Search PubMed⌕ Search

Biomedical subjects

Terry J Smith

Publications and source records attributed to Terry J Smith.

At least 37 records · Page 2Linked to original sources

Rho A/Rho kinase mRNA and protein levels in human myometrium during pregnancy and labor.

OBJECTIVE: To quantify mRNA levels of Rho A, and rho-associated coil-forming kinases I and II (ROCK I and ROCK II) in human pregnant (before and after labor onset) and nonpregnant myometrium, and to investigate protein expression of Rho A, ROCK I, and ROCK II in these three tissue types. METHODS: Real-time fluorescence reverse transcriptase-polymerase chain reaction (RT-PCR) using primers for Rho A, ROCK I, and ROCK II was performed on total RNA isolated from the three tissue types under investigation. Western blot analysis using antibodies specific to Rho A, ROCK I, and ROCK II was performed on protein isolated from the three tissue types. RESULTS: Real-time fluorescence RT-PCR, using primers for Rho A, ROCK I, and ROCK II, revealed Rho A mRNA expression was significantly greater in human pregnant myometrium after labor onset, in comparison to pregnant myometrium before labor onset (P < .05), or nonpregnant myometrium (P < .01). ROCK I and ROCK II mRNA expression levels were similar in the three tissue types (P > .05). With Western blot analysis, using antibodies specific to Rho A, ROCK I, and ROCK II, Rho A protein levels were significantly lower in pregnant (before and after labor onset) in comparison to nonpregnant myometrium (P < .01). ROCK I protein levels were similar in the three tissue types (P > .05). No signal for ROCK II was detected in myometrial tissue. CONCLUSIONS: These results outline the presence of the Rho A/Rho kinase system in modulating contractility of human myometrium. Total Rho A protein expression is down-regulated in the third trimester of pregnancy while up-regulation of Rho A mRNA occurs with labor onset.

Adult↗

Improved detection of DNA motifs using a self-organized clustering of familial binding profiles.

MOTIVATION: One of the limiting factors in deciphering transcriptional regulatory networks is the effectiveness of motif-finding software. An emerging avenue for improving motif-finding accuracy aims to incorporate generalized binding constraints of related transcription factors (TFs), named familial binding profiles (FBPs), as priors in motif identification methods. A motif-finder can thus be 'biased' towards finding motifs from a particular TF family. However, current motif-finders allow only a single FBP to be used as a prior in a given motif-finding run. In addition, current FBP construction methods are based on manual clustering of position specific scoring matrices (PSSMs) according to the known structural properties of the TF proteins. Manual clustering assumes that the binding preferences of structurally similar TFs will also be similar. This assumption is not true, at least not for some TF families. Automatic PSSM clustering methods are thus required for augmenting the usefulness of FBPs. RESULTS: A novel method is developed for automatic clustering of PSSM models. The resulting FBPs are incorporated into the SOMBRERO motif-finder, significantly improving its performance when finding motifs related to those that have been incorporated. SOMBRERO is thus the only existing de novo motif-finder that can incorporate knowledge of all known PSSMs in a given motif-finding run. AVAILABILITY: The methods outlined will be incorporated into the next release of SOMBRERO, which is available from http://bioinf.nuigalway.ie/sombrero

Algorithms↗

Isolation and phenotypic characterization of lung fibroblasts.

Primary fibroblasts represent a heterogeneous population of cells that can be separated into subsets on the basis of cell surface markers such as Thy-1. Deriving fibroblasts initially involves obtaining tissue explants from tissues such as the lung, heart, cornea, skin, and orbit. The tissue is mechanically dissociated and cells are allowed to proliferate from the fragments. Following establishment of a primary culture of fibroblasts, it is necessary to characterize the new strain of cells to ensure their purity and fibroblastic phenotype using immunofluorescence and immunohistochemistry to detect the presence or absence of cell-specific surface markers. Characterizing the cells as expressing or lacking Thy-1 can also be performed by immunofluorescence in concert with microscopy or by flow cytometry using an anti-human Thy-1 antibody. In addition, fibroblasts may be sorted according to their expression of Thy-1 by fluorescence-activated cell sorting and/or magnetic beading; use of these techniques can yield greater than 99% purity. Once separated, the pure Thy-1 expressing or lacking fibroblast subsets can be propagated. These subsets can then be used for experimentation to determine functional differences between fibroblasts derived from normal and pathological tissue such as scarred lung.

