Last data update: Mar 17, 2025. (Total: 48910 publications since 2009)
Records 1-10 (of 10 Records) |
Query Trace: Partin J[original query] |
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EGFR and TGF-beta signaling pathways cooperate to mediate Chlamydia pathogenesis
Igietseme JU , Partin J , George Z , Omosun Y , Goldstein J , Joseph K , Ellerson D , Eko FO , Pohl J , Bandea C , Black CM . Infect Immun 2020 88 (4) Human genital Chlamydia infection is a major public health concern due to the serious reproductive system complications. Chlamydia binds several receptor tyrosine kinases (RTKs) on host cells, including the epidermal growth factor receptor (EGFR) and activates cellular signaling cascades for host invasion, cytoskeletal remodeling, optimal inclusion development, and induction of pathogenic epithelial-mesenchyme transition (EMT). Chlamydia also upregulates TGF-beta expression whose signaling pathway synergizes with the EGFR cascade, but its role in infectivity, inclusions and EMT induction is unknown. We hypothesized that the EGFR and TGF-beta signaling pathways cooperate during chlamydial infection for optimal inclusion development and stable EMT induction. The results revealed that Chlamydia upregulated TGF-beta expression as early as 6 h post-infection of epithelial cells and stimulated both the EGFR and TGF-beta signaling pathways. Inhibition of either the EGFR or TGF-betaR1 signaling substantially reduced inclusions development; however, the combined inhibition of both EGFR and TGF-betaR1 signaling reduced inclusions by over 90% and prevented EMT induction. Importantly, EGFR inhibition suppressed TGF-beta expression, and an inhibitory thrombospondin-1 (Tsp1)-based peptide inhibited chlamydia-induced EMT, revealing a major source of active TGF-betaduring infection. Finally, TGF-betaR signaling inhibition suppressed the expression of transforming acidic coiled-coil protein-3 (TACC3) that stabilizes EGFR signaling, suggesting a reciprocal regulation between TGF-beta and EGFR signaling during chlamydial infection. Thus, RTK-mediated host invasion by chlamydia upregulated TGF-beta expression and signaling, which cooperated with other cellular signaling cascades and cytoskeletal remodeling to support optimal inclusion development and EMT induction. The finding may provide new targets for chlamydial disease biomarkers and prevention. |
The molecular mechanism of induction of unfolded protein response by Chlamydia
George Z , Omosun Y , Azenabor AA , Goldstein J , Partin J , Joseph K , Ellerson D , He Q , Eko F , McDonald MA , Reed M , Svoboda P , Stuchlik O , Pohl J , Lutter E , Bandea C , Black CM , Igietseme JU . Biochem Biophys Res Commun 2019 508 (2) 421-429 The unfolded protein response (UPR) contributes to chlamydial pathogenesis, as a source of lipids and ATP during replication, and for establishing the initial anti-apoptotic state of host cell that ensures successful inclusion development. The molecular mechanism(s) of UPR induction by Chlamydia is unknown. Chlamydia use type III secretion system (T3SS) effector proteins (e.g, the Translocated Actin-Recruiting Phosphoprotein (Tarp) to stimulate host cell's cytoskeletal reorganization that facilitates invasion and inclusion development. We investigated the hypothesis that T3SS effector-mediated assembly of myosin-II complex produces activated non-muscle myosin heavy chain II (NMMHC-II), which then binds the UPR master regulator (BiP) and/or transducers to induce UPR. Our results revealed the interaction of the chlamydial effector proteins (CT228 and Tarp) with components of the myosin II complex and UPR regulator and transducer during infection. These interactions caused the activation and binding of NMMHC-II to BiP and IRE1alpha leading to UPR induction. In addition, specific inhibitors of myosin light chain kinase, Tarp oligomerization and myosin ATPase significantly reduced UPR activation and Chlamydia replication. Thus, Chlamydia induce UPR through T3SS effector-mediated activation of NMMHC-II components of the myosin complex to facilitate infectivity. The finding provides greater insights into chlamydial pathogenesis with the potential to identify therapeutic targets and formulations. |
Molecular pathogenesis of chlamydia disease complications: Epithelial-mesenchyme transition and fibrosis
