Lysyl Hydroxylase Research Articles

Management of scoliosis in a pediatric patient with lysyl hydroxylase-3 deficiency: a case report

BackgroundA rare case report of lysyl hydroxylases deficiency undergoing scoliosis surgery.Case presentationAn 8-year-old Persian patient with a known case of lysyl hydroxylases deficiency presented with scoliosis. On physical examination, he had course facial hair, elbow flexion contracture, and knee flexion contracture. He had a history of eye surgery, clubfoot, and hearing problems. He underwent scoliosis surgery with growing rod instrumentation.ConclusionSurgery can be done in these patients with caution, and the surgeon and anesthesiologist should be aware of potential complications during and after surgery.

Substrate selectivity and inhibition of the human lysyl hydroxylase JMJD7.

Jumonji-C (JmjC) domain-containing protein 7 (JMJD7) is a human Fe(II) and 2-oxoglutarate dependent oxygenase that catalyzes stereospecific C3-hydroxylation of lysyl-residues in developmentally regulated GTP binding proteins 1 and 2 (DRG1/2). We report studies exploring a diverse set of lysine derivatives incorporated into the DRG1 peptides as potential human JMJD7 substrates and inhibitors. The results indicate that human JMJD7 has a relatively narrow substrate scope beyond lysine compared to some other JmjC hydroxylases and lysine-modifying enzymes. The geometrically constrained (E)-dehydrolysine is an efficient alternative to lysine for JMJD7-catalyzed C3-hydroxylation. γ-Thialysine and γ-azalysine undergo C3-hydroxylation, followed by degradation to formylglycine. JMJD7 also catalyzes the S-oxidation of DRG1-derived peptides possessing methionine and homomethionine residues in place of lysine. Inhibition assays show that DRG1 variants possessing cysteine/selenocysteine instead of the lysine residue efficiently inhibit JMJD7 via cross-linking. The overall results inform on the substrate selectivity and inhibition of human JMJD7, which will help enable the rational design of selective small-molecule and peptidomimetic inhibitors of JMJD7.

Oxygen-dependent regulation of F-box proteins in Toxoplasma gondii is mediated by Skp1 glycosylation

A dynamic proteome is required for cellular adaption to changing environments including levels of O2, and the SKP1/CULLIN-1/F-box protein/RBX1 (SCF) family of E3 ubiquitin ligases contributes importantly to proteasome-mediated degradation. We examine, in the apicomplexan parasite Toxoplasma gondii, the influence on the interactome of SKP1 by its novel glycan attached to a hydroxyproline generated by PHYa, the likely ortholog of the HIFα PHD2 oxygen-sensor of human host cells. Strikingly, the representation of several putative F-box proteins (FBPs) is substantially reduced in PHYaΔ parasites grown in fibroblasts. One, FBXO13, is a predicted lysyl hydroxylase related to the human JmjD6 oncogene except for its F-box domain. The abundance of FBXO13, epitope-tagged at its genetic locus, was reduced in PHYaΔ parasites thus explaining its diminished presence in the SKP1 interactome. A similar effect was observed for FBXO14, a cytoplasmic protein of unknown function that may have co-evolved with PHYa in apicomplexans. Similar findings in glycosylation-mutant cells, rescue by proteasomal inhibitors, and unchanged transcript levels, suggested the involvement of the SCF in their degradation. The effect was selective, because FBXO1 was not affected by loss of PHYa. These findings are physiologically significant because the effects were phenocopied in parasites reared at 0.5% O2. Modest impact on steady-state SKP1 modification levels suggests that effects are mediated during a lag phase in hydroxylation of nascent SKP1. The dependence of FBP abundance on O2-dependent SKP1 modification likely contributes to the reduced virulence of PHYaΔ parasites owing to impaired ability to sense O2 as an environmental signal.

Harnessing the Biomimetic Effect of Macromolecular Crowding in the Cell-Derived Model of Clubfoot Fibrosis.