Animals↗

Analysis of Maxi-K alpha subunit splice variants in human myometrium.

BACKGROUND: Large-conductance, calcium-activated potassium (Maxi-K) channels are implicated in the modulation of human uterine contractions and myometrial Ca2+ homeostasis. However, the regulatory mechanism(s) governing the expression of Maxi-K channels with decreased calcium sensitivity at parturition are unclear. The objectives of this study were to investigate mRNA expression of the Maxi-K alpha subunit, and that of its splice variants, in human non-pregnant and pregnant myometrium, prior to and after labour onset, to determine whether altered expression of these splice variants is associated with decreased calcium sensitivity observed at labour onset. METHODS: Myometrial biopsies were obtained at hysterectomy (non-pregnant, NP), and at Caesarean section, at elective (pregnant not-in-labour, PNL) and intrapartum (pregnant in-labour, PL) procedures. RNA was extracted from all biopsies and quantitative real-time RT-PCR was used to investigate for possible differential expression of the Maxi-K alpha subunit, and that of its splice variants, between these functionally-distinct myometrial tissue sets. RESULTS: RT-PCR analysis identified the presence of a 132 bp and an 87 bp spliced exon of the Maxi-K alpha subunit in all three myometrial tissue sets. Quantitative real-time PCR indicated a decrease in the expression of the Maxi-K alpha subunit with labour onset. While there was no change in the proportion of Maxi-K alpha subunits expressing the 87 bp spliced exon, the proportion of alpha subunits expressing the 132 bp spliced exon was significantly increased with labour onset, compared to both non-pregnant and pregnant not-in-labour tissues. An increased proportion of 132 bp exon-containing alpha subunit variants with labour onset is of interest, as channels expressing this spliced exon have decreased calcium and voltage sensitivities. CONCLUSIONS: Our findings suggest that decreased Maxi-K alpha subunit mRNA expression in human myometrium at labour onset, coupled to an increased proportion of Maxi-K channels expressing the 132 bp spliced exon, may be linked to decreased Maxi-K channel calcium and voltage sensitivity, thereby promoting enhanced uterine activity at the time of labour.

Adult↗

Synovial fibroblasts from patients with rheumatoid arthritis, like fibroblasts from Graves' disease, express high levels of IL-16 when treated with Igs against insulin-like growth factor-1 receptor.

We have reported recently that IgG from patients with Graves' disease (GD) can induce the expression of the CD4-specific T lymphocyte chemoattractant, IL-16, and RANTES, a C-C chemokine, in their fibroblasts. This induction is mediated through the insulin-like growth factor-1 receptor (IGF-1R) pathway. We now report that Abs from individuals with active rheumatoid arthritis (RA-IgG) stimulate in their synovial fibroblasts the expression of these same cytokines. IgG from individuals without known autoimmune disease fails to elicit this chemoattractant production. Furthermore, RA-IgG fails to induce IL-16 or RANTES expression in synovial fibroblasts from donors with osteoarthritis. RA-IgG-provoked IL-16 and RANTES production also appears to involve the IGF-1R because receptor-blocking Abs prevent the response. RA fibroblasts transfected with a dominant-negative mutant IGF-1R fail to respond to RA-IgG. IGF-1 and the IGF-1R-specific analog Des(1-3) also induce cytokine production in RA fibroblasts. RA-IgG-provoked IL-16 expression is inhibited by rapamycin, a specific macrolide inhibitor of the Akt/FRAP/mammalian target of rapamycin/p70(s6k) pathway, and by dexamethasone. GD-IgG can also induce IL-16 in RA fibroblasts, and RA-IgG shows similar activity in GD fibroblasts. Thus, IgGs from patients with RA, like those associated with GD, activate IGF-1R, and in so doing provoke T cell chemoattraction expression in fibroblasts, suggesting a potential common pathway in the two diseases. Immune-competent cell trafficking to synovial tissue is integral to the pathogenesis of RA. Recognition of this novel RA-IgG/fibroblast interaction and its functional consequences may help identify therapeutic targets.

Antibodies↗

Gene prediction using the Self-Organizing Map: automatic generation of multiple gene models.