Igietseme JU , Omosun Y , Nagy T , Stuchlik O , Reed MS , He Q , Partin J , Joseph K , Ellerson D , George Z , Goldstein J , Eko FO , Bandea C , Pohl J , Black CM . Infect Immun 2017 86 (1) The reproductive system complications of genital chlamydial infection include fallopian tube fibrosis and tubal factor infertility. However the molecular pathogenesis of these complications remain poorly understood. The induction of pathogenic epithelial-Mesenchyme Transition (EMT) through miRNA dysregulation was recently proposed as the pathogenic basis of chlamydial complications. Focusing on fibrogenesis, we investigated the hypothesis that chlamydial-induced fibrosis is caused by EMT-driven generation of myofibroblasts, the effector cells of fibrosis that produce excessive extracellular matrix (ECM) proteins. The results revealed that the targets of a major category of altered miRNAs during chlamydial infection are key components of the pathophysiological process of fibrogenesis; these target molecules include collagen types I, III and IV, TGF-beta, TGF-betaR1, the connective tissue growth factor (CTGF), E-cadherin, SRY-Box 7 (SOX7), and nuclear NFAT kinase dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1a (Dyrk1a). Chlamydial induction of EMT resulted in the generation of alpha-smooth muscle actin (alpha-SMA)-positive myofibroblasts that produced ECM proteins, including collagen type I, III and fibronectin. Furthermore, the inhibition of EMT prevented the generation of myofibroblasts and production of ECM proteins during chlamydial infection. These findings may provide useful avenues for targeting EMT or specific components of the EMT pathways as a therapeutic intervention strategy to prevent chlamydial-related complications. |
The roles of unfolded protein response pathways in chlamydia pathogenesis
George Z , Omosun Y , Azenabor AA , Partin J , Joseph K , Ellerson D , He Q , Eko F , Bandea C , Svoboda P , Pohl J , Black CM , Igietseme JU . J Infect Dis 2017 215 (3) 456-465 Chlamydia is an obligate intracellular bacterium that relies on host cells for essential nutrients and adenosine triphosphate (ATP) for a productive infection. Although the unfolded protein response (UPR) plays a major role in certain microbial infectivity, its role in chlamydial pathogenesis is unknown. We hypothesized that Chlamydia induces UPR and exploits it to upregulate host cell uptake and metabolism of glucose, production of ATP, phospholipids, and other molecules required for its replicative development and host survival. Using a combination of biochemical and pathway inhibition assays, we showed that the 3 UPR pathway transducers-protein kinase RNA-activated (PKR)-like ER kinase (PERK), inositol-requiring enzyme-1alpha (IRE1alpha), and activating transcription factor-6alpha (ATF6alpha)-were activated during Chlamydia infection. The kinase activity of PERK and ribonuclease (RNase) of IRE1alpha mediated the upregulation of hexokinase II and production of ATP via substrate-level phosphorylation. In addition, the activation of PERK and IRE1alpha promoted autophagy formation and apoptosis resistance for host survival. Moreover, the activation of IRE1alpha resulted in the generation of spliced X-box binding protein 1 (sXBP1) and upregulation of lipid production. The vital role of UPR pathways in Chlamydia development and pathogenesis could lead to the identification of potential molecular targets for therapeutics against Chlamydia. |
Role of Epithelial-Mesenchyme Transition in Chlamydia Pathogenesis.
Igietseme JU , Omosun Y , Stuchlik O , Reed MS , Partin J , He Q , Joseph K , Ellerson D , Bollweg B , George Z , Eko FO , Bandea C , Liu H , Yang G , Shieh WJ , Pohl J , Karem K , Black CM . PLoS One 2015 10 (12) e0145198 ![]() Chlamydia trachomatis genital infection in women causes serious adverse reproductive complications, and is a strong co-factor for human papilloma virus (HPV)-associated cervical epithelial carcinoma. We tested the hypothesis that Chlamydia induces epithelial-mesenchyme transition (EMT) involving T cell-derived TNF-alpha signaling, caspase activation, cleavage inactivation of dicer and dysregulation of micro-RNA (miRNA) in the reproductive epithelium; the pathologic process of EMT causes fibrosis and fertility-related epithelial dysfunction, and also provides the co-factor function for HPV-related cervical epithelial carcinoma. Using a combination of microarrays, immunohistochemistry and proteomics, we showed that chlamydia altered the expression of crucial miRNAs that control EMT, fibrosis and tumorigenesis; specifically, miR-15a, miR-29b, miR-382 and MiR-429 that maintain epithelial integrity were down-regulated, while miR-9, mi-R-19a, miR-22 and miR-205 that promote EMT, fibrosis and tumorigenesis were up-regulated. Chlamydia induced EMT in vitro and in vivo, marked by the suppression of normal epithelial cell markers