Fibrotic changes in pediatric clubfoot provide an opportunity to improve corrective therapy and prevent relapses with targeted drugs. This study defines the parameters of clubfoot fibrosis and presents a unique analysis of a simple pseudo-3D in vitro model for disease-specific high-throughput drug screening experiments. The model combines clubfoot-derived fibroblasts with a biomimetic cultivation environment induced by the water-soluble polymers Ficoll and Polyvinylpyrrolidone, utilizing the principle of macromolecular crowding. We achieved higher conversion of soluble collagen into insoluble collagen, accelerated formation of the extracellular matrix layer and upregulated fibrosis-related genes in the mixed Ficoll environment. To test the model, we evaluated the effect of a potential antifibrotic drug, minoxidil, emphasizing collagen content and cross-linking. While the model amplified overall collagen deposition, minoxidil effectively blocked the expression of lysyl hydroxylases, which are responsible for the increased occurrence of specific collagen cross-linking in various fibrotic tissues. This limited the formation of collagen cross-link in both the model and control environments. Our findings provide a tool for expanding preclinical research for clubfoot and similar fibroproliferative conditions.

Significant improvement of cardiac outflow tract septation defects in a DiGeorge syndrome model after minoxidil treatment

The T-BOX transcription factor TBX1 is essential for the development of the pharyngeal apparatus and it is haploinsufficient in DiGeorge syndrome (DGS), a developmental anomaly associated with congenital heart disease and other abnormalities. The murine model recapitulates the heart phenotype and showed collagen accumulation.We first used a cellular model to study gene expression during cardiogenic differentiation of WT and Tbx1−/− mouse embryonic stem cells. Then we used a mouse model of DGS to test whether interfering with collagen accumulation using an inhibitor of lysyl hydroxylase would modify the cardiac phenotype of the mutant.We found that loss of Tbx1 in a precardiac differentiation model was associated with up regulation of a subset of ECM-related genes, including several collagen genes. In the in vivo model, early prenatal treatment with Minoxidil, a lysyl hydroxylase inhibitor, ameliorated the cardiac outflow tract septation phenotype in Tbx1 mutant fetuses, but it had no effect on septation in WT fetuses. We conclude that TBX1 suppresses a defined subset of ECM-related genes. This function is critical for OFT septation because the inhibition of collagen cross-linking in the mutant reduces significantly the penetrance of septation defects.

Dietary hydroxyproline supplementation improves the muscle texture and extends the shelf life of abalone Haliotis discus hannai

In the present study, an 84-day growth trial was conducted in abalone Haliotis discus hannai to evaluate the influences of dietary hydroxyproline (Hyp) levels (0.05, 0.53 and 1.24%) on the growth, collagen metabolism, muscle texture and its changes during storage at 4 °C. The results showed that the weight gain rate of abalones in the groups with 0.53% and 1.24% of dietary Hyp were significantly higher than that in the group with 0.05% dietary Hyp. The 0.53% and 1.24% of dietary Hyp significantly increased lysyl hydroxylase and prolyl 4-hydroxylase activity and pyridinium crosslink content, and up-regulated collagen biosynthesis-related gene expression in abalone muscle. Meanwhile, dietary Hyp supplementation significantly inhibited the mRNA expression of mmp-1 and significantly up-regulated the mRNA expression of timp. During the same storage time, the springiness, hardness and water-holding capacity of muscle in the dietary Hyp supplementation treatments were significantly higher. The muscle hardness in the dietary Hyp supplementation groups on day 6 was higher than that in the control group on day 3. Meanwhile, dietary Hyp significantly decreased the content of carbonyl and malonaldehyde, as well as the activity of cathepsin B and cathepsin L in the muscle of abalone during the storage. In conclusion, dietary Hyp supplementation increased collagen content, improved texture and extended the shelf life of abalone.

Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 promotes collagen cross-linking and ECM stiffening to induce liver fibrosis

Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (Plod2) is a key collagen lysyl hydroxylase mediating the formation of collagen fiber and stabilized collagen cross-links, and has been identified in several forms of fibrosis. However, the potential role and regulatory mechanism of Plod2 in liver fibrosis remain unclear yet. Mouse liver fibrosis models were induced by injecting carbon tetrachloride (CCl4) intraperitoneally. The morphology and alignment of collagen was observed under transmission and scanning electron microscopy, and extracellular matrix (ECM) stiffness was measured by atomic force microscopy. Large amounts of densely packed fibrillar collagen fibers produced by myofibroblasts (MFs) were deposited in fibrotic liver of mice reaching very large diameters in the cross section, accompanied with ECM stiffening, which was positively correlated with collagen-crosslinking. The expression of Plod2 was dynamically up-regulated in fibrotic liver of mouse and human. In MFs transfection of Plod2 siRNA made collagen fibers more orderly and linear aligned which can be easily degraded and protected from ECM stiffness. Administration of Plod2 siRNA preventatively or therapeutically in CCl4 mice reduced the average size of collagen bundles in transverse section, increased collagen solubility, decreases the levels of crosslinking products hydroxylysylpyridinoline and lysylpyridinoline, prevented ECM stiffening and alleviated liver fibrosis. Altogether, Plod2 mediates the formation of stabilized profibrotic collagen cross-links in MFs, leading to the alteration of collagen solubility and ECM stiffness, and eventually aggravates liver fibrosis, which provide potential target for the treatment of liver disease.

Abstract 5571: Collagen stabilization directs immune suppression in the head and neck squamous cell carcinoma hypoxic subtype

Abstract Head & neck squamous cell carcinoma (HNSCC) show limited clinical benefit to immune checkpoint inhibitors (ICI). Interactions between extracellular matrix (ECM), tumor, and immune cells underly the mechanisms leading to immunosuppression and resistance to ICIs. Collagen matrix remodeling within tumor stroma can influence accessibility and function of immune cells. Specifically, telopeptidyl lysine residues in fibrillar collagen can be hydroxylated by Lysyl hydroxylase 2 (LH2) prior to cross-linking which leads to stiffened, stable collagen. We previously showed that this LH2-modified tumor microenvironment (TME) drives HNSCC invasion and metastasis. Here, we elucidate the interplay between LH2-modified collagen and the immune landscape within TME of hypoxic and immunosuppressive HNSCC. Bioinformatics analyses of RNAseq datasets were performed to assess pathways regulating collagen deposition and stabilization. Tissue microarray having 81 primary, 28 recurrent primary, and 3 lymph node metastases tumor cores was analyzed. Cores were classified according to our published Hypoxia-Immune signature (Chaudhary R. et al. 2023, Can Res Comm). We performed Second Harmonic Generation imaging of H&E stained TMA section to analyze the orientation and length of collagen fibrils. Picrosirius red (PSR) staining allowed quantification of total collagen and collagen maturation was assessed by polarized light imaging of birefringence. Further, we performed multiplex immunofluorescence staining for CD3+ (T-cell); CD14+ (Monocyte & Macrophage); CD11c+ (Dendritic); Pax5+ (B-cell); Pan-Cytokeratin+ (tumor), and LH2. Low (0-1) LH2 expression was seen in 29.5% of analyzed cores whereas 70.5% of cores scored high (2-3) for LH2 expression. Cores classified under the hypoxia subtype exhibit high LH2 and enrichment of collagen stability signature. Late-stage tumors have highly oriented collagen fibers compared to normal tissue or early-stage tumors which have randomly distributed fibers. CT-Fire-based measurements revealed that LH2hi cores have significantly increased fiber length and lower coefficient of variance for fiber angles. The area of collagen measured by PSR staining had no correlation with tumor stage or subtype indicating that collagen deposition is similarly high in HNSCCs. However, birefringence measurements showed that a higher fraction of mature fibrillar collagen is associated with late-stage LH2hi tumors. Interestingly, LH2 expression positively correlated with increased CD3+ T cells in stroma suggesting that anti-tumor T cells are physically obstructed by the presence of LH2-stabilized and stiffened collagen fibers. LH2 expression influences the quality of collagen but not the quantity. Understanding the effect of LH2-mediated collagen modifications on the TIME may have implications for therapeutic strategies to enhance anti-tumor immune response in HNSCC. Citation Format: Sonal Srivastava, John Powers, Ritu Chaudhary, Sadegh Marzban, Robbert J. Slebos, Jeffrey West, Xiaofei Song, Jose A. Guevara-Patino, Christine H. Chung, Antonio L. Amelio. Collagen stabilization directs immune suppression in the head and neck squamous cell carcinoma hypoxic subtype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5571.

