy transfer (FRET) internally quenched fluorescent (IQF) dye pair, linked by a Ctsk peptide substrate, GHPGGPQG. Key structural features contributing to the effectiveness of OFS-1 were defined by structure-activity relationship (SAR) and modeling studies comparing OFS-1 with two cognates, OFS-2 and OFS-3. In solution or when preadsorbed on HAp, OFS-1 exhibited strong fluorescence when exposed to Ctsk (2.5-20 nM). Time-lapse photomicrographs obtained after seeding human osteoclasts onto HAp-coated well plates containing preadsorbed OFS-1 revealed bright fluorescence at the periphery of resorbing cells. OFS-1 administered systemically detected early osteolysis colocalized with orthotopic engraftment of RPMI-8226-Luc human multiple myeloma cells at a metastatic skeletal site in a humanized mouse model. OFS-1 is thus a promising new imaging tool for detecting abnormal bone resorption.

This is the peer reviewed version of the following article: E. Añón, A. M. Costero, P. Amorós, J. El Haskouri, R. Martínez-Mánez, M. Parra, S. Gil, P. Gaviña, M. C. Terencio, M. Alfonso, ChemistrySelect 2020, 5, 3618., which has been published in final form at https://doi.org/10.1002/slct.202000417. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] Osteoporosis is an illness which appears when the osteoblast/osteoclast activities are unbalanced taking place bone resorption (caused by osteoclasts) in higher extension than bone formation (induced by osteoblasts). Alendronate is one of the most used drugs for osteoporosis treatment despite its scarce bioavailability. Here we present the synthesis and characterization of mesoporous gated nanoparticles (two sets) for the controlled release of alendronate. The first set of nanoparticles (S1) were loaded with sulforhodamine B and capped with a peptide that could be selectively hydrolyzed by cathepsin K enzyme (overexpressed in osteoclasts). The second set (S2) was functionalized with aminopropyl moieties, loaded with nitrobenzofurazan labelled alendronate and capped with the same peptide. Both nanoparticles were internalized by RAW 264.7 macrophages (which could differentiate in osteoclasts) and were able to release its entrapped cargo in the presence of cathepsin K added in the macrophage lysates. Using S2 nanoparticles 4.2% of the total alendronate amount in contact with the cells is liberated inside them and could produce its therapeutic effect.

This is the peer reviewed version of the following article: E. Añón, A. M. Costero, P. Amorós, J. El Haskouri, R. Martínez-Mánez, M. Parra, S. Gil, P. Gaviña, M. C. Terencio, M. Alfonso, ChemistrySelect 2020, 5, 3618., which has been published in final form at https://doi.org/10.1002/slct.202000417. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., [EN] Osteoporosis is an illness which appears when the osteoblast/osteoclast activities are unbalanced taking place bone resorption (caused by osteoclasts) in higher extension than bone formation (induced by osteoblasts). Alendronate is one of the most used drugs for osteoporosis treatment despite its scarce bioavailability. Here we present the synthesis and characterization of mesoporous gated nanoparticles (two sets) for the controlled release of alendronate. The first set of nanoparticles (S1) were loaded with sulforhodamine B and capped with a peptide that could be selectively hydrolyzed by cathepsin K enzyme (overexpressed in osteoclasts). The second set (S2) was functionalized with aminopropyl moieties, loaded with nitrobenzofurazan labelled alendronate and capped with the same peptide. Both nanoparticles were internalized by RAW 264.7 macrophages (which could differentiate in osteoclasts) and were able to release its entrapped cargo in the presence of cathepsin K added in the macrophage lysates. Using S2 nanoparticles 4.2% of the total alendronate amount in contact with the cells is liberated inside them and could produce its therapeutic effect.

[EN] Osteoarthritis (OA) is the most common joint disorder and a leading cause of disability. Current treatments for OA can improve symptoms but do not delay the progression of disease. In the last years, much effort has been devoted to developing new treatments for OA focused on pain control, inflammatory mediators or degradation of articular tissues. Although promising results have been obtained in ex vivo studies and animal models of OA, few of these agents have completed clinical trials. Available clinical data support the interest of nerve growth factor as a target in pain control as well as the disease-modifying potential of inhibitors of Wnt signaling or catabolic enzymes such as aggrecanases and cathepsin K, and anabolic strategies like fibroblast growth factor-18 or cellular therapies. Carefully controlled studies in patients selected according to OA phenotypes and with a long follow-up will help to confirm the relevance of these new approaches as emerging therapeutic treatments in OA.

