SARS-CoV-2 infection is effectively treated and prevented by EIDD-2801.

All coronaviruses known to have recently emerged as human pathogens probably originated in bats1. Here we use a single experimental platform based on immunodeficient mice implanted with human lung tissue (hereafter, human lung-only mice (LoM)) to demonstrate the efficient in vivo replication of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as well as two endogenous SARS-like bat coronaviruses that show potential for emergence as human pathogens. Virus replication in this model occurs in bona fide human lung tissue and does not require any type of adaptation of the virus or the host. Our results indicate that bats contain endogenous coronaviruses that are capable of direct transmission to humans. Our detailed analysis of in vivo infection with SARS-CoV-2 in human lung tissue from LoM showed a predominant infection of human lung epithelial cells, including type-2 pneumocytes that are present in alveoli and ciliated airway cells. Acute infection with SARS-CoV-2 was highly cytopathic and induced a robust and sustained type-I interferon and inflammatory cytokine and chemokine response. Finally, we evaluated a therapeutic and pre-exposure prophylaxis strategy for SARS-CoV-2 infection. Our results show that therapeutic and prophylactic administration of EIDD-2801-an oral broad-spectrum antiviral agent that is currently in phase II/III clinical trials-markedly inhibited SARS-CoV-2 replication in vivo, and thus has considerable potential for the prevention and treatment of COVID-19.

Classically conditioned modulation of pain depends on stimulus intensity.

Innocuous cues that become associated with pain can enhance pain. This is termed classically conditioned hyperalgesia. The size of this effect varies under different conditions. We aimed to test whether the sensitising effect of pain-associated cues depends on the intensity of the paired test stimulus. To do this, two virtual reality environments were paired with either painful or non-painful vibrotactile stimuli in a counterbalanced fashion. The differential effect of the two environments was evaluated using pain intensity ratings of paired electrocutaneous test stimuli at three different intensity levels. Forty healthy participants were included in the study; 30 participants experienced sufficient pain during the learning phase and were included in the main analysis. An effect of environment (p = 0.014) and interaction between environment and test stimulus intensity was found (p = 0.046). Only the most intense test stimulus was modulated by environment. While the effect was small, the results are consistent with the proposition that pain-associated cues may induce hyperalgesia to some degree, under certain conditions. In particular, results highlight the potential relevance of stimulus intensity during and after the initial painful experience. Further attention is needed to comprehensively understand the variables that impact classically conditioned hyperalgesia.

Quality control autophagy degrades soluble ERAD-resistant conformers of the misfolded membrane protein GnRHR.

Molecular chaperones triage misfolded proteins via action as substrate selectors for quality control (QC) machines that fold or degrade clients. Herein, the endoplasmic reticulum (ER)-associated Hsp40 JB12 is reported to participate in partitioning mutant conformers of gonadotropin-releasing hormone receptor (GnRHR), a G protein-coupled receptor, between ER-associated degradation (ERAD) and an ERQC autophagy pathway. ERQC autophagy degrades E90K-GnRHR because pools of its partially folded and detergent-soluble degradation intermediates are resistant to ERAD. S168R-GnRHR is globally misfolded and disposed of via ERAD, but inhibition of p97, the protein retrotranslocation motor, shunts S168R-GnRHR from ERAD to ERQC autophagy. Partially folded and grossly misfolded forms of GnRHR associate with JB12 and Hsp70. Elevation of JB12 promotes ERAD of S168R-GnRHR, with E90K-GnRHR being resistant. E90K-GnRHR elicits association of the Vps34 autophagy initiation complex with JB12. Interaction between ER-associated Hsp40s and the Vps34 complex permits the selective degradation of ERAD-resistant membrane proteins via ERQC autophagy.

Potassium starvation induces autophagy in yeast.

