Demonstration of skin-derived antileukoproteinase (skalp) and its target enzyme human leukocyte elastase in squamous cell carcinoma

Skin-derived antileukoproteinase (SKALP), also known as elafin, is a strong and specific inhibitor of elastase and proteinase 3. SKALP is not present in normal epidermis, but is expressed by epidermal keratinocytes under hyperproliferative conditions such as psoriasis, wound healing, and in cell culture. In human epidermal tumours, SKALP is differentially expressed and restricted to tumours with distinct squamous differentiation. We have studied the presence of both SKALP and one of its known target enzymes, leukocyte elastase, in 41 squamous cell carcinomas of the skin. SKALP expression correlated with the degree of differentiation: strong expression was seen in well-differentiated cells and expression was absent in poorly differentiated tumour cells. Most of the squamous cell carcinomas showed elastase-positive cells in the tumour stroma and also within the tumour cell nests. SKALP may interfere with the proteoloytic activity of infiltrating inflammatory cells or with hitherto unknown proteinases from the tumour cells. We hypothesize that in squamous cell carcinoma progressive loss of SKALP expression could facilitate tumour spread.     

Simultaneous changes in central and peripheral components of the hypothalamus-pituitary-thyroid axis in lipopolysaccharide-induced acute illness in mice

During illness, major changes in thyroid hormone metabolism and regulation occur; these are collectively known as non-thyroidal illness and are characterized by decreased serum triiodothyronine (T(3)) and thyroxine (T(4)) without an increase in serum TSH. Whether alterations in the central part of the hypothalamus-pituitary-thyroid (HPT) axis precede changes in peripheral thyroid hormone metabolism instead of vice versa, or occur simultaneously, is presently unknown. We therefore studied the time-course of changes in thyroid hormone metabolism in the HPT axis of mice during acute illness induced by bacterial endotoxin (lipopolysaccharide; LPS).LPS rapidly induced interleukin-1beta mRNA expression in the hypothalamus, pituitary, thyroid and liver. This was followed by almost simultaneous changes in the pituitary (decreased expression of thyroid receptor (TR)-beta2, TSHbeta and 5'-deiodinase (D1) mRNAs), the thyroid (decreased TSH receptor mRNA) and the liver (decreased TRbeta1 and D1 mRNA). In the hypothalamus, type 2 deiodinase mRNA expression was strongly increased whereas preproTRH mRNA expression did not change after LPS. Serum T(3) and T(4) fell only after 24 h.Our results suggested almost simultaneous involvement of the whole HPT axis in the downregulation of thyroid hormone metabolism during acute illness.     

Arginine Vasopressin Immunoreactivity is Decreased in the Hypothalamic Suprachiasmatic Nucleus of Subjects with Suprasellar Tumors

Suprasellar tumors with compression of the optic chiasm are associated with an impaired sleep–wake rhythm. We hypothesized that this reflects a disorder of the biological clock of the human brain, the suprachiasmatic nucleus (SCN), which is located just above the optic chiasm. In order to test this hypothesis, we investigated the expression of two key neuropeptides of the SCN, that is, arginine vasopressin (AVP) and vasoactive intestinal peptide (VIP), as assessed by quantitative immunocytochemistry in post‐mortem hypothalamic tissue of patients with a suprasellar tumor inducing permanent visual field defects. Post‐mortem hypothalamic tissue of 5 patients with a suprasellar tumor inducing permanent visual field defects (acromegaly n = 2, nonfunctioning macro‐adenoma n = 1, macroprolactinoma n = 1, infundibular metastasis of a colorectal adenocarcinoma n = 1) and 15 age‐ and gender‐matched controls was obtained from the Netherlands Brain Bank. Total AVP immunoreactivity in the SCN was lower in patients with a suprasellar tumor than in controls (P = 0.03). By contrast, total VIP immunoreactivity was not different between patients and controls (P = 0.44). Suprasellar tumors leading to permanent visual field defects are associated with reduced AVP, but not VIP immunoreactivity, in the SCN. These findings raise the possibility that selective impairment of the SCN contributes to sleep–wake disturbances in these patients.     