[EN] Osteoarthritis (OA) is the most common joint disorder and a leading cause of disability. Current treatments for OA can improve symptoms but do not delay the progression of disease. In the last years, much effort has been devoted to developing new treatments for OA focused on pain control, inflammatory mediators or degradation of articular tissues. Although promising results have been obtained in ex vivo studies and animal models of OA, few of these agents have completed clinical trials. Available clinical data support the interest of nerve growth factor as a target in pain control as well as the disease-modifying potential of inhibitors of Wnt signaling or catabolic enzymes such as aggrecanases and cathepsin K, and anabolic strategies like fibroblast growth factor-18 or cellular therapies. Carefully controlled studies in patients selected according to OA phenotypes and with a long follow-up will help to confirm the relevance of these new approaches as emerging therapeutic treatments in OA.

Purpose of reviewIn perilacunar/canalicular remodeling (PLR), osteocytes dynamically resorb, and then replace, the organic and mineral components of the pericellular extracellular matrix. Given the enormous surface area of the osteocyte lacuna-canalicular network (LCN), PLR is important for maintaining homeostasis of the skeleton. The goal of this review is to examine the motivations and critical considerations for the analysis of PLR, in both in vitro and in vivo systems.Recent findingsMorphological approaches alone are insufficient to elucidate the complex mechanisms regulating PLR in the healthy skeleton and in disease. Understanding the role and regulation of PLR will require the incorporation of standardized PLR outcomes as a routine part of skeletal phenotyping, as well as the development of improved molecular and cellular outcomes. Current PLR outcomes assess PLR enzyme expression, the LCN, and bone matrix composition and organization, among others. Here, we discuss current PLR outcomes and how they have been applied to study PLR induction and suppression in vitro and in vivo. Given the role of PLR in skeletal health and disease, integrated analysis of PLR has potential to elucidate new mechanisms by which osteocytes participate in skeletal health and disease.

Cathepsin K (CatK) inhibitors exhibited chondroprotective and pain-reducing effects in animal models, however, improvements were relatively modest at dose levels achieving maximal suppression of CatK biomarkers in urine. In this report, a previously characterized CatK inhibitor (MK-1256) is utilized to explore the potential of reduced target engagement and/or suboptimal exposure (free drug) as limiting factors to the pharmacological potential of CatK inhibitors in the knee joint. Following oral administration of MK-1256 at a dose level achieving maximal inhibition of urinary biomarker (helical peptide) in dogs, full suppression of the biomarker in synovial fluid was observed. Subsequent tissue distribution studies conducted in dogs and rabbits revealed that MK-1256 levels in synovial fluid and cartilage were consistent with the free-drug hypothesis. Reasonable projection (within twofold) of drug levels in these tissues can be made based on plasma drug concentration with adjustments for binding factors. These results indicate that the previously observed efficacies in the animal models were not limited by compound distribution or target engagement in the knee tissues.

Through a process called perilacunar remodeling, bone-embedded osteocytes dynamically resorb and replace the surrounding perilacunar bone matrix to maintain mineral homeostasis. The vital canalicular networks required for osteocyte nourishment and communication, as well as the exquisitely organized bone extracellular matrix, also depend upon perilacunar remodeling. Nonetheless, many questions remain about the regulation of perilacunar remodeling and its role in skeletal disease. Here, we find that suppression of osteocyte-driven perilacunar remodeling, a fundamental cellular mechanism, plays a critical role in the glucocorticoid-induced osteonecrosis. In glucocorticoid-treated mice, we find that glucocorticoids coordinately suppress expression of several proteases required for perilacunar remodeling while causing degeneration of the osteocyte lacunocanalicular network, collagen disorganization, and matrix hypermineralization; all of which are apparent in human osteonecrotic lesions. Thus, osteocyte-mediated perilacunar remodeling maintains bone homeostasis, is dysregulated in skeletal disease, and may represent an attractive therapeutic target for the treatment of osteonecrosis.

Through a process called perilacunar remodeling, bone-embedded osteocytes dynamically resorb and replace the surrounding perilacunar bone matrix to maintain mineral homeostasis. The vital canalicular networks required for osteocyte nourishment and communication, as well as the exquisitely organized bone extracellular matrix, also depend upon perilacunar remodeling. Nonetheless, many questions remain about the regulation of perilacunar remodeling and its role in skeletal disease. Here, we find that suppression of osteocyte-driven perilacunar remodeling, a fundamental cellular mechanism, plays a critical role in the glucocorticoid-induced osteonecrosis. In glucocorticoid-treated mice, we find that glucocorticoids coordinately suppress expression of several proteases required for perilacunar remodeling while causing degeneration of the osteocyte lacunocanalicular network, collagen disorganization, and matrix hypermineralization; all of which are apparent in human osteonecrotic lesions. Thus, osteocyte-mediated perilacunar remodeling maintains bone homeostasis, is dysregulated in skeletal disease, and may represent an attractive therapeutic target for the treatment of osteonecrosis.

