SARS-CoV-2 Receptor ACE2 Is an Interferon-Stimulated Gene in Human Airway Epithelial Cells and Is Detected in Specific Cell Subsets across Tissues.

There is pressing urgency to understand the pathogenesis of the severe acute respiratory syndrome coronavirus clade 2 (SARS-CoV-2), which causes the disease COVID-19. SARS-CoV-2 spike (S) protein binds angiotensin-converting enzyme 2 (ACE2), and in concert with host proteases, principally transmembrane serine protease 2 (TMPRSS2), promotes cellular entry. The cell subsets targeted by SARS-CoV-2 in host tissues and the factors that regulate ACE2 expression remain unknown. Here, we leverage human, non-human primate, and mouse single-cell RNA-sequencing (scRNA-seq) datasets across health and disease to uncover putative targets of SARS-CoV-2 among tissue-resident cell subsets. We identify ACE2 and TMPRSS2 co-expressing cells within lung type II pneumocytes, ileal absorptive enterocytes, and nasal goblet secretory cells. Strikingly, we discovered that ACE2 is a human interferon-stimulated gene (ISG) in vitro using airway epithelial cells and extend our findings to in vivo viral infections. Our data suggest that SARS-CoV-2 could exploit species-specific interferon-driven upregulation of ACE2, a tissue-protective mediator during lung injury, to enhance infection.

Systematic Discovery of Short Linear Motifs Decodes Calcineurin Phosphatase Signaling.

Short linear motifs (SLiMs) drive dynamic protein-protein interactions essential for signaling, but sequence degeneracy and low binding affinities make them difficult to identify. We harnessed unbiased systematic approaches for SLiM discovery to elucidate the regulatory network of calcineurin (CN)/PP2B, the Ca2+-activated phosphatase that recognizes LxVP and PxIxIT motifs. In vitro proteome-wide detection of CN-binding peptides, in vivo SLiM-dependent proximity labeling, and in silico modeling of motif determinants uncovered unanticipated CN interactors, including NOTCH1, which we establish as a CN substrate. Unexpectedly, CN shows SLiM-dependent proximity to centrosomal and nuclear pore complex (NPC) proteins-structures where Ca2+ signaling is largely uncharacterized. CN dephosphorylates human and yeast NPC proteins and promotes accumulation of a nuclear transport reporter, suggesting conserved NPC regulation by CN. The CN network assembled here provides a resource to investigate Ca2+ and CN signaling and demonstrates synergy between experimental and computational methods, establishing a blueprint for examining SLiM-based networks.

Divalent siRNAs are bioavailable in the lung and efficiently block SARS-CoV-2 infection.

The continuous evolution of SARS-CoV-2 variants complicates efforts to combat the ongoing pandemic, underscoring the need for a dynamic platform for the rapid development of pan-viral variant therapeutics. Oligonucleotide therapeutics are enhancing the treatment of numerous diseases with unprecedented potency, duration of effect, and safety. Through the systematic screening of hundreds of oligonucleotide sequences, we identified fully chemically stabilized siRNAs and ASOs that target regions of the SARS-CoV-2 genome conserved in all variants of concern, including delta and omicron. We successively evaluated candidates in cellular reporter assays, followed by viral inhibition in cell culture, with eventual testing of leads for in vivo antiviral activity in the lung. Previous attempts to deliver therapeutic oligonucleotides to the lung have met with only modest success. Here, we report the development of a platform for identifying and generating potent, chemically modified multimeric siRNAs bioavailable in the lung after local intranasal and intratracheal delivery. The optimized divalent siRNAs showed robust antiviral activity in human cells and mouse models of SARS-CoV-2 infection and represent a new paradigm for antiviral therapeutic development for current and future pandemics.

Tissue- and cell-type-specific molecular and functional signatures of 16p11.2 reciprocal genomic disorder across mouse brain and human neuronal models.