BACKGROUND: Many current gene prediction methods use only one model to represent protein-coding regions in a genome, and so are less likely to predict the location of genes that have an atypical sequence composition. It is likely that future improvements in gene finding will involve the development of methods that can adequately deal with intra-genomic compositional variation. RESULTS: This work explores a new approach to gene-prediction, based on the Self-Organizing Map, which has the ability to automatically identify multiple gene models within a genome. The current implementation, named RescueNet, uses relative synonymous codon usage as the indicator of protein-coding potential. CONCLUSIONS: While its raw accuracy rate can be less than other methods, RescueNet consistently identifies some genes that other methods do not, and should therefore be of interest to gene-prediction software developers and genome annotation teams alike. RescueNet is recommended for use in conjunction with, or as a complement to, other gene prediction methods.

Chromosome Mapping↗

A novel ELISpot method for adherent cells.

The purpose of this study was to develop an enzyme-linked immunospot assay (ELISpot assay) that can be used with human adherent cells. While standard enzyme-linked immunosorbent assays (ELISAs) are available and widely used and ELISpot assays are used for nonadherent lymphocytes, no ELISpot assay has been developed for adherent cells. We used primary human fibroblasts from four different tissues (myometrium, lung, gingiva, and orbit), either unstimulated or interleukin (IL)-1beta-activated, to evaluate an ELISpot assay. Antibody pairs for IL-6 and IL-8 were used and results were compared to a standard ELISA. We found that we could reliably detect IL-6 and IL-8 spots with as few as 10 fibroblasts. Optimal cell numbers were 50 cells per well incubated for 8 h, although spots appeared as early as 2 h after incubation. Spots were absent when cells, primary, or secondary anti-cytokine antibodies were omitted from the protocol. Spot number and size can be ascertained using current automated ELISpot reader technology. The frequency of IL-6 and IL-8-producing human fibroblasts could also be determined. For example, 60% of the lung fibroblasts express IL-6, but IL-8 can be detected from only 40% of the cells. Approximately 80% of the human orbital fibroblasts make IL-6, whereas approximately 50% generate IL-8 following IL-1beta stimulation. These new findings show that fibroblasts from different human tissues display different frequencies of cytokine production and this further supports the concept of fibroblast diversity. The sensitivity of this new ELISpot assay is adequate for cytokine detection in just a few cells, unlike the standard ELISA. It should permit ascertaining the frequency of fibroblasts and other adherent cells that produce cytokines and, if desired, can be used in tandem with a standard ELISA to determine total cytokine produced. Moreover, the assay is suitable for normal human adherent cells that are often short-lived and difficult to cultivate.

Cell Adhesion↗

Immunoglobulins from patients with Graves' disease induce hyaluronan synthesis in their orbital fibroblasts through the self-antigen, insulin-like growth factor-I receptor.

A distinctive histopathological feature associated with thyroid-associated ophthalmopathy is the disordered accumulation of the glycosaminoglycan, hyaluronan, in orbital connective tissues. This often occurs in the context of dramatic inflammation and tissue remodeling. Orbital fibroblasts exhibit a novel phenotype including exaggerated responses to cytokines. Here, we report for the first time the ability of IgG isolated from the sera of patients with Graves' disease (GD-IgG) to provoke in orbital fibroblasts the synthesis of hyaluronan. The effect of GD-IgG can be reproduced by IGF-I, appears to be mediated through the IGF-I receptor, and is abolished with glucocorticoid treatment. TSH failed to influence the synthesis of hyaluronan. In contrast to the effects in GD fibroblasts, cultures derived from donors without known thyroid disease fail to respond to GD-IgG or IGF-I. The observation that hyaluronan production is induced by GD-IgG in fibroblasts suggests that the IGF-I receptor and its activating antibodies may represent a key pathway through which important pathogenic events in thyroid-associated ophthalmopathy are mediated.

Autoantigens↗

Immunoglobulin activation of T cell chemoattractant expression in fibroblasts from patients with Graves' disease is mediated through the insulin-like growth factor I receptor pathway.