Abstract 1274: Investigating PLOD2 as a therapeutic target to overcome metastasis in radiorecurrent prostate cancer

Abstract Prostate cancer (PCa) is the second most common cancer in males, with 1 in 8 men developing the disease in their lifetime. For PCa, a common treatment strategy is external beam radiation therapy to the prostate. However, when cancer recurs (radiorecurrent PCa), it often behaves aggressively by invading into surrounding organs or spreading distantly. Radiorecurrent PCa metastasis is therefore a significant cause of morbidity and mortality that must be overcome to improve survival of advanced PCa patients. Proteomic analysis revealed the procollagen enzyme Lysyl Hydroxylase 2 (PLOD2) to be upregulated in our radiorecurrent, and highly aggressive, conventionally fractionated DU145 (DU145-CF) PCa cell line. Given its established function as a mediator of invasion in various other cancers, we sought to characterize the role of PLOD2 in the aggressive phenotype of our radiorecurrent PCa cells. Bioinformatic analysis of clinical data revealed PLOD2 genomic amplification to be significantly associated with biochemical recurrence in PCa patients. Upon further examination in vitro, it was revealed that PLOD2 knockdown significantly reduces matrigel invasion and migration in our radiorecurrent DU145-CF cell line, in addition to numerous other PCa cell lines, including primary cells we derived directly from PCa patients. Using the in vivo chick Chorioallantoic Membrane (CAM) model, we confirmed that PLOD2 knockdown significantly reduces the ability of DU145-CF cells to extravasate from the CAM vasculature into the surrounding stroma, a critical step of the metastatic cascade. To explore mechanisms of metastatic cellular reprogramming downstream of PLOD2, RNA sequencing of DU145-CF cells was conducted; a total of 681 genes were discovered to be dysregulated by PLOD2 knockdown, with their functional analysis suggesting changes in cellular metabolism and respiration. Finally, since PLOD2 is known to be regulated by hypoxia-induced protein HIF1α, we explored whether PLOD2 expression could be inhibited by the HIF1α inhibitor, PX-478. Treatment with PX-478 reduced both HIF1α and PLOD2 protein expression, and significantly reduced invasion, migration, and in vivo extravasation in DU145-CF cells, thereby indicating its potential as a pharmacological inhibitor of HIF1α-associated PLOD2 in radiorecurrent PCa. Together, our results demonstrate for the first time the role of PLOD2 in radiorecurrent PCa invasiveness, and point towards its potential as a therapeutic target to reduce metastasis and improve survival outcomes in PCa patients. Citation Format: Gavin Frame, Hon Leong, Roni Haas, Xiaoyong Huang, Jessica Wright, Paul C. Boutros, Thomas Kislinger, Stanley K. Liu. Investigating PLOD2 as a therapeutic target to overcome metastasis in radiorecurrent prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1274.