Chromosome 16p11.2 reciprocal genomic disorder, resulting from recurrent copy-number variants (CNVs), involves intellectual disability, autism spectrum disorder (ASD), and schizophrenia, but the responsible mechanisms are not known. To systemically dissect molecular effects, we performed transcriptome profiling of 350 libraries from six tissues (cortex, cerebellum, striatum, liver, brown fat, and white fat) in mouse models harboring CNVs of the syntenic 7qF3 region, as well as cellular, transcriptional, and single-cell analyses in 54 isogenic neural stem cell, induced neuron, and cerebral organoid models of CRISPR-engineered 16p11.2 CNVs. Transcriptome-wide differentially expressed genes were largely tissue-, cell-type-, and dosage-specific, although more effects were shared between deletion and duplication and across tissue than expected by chance. The broadest effects were observed in the cerebellum (2,163 differentially expressed genes), and the greatest enrichments were associated with synaptic pathways in mouse cerebellum and human induced neurons. Pathway and co-expression analyses identified energy and RNA metabolism as shared processes and enrichment for ASD-associated, loss-of-function constraint, and fragile X messenger ribonucleoprotein target gene sets. Intriguingly, reciprocal 16p11.2 dosage changes resulted in consistent decrements in neurite and electrophysiological features, and single-cell profiling of organoids showed reciprocal alterations to the proportions of excitatory and inhibitory GABAergic neurons. Changes both in neuronal ratios and in gene expression in our organoid analyses point most directly to calretinin GABAergic inhibitory neurons and the excitatory/inhibitory balance as targets of disruption that might contribute to changes in neurodevelopmental and cognitive function in 16p11.2 carriers. Collectively, our data indicate the genomic disorder involves disruption of multiple contributing biological processes and that this disruption has relative impacts that are context specific.

Calcineurin associates with centrosomes and regulates cilia length maintenance.

Calcineurin, or protein phosphatase 2B (PP2B), the Ca2+ and calmodulin-activated phosphatase and target of immunosuppressants, has many substrates and functions that remain uncharacterized. By combining rapid proximity-dependent labeling with cell cycle synchronization, we mapped the spatial distribution of calcineurin in different cell cycle stages. While calcineurin-proximal proteins did not vary significantly between interphase and mitosis, calcineurin consistently associated with multiple centrosomal and/or ciliary proteins. These include POC5, which binds centrins in a Ca2+-dependent manner and is a component of the luminal scaffold that stabilizes centrioles. We show that POC5 contains a calcineurin substrate motif (PxIxIT type) that mediates calcineurin binding in vivo and in vitro. Using indirect immunofluorescence and ultrastructure expansion microscopy, we demonstrate that calcineurin colocalizes with POC5 at the centriole, and further show that calcineurin inhibitors alter POC5 distribution within the centriole lumen. Our discovery that calcineurin directly associates with centriolar proteins highlights a role for Ca2+ and calcineurin signaling at these organelles. Calcineurin inhibition promotes elongation of primary cilia without affecting ciliogenesis. Thus, Ca2+ signaling within cilia includes previously unknown functions for calcineurin in maintenance of cilia length, a process that is frequently disrupted in ciliopathies.

Racialized inequities in live birth after cancer: A population-based study of 63,000 female adolescents and young adults with cancer.

INTRODUCTION: Fertility after cancer is a top concern for adolescents and young adults with cancer (AYAs) (15-39 years old at diagnosis). The authors characterized live births after cancer by race and ethnicity ("race/ethnicity") in a population-based sample of female AYAs. METHODS: This study used Texas Cancer Registry data linked to birth certificates (1995-2016) to estimate cumulative incidence of live birth, based on first live birth after cancer, and compared differences by race/ethnicity. Proportional subdistribution hazards models were used to estimate associations between race/ethnicity and live birth, adjusted for diagnosis age, cancer type, stage, year, and prior live birth, overall and for each cancer type. RESULTS: Among 65,804 AYAs, 10-year cumulative incidence of live birth was lower among non-Hispanic Black AYAs than other racial/ethnic groups: 10.2% (95% confidence interval [CI], 9.4-10.9) compared to 15.9% (95% CI, 14.1-17.9) among Asian or Pacific Islander, 14.7% (95% CI, 14.2-15.3) among Hispanic, and 15.2% (95% CI, 14.8-15.6) among non-Hispanic White AYAs (p < .01). In the adjusted overall model, Black AYAs were less likely to have a live birth after cancer than all other groups. In adjusted models for each cancer type, live birth was significantly less likely for Black AYAs with gynecologic cancers or lymphomas (compared to White AYAs) or thyroid cancers (compared to Hispanic AYAs). CONCLUSION: Black AYAs are less likely than AYAs of other races/ethnicities to have a live birth after cancer, in contrast to patterns of live birth in the general population. Research and action to promote childbearing equity after cancer are imperative.