Graves' disease (GD) is associated with T cell infiltration, but the mechanism for lymphocyte trafficking has remained uncertain. We reported previously that fibroblasts from patients with GD express IL-16, a CD4-specific chemoattractant, and RANTES, a C-C chemokine, in response to GD-specific IgG (GD-IgG). We unexpectedly found that these responses result from a functional interaction between GD-IgG and the insulin-like growth factor (IGF)-I receptor (IGF-IR). IGF-I and the IGF-IR-specific IGF-I analog, des(1-3), mimic the effects of GD-IgG. Neither GD-IgG nor IGF-I activates chemoattractant expression in control fibroblasts from donors without GD. Interrupting IGF-IR function with specific receptor-blocking Abs or by transiently transfecting fibroblasts with a dominant negative mutant IGF-IR completely attenuates signaling provoked by GD-IgG. Moreover, GD-IgG displaces specific (125)I-labeled IGF-I binding to fibroblasts and attenuates IGF-IR detection by flow cytometry. These findings identify a novel disease mechanism involving a functional GD-IgG/IGF-IR bridge, which potentially explains T cell infiltration in GD. Interrupting this pathway may constitute a specific therapeutic strategy.

Adjuvants, Immunologic↗

Robust induction of PGHS-2 by IL-1 in orbital fibroblasts results from low levels of IL-1 receptor antagonist expression.

Human orbital fibroblasts are more susceptible to some actions of proinflammatory cytokines than are fibroblasts from other anatomic regions. These cells produce high levels of PGE(2) when activated by cytokines. Here we report that they express high levels of prostaglandin-endoperoxide H synthase (PGHS)-2, the inflammatory cyclooxygenase, when treated with IL-1beta. This induction results from enhanced PGHS-2 mRNA stability and small increases in gene promoter activity. The enhanced transcript stability is a result of actions of the cytokine on the 3'-untranslated region. Orbital fibroblasts, unlike those from skin, fail to express high levels of IL-1 receptor antagonist (IL-1ra) when treated with IL-1beta, leading to loss of modulation of IL-1 action. This can be overcome by transiently transfecting cells with IL-1ra. Thus a decreased level of IL-1ra expression in orbital fibroblasts may underlie the exaggerated responses to IL-1 observed in those cells and, therefore, the susceptibility of the orbit to inflammation.

Cell Nucleus↗

Thy-1 expression in human fibroblast subsets defines myofibroblastic or lipofibroblastic phenotypes.

Fibroblasts represent a dynamic population of cells, exhibiting functional heterogeneity within and among tissues. Fibroblast heterogeneity also results from phenotypic differences and may arise from activation or differentiation processes taking place in the cells. We previously reported that human fibroblasts were heterogeneous with respect to surface Thy-1 expression and that separation into Thy-1(+) and Thy-1(-) subsets resulted in functionally distinct subpopulations, leading to the concept of fibroblast subset specialization. In this report we investigated whether Thy-1(+) and/or Thy-1(-) fibroblasts were capable of differentiating into myofibroblasts or lipofibroblasts. Fibroblast subsets were used from human myometrium and orbit to test this hypothesis. Only Thy-1(+) human myometrial and orbital fibroblasts were capable of myofibroblast differentiation after treatment with TGFbeta or platelet concentrate supernatant, assessed by alpha smooth muscle actin expression. Interestingly, only Thy-1(-), but not Thy-1(+) subsets differentiated to lipofibroblasts, as determined by the accumulation of cytoplasmic lipid droplets after treatment with 15-deoxy-Delta(12, 14)-PGJ(2) or ciglitazone. We propose that fibroblast Thy-1 display pre-determines lineage to a contractile or lipid-like phenotype in the human myometrium and orbit. This additional distinction between Thy-1(+) and Thy-1(-) human fibroblast subtypes has important consequences in normal tissue homeostasis and in pathogenesis of orbital and myometrial diseases characterized by persistent myofibroblasts or fat accumulation, such as occurs in Graves' ophthalmopathy, tissue fibrosis, abnormal wound healing, and scarring.

Actins↗

Cytokine-induced lymphocyte chemoattraction from cultured human thyrocytes: evidence for interleukin-16 and regulated upon activation, normal T cell expressed, and secreted expression.