Autophagy is a conserved process that recycles cellular contents to promote survival. Although nitrogen limitation is the canonical inducer of autophagy, recent studies have revealed several other nutrients important to this process. In this study, we used a quantitative, high-throughput assay to identify potassium starvation as a new and potent inducer of autophagy in the yeast Saccharomyces cerevisiae We found that potassium-dependent autophagy requires the core pathway kinases Atg1, Atg5, and Vps34, and other components of the phosphatidylinositol 3-kinase complex. Transmission EM revealed abundant autophagosome formation in response to both stimuli. RNA-Seq indicated distinct transcriptional responses: nitrogen affects transport of ions such as copper, whereas potassium targets the organization of other cellular components. Thus, nitrogen and potassium share the ability to influence molecular supply and demand but do so in different ways. Both inputs promote catabolism through bulk autophagy, but result in distinct mechanisms of cellular remodeling and synthesis.

An image-based small-molecule screen identifies vimentin as a pharmacologically relevant target of simvastatin in cancer cells.

Vimentin is a cytoskeletal intermediate filament protein that is expressed in mesenchymal cells and cancer cells during the epithelial-mesenchymal transition. The goal of this study was to identify vimentin-targeting small molecules by using the Tocriscreen library of 1120 biochemically active compounds. We monitored vimentin filament reorganization and bundling in adrenal carcinoma SW13 vimentin-positive (SW13-vim+) cells via indirect immunofluorescence. The screen identified 18 pharmacologically diverse hits that included 2 statins-simvastatin and mevastatin. Simvastatin induced vimentin reorganization within 15-30 min and significant perinuclear bundling within 60 min (IC50 = 6.7 nM). Early filament reorganization coincided with increased vimentin solubility. Mevastatin produced similar effects at >1 µM, whereas the structurally related pravastatin and lovastatin did not affect vimentin. In vitro vimentin filament assembly assays revealed a direct targeting mechanism, as determined biochemically and by electron microscopy. In SW13-vim+ cells, simvastatin, but not pravastatin, reduced total cell numbers (IC50 = 48.1 nM) and promoted apoptosis after 24 h. In contrast, SW13-vim- cell viability was unaffected by simvastatin, unless vimentin was ectopically expressed. Simvastatin similarly targeted vimentin filaments and induced cell death in MDA-MB-231 (vim+), but lacked effect in MCF7 (vim-) breast cancer cells. In conclusion, this study identified vimentin as a direct molecular target that mediates simvastatin-induced cell death in 2 different cancer cell lines.-Trogden, K. P., Battaglia, R. A., Kabiraj, P., Madden, V. J., Herrmann, H., Snider, N. T. An image-based small-molecule screen identifies vimentin as a pharmacologically relevant target of simvastatin in cancer cells.

High Elmo1 expression aggravates and low Elmo1 expression prevents diabetic nephropathy.

Human genome-wide association studies have demonstrated that polymorphisms in the engulfment and cell motility protein 1 gene (ELMO1) are strongly associated with susceptibility to diabetic nephropathy. However, proof of causation is lacking. To test whether modest changes in its expression alter the severity of the renal phenotype in diabetic mice, we have generated mice that are type 1 diabetic because they have the Ins2(Akita) gene, and also have genetically graded expression of Elmo1 in all tissues ranging in five steps from ∼30% to ∼200% normal. We here show that the Elmo1 hypermorphs have albuminuria, glomerulosclerosis, and changes in the ultrastructure of the glomerular basement membrane that increase in severity in parallel with the expression of Elmo 1. Progressive changes in renal mRNA expression of transforming growth factor ß1 (TGFß1), endothelin-1, and NAD(P)H oxidase 4 also occur in parallel with Elmo1, as do the plasma levels of cystatin C, lipid peroxides, and TGFß1, and erythrocyte levels of reduced glutathione. In contrast, Akita type 1 diabetic mice with below-normal Elmo1 expression have reduced expression of these various factors and less severe diabetic complications. Remarkably, the reduced Elmo1 expression in the 30% hypomorphs almost abolishes the pathological features of diabetic nephropathy, although it does not affect the hyperglycemia caused by the Akita mutation. Thus, ELMO1 plays an important role in the development of type 1 diabetic nephropathy, and its inhibition could be a promising option for slowing or preventing progression of the condition to end-stage renal disease.