Multi-center retrospective review of vitiligo-like lesions in breast cancer patients treated with cyclin-dependent kinase 4 and 6 inhibitors.

PURPOSE: Cutaneous adverse effects from cyclin-dependent 4 and 6 kinase inhibitors (CDK4/6i) used in metastatic breast cancer are prevalent and well described. Vitiligo-like lesions have been reported and are rare. They can negatively impact patients' quality of life and may be associated with survival benefits. We describe the clinical characteristics of vitiligo-like lesions in an international cohort of patients treated with CDK4/6i to help improve recognition and management. METHODS: Retrospective review of patients diagnosed with vitiligo-like lesions from CDK4/6i from five academic institutions in the USA and Europe was performed. Ten patients were included in the study. RESULTS: Median age of our patients was 55 (range 37-86). Median progression-free survival was 24 months in 5 patients. The median time to rash was 10 months. Sun-exposed areas such as the arms and face were the most affected areas. Multiple skin-directed therapies such as topicals, laser, and phototherapy were trialed with minor success. Mild repigmentation was seen in one patient treated with ruxolitinib cream. CDK4/6 treatment was discontinued due to the vitiligo-like lesions in one patient. CONCLUSION: Clinical characteristics are similar to previously reported findings in case reports and series. We add topical ruxolitinib as a potential treatment option for these patients and include data regarding progression-free survival that should continue to be collected. No definitive conclusions can be made regarding survival benefits from our cohort. Clinicians should refer these patients to dermatologists to aid with management.

Local heterogeneity of normal lung parenchyma and small airways disease are associated with COPD severity and progression.

BACKGROUND: Small airways disease (SAD) is a major cause of airflow obstruction in COPD patients and has been identified as a precursor to emphysema. Although the amount of SAD in the lungs can be quantified using our Parametric Response Mapping (PRM) approach, the full breadth of this readout as a measure of emphysema and COPD progression has yet to be explored. We evaluated topological features of PRM-derived normal parenchyma and SAD as surrogates of emphysema and predictors of spirometric decline. METHODS: PRM metrics of normal lung (PRMNorm) and functional SAD (PRMfSAD) were generated from CT scans collected as part of the COPDGene study (n = 8956). Volume density (V) and Euler-Poincaré Characteristic (χ) image maps, measures of the extent and coalescence of pocket formations (i.e., topologies), respectively, were determined for both PRMNorm and PRMfSAD. Association with COPD severity, emphysema, and spirometric measures were assessed via multivariable regression models. Readouts were evaluated as inputs for predicting FEV1 decline using a machine learning model. RESULTS: Multivariable cross-sectional analysis of COPD subjects showed that V and χ measures for PRMfSAD and PRMNorm were independently associated with the amount of emphysema. Readouts χfSAD (ß of 0.106, p < 0.001) and VfSAD (ß of 0.065, p = 0.004) were also independently associated with FEV1% predicted. The machine learning model using PRM topologies as inputs predicted FEV1 decline over five years with an AUC of 0.69. CONCLUSIONS: We demonstrated that V and χ of fSAD and Norm have independent value when associated with lung function and emphysema. In addition, we demonstrated that these readouts are predictive of spirometric decline when used as inputs in a ML model. Our topological PRM approach using PRMfSAD and PRMNorm may show promise as an early indicator of emphysema onset and COPD progression.

Bipolar disorder-iPSC derived neural progenitor cells exhibit dysregulation of store-operated Ca2+ entry and accelerated differentiation.

While most of the efforts to uncover mechanisms contributing to bipolar disorder (BD) focused on phenotypes at the mature neuron stage, little research has considered events that may occur during earlier timepoints of neurodevelopment. Further, although aberrant calcium (Ca2+) signaling has been implicated in the etiology of this condition, the possible contribution of store-operated Ca2+ entry (SOCE) is not well understood. Here, we report Ca2+ and developmental dysregulations related to SOCE in BD patient induced pluripotent stem cell (iPSC)-derived neural progenitor cells (BD-NPCs) and cortical-like glutamatergic neurons. First, using a Ca2+ re-addition assay we found that BD-NPCs and neurons had attenuated SOCE. Intrigued by this finding, we then performed RNA-sequencing and uncovered a unique transcriptome profile in BD-NPCs suggesting accelerated neurodifferentiation. Consistent with these results, we measured a slower rate of proliferation, increased neurite outgrowth, and decreased size in neurosphere formations with BD-NPCs. Also, we observed decreased subventricular areas in developing BD cerebral organoids. Finally, BD NPCs demonstrated high expression of the let-7 family while BD neurons had increased miR-34a, both being microRNAs previously implicated in neurodevelopmental deviations and BD etiology. In summary, we present evidence supporting an accelerated transition towards the neuronal stage in BD-NPCs that may be indicative of early pathophysiological features of the disorder.