Oral lichen planus (OLP) is a chronic immune-mediated mucosal disease with unknown etiology. According to the current view, the pathogenesis of OLP involves activation of T-cell mediated immunity against the epithelial keratinocytes. A proportion of OLP patients are affected by painful symptoms, and the risk of oral cancer is increased in OLP. There is no curative treatment for OLP. Topical corticosteroids are used most commonly in the management of OLP. However, the evidence base for the effectiveness of any therapy is weak. The objective of this thesis was to study novel aspects of OLP etiopathogenesis and management. An epidemiologic, retrospective case-control study was conducted to determine whether systemic diseases, in particular thyroid diseases, are associated with OLP. In addition, a randomized controlled trial comparing the effectiveness of topical tacrolimus, triamcinolone acetonide and placebo in symptomatic OLP was carried out. Furthermore, immunohistochemical expression of toll-like receptors 4 and 9, hyaluronan and its principal receptor CD44 antigen, hyaluronan synthases 1-3, hyaluronidases 1-2 and cathepsin K was studied in OLP tissue samples and in healthy oral mucosa. The effect of topical tacrolimus on the expression of these molecules in OLP was also studied. The results of the present study showed that a history of hypothyroidism was associated with an approximately twofold risk of having OLP. Furthermore, both tacrolimus and triamcinolone acetonide were more efficient than placebo in reducing the signs and symptoms of OLP. No statistically significant differences were noted in the efficacy between tacrolimus and triamcinolone acetonide. In addition, the expression of the studied molecules was altered in the epithelium or stroma in OLP compared to healthy oral mucosa. Tacrolimus treatment decreased the expression of CD44 antigen in the stroma and the expression of cathepsin K in the epithelium in OLP. In conclusion, the present study, Tiivistelmä Suun punajäkälä on krooninen immuunivälitteinen limakalvotauti, jonka etiologia on tuntematon. Taudin syntymekanismiin liittyy tämän hetkisen näkemyksen mukaan T-soluvälitteisen immuniteetin aktivoituminen epiteelin keratinosyyttejä vastaan. Suun punajäkälä aiheuttaa osalle potilaista kivuliaita oireita ja lisää suusyövän riskiä. Parantavaa hoitoa tautiin ei ole. Yleisimmin suun punajäkälän oireiden hoidossa käytetään paikallisia kortikosteroidivalmisteita. Kuitenkin eri hoitomuotojen tehosta on vain heikkoa näyttöä. Tämän väitöskirjatyön tarkoituksena oli tutkia uusia näkökohtia liittyen suun punajäkälän etiopatogeneesiin ja hoitoon. Epidemiologisessa tapaus-verrokkitutkimuksessa selvitettiin, liittyvätkö yleissairaudet, erityisesti kilpirauhassairaudet, suun punajäkälään. Lisäksi satunnaistetussa kontrolloidussa tutkimuksessa verrattiin paikallisen takrolimuusin, triamsinoloniasetonidin ja lumelääkkeen tehoa oireisesta suun punajäkälästä kärsivillä potilailla. Tutkimuksessa selvitettiin myös tollin kaltaisten reseptorien 4 ja 9, hyaluronaanin ja sen pääasiallisen reseptorin CD44-antigeenin, hyaluronaanisyntaasien 1–3, hyaluronidaasien 1–2 sekä katepsiini K:n immunohistokemiallista ilmentymistä suun punajäkälänäytteissä ja terveessä suun limakalvossa. Lisäksi tutkittiin takrolimuusihoidon vaikutusta näiden molekyylien ilmentymiseen suun punajäkälässä. Tämän tutkimuksen tulokset osoittivat, että kilpirauhasen vajaatoimintaan liittyi noin kaksinkertainen riski sairastaa suun punajäkälää. Lisäksi havaittiin, että suun punajäkälässä sekä takrolimuusi että triamsinoloniasetonidi ovat tehokkaampia kuin lumelääke oireiden ja kliinisen taudinkuvan lievittämisessä. Takrolimuusin ja triamsinoloniasetonidin tehossa ei todettu tilastollisesti merkitseviä eroja. Lisäksi suun punajäkälänäytteissä tutkittujen molekyylien ilmentyminen oli muuttunut joko epiteelissä tai stroomassa verrattuna terveeseen limakalvoon. Takrolimuusihoito vähensi CD44-antigeenin ilmentymistä