Using Latent Class Analysis to Support the ICD-11 Complex Posttraumatic Stress Disorder Diagnosis in a Sample of Homeless Adults

The 11th revision of the International Classification of Diseases (ICD-11), ratified at the World Health Assembly in May 2019, introduced revised diagnostic guidelines for posttraumatic stress disorder (PTSD) as well as a separate diagnosis of complex PTSD (CPTSD). We aimed to test the new ICD-11 symptom structure for PTSD and CPTSD in a sample of individuals who have experienced homelessness. Experiences of trauma exposure and the associated mental health outcomes have been underresearched in this population. A sample of adults experiencing homelessness (N = 206) completed structured and semi-structured interviews that collected information about trauma exposure and symptoms of PTSD and CPTSD. We conducted a latent class analysis (LCA) using six symptom clusters (three PTSD symptom clusters that are components of CPTSD and three CPTSD symptom clusters). All participants reported trauma exposure, with 88.6% having experienced at least one event before 16 years of age. Four distinct classes of participants emerged in relation to the potential to meet the diagnosis: LCA CPTSD (n = 122, 59.8%), LCA no diagnosis (n = 27: 13.2%), LCA PTSD (n = 33; 16.2%), and LCA disturbance in self-organization (DSO; n = 22; 10.8%). Of note, participants with an ICD-11 CPTSD as well as those with an ICD-11 PTSD diagnosis fell into the LCA CPTSD class. Our findings provide some support for the distinction between CPTSD and PTSD within this population specifically but potentially have broader implications. Clear diagnoses will allow targeted PTSD and CPTSD treatment development.     

Cross-linkers at growing microtubule ends generate forces that drive actin transport

The actin and microtubule cytoskeletons form active networks in the cell that can contract and remodel, resulting in vital cellular processes such as cell division and motility. Motor proteins play an important role in generating the forces required for these processes, but more recently the concept of passive cross-linkers being able to generate forces has emerged. So far, these passive cross-linkers have been studied in the context of separate actin and microtubule systems. Here, we show that cross-linkers also allow actin and microtubules to exert forces on each other. More specifically, we study single actin filaments that are cross-linked to growing microtubule ends, using in vitro reconstitution, computer simulations, and a minimal theoretical model. We show that microtubules can transport actin filaments over large (micrometer-range) distances and find that this transport results from two antagonistic forces arising from the binding of cross-linkers to the overlap between the actin and microtubule filaments. The cross-linkers attempt to maximize the overlap between the actin and the tip of the growing microtubules, creating an affinity-driven forward condensation force, and simultaneously create a competing friction force along the microtubule lattice. We predict and verify experimentally how the average transport time depends on the actin filament length and the microtubule growth velocity, confirming the competition between a forward condensation force and a backward friction force. In addition, we theoretically predict and experimentally verify that the condensation force is of the order of 0.1 pN. Thus, our results reveal an active mechanism for local actin remodeling by growing microtubules that relies on passive cross-linkers.