An analysis of keloid patient questions on Reddit.

Reddit is one of the world's leading social media platforms, fostering active community discussions on a variety of topics including keloids. The prevalence and reach of conversations on Reddit underscore the need to investigate and understand patient perspectives and gaps in knowledge. Herein, we present an in-depth analysis of questions and concerns of Reddit users on keloids, offering valuable insights into patient experiences, knowledge gaps and treatment preferences. The study presents a distinct approach by harnessing the power of social media data to understand patient perspectives, which may not be readily apparent in clinical settings. All posts on the 'Hot' page of the subreddit r/Keloids were analyzed. Questions were categorized and subcategorized to reveal common themes. A total of 644 questions from 513 posts between 26 March 2017 and 28 August 2023 were identified and analyzed. Reddit users most frequently asked questions regarding keloid management (57.5%). Other common categories included uncertainty regarding diagnosis or symptoms (15.1%), living with keloids (7.5%) and causes or triggers (6.2%). This analysis highlights critical areas of patient knowledge gaps and potential misconceptions regarding keloids. For dermatologists, understanding these patient questions is crucial. Such insights allow for patient-centric education and treatments, ensuring more effective and comprehensive care.

Erythema dyschromicum perstans-like eruptions induced by epidermal growth factor receptor inhibitors in patients with lung cancer.