Cavitation in tuberculosis enables highly efficient person-to-person aerosol transmission. We performed transcriptomics in the rabbit cavitary tuberculosis model. Among 17 318 transcripts, we identified 22 upregulated proteases. Five type I collagenases were overrepresented: cathepsin K (CTSK), mast cell chymase-1 (CMA1), matrix metalloproteinase 1 (MMP-1), MMP-13, and MMP-14. Studies of collagen turnover markers, specifically, collagen type I C-terminal propeptide (CICP), urinary deoxypyridinoline (DPD), and urinary helical peptide, revealed that cavitation in tuberculosis leads to both type I collagen destruction and synthesis and that proteases other than MMP-1, MMP-13, and MMP-14 are involved, suggesting a key role for CTSK. We confirmed the importance of CTSK upregulation in human lung specimens, using immunohistochemical analysis, which revealed perigranulomatous staining for CTSK, and we showed that CTSK levels were increased in the serum of patients with tuberculosis, compared with those in controls (3.3 vs 0.3 ng/mL; P = .005).

ObjectiveJoint injuries initiate a surge of inflammatory cytokines and proteases that contribute to cartilage and subchondral bone degeneration. Detecting these early processes in animal models of post-traumatic osteoarthritis (PTOA) typically involves ex vivo analysis of blood serum or synovial fluid biomarkers, or histological analysis of the joint. In this study, we used in vivo fluorescence reflectance imaging (FRI) to quantify protease, matrix metalloproteinase (MMP), and Cathepsin K activity in mice following anterior cruciate ligament (ACL) rupture. We hypothesized that these processes would be elevated at early time points following joint injury, but would return to control levels at later time points.DesignMice were injured via tibial compression overload, and FRI was performed at time points from 1 to 56 days after injury using commercially available activatable fluorescent tracers to quantify protease, MMP, and cathepsin K activity in injured vs uninjured knees. PTOA was assessed at 56 days post-injury using micro-computed tomography and whole-joint histology.ResultsProtease activity, MMP activity, and cathepsin K activity were all significantly increased in injured knees relative to uninjured knees at all time points, peaking at 1-7 days post-injury, then decreasing at later time points while still remaining elevated relative to controls.ConclusionsThis study establishes FRI as a reliable method for in vivo quantification of early biological processes in a translatable mouse model of PTOA, and provides crucial information about the time course of inflammation and biological activity following joint injury. These data may inform future studies aimed at targeting these early processes to inhibit PTOA development.

INTRODUCTION: The metabolic bone disease osteoporosis is a growing health and health-economic problem worldwide. Bisphosphonates are the most widely used antiresorptive medication and the de facto gold standard in fracture prophylaxis all over the world, in conjunction with calcium and vitamin D supplementation. Several new medications for the treatment of postmenopausal osteoporosis are in the pipeline.AREAS COVERED: The authors present the most recent studies on new and current antiresorptive as well as anabolic drugs. Specifically, the authors present the current knowledge on drugs directed against cathepsin K and sclerostin as well as the new pathways of interest from preclinical studies.EXPERT OPINION: New scientific results have identified novel signaling pathways as potential targets for future development of anti-osteoporotic drugs. The treatments close to marketing at the moment are odanacatib and romosozumab and these are both promising new medications based on bone mineral density results, safety profile and administration. Theoretically, romosozumab may hold the potential to be a drug to 'cure' even advanced stages of osteoporosis with short-term treatment. However, safety, fracture data and cost are key elements that will determine the extent of use.

INTRODUCTION: The metabolic bone disease osteoporosis is a growing health and health-economic problem worldwide. Bisphosphonates are the most widely used antiresorptive medication and the de facto gold standard in fracture prophylaxis all over the world, in conjunction with calcium and vitamin D supplementation. Several new medications for the treatment of postmenopausal osteoporosis are in the pipeline.AREAS COVERED: The authors present the most recent studies on new and current antiresorptive as well as anabolic drugs. Specifically, the authors present the current knowledge on drugs directed against cathepsin K and sclerostin as well as the new pathways of interest from preclinical studies.EXPERT OPINION: New scientific results have identified novel signaling pathways as potential targets for future development of anti-osteoporotic drugs. The treatments close to marketing at the moment are odanacatib and romosozumab and these are both promising new medications based on bone mineral density results, safety profile and administration. Theoretically, romosozumab may hold the potential to be a drug to 'cure' even advanced stages of osteoporosis with short-term treatment. However, safety, fracture data and cost are key elements that will determine the extent of use.

