RESUMEN
Two men were wrongfully convicted of murder in 2017 and sentenced to life imprisonment. After a physical altercation inside a flat, the victim (A) was found dead approximately 60 m away outside a residential address. He had sustained a number of injuries including a stab wound to the left side of his neck which was found to have divided the right carotid artery. The location where A was found was not regarded as a crime scene and not subjected to a specialist forensic examination by scientists as it was assumed that the fatal injury was sustained in the flat. The pathologist, who subsequently carried out the autopsy on A, was not asked to attend the scene. A review of the blood distribution at the scene in conjunction with the pathology findings indicated however that the fatal neck wound had been inflicted outside the flat, near to where the victim was found. An appeal against the convictions for murder was upheld in 2021 and a re-trial ordered. Following this second trial, both accused were acquitted of murder and released from custody. The new pathology and blood pattern evidence introduced at the second trial was a major part of the defense strategy which led to the acquittal of the accused. The case illustrates that a more inclusive and detailed crime scene strategy had been undertaken, including an assessment of the bloodstains present, in conjunction with discussion with the pathologist, then the likelihood is that the two men subsequently charged with murder would have been eliminated as suspects and a miscarriage of justice would have been avoided.
Asunto(s)
Manchas de Sangre , Traumatismos del Cuello , Heridas Punzantes , Humanos , Masculino , Homicidio , Heridas Punzantes/patologíaRESUMEN
Endothelial-dependent regulation of vascular tone occurs in part via protein kinase G1α-mediated changes in smooth muscle myofilament sensitivity to Ca(2+). Tissue-specific differences in PKG-dependent relaxation have been attributed to altered expression of myofilament-associated proteins that are substrates for PKG binding. These include the alternative splicing of the myosin targeting subunit (MYPT1) of myosin light chain phosphatase to yield leucine zipper positive (LZ(+)) and negative (LZ(-)) isovariants, with the former being required for PKG-mediated relaxation, and/or altered expressions of telokin, vasodilator-stimulated phosphoprotein (VASP) or heat shock protein Hsp20. During human pregnancy the uterine and placental circulations remain distinct entities and, as such, their mechanisms of vascular tone regulation may differ. Indeed, the sensitivity of myometrial arteries to endothelial-dependent agonists has been suggested to be greater than that of placental arteries. We tested the hypothesis that this was related to tissue-specific changes in PKG-mediated myofilament Ca(2+)-desensitization and/or the expressions of PKG-interacting myofilament-associated proteins. Permeabilized human placental and myometrial arteries were constricted with maximal activating Ca(2+) (pCa 4.5), or sub-maximal Ca(2+) (pCa 6.7) and the thrombane mimetic U46619, and exposed to 8-Br-cGMP. In each case, relaxation was significantly greater in myometrial arteries (e.g. relaxation in pCa 4.5 to 8-Br-cGMP was 49 ± 9.7%, n = 7) than placental arteries (relaxation of 23 ± 6.6%, n = 6, P < 0.05). MYPT1 protein levels, or MYPT1 LZ(+)/LZ(-) mRNA ratios, were similar for both artery types. Of other proteins examined, only Hsp20 expression was significantly elevated in myometrial arteries than placental arteries. These results demonstrate that the reduced human placental artery relaxation to PKG stimulation lies partly at the level of myofilament (de)activation and may be related to a lower expression of Hsp20 than in myometrial arteries.