Enhancing wound regeneration potential of fibroblasts using ascorbic acid-loaded decellularized baby spinach leaves

Decellularization of plant tissues is an emerging route to fabricate scaffolds for tissue engineering and regenerative medicine. Although significant progress has been made in the field of plant tissue decellularization, functionalization of plant scaffolds is still an emerging field, and loading them with L-ascorbic acid to promote skin regeneration has not yet been reported. L-ascorbic acid is an antioxidant that plays a key role in collagen synthesis as a cofactor of lysyl hydroxylase and prolyl hydroxylase. It has been shown to have significant importance in physiological wound healing by stimulating fibroblasts to produce collagen at both the molecular and the genetic levels. In this work, we aimed to fabricate an ascorbic acid-releasing bioactive scaffold by introducing a stable form of ascorbic acid, L-ascorbic acid 2-phosphate (AA2P), into decellularized baby spinach leaves and investigated its biological activity in vitro. Our results demonstrated that AA2P could be easily introduced into decellularized baby spinach leaf scaffolds and subsequently released within the effective dose range. AA2P-releasing baby spinach leaves were found to increase metabolic activity and enhance collagen synthesis in L929 fibroblasts after 21 days. In conclusion, this study demonstrated the fabrication of a novel functionalized skin tissue engineering scaffold and made a significant contribution to the fields of plant decellularization and skin tissue engineering.Graphical abstract

The role of exogenous glutamine on germination, plant development and transcriptional expression of some stress-related genes in onion under salt stress

ABSTRACT The purpose of this research was to explore the role of glutamine (Gln) on plant germination and growth under salinity [0, 50, 100, 150, 200 mM sodium chloride (NaCl)], and on the activation of some stress-related genes [CuZn-Superoxide Dismutase (SOD), Mn-SOD, L-ascorbate oxidase (AO), DNA Polymerase Delta 1 (POLD)-1, Chaperon (CHAPE) and Heat Shock Protein (HSP)-21], genetic template stability and photosynthetic pigment activation. Under salt stress, 2 mM Gln application reduced the mean germination time (MGT) (4.51 days), increased the coefficient of velocity of germination (CVG) (75.85), germination index (GI) (1.46) and germination percentage (GP) (82%), indicating that it was the best application for germination under stress. Gln promoted the development of aboveground plant organs. 3 mM Gln increased the number of leaves from 5.3 to 13.7 and 4.3 to 6.6 under unstress and stress conditions, respectively. Under salt stress, Gln increased photosynthetic pigments and genomic template stability (GTS) (80%). At 2 mM Gln, total chlorophyll and carotenoid content increased from 1.59 mg · g-1 TA to 2.23 mg · g-1 TA and from 0.28 mg · g-1 TA to 0.37 mg · g-1 TA, respectively. The effect on gene expression levels varied with the concentration. The application of 2 mM Gln, which enhanced germination and vegetative parameters under stress, caused a raise in CuZn-SOD gene expression and a 43% decrease in the transcriptional expression of the HSP-21 gene as an indicator of the functionality of the repair mechanism. The improved growth of Gln-treated plants under stress suggests that Gln is involved in bridging the energy deficit of the plant by acting as an alternative fuel for metabolic activities under stress.

Effect of dexamethasone on human neutrophil adhesion and concomitant secretion

Neutrophils play a dual role in protecting the body. They are able to penetrate infected tissues and destroy pathogens there, releasing aggressive bactericidal substances. Getting into the surrounding tissues, aggressive secretion products of neutrophils initiate the development of inflammatory processes. Invasion of neutrophils into tissues is observed during the development of pneumonia in patients with lung diseases of various etiologies, including acute respiratory distress syndrome caused by coronavirus disease. The synthetic corticosteroid hormone dexamethasone has a therapeutic effect in the treatment of lung diseases, including reducing mortality in patients with severe Covid-19. The acute (short-term) effect of dexamethasone on neutrophil adhesion to fibrinogen and concomitant secretion was studied. Dexamethasone did not affect either the attachment of neutrophils to the substrate or their morphology. The production of reactive oxygen species (ROS) and nitric oxide (NO) by neutrophils during adhesion also did not change in the presence of dexamethasone. Dexamethasone stimulated the release of metalloproteinases in addition to proteins secreted by neutrophil adhesion under control conditions, and selectively stimulated the release of the free amino acid hydroxylysine, a product of lysyl hydroxylase. Metalloproteinases play a key role and closely interact with lysyl hydroxylase in the processes of rearrangement of the extracellular matrix. The therapeutic effect of dexamethasone may be associated with its ability, by changing the composition of neutrophil secretions, to reorganize the extracellular matrix in tissues, which can lead to improved gas exchange in patients with severe lung diseases.