Mediators of lymphocyte infiltration in inflammatory thyroid disease have yet to be identified. Here we examine the ability of IL-1beta to enhance the production of chemoattractants by human thyrocytes. Primary cultures, when treated with the cytokine, release T lymphocyte chemotactic activity. The effect of IL-1beta is time dependent, and the chemoattraction activity can be partially attenuated by the addition of either anti-IL-16 or anti-regulated upon activation, normal T cell expressed, and secreted (RANTES) neutralizing antibodies. IL-16 is a CD4(+)-specific ligand, and RANTES is a C-C type chemokine that targets monocytes and lymphocytes. These chemoattractants could be detected by specific ELISAs in conditioned medium from IL-1beta treated thyrocytes. Northern analysis revealed that thyrocytes express high constitutive levels of IL-16 mRNA, which were invariant with regard to IL-1beta (10 ng/ml) or glucocorticoid treatment. RANTES mRNA was not detected in control cultures but was strongly induced by the cytokine. IL-16 but not RANTES expression was dependent on the activity of caspase-3. Pro-IL-16 protein could be detected in homogenates of thyroid tissue from patients with multinodular goiter and Graves' disease. Thus, human thyrocytes, through the expression of chemoattractants, may participate in the recruitment of lymphocytes to the thyroid in inflammatory states.

CD4-Positive T-Lymphocytes↗

Current perspective on the pathogenesis of Graves' disease and ophthalmopathy.

Graves' disease (GD) is a very common autoimmune disorder of the thyroid in which stimulatory antibodies bind to the thyrotropin receptor and activate glandular function, resulting in hyperthyroidism. In addition, some patients with GD develop localized manifestations including ophthalmopathy (GO) and dermopathy. Since the cloning of the receptor cDNA, significant progress has been made in understanding the structure-function relationship of the receptor, which has been discussed in a number of earlier reviews. In this paper, we have focused our discussion on studies related to the molecular mechanisms of the disease pathogenesis and the development of animal models for GD. It has become apparent that multiple factors contribute to the etiology of GD, including host genetic as well as environmental factors. Studies in experimental animals indicate that GD is a slowly progressing disease that involves activation and recruitment of thyrotropin receptor-specific T and B cells. This activation eventually results in the production of stimulatory antibodies that can cause hyperthyroidism. Similarly, significant new insights have been gained in our understanding of GO that occurs in a subset of patients with GD. As in GD, both environmental and genetic factors play important roles in the development of GO. Although a number of putative ocular autoantigens have been identified, their role in the pathogenesis of GO awaits confirmation. Extensive analyses of orbital tissues obtained from patients with GO have provided a clearer understanding of the roles of T and B cells, cytokines and chemokines, and various ocular tissues including ocular muscles and fibroblasts. Equally impressive is the progress made in understanding why connective tissues of the orbit and the skin in GO are singled out for activation and undergo extensive remodeling. Results to date indicate that fibroblasts can act as sentinel cells and initiate lymphocyte recruitment and tissue remodeling. Moreover, these fibroblasts can be readily activated by Ig in the sera of patients with GD, suggesting a central role for them in the pathogenesis. Collectively, recent studies have led to a better understanding of the pathogenesis of GD and GO and have opened up potential new avenues for developing novel treatments for GD and GO.

Autoantigens↗

Human chorionic gonadotrophin relaxation of human pregnant myometrium and activation of the BKCa channel.

The uterorelaxant effect of human chorionic gonadotropin (hCG) is regarded as an important mediator in maintenance of uterine quiescence during pregnancy with clinical potential for tocolysis, the mechanisms of which are unknown. The large conductance calcium-activated K(+) channel (BK(Ca)) is ubiquitously encountered in human uterine tissue and plays a significant role in modulating myometrial cell membrane potential and excitability. The objective of this study was to investigate the involvement of BK(Ca) channel function in the response of human myometrial cells to hCG. Single electrophysiological BK(Ca) channel recordings from freshly dispersed myocytes were obtained in the presence and absence of increasing hCG concentrations. Isometric tension studies, investigating the effects of hCG on isolated myometrial contractions, in the presence and absence of the BK(Ca) channel blocker, iberiotoxin, were performed. The hCG significantly increased the open-state probability of these channels in a concentration-dependent manner [control 0.036 +/- 0.01; 1 IU/ml hCG 0.065 +/- 0.014 (P = 0.262); 10 IU/ml hCG 0.111 +/- 0.009 (P = 0.001); and 100 IU/ml hCG 0.098 +/- 0.004 (P = 0.007)]. In vitro functional studies demonstrated that hCG exerted a significant concentration-dependent relaxant effect on human myometrial tissue. This effect was significantly attenuated by preincubation with iberiotoxin (P < 0.05). These findings outline that activation of BK(Ca) channel activity may explain the potent uterorelaxant effect of hCG.