INTRODUCTION: Cutaneous adverse reactions to epidermal growth factor receptor inhibitors (EGFRi) are some of the most common side effects that patients experience. However, cutaneous adverse reactions that cause dyspigmentation in patients have been rarely reported. Erythema dyschromicum perstans (EDP) is a rare pigmentary condition that causes ashy-grey hyperpigmented macules and patches, with a few cases reported from EGFRi in the literature. The disfiguration caused by this condition may negatively impact patients' quality of life. Our study aimed to describe the clinical characteristics of EDP induced by EGFRi to better recognize and manage the condition. METHODS: We conducted a multicenter retrospective review at three academic institutions to identify patients with EDP induced by EGFRi from 2017 to 2023 and included sixteen patients in our study. RESULTS: The median age of patients was 66 years old, with 63% female and 37% male (Table 1). The majority of our patients were Asian (88%). All patients had non-small cell lung cancer and most patients received osimertinib. Median time to EDP was 6 months. The most common areas of distribution were the head/neck region, lower extremities, and upper extremities. Various topical ointments were trialed; however, approximately less than half had improvement in their disease and most patients had persistent EDP with no resolution. All patients desired treatment except one with EDP on the tongue, and there was no cancer treatment discontinuation or interruption due to EDP. Table 1 Patient demographics and clinical characteristics of 16 patients with EDP induced by EGFRi Case no Demographics: age, race, and sex Fitzpatrick skin type Cancer type EGFR therapy Concomitant photosensitive drug(s) Time to EDP (months) Clinical features Distribution Symptoms Treatments and clinical course EDP status from most recent follow up 1 47 y/o Asian male III Stage IV NSCLC Erlotinib None Unknown Brown-blue-gray hyperpigmented patches Bilateral shins Left thigh Xerosis Pruritus Triamcinolone 0.1% ointment for 4 months, improvement of blue discoloration Tacrolimus 0.1% BID for 9 months, improvement but no resolution Ongoing 2 62 y/o Asian female IV Stage IV NSCLC Osimertinib None 4 Gray-brown hyperpigmented patches Bilateral arms Back Forehead Neck Right shin None Tacrolimus 0.1% ointment for 1 year with minor improvement Ongoing 3 69 y/o Asian female IV Stage IV NSCLC Osimertinib None 4 Gray-brown macules and patches Chest Face Forehead Bilateral legs None Tacrolimus 0.1% ointment for 10 months, no improvement Ongoing 4 79 y/o White male II Stage IV NSCLC Osimertinib None 15 Mottled grey-blue hyperpigmented patches and plaques with mild scaling Bilateral arms Back Forehead Neck None Photoprotection, no improvement Ongoing 5 69 y/o Asian female III Stage IV NSCLC Osimertinib Ibuprofen 4 Blue-grey hyperpigmented macules and patches Abdomen Bilateral arms None Tacrolimus 0.1% ointment for 7 months, no improvement Ongoing 6 65 y/o Asian male III Stage IV NSCLC Osimertinib None 20 Hyperpigmented blue gray macules and patches Helix Bilateral shins None Photoprotection, no improvement Ongoing 7 66 y/o Asian female IV Stage IV NSCLC Erlotinib TMP-SMX 6 Ashy grey-brown thin plaques Back Forehead None 2.5% hydrocortisone ointment for 8 months, resolved Resolved 8 82 y/o Asian male III Stage III NSCLC Erlotinib Simvastatin 20 Ash-grey hyperpigmented patches Dorsal feet Forehead Scalp None Photoprotection Ongoing 9 57 y/o Asian female III Stage II NSCLC Erlotinib None 1 Bue-grey discoloration Tongue None No intervention Ongoing 10 51 y/o Asian female III Stage IV NSCLC Osimertinib None 9 Blue-grey hyperpigmented macules and patches Bilateral arms Axillae Groin Neck Trunk None 2.5% hydrocortisone ointment, triamcinolone 0.1% ointment, photoprotection with mild improvement Ongoing 11 67 y/o Asian male III Stage IV NSCLC Osimertinib None 7 Gray-blue macules and patches with mild background erythema and scaling Bilateral arms Ears Face Bilateral shins None Triamcinolone 0.1% ointment, protection for 6 months with mild improvement Ongoing 12 75 y/o Asian female IV Stage III NSCLC Osimertinib TMP-SMX 3 Gray-blue hyperpigmented patches Bilateral arms Abdomen Back Face Bilateral shins Pruritus Triamcinolone 0.1% and betamethasone 0.01% with relief of pruritus, lesions unchanged Triluma cream 6 months, mild improvement Ongoing 13 42 y/o Asian male IV Stage IV NSCLC Afatinib TMP-SMX 24 Grey-brown hyperpigmented patches Back Face None Hydroquinone 4% cream for 2 years with mild improvement Ongoing 14 74 y/o White female III Stage II NSCLC Osimertinib Atorvastatin 4 Grey-brown hyperpigmented patches Bilateral legs Trunk None Photoprotection Ongoing 15 64 y/o Asian female IV Stage IV NSCLC Osimertinib None 3 Gray-brown hyperpigmentation Abdomen Bilateral arms Back Bilateral legs Pruritus Triamcinolone 0.1% cream; No change, minimal concern to patient Ongoing 16 52 y/o Asian female IV Stage IV NSCLC Osimertinib None 42 Gray hyperpigmented patches with digitate shape Abdomen Bilateral flanks None Triamcinolone 0.1% cream Ongoing NSCLC, non-small cell lung cancer, TMP-SMX, Trimethoprim/Sulfamethoxazole CONCLUSIONS: We highlight the largest case series describing EDP from EGFR inhibitors, which mostly affected Asian patients with lung malignancy and on EGFR tyrosine kinase inhibitors. Clinicians should be able to recognize this condition in their patients and assess how it is affecting their quality of life, and refer to dermatology to help with management.

An Analysis of Dermatology-Related Red-Light Therapy Patient Questions on Reddit.

BACKGROUND: Reddit is one of the world's most popular social media platforms and is increasingly used as a health information resource for patients on topics such as red-light (RL) therapy. OBJECTIVE: In this article, the authors present an analysis of prevalent patient questions and concerns regarding RL therapy. METHODS: All posts on the "Hot" page of the r/redlighttherapy subreddit were analyzed and categorized. RESULTS: A total of 930 questions from 664 posts were analyzed. The most commonly asked question category was related to product recommendations or feedback (29.7%), followed by usage instructions (15.3%), safety and side effects (12.6%), and indications and efficacy (12.3%). CONCLUSION: Understanding patient concerns and questions about RL, as expressed on online platforms like Reddit, can help clinicians improve patient satisfaction, education, and clinical outcomes. The study offers an innovative approach by using social media to uncover valuable patient insights that might not be easily observable within clinical settings.