especially E-cadherin but up-regulation of mesenchymal markers of pathological EMT, including T-cadherin, MMP9, and fibronectin. Also, Chlamydia upregulated pro-EMT regulators, including the zinc finger E-box binding homeobox protein, ZEB1, Snail1/2, and thrombospondin1 (Thbs1), but down-regulated anti-EMT and fertility promoting proteins (i.e., the major gap junction protein connexin 43 (Cx43), Mets1, Add1Scarb1 and MARCKSL1). T cell-derived TNF-alpha signaling was required for chlamydial-induced infertility and caspase inhibitors prevented both infertility and EMT. Thus, chlamydial-induced T cell-derived TNF-alpha activated caspases that inactivated dicer, causing alteration in the expression of reproductive epithelial miRNAs and induction of EMT. EMT causes epithelial malfunction, fibrosis, infertility, and the enhancement of tumorigenesis of HPV oncogene-transformed epithelial cells. These findings provide a novel understanding of the molecular pathogenesis of chlamydia-associated diseases, which may guide a rational prevention strategy. |
Les lanternes rouges: the race for information about cycling-related female sexual dysfunction
Partin SN , Connell KA , Schrader SM , Guess MK . J Sex Med 2014 11 (8) 2039-47 INTRODUCTION: Cycling is growing in popularity among women. As in men, it is associated with genital neuropathies and decreased sensation in female riders. However, there is a gap in research and information addressing the relationship between cycling and female sexual dysfunction (FSD) in women. AIMS: To review the literature investigating pelvic floor injuries and sexual dysfunction in female cyclists. METHODS: Searches in several electronic databases were conducted, and relevant articles that met the inclusion criteria were identified for critical review. MAIN OUTCOME MEASURES: The main outcome measure to be determined was the strength of the current body of evidence in published literature of a correlation between cycling-related pelvic floor injuries and FSD. RESULTS: Data on FSD from cycling-related injuries in women are limited. Research indicates that bicycle setup and riding equipment may be contributing factors. Women's ergonomics and physiology interact differently with the bicycle than men's. Current evidence offers insufficient foundation to recommend various effect-mitigating equipment and products. CONCLUSIONS: While gender-specific cycling products offer a promising direction for protecting women riders, studies addressing FSD and pelvic floor injuries in women cyclists are inadequate to indicate clear etiology or provide treatment recommendations. Current evidence is also insufficient to recommend effect-mitigating equipment and products. |
Prevention of Chlamydia-induced infertility by inhibition of local caspase activity
Igietseme JU , Omosun Y , Partin J , Goldstein J , He Q , Joseph K , Ellerson D , Ansari U , Eko FO , Bandea C , Zhong G , Black CM . J Infect Dis 2013 207 (7) 1095-104 Tubal factor infertility (TFI) represents 36% of female infertility and genital infection by Chlamydia trachomatis (Ct) as a major cause. While TFI is associated with host inflammatory responses to bacterial components, the molecular pathogenesis of Chlamydia-induced infertility remains poorly understood. We investigated the hypothesis that activation of specific cysteine proteases, the caspases, during Ct genital infection causes the disruption of key fertility-promoting molecules required for embryo development and implantation. We analyzed the effect of caspase inhibition on infertility and the integrity of Dicer, a caspase-sensitive, fertility-promoting ribonuclease III enzyme, and key micro-RNAs in the reproductive system. Genital infection with the inflammation- and caspase-inducing, wild-type Ct serovar L2 led to infertility, but the non-inflammation-inducing, plasmid-free strain did not. We confirmed that caspase-mediated apoptotic tissue destruction may contribute to chlamydial pathogenesis. Caspase-1 or -3-deficiency, or local administration of the pan caspase inhibitor, Z-VAD-FMK into normal mice protected against Chlamydia-induced infertility. Finally, the oviducts of infected infertile mice showed evidence of caspase-mediated cleavage inactivation of Dicer and alteration in critical miRNAs that regulate growth, differentiation and development, including mir-21. These results provide new insight into the molecular pathogenesis of TFI with significant implications for new strategies for treatment and prevention of chlamydial complications. |
The bar sinister: does handlebar level damage the pelvic floor in female cyclists?