Low TGFß1 expression prevents and high expression exacerbates diabetic nephropathy in mice.

Nephropathy develops in many but not all patients with long-standing type 1 diabetes. Substantial efforts to identify genotypic differences explaining this differential susceptibility have been made, with limited success. Here, we show that the expression of the transforming growth factor ß1 gene (Tgfb1) affects the development of diabetic nephropathy in mice. To do this we genetically varied Tgfb1 expression in five steps, 10%, 60%, 100%, 150%, and 300% of normal, in mice with type 1 diabetes caused by the Akita mutation in the insulin gene (Ins2(Akita)). Although plasma glucose levels were not affected by Tgfb1 genotype, many features of diabetic nephropathy (mesangial expansion, elevated plasma creatinine and urea, decreased creatinine clearance and albuminuria) were progressively ameliorated as Tgfb1 expression decreased and were progressively exacerbated when expression was increased. The diabetic 10% hypomorphs had comparable creatinine clearance and albumin excretion to wild-type mice and no harmful changes in renal morphology. The diabetic 300% hypermorphs had ∼1/3 the creatinine clearance of wild-type mice, >20× their albumin excretion, ∼3× thicker glomerular basement membranes and severe podocyte effacement, matching human diabetic nephropathy. Switching Tgfb1 expression from low to high in the tubules of the hypomorphs increased their albumin excretion more than 10-fold but creatinine clearance remained high. Switching Tgfb1 expression from low to high in the podocytes markedly decreased creatinine clearance, but minimally increased albumin excretion. Decreasing expression of Tgfb1 could be a promising option for preventing loss of renal function in diabetes.

Endothelin-1 critically influences cardiac function via superoxide-MMP9 cascade.

We have generated low-expressing and high-expressing endothelin-1 genes (L and H) and have bred mice with four levels of expression: L/L, ∼20%; L/+, ∼65%; +/+ (wild type), 100%; and H/+, ∼350%. The hypomorphic L allele can be spatiotemporally switched to the hypermorphic H allele by Cre-loxP recombination. Young adult L/L and L/+ mice have dilated cardiomyopathy, hypertension, and increased plasma volumes, together with increased ventricular superoxide levels, increased matrix metalloproteinase 9 (Mmp9) expression, and reduced ventricular stiffness. H/+ mice have decreased plasma volumes and significantly heavy stiff hearts. Global or cardiomyocyte-specific switching expression from L to H normalized the abnormalities already present in young adult L/L mice. An epithelial sodium channel antagonist normalized plasma volume and blood pressure, but only partially corrected the cardiomyopathy. A superoxide dismutase mimetic made superoxide levels subnormal, reduced Mmp9 overexpression, and substantially improved cardiac function. Genetic absence of Mmp9 also improved cardiac function, but increased superoxide remained. We conclude that endothelin-1 is critical for maintaining normal contractile function, for controlling superoxide and Mmp9 levels, and for ensuring that the myocardium has sufficient collagen to prevent overstretching. Even a modest (∼35%) decrease in endothelin-1 gene (Edn1) expression is sufficient to cause cardiac dysfunction.

Classical Conditioning Fails to Elicit Allodynia in an Experimental Study with Healthy Humans.