Inverse Eruptive Syringoma in a Skin of Color Patient.

Syringomas are benign neoplasms derived from eccrine sweat glands. Eruptive syringomas are a subtype of syringomas and are typically located on the chest, neck, and abdomen during puberty or childhood. Herein, we present a 20-year-old African American female with an atypical case of eruptive syringomas, characterized by an unusual distribution on her chest, abdomen, and anterior and posterior bilateral extremities. This case underscores the importance of recognizing diverse presentations of skin conditions in patients with skin of color and adds to the limited reports of eruptive syringoma in these populations. We present and emphasize this atypical manifestation of eruptive syringomas in an individual with darker skin to promote awareness and improve diagnosis and patient outcomes.J Drugs Dermatol. 2024;23(7):564-566. doi:10.36849/JDD.8103.

Investigating the Relationship Between Acne and Vasodilatory Medications in a Hospital-Wide Adult Population.

Acne vulgaris is a common chronic dermatological condition characterized by obstruction and inflammation of pilosebaceous units. Recent research on a different dermatologic condition has demonstrated that the use of vasodilatory medications is associated with a decreased relative risk of rosacea. This finding is significant due to the overlapping inflammatory pathways involved in rosacea and acne. Herein, a retrospective cohort study was designed to determine the correlation between vasodilator usage and the risk of developing acne within 5 years, contrasting it with thiazide diuretics, chosen as a control due to its non-vasodilatory antihypertensive mechanism and availability of data. Angiotensin-converting enzyme (ACE) inhibitors (RR, 0.775; 95% CI, 0.727-0.826; P<0.05), angiotensin receptor blockers (ARBs) (RR, 0.739; 95% CI, 0.685-0.797; P<0.05), beta-blockers (BB) (RR, 0.829; 95% CI, 0.777-0.885; P<0.05), and calcium channel blockers (CCB) usage (RR, 0.821, 95% CI, 0.773-0.873; P<0.05) were associated with a significantly lower risk of developing acne within 5 years of initiating therapy compared to thiazide diuretics. It is unclear if thiazide diuretics are more likely to cause acne within the adult population or if vasodilators are protective against the development of acne. Finding mechanisms and therapeutics that lower the risk of developing acne is of significant public health interest, and this study provides a step toward this endeavor. Further research is required to uncover the underlying mechanisms for this reduction in the development of acne.  J Drugs Dermatol. 2024;23(6):446-449.     doi:10.36849/JDD.8362.

Sunscreen Practices and Preferences of Skin of Color Patients.

Sunscreen is an essential way to protect against photodamage from ultraviolet (UV) radiation. Despite the recognized benefits of sunscreen in preventing skin damage from UV light, its use varies across different patient groups. This cross-sectional, questionnaire-based study aims to uncover the sunscreen usage patterns, preferences, and barriers among non-Hispanic White (NHW) and skin of color (SOC) individuals. Our findings demonstrate that NHW individuals are more likely to wear sunscreen daily (31% NHW vs 25% SOC) and reapply sunscreen at least once a day (76% NHW vs 45% SOC) compared with SOC individuals. SOC individuals demonstrate a willingness to use sunscreen, but they face barriers such as cost (2% NHW vs 16% SOC), lack of knowledge in finding suitable products (22% NHW vs 41% SOC), and concerns about white cast (7% NHW vs 25% SOC). SOC individuals are less likely to know the difference between mineral and chemical sunscreen (49% NHW vs 29% SOC), less likely to learn about sunscreen from dermatologists (36% NHW vs 22% SOC), and more likely to prefer sunscreen from brands owned by people of color (13% NHW vs 47% SOC).  In addition to analyzing the broader categories of NHW and SOC, subgroup analysis was conducted on specific subgroups, including Black, Asian, and Hispanic groups. Herein, we highlight differences in motivations, sunscreen preferences, sources of information, and knowledge levels about sun protection between NHW and SOC individuals. By uncovering the unique needs and challenges faced by SOC individuals, we aim to improve culturally competent patient education and promote effective sun protection practices across diverse populations. J Drugs Dermatol. 2024;23(6):456-462.     doi:10.36849/JDD.8268.