Tato práce pojednává o základních krocích rozvoje aterosklerózy, včetně jejího důsledku v rozvíjení dalších onemocnění a rizikových faktorů ovlivňujících aterogenezi. Dále popisuje základní druhy klinicky významných katepsinů, z nichž některé významně ovlivňují stabilitu aterosklerotického plátu. V této práci je podrobně popsán mechanismus účinku katepsinu K a S na degradaci kolagenu a elastinu, leukocytární transmigraci a prostup hladkých svalových buněk do cévní intimy, zvýšenou tvorbu pěnových buněk, degradaci lipoproteinů o nízké hustotě LDL, zvýšení apoptózy makrofágů a kolagenu a na prezentaci antigenu a následné ovlivnění imunitního systému, přičemž všechny tyto účinky katepsinů K a S většinou negativně ovlivňují stabilitu aterosklerotického plátu. Práce je zaměřena nejen na podstatu zapojení vybraných katepsinů do mechanismů ovlivňujících stabilitu aterosklerotického plátu, ale i na metodiku stanovení katepsinů K a S v lidské plazmě. Nejvíce používanou je metoda ELISA, druhou nejčastější pak cenově dostupnější zymografie. Pro stanovení katepsinů se vzorek dopravuje nejlépe do 24 hodin, při transportu se udržuje teplota v rozmezí od 4 do 8 °C., This paper discusses the basic steps of atherosclerosis, including its implications in the development of other diseases and risk factors affecting atherogenesis. It also describes the basic types of clinically significant cathepsins, some of which significantly affect the stability of atherosclerotic plaque. This paper describes in detail the mechanism of action cathepsin K and S as the degradation of collagen and elastin, leukocyte transmigration and penetration of smooth muscle cells in vascular intima, increased formation of foam cells, degradation of low density lipoproteins LDL, increased apoptosis of macrophages and collagen, on antigen presentation and follow effect on the immune system, while all of these effects of cathepsin K and S mostly negatively influence the stability of atherosclerotic plaque. The work is focused not only on the nature of the involvement of selected cathepsins into the mechanisms affecting the stability of atherosclerotic plaque, but also on the method for determination of cathepsins K and S in human plasma. The most widely used is the ELISA method, then the second most affordable zymography. For the determination of transported to set preferably within 24 hours, during transportation maintaining a temperature in the range of 4 to 8 ° C., Katedra biologických a biochemických věd, 1. Prezentace výsledků bakalářské práce. 2. Diskuse k posudku vedoucího bakalářské práce. 3. Studentka zodpověděla všechny dotazy a připomínky k BP.

We have previously shown that CatK is expressed not only by osteoclasts but also by prostate cancer (PCa) cells and stromal cells. Zledronic acid (ZA), a bisphosphonate which exerts beneficial effects in PCa patients with bone metastases, reduces both pain and skeletal related events. We hypothesized that combination of a bisphosphonate with the CatK inhibitor, through different inhibitory mechanisms, could diminish PCa progression in vivo. Accordingly, PCa C4-2B cells were inoculated into the tibiae of SCID mice. The mice were randomized into the following treatment groups (n=10/group):ZA, CatK inhibitor, the combination of ZA and CatK inhibitor, and saline vehicle alone. Test drugs were initiated at 4 weeks after the tumor cell inoculation and treatments were continued for 8 weeks. We found that CatK inhibitor significantly reduced skeletal tumor burden as determined by both tumor volume vs soft tissue volume ratio and serum PSA levels. In contrast, ZA less effectively diminished the skeletal tumor volume. ZA failed to decrease PSA levels. Importantly, combinations of the two agents were more effective in decreasing tumor volume than any single agent. Therefore, we show for the first time that a CatK inhibitor diminishes PCa growth in bone and the inhibitory effects are enhanced in combination with ZA.