Effect of Dexamethasone on Adhesion of Human Neutrophils and Concomitant Secretion.

Neutrophils play a dual role in protecting the body. They are able to penetrate infected tissues and destroy pathogens there by releasing aggressive bactericidal substances. While into the surrounding tissues, the aggressive products secreted by neutrophils initiate development of inflammatory processes. Invasion of neutrophils into tissues is observed during the development of pneumonia in the patients with lung diseases of various etiologies, including acute respiratory distress syndrome caused by coronavirus disease. Synthetic corticosteroid hormone dexamethasone has a therapeutic effect in treatment of lung diseases, including reducing mortality in the patients with severe COVID-19. The acute (short-term) effect of dexamethasone on neutrophil adhesion to fibrinogen and concomitant secretion was studied. Dexamethasone did not affect either attachment of neutrophils to the substrate or their morphology. Production of reactive oxygen species (ROS) and nitric oxide (NO) by neutrophils during adhesion also did not change in the presence of dexamethasone. Dexamethasone stimulated release of metalloproteinases in addition to the proteins secreted by neutrophils during adhesion under control conditions, and selectively stimulated release of free amino acid hydroxylysine, a product of lysyl hydroxylase. Metalloproteinases play a key role and closely interact with lysyl hydroxylase in the processes of modification of the extracellular matrix. Therapeutic effect of dexamethasone could be associated with its ability to reorganize extracellular matrix in the tissues by changing composition of the neutrophil secretions, which could result in the improved gas exchange in the patients with severe lung diseases.

SIRT6 deficiency causes ovarian hypoplasia by affecting Plod1-related collagen formation.

SIRT6 is a key member of the mammalian sirtuin family of conserved nicotinamide adenine dinucleotide (NAD+ )-dependent deacetylases. Previous studies have shown that SIRT6 can regulate metabolism, DNA damage repair and aging. Ovarian aging process usually share similar mechanisms with general aging, which is characterized by decreases in both numbers of ovarian follicles and the quality of oocytes. It is reported that the expression level of SIRT6 was significantly decreased in the ovaries of aged mice, and the level of SIRT6 was positively correlated with ovarian reserve, indicating that SIRT6 may be potential markers of ovarian aging. However, its biological roles in follicular development are still unclear. Here, we explored the effect of SIRT6 on follicular development and found that ovarian development was interrupted in SIRT6 knockout (KO) mice, leading to disruptions of puberty and the estrus cycle, significant decreases in numbers of secondary and antral follicles, and decreased collagen in the ovarian stroma. Plod1, a lysyl hydroxylase that is vital for collagen crosslinking and deposition, was decreased at both the mRNA and protein levels in SIRT6-deficient ovaries and granulosa cells (GCs). Additionally, we found abnormal estrogen levels in both SIRT6 KO mice and SIRT6 KD GCs, accompanied by decreases in the levels of the estrogen biosynthesis genes Cyp11a1, Cyp19a1, Mgarp, and increases in the levels of TNF-α and NF-κB. These results confirmed the effect of SIRT6 on follicular development and revealed a possible molecular mechanism for SIRT6 involvement in follicular development via effects on estrogen biosynthesis and collagen formation.