Asunto(s)
Calcio/metabolismo , Miofibrillas/metabolismo , Miometrio/irrigación sanguínea , Placenta/irrigación sanguínea , Arteria Uterina/fisiología , Vasodilatación/fisiología , Adulto , Biopsia , Femenino , Proteínas del Choque Térmico HSP20/genética , Proteínas del Choque Térmico HSP20/metabolismo , Humanos , Miofibrillas/patología , Miografía , Miometrio/metabolismo , Miometrio/patología , Fosfatasa de Miosina de Cadena Ligera/genética , Fosfatasa de Miosina de Cadena Ligera/metabolismo , Placenta/metabolismo , Placenta/patología , Embarazo , Adulto JovenRESUMEN
The state of contraction in smooth muscle cells of the human uterus is dependent on the interaction of activated forms of actin and myosin. Ras homology (RHO) proteins are small monomeric GTP-binding proteins that regulate actin polymerisation and myosin phosphorylation in smooth muscle cells. Their action is determined by their level of expression, GTP-bound state, intracellular localisation and phosphorylated status. Agonist activated RHO proteins bind to effector kinases such as RHO kinase (ROCK) and diaphanous proteins (DIAPH) to regulate smooth muscle contraction by two mechanisms: ROCK activates smooth muscle myosin either by direct phosphorylation at Ser19/Thr18 or through inhibition of myosin phosphatase which is a trimeric protein regulated by ROCK and by other protein kinases. Actin-polymerising proteins such as DIAPH homolog 1 increase filamentous actin assembly to enhance acto-myosin cross bridge formation and contraction. This review explores recent advances in RHO protein signalling in human myometrium and proposes areas of further research to investigate the involvement of these proteins in the regulation of uterine contractility in pregnancy and labour.
Asunto(s)
Contracción Uterina/fisiología , Proteínas de Unión al GTP rho/fisiología , Secuencia de Bases , Femenino , Humanos , Modelos Biológicos , Datos de Secuencia Molecular , Contracción Muscular/genética , Contracción Muscular/fisiología , Miometrio/metabolismo , Miometrio/fisiología , Embarazo , Contracción Uterina/genética , Contracción Uterina/metabolismo , Útero/metabolismo , Útero/fisiología , Proteínas de Unión al GTP rho/genética , Proteínas de Unión al GTP rho/metabolismoRESUMEN
RHO GTP-binding proteins are important regulators of actin-myosin interactions in uterine smooth muscle cells. Active (GTP-bound) RHOA binds to RHO-associated protein kinase (ROCK1), which inhibits the myosin-binding subunit (PPP1R12A) of myosin light chain phosphatase, leading to calcium-independent increases in myosin light chain phosphorylation and tension, which are termed "calcium sensitization." The RHO effector protein kinase N (PKN1) also increases calcium sensitization by phosphorylating the protein kinase C (PRKCB)-dependent protein CPI-17 (PPP1R14A) to inhibit the PPP1c subunit of myosin phosphatase. Moreover, other RHO proteins, such as RHOB, RHOD, and their effectors (DIAPH1 and DIAPH2), may modulate PKN1/ ROCK1 signaling to effect changes in myosin phosphatase activity and myosin light chain phosphorylation. The increases in contractile activity observed in term and preterm labor may be due to an increase in RHO activity and/or changes in RHO-related proteins. We found that the RHOA and RHOB mRNA levels in the myometrium were increased in pregnancy, although the expression levels of the RHOA and RHOB proteins did not change with pregnancy or labor. GTP-bound RHOA was increased in pregnancy, and this increase was significant in spontaneous preterm labor myometrium. PKN1 expression and PPP1R14A phosphorylation were dramatically increased in the pregnant myometrium. We also observed increases in DIAPH1 expression in spontaneous term and preterm labor myometrial tissues. The present study shows that human pregnancy is characterized by increases in PKN1 expression and PPP1R14A phosphorylation in the myometrium. Moreover, increases in GTP-bound RHOA and DIAPH1 expression may contribute to the increase in uterine activity in idiopathic preterm labor.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Miometrio/metabolismo , Trabajo de Parto Prematuro/metabolismo , Fosfoproteínas Fosfatasas/metabolismo , Proteína Quinasa C/metabolismo , Regulación hacia Arriba , Proteína de Unión al GTP rhoA/genética , Células Cultivadas , Femenino , Forminas , Humanos , Péptidos y Proteínas de Señalización Intracelular , Modelos Biológicos , Proteínas Musculares , Fosforilación , Embarazo , Proteína Quinasa C/genética , ARN Mensajero/metabolismo , Nacimiento a Término/genética , Nacimiento a Término/metabolismo , Proteínas de Unión al GTP rho/genética , Proteínas de Unión al GTP rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Proteína de Unión al GTP rhoB/genética , Proteína de Unión al GTP rhoB/metabolismoRESUMEN