PACAP is a pathogen-inducible resident antimicrobial neuropeptide affording rapid and contextual molecular host defense of the brain.

Defense of the central nervous system (CNS) against infection must be accomplished without generation of potentially injurious immune cell-mediated or off-target inflammation which could impair key functions. As the CNS is an immune-privileged compartment, inducible innate defense mechanisms endogenous to the CNS likely play an essential role in this regard. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide known to regulate neurodevelopment, emotion, and certain stress responses. While PACAP is known to interact with the immune system, its significance in direct defense of brain or other tissues is not established. Here, we show that our machine-learning classifier can screen for immune activity in neuropeptides, and correctly identified PACAP as an antimicrobial neuropeptide in agreement with previous experimental work. Furthermore, synchrotron X-ray scattering, antimicrobial assays, and mechanistic fingerprinting provided precise insights into how PACAP exerts antimicrobial activities vs. pathogens via multiple and synergistic mechanisms, including dysregulation of membrane integrity and energetics and activation of cell death pathways. Importantly, resident PACAP is selectively induced up to 50-fold in the brain in mouse models of Staphylococcus aureus or Candida albicans infection in vivo, without inducing immune cell infiltration. We show differential PACAP induction even in various tissues outside the CNS, and how these observed patterns of induction are consistent with the antimicrobial efficacy of PACAP measured in conditions simulating specific physiologic contexts of those tissues. Phylogenetic analysis of PACAP revealed close conservation of predicted antimicrobial properties spanning primitive invertebrates to modern mammals. Together, these findings substantiate our hypothesis that PACAP is an ancient neuro-endocrine-immune effector that defends the CNS against infection while minimizing potentially injurious neuroinflammation.

Can ChatGPT generate practice question explanations for medical students, a new faculty teaching tool?

INTRODUCTION: Multiple-choice questions (MCQs) are frequently used for formative assessment in medical school but often lack sufficient answer explanations given time-restraints of faculty. Chat Generated Pre-trained Transformer (ChatGPT) has emerged as a potential student learning aid and faculty teaching tool. This study aims to evaluate ChatGPT's performance in answering and providing explanations for MCQs. METHOD: Ninety-four faculty-generated MCQs were collected from the pre-clerkship curriculum at a US medical school. ChatGPT's accuracy in answering MCQ's were tracked on first attempt without an answer prompt (Pass 1) and after being given a prompt for the correct answer (Pass 2). Explanations provided by ChatGPT were compared with faculty-generated explanations, and a 3-point evaluation scale was used to assess accuracy and thoroughness compared to faculty-generated answers. RESULTS: On first attempt, ChatGPT demonstrated a 75% accuracy in correctly answering faculty-generated MCQs. Among correctly answered questions, 66.4% of ChatGPT's explanations matched faculty explanations, and 89.1% captured some key aspects without providing inaccurate information. The amount of inaccurately generated explanations increases significantly if the questions was not answered correctly on the first pass (2.7% if correct on first pass vs. 34.6% if incorrect on first pass, p < 0.001). CONCLUSION: ChatGPT shows promise in assisting faculty and students with explanations for practice MCQ's but should be used with caution. Faculty should review explanations and supplement to ensure coverage of learning objectives. Students can benefit from ChatGPT for immediate feedback through explanations if ChatGPT answers the question correctly on the first try. If the question is answered incorrectly students should remain cautious of the explanation and seek clarification from instructors.

Monitoring for Breast Cancer Recurrence Following Goldilocks Breast Reconstruction.

BACKGROUND: The Goldilocks breast reconstruction utilizes redundant mastectomy skin flaps to fashion a breast mound; however, there is concern that imbrication of these skin flaps may predispose to fat necrosis and make detection of local breast cancer recurrence more difficult. Goldilocks patients follow a traditional postmastectomy screening pathway that includes clinical examination for locoregional recurrence, but it is unclear if this is sufficient. We evaluate our Goldilocks reconstruction case series to determine rates of diagnostic imaging, biopsy, and locoregional and distant recurrence. METHODS: Sixty-six patients (94 breasts) undergoing Goldilocks breast reconstruction were retrospectively reviewed. Any diagnostic postoperative imaging/biopsies performed and that confirmed local or distant breast cancer recurrence were noted. RESULTS: Average time of follow-up was 45 months. Most patients in this cohort had stage 0 (27.3%) or stage I (40.9%) breast cancer. There were a total of 11 (11.7%) concerning breast masses identified. Seven (7.4%) masses were biopsied, of which 5 were benign and 2 were invasive cancer recurrence. Four masses (4.3%) underwent diagnostic imaging only, all with benign findings. Five patients in this series were found to have either distant disease or a second primary cancer in the nonoperative contralateral breast. CONCLUSIONS: Rates of local recurrence following Goldilocks are not higher than expected after other types of postmastectomy reconstruction. Clinical monitoring successfully detected local recurrence in all affected patients in this series. More definite guidelines around the routine screening of Goldilocks mastectomy patients may aid in early detection of local breast cancer recurrence.