The major site of metastasis of breast cancer cells is bone. Bone metastases occur in 80% of patients with advanced disease and causes significant morbidity. The mechanisms of osteolysis and targeting of bone by the breast cancer cells are still unknown. The osteolysis that occurs in patients is mediated by factors that come from the tumor cells. The tumor cells provide a microenvironment to the osteoblasts and osteoclasts. Bone remodeling requires the degradation and turnover of type I collagen. Type I collagen is a triple helical fibrillar collagen that can be cleaved by cathepsin K found only in osteoclasts. Recently, studies of breakdown fragments of extracellular matrix (ECM) proteins have shown novel biological activity of the fragments. We believe that these fragments may be chemotactic to breast tumor cells. Once the breast tumor cells metastasize to the bone, the tumor cells secrete factors that stimulate the increase in osteolysis of bone. This leads to increase of type I collagen fragments that signal back to the tumor cells, osteoblasts and osteoclasts perpetuating this cascade. This study proposes to map the active sequences in the type I collagen breakdown fragments that can contribute to breast tumor metastasis to bone. The understanding of this pathway can lead to development of biomarkers assays to detect early bone metastases, monitor treatments in targeting bone metastases and staging of metastatic bone tumors. Prevention, early detection and treatment of bone metastasis breast tumors to bone would benefit the survival and quality of life of breast cancer patients.

We have previously shown that CatK is expressed not only by osteoclasts but also by prostate cancer (PCa) cells and stromal cells. Zoledronic acid (ZA), a bisphosphonate which exerts beneficial effects in PCa patients with bone metastases, reduces both pain and skeletal related events. We hypothesized that combination of a bisphosphonate with the CatK inhibitor, through different inhibitory mechanisms, could diminish PCa progression in vivo. Accordingly, PCa C4-2B cells were inoculated into the tibiae of SCID mice. The mice were randomized into the following treatment groups (n=10/group): ZA, CatK inhibitor, the combination of ZA and CatK inhibitor, and saline vehicle alone. Test drugs were initiated at 4 weeks after the tumor cell inoculation and treatments were continued for 8 weeks. We found that CatK inhibitor significantly reduced skeletal tumor burden as determined by both tumor volume vs soft tissue volume ratio and serum PSA levels. In contrast, ZA less effectively diminished the skeletal tumor volume. ZA failed to decrease PSA levels. Importantly, combinations of the two agents were more effective in decreasing tumor volume than any single agent. Using one PCa cell line, we show for the first time that a CatK inhibitor diminishes PCa growth in bone and the inhibitory effects are enhanced in combination with ZA. More cell lines need to be tested., The original document contains color images.

Highly potent and selective 4-amidofuran-3-one inhibitors of cathepsin S are described. The synthesis and structure–activity relationship of a series of inhibitors with a sulfonamide moiety in the P3 position is presented. Several members of the series show sub-nanomolar inhibition of the target enzyme as well as an excellent selectivity profile and good cellular potency. Molecular modeling of the most interesting inhibitors describes interactions in the extended S3 pocket and explains the observed selectivity towards cathepsin K.

The prostate cancer (PCa) metastasis processes are facilitated by proteolytic cascade involving cathepsin K (CatK). CatK expression level is higher in PCa bone metastatic sites than primary tumor or normal prostate tissues. The role of CatK in PCa skeletal metastasis, however, is not known. We first confirmed the expression of CatK in LNCaP, C4-2B, and PC3 PCa cell lines. Then, we observed the inhibitory effect of CatK inhibitor on the PCa cell invasion suggesting the role of CaK in PCa tumor invasion. Finally, we injected C4-2B cells into the tibiae of SCID mice and then the animals received either vehicle or Cat K inhibitor for 8 weeks either at the time of tumor cells injection (tumor establishment model) or 4 weeks after tumor cells were injected (tumor progression model). In the tumor establishment model, CatK inhibitor significantly prevented the establishment of mixed osteolytic/osteoblastic tibial tumors as were observed in vehicle-treated animals. In the progression model, CatK inhibitor diminished tumor-induced bone lesions. We conclude that CatK inhibitor is an effective drug to prevent the establishment and diminish progression of PCa growth in bone. The overall goal of this project is to identify a clinically relevant strategy to inhibit PCa skeletal metastasis.

The hyaluronan (HA) receptor CD44 has a well documented role in tumour metastasis. This review focuses on the potential significance of CD44 expression and function in regulating the metastasis of both haematological malignancies and solid tumours to the bone. Specifically, the review will discuss the evidence that HA-CD44 interactions facilitate the arrest of circulating malignant cells upon the bone marrow endothelial cells and discuss data that suggests CD44 may orchestrate the ability of tumour cells to regulate the modification of the bone matrix and support its colonisation by malignant cells.

Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix in the absence of cathepsin K.

Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix in the absence of cathepsin K.

Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix in the absence of cathepsin K.

Autosomal dominant osteopetrosis II (ADOII) is a relatively benign disorder caused by a missense mutation in the ClCN7 gene. In this study, we characterize the osteoclasts from patients with ADOII, caused by a G215R mutation, and investigate the effect on osteoclast function in vitro. Osteoclasts from ADOII patients and healthy age- and sex-matched controls, were used to evaluate osteoclastogenesis, cell fusion, acidification, and resorptive activity. ADOII osteoclasts in vivo have increased number and size. However, in vitro we observed no significant changes in the osteoclast formation rate, the morphology, and the expression of markers, such as cathepsin K and tartrate-resistant acid phosphatase. When mature ADOII osteoclasts were investigated on mineralized bone, they degraded the bone material, however only to 10 to 20% of the level in controls. We show by acridine orange, that the reduced chloride transport leads to reduced acidification. We show that the residual activity is sensitive to inhibitors of cathepsins and chloride channels, confirming that resorption is reduced but present. In conclusion, this is the first functional in vitro study of human ADOII osteoclasts. We show normal osteoclastogenesis in ADOII osteoclasts. However, the residual activity of the ClC-7 channel in ADOII osteoclasts does not allow sufficient acidification and thereby resorption.

Autosomal dominant osteopetrosis II (ADOII) is a relatively benign disorder caused by a missense mutation in the ClCN7 gene. In this study, we characterize the osteoclasts from patients with ADOII, caused by a G215R mutation, and investigate the effect on osteoclast function in vitro. Osteoclasts from ADOII patients and healthy age- and sex-matched controls, were used to evaluate osteoclastogenesis, cell fusion, acidification, and resorptive activity. ADOII osteoclasts in vivo have increased number and size. However, in vitro we observed no significant changes in the osteoclast formation rate, the morphology, and the expression of markers, such as cathepsin K and tartrate-resistant acid phosphatase. When mature ADOII osteoclasts were investigated on mineralized bone, they degraded the bone material, however only to 10 to 20% of the level in controls. We show by acridine orange, that the reduced chloride transport leads to reduced acidification. We show that the residual activity is sensitive to inhibitors of cathepsins and chloride channels, confirming that resorption is reduced but present. In conclusion, this is the first functional in vitro study of human ADOII osteoclasts. We show normal osteoclastogenesis in ADOII osteoclasts. However, the residual activity of the ClC-7 channel in ADOII osteoclasts does not allow sufficient acidification and thereby resorption.

Prostate cancer (Cap) is often associated with bone metastases, which cause much of the morbidity associated with Cap. CaP bone metastases exhibit increases in both bone formation and resorption. Zn studies under this award, we have investigated the expression and activity of Cathepsin K (Cat K), an enzyme involved in bone lysis in CaP in vitro and in vivo. The Cat K message and protein were detected in CaP cell lines, primary Cap samples, and metastatic samples. Expression of Cat K in bone metastases was significantly higher than in primary CaP. Cat K enzymatic activity was detected in CaP cell lines. ZA decreased the proliferation of CaP cells and caused apoptosis of CaP cells in vitro. Zn vivo, growth of osteoblastic and osteolytic metastases of CaP was significantly inhibited; however, growth of subcutaneous tumors was unaffected by ZA, indicating that he growth inhibition effects were directly related to the interactions between ZA and bone, and/or CaP metastases in bone. Treatment of C4-2 mixed CaP bone metastases resulted in decreased numbers of osteoclasts, but the effects on tumor volume were method-dependent. Evaluation of the effects of ZA on bone seeding, using cardiac injection model, is ongoing.

AIMS: To investigate the potential predictive value of cathepsins B, D and K in a series of 51 adamantinomatous craniopharyngiomas. While almost always benign, craniopharyngiomas exhibit a high propensity to recur postsurgically and biological markers are therefore needed to predict their recurrence. We have previously demonstrated the potential predictive value of retinoic acid receptors (RARs) (Lefranc et al. J. Neurosurg. 2003; 98; 145-153). METHODS AND RESULTS: Computer-assisted microscopy was used to determine quantitatively the immunohistochemical levels of expression of the alpha, beta and gamma RAR subtypes and cathepsins B, D and K. The levels of expression of cathepsin D and of cathepsin B correlated significantly with the levels of expression of RARbeta. The levels of expression of cathepsin K correlated significantly with the levels of expression of RARgamma. CONCLUSIONS: Recurrent adamantinomatous craniopharyngiomas are characterized by low levels of RARbeta and high levels of RARgamma. The tendency to recurrence seems, at least partly, to relate to the fact that (i) craniopharyngiomas with low levels of RARbeta express low levels of cathepsin D, and (ii) craniopharyngiomas with high levels of RARgamma express high levels of cathepsin K., Journal Article, Research Support, Non-U.S. Gov't, FLWIN, info:eu-repo/semantics/published