RHO GTPases are key regulators of the actin cytoskeleton and stress fiber formation. In the human uterus, activated RHOA forms a complex with RHO-associated protein kinase (ROCK) which inhibits myosin light chain phosphatase (PPP1R12A), causing a calcium-independent increase in myosin light chain phosphorylation and tension (Ca2+ sensitization). Recently discovered small GTP binding RND proteins can inhibit RHOA and ROCK interaction to reduce calcium sensitization. Very little is known about the expression of RND proteins in the human uterus. We tested the hypothesis that the uterine quiescence observed during gestation is mediated by an increase in RND protein expression inhibiting RHOA-ROCK-mediated PPP1R12A phosphorylation. Immunohistochemistry and immunoblotting were used to determine RHOA and RND protein expression and localization in nonpregnant, pregnant nonlaboring, and laboring patients at term and patients in spontaneous preterm labor. Changes in protein expression estimated by densitometry between different patient groups were measured. A significant increase of RND2 and RND3 protein expression was observed in pregnant relative to nonpregnant myometrium associated with a loss of PPP1R12A phosphorylation. RND transfected myometrial cells demonstrated a dramatic loss of stress fiber formation and a "rounding" phenotype. RND upregulation in pregnancy may inhibit RHOA-ROCK-mediated increase in calcium sensitization to facilitate the uterine quiescence observed during gestation.
Asunto(s)
Miometrio/metabolismo , Proteínas de Unión al GTP rho/biosíntesis , Adulto , Western Blotting , Densitometría , Femenino , Técnica del Anticuerpo Fluorescente , GTP Fosfohidrolasas/biosíntesis , Humanos , Inmunohistoquímica , Técnicas In Vitro , Recién Nacido , Péptidos y Proteínas de Señalización Intracelular/genética , Persona de Mediana Edad , Músculo Liso/fisiología , Miometrio/citología , Fosfatasa de Miosina de Cadena Ligera/biosíntesis , Fosfatasa de Miosina de Cadena Ligera/genética , Embarazo , Proteínas Serina-Treonina Quinasas/biosíntesis , Proteínas Serina-Treonina Quinasas/genética , Transfección , Útero/fisiología , Proteínas de Unión al GTP rho/genética , Quinasas Asociadas a rhoRESUMEN
In the period of 1966-1975 the authors treated 228 patients with a fractures of diaphysis of humerus, 103 of whom underwent surgery; in 36 of them a paralysis of the radial nerve occurred. These 36 patients were divided into two groups: primary lesions (22 cases) which were discovered during hospitalization, and secondary lesions which occurred in postoperative course. The aim of clinical research with the primary lesion (respectively 22 patients) was to ascertain which method would have the best effect. In 77,2% of these patients, a radial nerve was not interrupted, while in 13.6% its continuity was partially preserved, and only in 9.09% a complete interruption occurred. Complete recovery of the nerve was in 50% of patients, 22.7% had a small conduction deficit, while its paralysis was further present in 18.8% of cases. Accordingly to this, the authors attained an excellent and very good results in 59% of patients, while in the remaining 41% of cases the results was satisfactory. It has been established that primary lesions of radial nerve has been occurring in 7.64% of cases (similar date do exist in reviewed reports), and in the majority of patients a spontaneously recovery will occur in the course of 2-3 months. Therefore the authors are not for a primary exploration of n.radialis if it is a question of closed fractures. In rare cases with interruption of the radial nerve with extensive contusions of both simultaneously interrupted nervous stumps a primary suture is not indicated. Therefore an eventual surgical exploration to establish whether an interruption of the nerve exists, does not contribute to attain recovery.