Vital cellular processes such as cell division and motility are driven by contraction and remodeling of active networks within the cell: the actin and microtubule cytoskeletons. These contraction and remodeling processes require the generation of forces and relative movement of filaments. It is well known that motor proteins can cross-link filaments and organize the network by driving the relative movements of the filaments (1). Besides the well-appreciated role of motor proteins, also polymerization dynamics have been shown to generate forces required for self-organization and remodeling (2–4). In addition, the importance of passive (nonmotor) cross-linkers has recently been increasingly recognized. It is now clear that passive cross-linkers can generate driving forces too, as has been shown for anillin in the contractile ring (5) and Ase1 in the spindle (6). These forces are generated via the entropy associated with the cross-linker’s diffusion within the overlap region (6) or via the condensation (or preferential binding) of cross-linkers to the overlap between filaments (5, 6), therefore named “condensation force.” In addition, passive cross-linkers create frictional forces (6, 7), which not only affect the speed at which cytoskeletal structures are remodeled, but can even be essential for their stability by opposing the motor proteins (8, 9).Prior studies on force generation by passive cross-linkers have focused on individual cytoskeletal systems. However, passive cross-linkers could also be a way for two systems to exert forces on each other. In particular, there is a growing body of work showing the importance of microtubule/actin crosstalk in vital cellular functions (10). Besides crosstalk via signaling pathways, it has been shown that crosstalk via motor proteins such as myosin-X (Myo10) is among the drivers of remodeling the microtubule spindle network during cell division (11, 12). In addition, various passive cross-linking proteins have been identified to enable crosstalk, such as the family of spectraplakins, which are proteins that can bind both actin and microtubules. The most prominent and best-studied member is ACF7 (MACF1) and its Drosophila homolog Short stop (Shot), which contain both microtubule lattice- and end-binding activities. These ubiquitous and conserved cross-linkers (traced back to lower metazoans; ref. 13) play a crucial role in a number of cellular processes, such as cell migration, cell–cell connections, vesicular transport, cell polarity, and cell division (10, 14). For example in the context of cell migration, ACF7 is shown to anchor microtubules at the cell’s leading edge (15) and to guide microtubules along actin bundles toward focal adhesions, where ACF7 depletion resulted in a phenotype with lost coalignment and failure of microtubules to target focal adhesions (16). In addition to ACF7, also other passive cross-linking proteins such as tau and Gas2Like1 have been shown to result in coalignment and stabilization of the actin and microtubule networks (16–19). Another example of a microtubule end-binding cross-linker that links actin to microtubule ends via EB3-mediated interactions is drebrin, which is required for sprouting neurites from a neuronal cell (20).Recent experiments suggest that the driving condensation forces and friction forces associated with passive cross-linkers can also couple to the growth dynamics of filaments and thereby allow passive cross-linkers to play a central role not only in contraction but also in transport. It was shown that an engineered passive cross-linker called TipAct can mediate transport of actin filaments by binding to the tips of growing microtubules (17). The microtubule tip region is chemically different from the microtubule lattice region, due to delayed hydrolysis of guanosine triphosphate (GTP) that is associated with tubulin subunits that incorporate into growing microtubules. This region is recognized by microtubule end-binding (EB) proteins (21–23) as well as EB partners such as TipAct. However, the processivity of the actin transport mechanism and its dependency on relevant parameters such as actin filament length and microtubule growth velocity, as well as the magnitude of the generated forces, are currently unresolved.Here, we investigate the conditions necessary for microtubule-mediated actin transport and elucidate the cross-linker–dependent mechanism. We combine biochemical reconstitution experiments with coarse-grained computer simulations and a minimal theoretical model and show that in the presence of passive cross-linkers, microtubules can transport actin filaments over large (micrometer-range) distances during periods that last up to several minutes. We propose and test a mechanism to explain this movement, in which actin transport is the result of a competition between a forward force that tends to maximize the overlap of the actin filament with the plus end of a growing microtubule and a backward force caused by the friction between the actin and microtubule lattice. These two antagonistic forces are both caused by the binding of cross-linkers. The preferential binding of cross-linkers at the interface between two objects (such as filaments) creates a driving force that tends to maximize the overlap region. This type of force, which, following earlier work (6, 7), we call condensation force, can drive the movement of intracellular cargos (2, 24–26) and the contraction of filament bundles (5, 6, 27, 28) in various biological contexts. However, the combination of a processive transport of cargo by a cross-linker–based condensation force toward a chemically distinct region that is simultaneously hindered by a friction force caused by the same cross-linkers is specific to filament transport and has to our knowledge not been studied before. The active transport of filaments by growing microtubule plus ends thus provides a minimal mechanism by which two cytoskeletal systems can interact, which is distinct from cytoskeletal crosstalk that is driven by motor proteins (11, 29–32). We expect this mechanism to be especially relevant in migrating cells, where growing microtubules nucleate actin filaments and encounter membrane-bound actin arrays.     

Maintenance of ovulation inhibition with the 75-microg desogestrel-only contraceptive pill (Cerazette) after scheduled 12-h delays in tablet intake

BACKGROUND: In contrast to traditional progestagen-only pills (POPs), the desogestrel-only pill Cerazette consistently inhibits ovulation. This study was performed to test the hypothesis that desogestrel alone will keep inhibiting ovulation even when pills are taken 12 h late, indicating that delays in tablet intake of up to 12 h do not jeopardize contraceptive efficacy. METHODS: Women aged between 19 and 40 years with confirmed ovulation were admitted to this open-label pharmacodynamic study. They were treated with Cerazette for 56 days with three tablets to be taken 12 h late, having been randomized to a regimen with scheduled late tablets on Days 39, 42 and 49 (Group A) or on Days 11, 14 and 21 (Group B). The occurrence of ovulation during treatment was determined by measuring progesterone serum levels every 2 days. RESULTS: One of the 103 treated subjects ovulated during treatment. The ovulation incidence thus amounts to 1.0% (two-sided 95% confidence interval 0.02-5.29%). There was no apparent relationship between these ovulations and scheduled late tablets. The minimum time to first posttreatment ovulation was 7 days, whereas it took 17.2 days on average from last tablet intake until ovulation. CONCLUSIONS: Ovulation inhibition with Cerazette is maintained after 12-h delays in tablet intake and return of ovulation takes at least 7 days. These properties distinguish Cerazette from all other POPs.     