OBJECTIVE: Associative learning has been proposed as a mechanism behind the persistence of pain after tissue healing. The simultaneous occurrence of nociceptive and non-nociceptive input during acute injury mimics the pairings thought to drive classical conditioning effects. However, empirical evidence for classically conditioned allodynia is lacking. We aimed to manipulate pain thresholds with a classical conditioning procedure that used non-nociceptive somatosensory stimuli as conditioned stimuli (CS) and nociceptive stimuli as unconditioned stimuli. We also explored the influence of gender, depression, anxiety, negative affect, and pain catastrophizing on the main manipulation. DESIGN: Thirty-four healthy humans participated in a differential classical conditioning procedure that used vibrotactile stimulations at two different locations as CS. In an acquisition phase, CS+ was paired with painful thermal stimulation, and CS- with nonpainful thermal stimulation. Heat pain threshold was assessed during paired heat-CS trials before and after acquisition. A 2 (time: 1 and 2) x 2 (condition: CS+ and CS-) repeated-measures analysis of variance compared pain thresholds before and after acquisition. Exploratory analyses explored the influence of gender, depression, anxiety, negative affect, and pain catastrophizing. Postexperiment questions investigated participants' awareness of the contingencies employed. RESULTS: The classical conditioning procedure did not alter pain thresholds. Exploratory analyses did not reveal any influence of individual differences. Thirty of the 34 participants were unaware of the contingencies between stimuli. CONCLUSIONS: The results of this study provide no evidence that allodynia can be induced in healthy humans using a classical conditioning procedure with simultaneous timing.

Can Pain or Hyperalgesia Be a Classically Conditioned Response in Humans? A Systematic Review and Meta-Analysis.

BACKGROUND: Clinical scenarios of repeated pain usually involve both nociceptive and non-nociceptive input. It is likely that associations between these stimuli are learned over time. Such learning may underlie subsequent amplification of pain, or evocation of pain in the absence of nociception. METHODS: We undertook a systematic review and meta-analysis to evaluate the evidence that allodynia or hyperalgesia can be a classically conditioned response. A sensitive search of the literature covered Medline, Embase, CINAHL, AMED, PubMed, Scopus, PsycArticles, PsycINFO, Cochrane Library, and Web of Science. Additional studies were identified by contacting experts and searching published reviews. Two reviewers independently assessed studies for inclusion, evaluated risk of bias, and extracted data. Studies were included if they aimed to elicit or amplify pain using a classical conditioning procedure in healthy, adult humans. Studies were excluded if they did not distinguish between classical conditioning and explicit verbal suggestion as learning sources, or did not use experiential learning. RESULTS: Thirteen studies, with varying risk of bias, were included. Ten studies evaluated classically conditioned hyperalgesia: nine found hyperalgesia; one did not. Pooled effects (n = 8 with full data) showed a significant pain increase after conditioning (mean difference of 7.40 [95%CI: 4.00-10.80] on a 0-100 pain scale). Three studies evaluated conditioned allodynia and found conflicting results. CONCLUSION: The existing literature suggests that classical conditioning can amplify pain. No conclusions can be drawn about whether or not classical conditioning can elicit pain. Rigorous experimental conditioning studies with nociceptive unconditioned stimuli are needed to fill this gap in knowledge.

Bogus visual feedback alters onset of movement-evoked pain in people with neck pain.

Pain is a protective perceptual response shaped by contextual, psychological, and sensory inputs that suggest danger to the body. Sensory cues suggesting that a body part is moving toward a painful position may credibly signal the threat and thereby modulate pain. In this experiment, we used virtual reality to investigate whether manipulating visual proprioceptive cues could alter movement-evoked pain in 24 people with neck pain. We hypothesized that pain would occur at a lesser degree of head rotation when visual feedback overstated true rotation and at a greater degree of rotation when visual feedback understated true rotation. Our hypothesis was clearly supported: When vision overstated the amount of rotation, pain occurred at 7% less rotation than under conditions of accurate visual feedback, and when vision understated rotation, pain occurred at 6% greater rotation than under conditions of accurate visual feedback. We concluded that visual-proprioceptive information modulated the threshold for movement-evoked pain, which suggests that stimuli that become associated with pain can themselves trigger pain.

Functional redundancy of SWI/SNF catalytic subunits in maintaining vascular endothelial cells in the adult heart.