AIMS: To investigate the potential predictive value of cathepsins B, D and K in a series of 51 adamantinomatous craniopharyngiomas. While almost always benign, craniopharyngiomas exhibit a high propensity to recur postsurgically and biological markers are therefore needed to predict their recurrence. We have previously demonstrated the potential predictive value of retinoic acid receptors (RARs) (Lefranc et al. J. Neurosurg. 2003; 98; 145-153). METHODS AND RESULTS: Computer-assisted microscopy was used to determine quantitatively the immunohistochemical levels of expression of the alpha, beta and gamma RAR subtypes and cathepsins B, D and K. The levels of expression of cathepsin D and of cathepsin B correlated significantly with the levels of expression of RARbeta. The levels of expression of cathepsin K correlated significantly with the levels of expression of RARgamma. CONCLUSIONS: Recurrent adamantinomatous craniopharyngiomas are characterized by low levels of RARbeta and high levels of RARgamma. The tendency to recurrence seems, at least partly, to relate to the fact that (i) craniopharyngiomas with low levels of RARbeta express low levels of cathepsin D, and (ii) craniopharyngiomas with high levels of RARgamma express high levels of cathepsin K., Journal Article, Research Support, Non-U.S. Gov't, FLWIN, info:eu-repo/semantics/published

Pycnodysostosis (PKND) is a type of osteosclerosing bone disease. Recent studies have demonstrated that several cathepsin K mutations can be identified in PKND families. A fifty-three-year-old Japanese woman diagnosed with PKND with typical features suffered from the nonunion of the right tibial shaft. We did open reduction and performed a vascularized fibular graft using an external fixator. A low-intensity pulsed ultrasound device was used three months after surgery. Union of the tibia was completed about one year after surgery. Histomorphometric analysis of the iliac bone revealed that the patient had low turnover bone with increased bone volume. Analysis of the cathepsin K coding region from the genomic DNA of the patient and her family (consanguineous parents and three sisters who were all of normal stature) revealed that the patient had a deletion of genomic DNA nucleotide 426 T in exon 5. Her parents and two sisters had a heterozygous mutation, while one sister had a normal sequence. In summary, a mutation in the cathepsin K gene was identified, providing further evidence that a deficiency in the activity of this enzyme causes PKND., departmental bulletin paper

The assay for the carboxyterminal telopeptide of type I collagen, ICTP, has been shown to be a reliable marker in many pathological conditions but insensitive to changes in physiological bone turnover. This has induced uncertainty and confusion regarding the role of ICTP assay in the study of collagen metabolism in bones. Especially, since another assay for the carboxyterminal telopeptide of type I collagen, serum CrossLaps ELISA, sensitively follows the changes in physiological bone turnover. To find out the reasons for the discrepancy we characterized the antigenic determinant of the ICTP assay by comparing human and bovine antigens after trypsin and chymotrypsin treatments. An assay for bovine ICTP was developed contemporarily with the present study. The epitope lies on the phenylalanine rich region of two telopeptide chains. We were able to show that the region is destroyed by cathepsin K, an osteoclastic enzyme responsible for physiological bone turnover, but not by several matrix metalloproteinases (MMPs), which are important collagen degrading enzymes in pathological conditions. Cathepsin K treatment had no effect on the CrossLaps assay. The CrossLaps assay is also able to measure the MMP-derived fragments, but usually their amount is so low in serum that it is masked by the cathepsin K-derived collagen degradation. The results explain the apparent discrepancy regarding the different behaviour of ICTP and CrossLaps assays in various conditions as also verified in our study with rheumatoid arthritis patients. The ICTP assay was also found to measure only trivalently cross-linked forms of the carboxyterminal telopeptide which contains two telopeptide chains, and is therefore unable to react with divalently or histidinohydroxylysinonorleucine (HHL)-cross-linked forms of the carboxyterminal telopeptide. These forms can be measured with the SP4 (synthetic peptide 4) assay. We utilized this property in analyzing the skin samples of 18 breast cancer patient