Mmp14 is required for matrisome homeostasis and circadian rhythm in fibroblasts

The circadian clock in tendon regulates the daily rhythmic synthesis of collagen-I and the appearance and disappearance of small-diameter collagen fibrils in the extracellular matrix. How the fibrils are assembled and removed is not fully understood. Here, we first showed that the collagenase, membrane type I-matrix metalloproteinase (MT1-MMP, encoded by Mmp14), is regulated by the circadian clock in postnatal mouse tendon. Next, we generated tamoxifen-induced Col1a2-Cre-ERT2::Mmp14 KO mice (Mmp14 conditional knockout (CKO)). The CKO mice developed hind limb dorsiflexion and thickened tendons, which accumulated narrow-diameter collagen fibrils causing ultrastructural disorganization. Mass spectrometry of control tendons identified 1195 proteins of which 212 showed time-dependent abundance. In Mmp14 CKO mice 19 proteins had reversed temporal abundance and 176 proteins lost time dependency. Among these, the collagen crosslinking enzymes lysyl oxidase-like 1 (LOXL1) and lysyl hydroxylase 1 (LH1; encoded by Plod2) were elevated and had lost time-dependent regulation. High-pressure chromatography confirmed elevated levels of hydroxylysine aldehyde (pyridinoline) crosslinking of collagen in CKO tendons. As a result, collagen-I was refractory to extraction. We also showed that CRISPR-Cas9 deletion of Mmp14 from cultured fibroblasts resulted in loss of circadian clock rhythmicity of period 2 (PER2), and recombinant MT1-MMP was highly effective at cleaving soluble collagen-I but less effective at cleaving collagen pre-assembled into fibrils. In conclusion, our study shows that circadian clock-regulated Mmp14 controls the rhythmic synthesis of small diameter collagen fibrils, regulates collagen crosslinking, and its absence disrupts the circadian clock and matrisome in tendon fibroblasts.

Common Beans as a Source of Amino Acids and Cofactors for Collagen Biosynthesis.

Common beans (Phaseolus vulgaris L.) are widely consumed in diets all over the world and have a significant impact on human health. Proteins, vitamins, minerals, phytochemicals, and other micro- and macronutrients are abundant in these legumes. On the other hand, collagens, the most important constituent of extracellular matrices, account for approximately 25-30 percent of the overall total protein composition within the human body. Hence, the presence of amino acids and other dietary components, including glycine, proline, and lysine, which are constituents of the primary structure of the protein, is required for collagen formation. In this particular context, protein quality is associated with the availability of macronutrients such as the essential amino acid lysine, which can be acquired from meals containing beans. Lysine plays a critical role in the process of post-translational modifications facilitated with enzymes lysyl hydroxylase and lysyl oxidase, which are directly involved in the synthesis and maturation of collagens. Furthermore, collagen biogenesis is influenced by the cellular redox state, which includes important minerals and bioactive chemicals such as iron, copper, and certain quinone cofactors. This study provides a novel perspective on the significant macro- and micronutrients present in Phaseolus vulgaris L., as well as explores the potential application of amino acids and cofactors derived from this legume in the production of collagens and bioavailability. The utilization of macro- and micronutrients obtained from Phaseolus vulgaris L. as a protein source, minerals, and natural bioactive compounds could optimize the capacity to promote the development and durability of collagen macromolecules within the human body.

Retraction: Procollagen Lysyl Hydroxylase 2 Is Essential for Hypoxia-Induced Breast Cancer Metastasis.

Retraction: Procollagen Lysyl Hydroxylase 2 Is Essential for Hypoxia-Induced Breast Cancer Metastasis.

Unleashing the Potential of 1,3-Diketone Analogues as Selective LH2 Inhibitors.