Calcium Channel Agonists↗

Cytoplasmic prostaglandin E2 synthase is dominantly expressed in cultured KAT-50 thyrocytes, cells that express constitutive prostaglandin-endoperoxide H synthase-2. Basis for low protaglandin E2 production.

The recent identification and cloning of two glutathione-dependent prostaglandin E(2) synthase (PGES) genes has yielded important insights into the terminal step of PGE(2) synthesis. These enzymes form efficient functional pairs with specific members of the prostaglandin-endoperoxide H synthase (PGHS) family. Microsomal PGES (mPGES) is inducible and works more efficiently with PGHS-2, the inflammatory cyclooxygenase, while the cytoplasmic isoform (cPGES) pairs functionally with PGHS-1, the cyclooxygenase that ordinarily exhibits constitutive expression. KAT-50, a well differentiated thyroid epithelial cell line, expresses high levels of PGHS-2 but surprisingly low levels of PGE(2) when compared with human orbital fibroblasts. Moreover, PGHS-1 protein cannot be detected in KAT-50. We report here that KAT-50 cells express high basal levels of cPGES but mPGES mRNA and protein are undetectable. Thus, KAT-50 cells express the inefficient PGHS-2/cPGES pair, and this results in modest PGE(2) production. The high levels of cPGES and the absence of mPGES expression result from dramatic differences in the activities of their respective gene promoters. When mPGES is expressed in KAT-50 by transiently transfecting the cells, PGE(2) production is up-regulated substantially. These observations indicate that naturally occurring cells can express a suboptimal profile of PGHS and PGES isoforms, resulting in diminished levels of PGE(2) generation.

Blotting, Northern↗

Up-regulation of prostaglandin E2 synthesis by interleukin-1beta in human orbital fibroblasts involves coordinate induction of prostaglandin-endoperoxide H synthase-2 and glutathione-dependent prostaglandin E2 synthase expression.

Prostaglandin E(2) (PGE(2)) production involves the activity of a multistep biosynthetic pathway. The terminal components of this cascade, two PGE(2) synthases (PGES), have very recently been identified as glutathione-dependent proteins. cPGES is cytoplasmic, apparently identical to the hsp90 chaperone, p23, and associates functionally with prostaglandin-endoperoxide H synthase-1 (PGHS-1), the constitutive cyclooxygenase. A second synthase, designated mPGES, is microsomal and can be regulated. Here we demonstrate that mPGES and PGHS-2 are expressed at very low levels in untreated human orbital fibroblasts. Interleukin (IL)-1beta treatment elicits high levels of PGHS-2 and mPGES expression. The induction of both enzymes occurs at the pretranslational level, is the consequence of enhanced gene promoter activities, and can be blocked by dexamethasone (10 nm). SC58125, a PGHS-2-selective inhibitor, could attenuate the induction of mPGES, suggesting a dependence of this enzyme on PGHS-2 activity. IL-1beta treatment activates p38 and ERK mitogen-activated protein kinases. Induction of both mPGES and PGHS-2 was susceptible to either chemical inhibition or molecular interruption of these pathways with dominant negative constructs. These results indicate that the induction of PGHS-2 and mPGES by IL-1beta underlies robust PGE(2) production in orbital fibroblasts.

Blotting, Northern↗

Molecular cloning of an IL-8-like CXC chemokine and tissue factor in rainbow trout (Oncorhynchus mykiss) by use of suppression subtractive hybridization.

Suppression subtractive hybridization (SSH) was performed to construct a Rainbow trout cDNA library enriched in sequences up-regulated in head kidney leukocytes after lipopolysaccharide (LPS) and tumour necrosis factor alpha (TNFalpha) stimulation. Random sequencing of fifty clones allowed the identification of a Rainbow trout interleukin 8 (IL-8)-related CXC chemokine, as well as the Rainbow trout tissue factor (TF) precursor. Expression of both the IL-8-like chemokine and TF is induced after LPS and TNFalpha stimulation, indicating that they are associated with inflammatory responses in fish, as has been suggested in mammals. These results confirm the potential of SSH to identify cytokines and immuno-regulatory genes in fish.

Amino Acid Sequence↗