Partin SN , Connell KA , Schrader S , Lacombe J , Lowe B , Sweeney A , Reutman S , Wang A , Toennis C , Melman A , Mikhail M , Guess MK . J Sex Med 2012 9 (5) 1367-73 INTRODUCTION: Cycling is associated with genital neuropathies and erectile dysfunction in males. Women riders also have decreased genital sensation; however, sparse information exists addressing the effects of modifiable risks on neurological injuries in females. AIM: This study assesses the effects of bicycle setup and cyclists' attributes on GS and saddle pressures among female cyclists. METHODS: Previously, we compared genital sensation in competitive female cyclists (N = 48) to that of female runners (N = 22). The current study is a subanalysis of the 48 cyclists from the original study group. Nonpregnant, premenopausal women who rode at least 10 miles per week, 4 weeks per month were eligible for participation. MAIN OUTCOME MEASURES: Genital sensation was measured in microns using biosthesiometry measures of vibratory thresholds (VTs). Perineal and total saddle pressures were determined using a specialized pressure map and recorded in kilopascals (kPA). RESULTS: Handlebars positioned lower than the saddle correlated with increased perineum saddle pressures and decreased anterior vaginal and left labial genital sensation (P < 0.05, P < 0.02, P < 0.03, respectively). Low handlebars were not associated with total saddle pressures or altered genital sensation in other areas. After adjusting for age and saddle type, low handlebars were associated with a 3.47-kPA increase in mean perineum saddle pressures (P < 0.04) and a 0.86-micron increase in anterior vagina VT (P < 0.01). CONCLUSION: Handlebars positioned lower than the saddle were significantly associated with increased perineum saddle pressures and decreased genital sensation in female cyclists. Modifying bicycle setup may help alleviate neuropathies in females. Additional research is warranted to further assess the extent of the associations. |
Women's bike seats: a pressing matter for competitive female cyclists
Guess MK , Partin SN , Schrader S , Lowe B , Lacombe J , Reutman S , Wang A , Toennis C , Melman A , Mikhail M , Connell KA . J Sex Med 2011 8 (11) 3144-53 INTRODUCTION: There are numerous genital complaints in women cyclists, including pain, numbness, and edema of pelvic floor structures. Debate ensues about the best saddle design for protection of the pelvic floor. AIM: To investigate the relationships between saddle design, seat pressures, and genital nerve function in female, competitive cyclists. METHODS: We previously compared genital sensation in healthy, premenopausal, competitive women bicyclists and runners. The 48 cyclists from our original study comprise the study group in this subanalysis. MAIN OUTCOME MEASURES: Main outcome measures were: (i) genital vibratory thresholds (VTs) determined using the Medoc Vibratory Sensation Analyzer 3000 and (ii) saddle pressures as determined using a specially designed map sensor. RESULTS: More than half of the participants (54.8%) used traditional saddles, and the remainder (45.2%) rode with cut-out saddles. On bivariate analysis, use of traditional saddles was associated with lower mean perineal saddle pressures (MPSP) than riding on cut-out saddles. Peak perineal saddle pressures (PPSP) were also lower; however, the difference did not reach statistical significance. Saddle design did not affect mean or peak total saddle pressures (MTSP, PTSP). Saddle width was significantly associated with PPSP, MTSP, and PTSP but not with MPSP. Women riding cut-out saddles had, on average, a 4 and 11 kPa increase in MPSP and PPSP, respectively, compared with women using traditional saddles (P = 0.008 and P = 0.010), after adjustment for other variables. Use of wider saddles was associated with lower PPSP and MTSP after adjustment. Although an inverse correlation was seen between saddle pressures and VTs on bivariate analysis, these differences were not significant after adjusting for age. CONCLUSION: Cut-out and narrower saddles negatively affect saddle pressures in female cyclists. Effects of saddle design on pudendal nerve sensory function were not apparent in this cross-sectional analysis. Longitudinal studies evaluating the long-term effects of saddle pressure on the integrity of the pudendal nerve, pelvic floor, and sexual function are warranted. |
Comparative analysis of direct fluorescence, zenon labeling, and quantum dot nanocrystal technology in immunofluorescence staining
Tang X , He J , Partin J , Vafai A . J Immunoassay Immunochem 2010 31 (3) 250-7 A comparative analysis was performed to determine the sensitivity and efficiency of three fluorescent labeling techniques, including direct fluorescent-antibody staining (FA), Zenon labeling, and quantum dot (QD) nanocrystal technology. Two varicella-zoster virus immunoglobin (Ig) G forms, mAb 4F9 and mAb g62, were selected for these studies. The results indicated that: (1) All three methods demonstrated similar brightness and photostability; (2) the time required to conjugate the antibody varied, with Zenon labeling being the quickest; and (3) the stability of each conjugated complex was different, with FITC/rhodamine-conjugated antibody being the most stable. |
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