RATIONALE: Mating type switching/sucrose non-fermenting (SWI/SNF) chromatin-remodeling complexes utilize either BRG1 or BRM as a catalytic subunit to alter nucleosome position and regulate gene expression. BRG1 is required for vascular endothelial cell (VEC) development and embryonic survival, whereas BRM is dispensable. OBJECTIVE: To circumvent embryonic lethality and study Brg1 function in adult tissues, we used conditional gene targeting. To evaluate possible Brg1-Brm redundancy, we analyzed Brg1 mutant mice on wild-type and Brm-deficient backgrounds. METHODS AND RESULTS: The inducible Mx1-Cre driver was used to mutate Brg1 in adult mice. These conditional-null mutants exhibited a tissue-specific phenotype and unanticipated functional compensation between Brg1 and Brm. Brg1 single mutants were healthy and had a normal lifespan, whereas Brg1/Brm double mutants exhibited cardiovascular defects and died within 1 month. BRG1 and BRM were required for the viability of VECs but not other cell types where both genes were also knocked out. The VEC phenotype was most evident in the heart, particularly in the microvasculature of the outer myocardium, and was recapitulated in primary cells ex vivo. VEC death resulted in vascular leakage, cardiac hemorrhage, secondary death of cardiomyocytes due to ischemia, and ventricular dissections. CONCLUSIONS: BRG1-catalyzed SWI/SNF complexes are particularly important in cardiovascular tissues. However, in contrast to embryonic development, in which Brm does not compensate, Brg1 is required in adult VECs only when Brm is also mutated. These results demonstrate for the first time that Brm functionally compensates for Brg1 in vivo and that there are significant changes in the relative importance of BRG1- and BRM-catalyzed SWI/SNF complexes during the development of an essential cell lineage.

NLRX1 is a regulator of mitochondrial antiviral immunity.

The RIG-like helicase (RLH) family of intracellular receptors detect viral nucleic acid and signal through the mitochondrial antiviral signalling adaptor MAVS (also known as Cardif, VISA and IPS-1) during a viral infection. MAVS activation leads to the rapid production of antiviral cytokines, including type 1 interferons. Although MAVS is vital to antiviral immunity, its regulation from within the mitochondria remains unknown. Here we describe human NLRX1, a highly conserved nucleotide-binding domain (NBD)- and leucine-rich-repeat (LRR)-containing family member (known as NLR) that localizes to the mitochondrial outer membrane and interacts with MAVS. Expression of NLRX1 results in the potent inhibition of RLH- and MAVS-mediated interferon-beta promoter activity and in the disruption of virus-induced RLH-MAVS interactions. Depletion of NLRX1 with small interference RNA promotes virus-induced type I interferon production and decreases viral replication. This work identifies NLRX1 as a check against mitochondrial antiviral responses and represents an intersection of three ancient cellular processes: NLR signalling, intracellular virus detection and the use of mitochondria as a platform for anti-pathogen signalling. This represents a conceptual advance, in that NLRX1 is a modulator of pathogen-associated molecular pattern receptors rather than a receptor, and identifies a key therapeutic target for enhancing antiviral responses.

The Sensation and Pain Rating Scale: easy to use, clear to interpret, and responsive to clinical change.

Background: The Sensation and Pain Rating Scale (SPARS) allows rating of non-painful as well as painful percepts. While it performs well in the experimental context, its clinical utility is untested. This prospective, repeated-measures study mixed qualitative and quantitative methods to examine the utility and performance of the SPARS in a clinical context, and to compare it with the widely used 11-point NRS for pain. Methods: People presenting for outpatient physiotherapy (n = 121) provided ratings on the SPARS and NRS at first consultation, before and after sham and active clinical interventions, and at follow-up consultation. Clinicians (n = 9) reported each scale's usability and interpretability using Likert-type scales and free text, and answered additional questions with free text. Each data type was initially analysed separately: quantitative data were visualised and the ES II metric was used to estimate SPARS internal responsiveness; qualitative data were analysed with a reflexive inductive thematic approach. Data types were then integrated for triangulation and complementarity. Results: The SPARS was well received and considered easy to use, after initial familiarisation. Clinicians favoured the SPARS over the NRS for clarity of interpretation and inter-rater reliability. SPARS sensitivity to change was good (ESII=0.9; 95%CI: 0.75-1.10). The greater perceptual range of the SPARS was deemed especially relevant in the later phases of recovery, when pain may recede into discomfort that still warrants clinical attention. Conclusion: The SPARS is a promising tool for assessing patient percept, with strong endorsement from clinicians for its clarity and superior perceptual scope.