Lysyl hydroxylase 2 (LH2) catalyzes the formation of highly stable hydroxylysine aldehyde-derived collagen cross-links (HLCCs), thus promoting lung cancer metastasis through its capacity to modulate specific types of collagen cross-links within the tumor stroma. Using 1 and 2 from our previous high-throughput screening (HTS) as lead probes, we prepared a series of 1,3-diketone analogues, 1-18, and identified 12 and 13 that inhibit LH2 with IC50's of approximately 300 and 500 nM, respectively. Compounds 12 and 13 demonstrate selectivity for LH2 over LH1 and LH3. Quantum mechanics/molecular mechanics (QM/MM) modeling indicates that the selectivity of 12 and 13 may stem from noncovalent interactions like hydrogen bonding between the morpholine/piperazine rings with the LH2-specific Arg661. Treatment of 344SQ WT cells with 13 resulted in a dose-dependent reduction in their migration potential, whereas the compound did not impede the migration of the same cell line with an LH2 knockout (LH2KO).

Whole Exome Sequencing Reveals Two Novel Homozygous Variants in the TRAPPC9 and PLOD3 Genes Leading to Intellectual Disability and Bone Fragility with Contractures

Salt and Pepper’ syndrome is an autosomal recessive condition characterized by severe intellectual disability (ID), epilepsy, scoliosis, choreoathetosis, dysmorphic facial features, and altered dermal pigmentation. IDs are heterogeneous group of disorders prevalent in highly consanguineous populations and genetically variable condition of cognitive impairment linked with behavioral, syndromic, or dysmorphic features. Trafficking protein particle complex subunit 9 ( TRAPPC9) (MIM 611966) is an important gene, and mutations in this gene have been reported to be involved in ID conditions. Lysyl hydroxylase 3 (encoded by ( PLOD3)) is a multifunctional enzyme responsible for catalyzing hydroxylation of lysyl residues and O-glycosylation of hydroxylysyl residues, an important step during posttranslational modifications for collagen biosynthesis. In this study, whole exome sequencing was done for a family member having ID, microcephaly, included joint contractures, low bone mineral density, and dysmorphic feature. We identified a novel missense variant (NM_001160372.3) c.3211G>A, p.G1071S in the exon 22 of TRAPPC9 causing ID and other missense variant c.346G>A, p.V116M (NM_001084.4) in the exon 4 of the PLOD3 gene causing bone fragility with contractures in the affected member of the family. The obtained results were further validated by using Sanger sequencing analysis. The identified variant has not been reported in either gnomAD or Exac databases. Both parents were heterozygous (carriers) to these identified mutations. Our results for the first time suggest that identified novel TRAPPC9 and PLOD3 gene mutations are the main cause of the disease leading to the ID-associated conditions along with cognitive deficits along with microcephaly. This is the first study to report patients with TRAPPC9- and PLOD3-related disorder from Saudi Arabia. This study will add to the literature of the disease and will enable the creation of a database that will provide a strong base to understanding the critical genomic regions to control ID and related disorders in Saudi patients.

Acne Scar Management: Minoxidil as a Promising Approach or a Mirage?

Atrophic and hypertrophic scars can result from various conditions, such as acne, trauma, and surgery. Minoxidil, a medication used for the treatment of severe hypertension and hair loss, has been explored as a potential treatment for scars. This review aims to evaluate the current evidence regarding the role of minoxidil in the treatment of scars. Previously published reviews have primarily focused on the use of minoxidil in hair loss and have only briefly mentioned its potential use for scars. However, minoxidil may have a beneficial effect as an antifibrotic agent. Several studies have reported reduced collagen accumulation and fibrosis after treatment with minoxidil. The proposed mechanism of action is inhibition of the production of lysyl hydroxylases (LHs), which modify and cross-link proteins by converting lysine to hydroxylysine, making collagen more resistant to degradation. Minoxidil, as an LH inhibitor, has been shown to potentially benefit wound healing and regeneration in vitro by inhibiting the proliferation and migration of fibroblasts. To date, direct studies of the efficacy of minoxidil in treating acne scars have not been conducted; however, its inhibitory effects on fibroblast function and antifibrotic outcomes in some in vivo studies suggest that such use may be considered.