Assessing the impacts of livestock production on biodiversity in rangeland ecosystems

Biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food. Here we assess the impact of future livestock production on the global rangelands area and their biodiversity. First we formalized existing knowledge about livestock grazing impacts on biodiversity, expressed in mean species abundance (MSA) of the original rangeland native species assemblages, through metaanalysis of peer-reviewed literature. MSA values, ranging from 1 in natural rangelands to 0.3 in man-made grasslands, were entered in the IMAGE-GLOBIO model. This model was used to assess the impact of change in food demand and livestock production on future rangeland biodiversity. The model revealed remarkable regional variation in impact on rangeland area and MSA between two agricultural production scenarios. The area of used rangelands slightly increases globally between 2000 and 2050 in the baseline scenario and reduces under a scenario of enhanced uptake of resource-efficient production technologies increasing production [high levels of agricultural knowledge, science, and technology (high-AKST)], particularly in Africa. Both scenarios suggest a global decrease in MSA for rangelands until 2050. The contribution of livestock grazing to MSA loss is, however, expected to diminish after 2030, in particular in Africa under the high-AKST scenario. Policies fostering agricultural intensification can reduce the overall pressure on rangeland biodiversity, but additional measures, addressing factors such as climate change and infrastructural development, are necessary to totally halt biodiversity loss.     

Treatment Outcomes for Military Veterans With Posttraumatic Stress Disorder: Response Trajectories by Symptom Cluster

Although effective posttraumatic stress disorder (PTSD) treatments are available, outcomes for veterans with PTSD are relatively modest. Previous researchers have identified subgroups of veterans with different response trajectories but have not investigated whether PTSD symptom clusters (based on a four‐factor model) have different patterns of response to treatment. The importance of this lies in the potential to increase treatment focus on less responsive symptoms. We investigated treatment outcomes by symptom cluster for 2,685 Australian veterans with PTSD. We used Posttraumatic Stress Disorder Checklist scores obtained at treatment intake, posttreatment, and 3‐ and 9‐month follow‐ups to define change across symptom clusters. Repeated measures effect sizes indicated that arousal and numbing symptoms exhibited the largest changes between intake and posttreatment, d_RM = ?0.61 and d_RM = ?0.52, respectively, whereas avoidance and intrusion symptoms showed more modest reductions, d_RM = ?0.36 and d_RM = ?0.30, respectively. However, unlike the other symptom clusters, the intrusions cluster continued to show significant changes between posttreatment and 3‐month follow‐up, d_RM = ?0.21. Intrusion and arousal symptoms also showed continued changes between 3‐ and 9‐month follow‐ups although these effects were very small, d_RM = ?0.09. Growth curve model analyses produced consistent findings and indicated modest initial changes in intrusion symptoms that continued posttreatment. These findings may reflect the longer time required for emotional processing, relative to behavioral changes in avoidance, numbing, and arousal, during the program; they also reinforce the importance of prioritizing individual trauma‐focused therapy directly targeting intrusions as the core component of programmatic treatment.     

The relative contributions of hostility and depressive symptoms to the income gradient in hospital-based incidence of ischaemic heart disease: 12-Year follow-up findings from the GLOBE study

There is evidence to support the view that both hostility and depressive symptoms are psychological risk factors for ischaemic heart disease (IHD), additional to the effects of lifestyle and biomedical risk factors. Both are also more common in lower socioeconomic groups. Studies to find out how socioeconomic status (SES) gets under the skin have not yet determined the relative contributions of hostility and depression to the income gradient in IHD. This has been examined in a Dutch prospective population-based cohort study (GLOBE study), with participants aged 15–74 years (n = 2374). Self-reported data at baseline (1991) and in 1997 provided detailed information on income and on psychological, lifestyle and biomedical factors, which were linked to hospital admissions due to incident IHD over a period of 12 years since baseline. Cox proportional hazard models were used to study the contributions of hostility and depressive symptoms to the association between income and time to incident IHD. The relative risk of incident IHD was highest in the lowest income group, with a hazard ratio of 2.71. Men on the lowest incomes reported more adverse lifestyles and biomedical factors, which contributed to their higher risk of incident IHD. An unhealthy psychological profile, particularly hostility, contributed to the income differences in incident IHD among women. The low number of IHD incidents in the women however, warrants additional research in larger samples.