Harnessing Children's Picture Books to Socialize Children About Pain and Injury: A Qualitative Study.

Pain experiences are common during childhood (eg, "everyday" pain, vaccine injections) and are powerful opportunities for children to learn about pain and injury. These experiences likely inform fundamental and life-long beliefs about pain. There is scant research investigating the sociocultural contexts in which children learn about pain and injury. One unexplored context is the shared reading of picture books (eg, between parents/caregivers and children). In this study, we investigated whether shared reading of picture books that included depictions of pain and/or injury prompted parent/caregiver-child interactions. If interactions were observed, we explored what those interactions entailed. Twenty parents/caregivers (8 men, 12 women) and their children (n = 27; 10 boys, 17 girls) were recruited from libraries in South Australia. Parent/caregiver-child families chose from 8 books (7 fiction, 1 nonfiction) with varying amounts of pain/injury-related content. Shared reading interactions were video recorded, transcribed, and analyzed alongside analysis of the picture books using reflexive thematic analysis. Pain/injury-related interactions were observed between parents/caregivers and children during shared reading of picture books. Qualitative analyses generated 1 main theme and 3 subthemes. Findings identified that shared reading presented an opportunity for children's understanding of pain and injury to be socialized through discussion of characters' experiences. This included teaching children about pain and injury, as well as promoting empathy and emotional attunement toward characters who were depicted as being in pain. Finally, parents/caregivers often responded with observable/expressed amusement if pain/injury was depicted in a light-hearted or unrealistic way. Overall, shared reading of picture books presents an untapped opportunity to socialize children about pain and injury. PERSPECTIVE: Shared reading of picture books that have depictions of pain and/or injury can prompt parent/caregiver-child interactions about pain and injury. These interactions present critical opportunities that can be harnessed to promote children's learning of adaptive pain-related concepts and behaviors during a critical developmental period.

A novel self-replicating chimeric lentivirus-like particle.

Successful live attenuated vaccines mimic natural exposure to pathogens without causing disease and have been successful against several viruses. However, safety concerns prevent the development of attenuated human immunodeficiency virus (HIV) as a vaccine candidate. If a safe, replicating virus vaccine could be developed, it might have the potential to offer significant protection against HIV infection and disease. Described here is the development of a novel self-replicating chimeric virus vaccine candidate that is designed to provide natural exposure to a lentivirus-like particle and to incorporate the properties of a live attenuated virus vaccine without the inherent safety issues associated with attenuated lentiviruses. The genome from the alphavirus Venezuelan equine encephalitis virus (VEE) was modified to express SHIV89.6P genes encoding the structural proteins Gag and Env. Expression of Gag and Env from VEE RNA in primate cells led to the assembly of particles that morphologically and functionally resembled lentivirus virions and that incorporated alphavirus RNA. Infection of CD4⁺ cells with chimeric lentivirus-like particles was specific and productive, resulting in RNA replication, expression of Gag and Env, and generation of progeny chimeric particles. Further genome modifications designed to enhance encapsidation of the chimeric virus genome and to express an attenuated simian immunodeficiency virus (SIV) protease for particle maturation improved the ability of chimeric lentivirus-like particles to propagate in cell culture. This study provides proof of concept for the feasibility of creating chimeric virus genomes that express lentivirus structural proteins and assemble into infectious particles for presentation of lentivirus immunogens in their native and functional conformation.