Evaluation of spin in reviews of biodegradable balloon spacers for massive irreparable rotator cuff tears.

HYPOTHESIS: Clinical studies are often at risk of spin, a form of bias where beneficial claims are overstated while negative findings are minimized or dismissed. Spin is often more problematic in abstracts given their brevity and can result in the misrepresentation of a study's actual findings. The goal of this study is to aggregate primary and secondary studies reporting the clinical outcomes of the use of subacromial balloon spacers in the treatment of massive irreparable rotator cuff tears to identify the incidence of spin and find any significant association with study design parameters. MATERIALS AND METHODS: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Independent searches were completed on 2 databases (PubMed and Embase) for primary studies, systematic and current concepts reviews, and meta-analyses and the results were compiled. Two authors independently screened the studies using a predetermined inclusion criteria and aggregated data including titles, publication journals and years, authors, study design, etc. Each study was independently assessed for the presence of 15 different types of spin. Statistical analysis was conducted to identify associations between study characteristics and spin. RESULTS: Twenty-nine studies met the inclusion criteria for our analysis, of which 10 were reviews or meta-analyses and 19 were primary studies. Spin was identified in every study except for 2 (27/29, 93.1%). Type 3 spin, "Selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention" and type 9 spin, "Conclusion claims the beneficial effect of the experimental treatment despite reporting bias" were most frequently noted in our study, both observed in 12/29 studies (41.4%). Date of publication, and adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses or "The International Prospective Register of Systematic Reviews" were study characteristics associated with a higher rate of certain types of spin. There was a statistically significant association between disclosure of external study funding source and the presence of spin type 4, but none of the other forms of spin. CONCLUSION: Spin is highly prevalent in the abstracts of primary studies, systematic reviews, and meta-analyses discussing the use of subacromial balloon spacer technology in the treatment of massive irreparable rotator cuff tears. Our findings revealed that spin in the abstract tended to favor the balloon spacer intervention. Further efforts are required in the future to mitigate spin within the abstracts of published manuscripts.

The impact of high-fat feeding and parkin overexpression on skeletal muscle mass, mitochondrial respiration, and H2O2 emission.

Obesity is a major risk factor for developing various health problems, including insulin resistance and type 2 diabetes. Although controversial, accumulation of mitochondrial dysfunction, and notably an increase in mitochondrial reactive oxygen species (ROS) production, was proposed as a key contributor leading to obesity-induced insulin resistance. Here, our goal was to investigate whether Parkin overexpression, a key regulator of the removal of dysfunctional mitochondria through mitophagy, could confer protection against obesity-induced mitochondrial dysfunction. To this end, intramuscular injections of adeno-associated viruses (AAVs) were performed to overexpress Parkin in limb muscle of 6-mo-old mice fed a control diet (CD) or a high-fat diet (HFD) for 12 wk. An AAV-expressing the green fluorescent protein (GFP) was used as control. HFD increased fat mass, altered glycemia, and resulted in insulin resistance. Parkin overexpression resulted in an increase in muscle mass in both CD and HFD mice. In CD mice, Parkin overexpression increased maximal mitochondrial respiration and lowered H2O2 emission. HFD increased mitochondrial respiration and, surprisingly, also lowered H2O2 emission. Parkin overexpression did not significantly impact mitochondrial function in HFD mice. Taken altogether, our results indicate that Parkin overexpression positively impacts muscle and mitochondrial health under basal conditions and challenges the notion that intrinsic mitochondrial dysfunction is involved in the development of insulin resistance caused by high-fat feeding.