A Systematic Review and Meta-analysis of Non-pharmacological Methods to Manipulate Experimentally Induced Secondary Hypersensitivity.

This systematic review and meta-analysis investigated the effects of non-pharmacological manipulations on experimentally induced secondary hypersensitivity in pain-free humans. We investigated the magnitude (change/difference in follow-up ratings from pre-manipulation ratings) of secondary hypersensitivity (primary outcome), and surface area of secondary hypersensitivity (secondary outcome), in 27 studies representing 847 participants. Risk of bias assessment concluded most studies (23 of 27) had an unclear or high risk of performance and detection bias. Further, 2 (of 27) studies had a high risk of measurement bias. Datasets were pooled by the method of manipulation and outcome. The magnitude of secondary hypersensitivity was decreased by diverting attention, anodal transcranial direct current stimulation, or emotional disclosure; increased by directing attention toward the induction site, nicotine deprivation, or negative suggestion; and unaffected by cathodal transcranial direct current stimulation or thermal change. Area of secondary hypersensitivity was decreased by anodal transcranial direct current stimulation, emotional disclosure, cognitive behavioral therapy, hyperbaric oxygen therapy, placebo analgesia, or spinal manipulation; increased by directing attention to the induction site, nicotine deprivation, or sleep disruption (in males only); and unaffected by cathodal transcranial direct current stimulation, thermal change, acupuncture, or electroacupuncture. Meta-analytical pooling was only appropriate for studies that used transcranial direct current stimulation or hyperbaric oxygen therapy, given the high clinical heterogeneity among the studies and unavailability of data. The evidence base for this question remains small. We discuss opportunities to improve methodological rigor including manipulation checks, structured blinding strategies, control conditions or time points, and public sharing of raw data. PERSPECTIVE: We described the effects of several non-pharmacological manipulations on experimentally induced secondary hypersensitivity in humans. By shedding light on the potential for non-pharmacological therapies to influence secondary hypersensitivity, it provides a foundation for the development and testing of targeted therapies for secondary hypersensitivity.

Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing.

Background and Objectives: Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from presurgery to 3 months postsurgery and explored associations among these pre-post changes. Research Design and Methods: This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N = 92) using in-person performance-based tests (6-min walk test [6MWT], stair-climb test [SCT]) prior to and 3 months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale, presurgery and 3- and 6-months postsurgery. Results: Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-month post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3 months was associated with better WOMAC function, but not related to WOMAC pain at 6 months. Discussion and Implications: Findings highlight the importance of situation-specific and in vivo assessments of pain and catastrophizing during physical activity.

Lysosome docking to WIPI1 rings and ER-connected phagophores occurs during DNAJB12- and GABARAP-dependent selective autophagy of misfolded P23H-rhodopsin.

We report on how the endoplasmic reticulum (ER)-associated-autophagy pathway (ERAA) delivers P23H-rhodopsin (P23H-R) to the lysosome. P23H-R accumulates in an ERAD-resistant conformation that is stabilized in a detergent-soluble state by DNAJB12 and Hsp70. P23H-R, DNAJB12, and FIP200 colocalize in discrete foci that punctuate the rim of omegasome rings coated by WIPI1. Loss of DNAJB12 function prevents the association of P23H-R containing ER tubules with omegasomes. P23H-R tubules thread through the wall of WIPI1 rings into their central cavity. Transfer of P23H-R from ER-connected phagophores to lysosomes requires GABARAP and is associated with the transient docking of lysosomes to WIPI1 rings. After departure from WIPI1 rings, new patches of P23H-R are seen in the membranes of lysosomes. The absence of GABARAP prevents transfer of P23H-R from phagophores to lysosomes without interfering with docking. These data identify lysosome docking to omegasomes as an important step in the DNAJB12- and GABARAP-dependent autophagic disposal of dominantly toxic P23H-R.