Elevated Expression of MiR-17 in Microglia of Alzheimer's Disease Patients Abrogates Autophagy-Mediated Amyloid-ß Degradation.

Autophagy is a proposed route of amyloid-ß (Aß) clearance by microglia that is halted in Alzheimer's Disease (AD), though mechanisms underlying this dysfunction remain elusive. Here, primary microglia from adult AD (5xFAD) mice were utilized to demonstrate that 5xFAD microglia fail to degrade Aß and express low levels of autophagy cargo receptor NBR1. In 5xFAD mouse brains, we show for the first time that AD microglia express elevated levels of microRNA cluster Mirc1/Mir17-92a, which is known to downregulate autophagy proteins. By in situ hybridization in post-mortem AD human tissue sections, we observed that the Mirc1/Mir17-92a cluster member miR-17 is also elevated in human AD microglia, specifically in the vicinity of Aß deposits, compared to non-disease controls. We show that NBR1 expression is negatively correlated with expression of miR-17 in human AD microglia via immunohistopathologic staining in human AD brain tissue sections. We demonstrate in healthy microglia that autophagy cargo receptor NBR1 is required for Aß degradation. Inhibiting elevated miR-17 in 5xFAD mouse microglia improves Aß degradation, autophagy, and NBR1 puncta formation in vitro and improves NBR1 expression in vivo. These findings offer a mechanism behind dysfunctional autophagy in AD microglia which may be useful for therapeutic interventions aiming to improve autophagy function in AD.

Endovascular repair and open repair surgery of thoraco-abdominal aortic aneurysms cause drastically different types of spinal cord injury.

Both endovascular repair (EVR) and open repair (OR) surgery of thoraco-abdominal aortic aneurysms cause spinal cord (SC) injury that can lead to paraparesis or paraplegia. It has been assumed that mechanisms responsible for SC damage after EVR are similar to those after OR. This pilot study compared the pathophysiology of SC injury after EVR versus OR using a newly developed EVR dog model. An increasing number of stents similar to those used in patients were inserted in the aorta of three dogs to ensure thoracic or thoracic plus lumbar coverage. The aorta of OR dogs was cross-clamped for 45 min. Behavior assessment demonstrated unique patterns of proprioceptive ataxia and evolving paraparesis in EVR versus irreversible paraplegia in OR. MRI showed posterior signal in lumbar SC after EVR versus central cord edema after OR. Histopathology showed white matter edema in L3-L5 localized to the dorsal column medial lemniscus area associated with loss of myelin basic protein but not neurons after EVR, versus massive neuronal loss in the gray matter in L3-L5 after OR. Metabolome analysis demonstrates a distinctive chemical fingerprint of cellular processes in both interventions. Our results call for the development of new therapeutics tailored to these distinct pathophysiologic findings.

Cytologic and molecular correlates of SARS-CoV-2 infection of the nasopharynx.

Infection by SARS-CoV-2 commonly begins in the nasopharynx, and the cytologic and molecular correlates are not characterized. Fifty-eight cytologic preps (20 oral and 38 from the nasopharynx) were obtained from ten patients and analyzed in a blinded fashion for SARS-CoV-2 spike and envelope protein by immunohistochemistry and viral RNA by in situ hybridization. qRTPCR identified three positive cases and seven controls; the three cases reported mild symptoms that resolved in 2-3 days. Blinded analyses confirmed the presence of the SARS-CoV-2 spike and envelope proteins and viral RNA in the three cases and viral absence in the seven controls. A signal for the positive cases was evident in each nasopharyngeal and none of the oral samples. Viral RNA/proteins localized exclusively to glandular cells and was present in high copy number. Blinded analysis of the cytology documented that the glandular cells infected by SARS-CoV-2 showed marked degeneration with ciliocytophthoria; viral inclusions were not evident. Co-expression analysis showed viral infected cells had increased apoptosis, marked by strong expression of activated caspase 3. Weekly serial testing of two of the cases showed persistence of productive viral infection for up to 2 weeks after symptom onset. It is concluded that the target cell of SARS-CoV-2 in the head and neck region is the glandular cell of the nasal passages, that viral infection is lytic and associated with high copy number that facilitates viral spread. The method outlines a simple, rapid test for productive SARS-CoV-2 based on immunohistochemistry or in situ hybridization of the glandular cells from the nasopharynx.

microRNA 155 up regulation in the CNS is strongly correlated to Down's syndrome dementia.

This study examined the molecular correlates of Down's dementia. qRTPCR for chromosome 21 microRNAs was correlated with in situ hybridization, immunohistochemistry for microRNA targets, mRNAs located on chromosome 21, and neurofibrillary tangles in human and the Ts65 dn mouse Down's model. qRTPCR for the microRNAs on the triplicated chromosome showed miR-155 dominance in brain tissues (14.3 fold increase, human and 24.2 fold increase, mouse model) that co-expressed with hyperphosphorylated tau protein. miR-155 was not elevated in Alzheimer's disease or neonates with Downs' syndrome. Chromosome 21 genes APP/BA-42, DYRK1a and BACH1 were not correlated to pathologic changes in Down's dementia. Validated CNS targets of miR-155 that were present in controls and Alzheimer's disease but lacking in Down's dementia brains included BACH1, CoREST1, bcl6, BIM, bcl10, cyclin D, and SAPK4. It is concluded that Down's dementia strongly correlated with overexpression of chromosome 21 microRNA 155 with concomitant reduction of multiple CNS-functional targets. This study highlights the need for anatomic pathologists to determine the specific and diverse pathways cells may take to form neurofibrillary tangles in the different dementias.

Increased expression of importin-ß, exportin-5 and nuclear transportable proteins in Alzheimer's disease aids anatomic pathologists in its diagnosis.

Understanding the metabolic profile of neurons with the hyperphosphorylated tau protein characteristic of Alzheimer's disease is essential to unraveling new potential therapies and diagnostics for the surgical pathologist. We stratified 75 brain tissues from Alzheimer's disease into hyperphosphorylated tau positive or negative and did co-expression analyses and qRTPCR for importin-ß and exportin-5 plus several bcl2 family members and compared the data to controls, Down's dementia and Parkinson's disease. There was a significant increase in the expression of importin-ß and exportin-5 in Alzheimer's disease relative to the three other categories (each p value<0.0001) where each protein co-localized with hyperphosphorylated tau. Both apoptotic and anti-apoptotic proteins were each significantly increased in Alzheimer's disease relative to the three other groups. Neurons with hyperphosphorylated tau in Alzheimer's disease have the profile of metabolically active cells including increased exportin-5 and importin-ß mRNA and proteins which indicates that immunohistochemistry testing of these proteins may aid the surgical pathologist in making a definitive diagnosis.

High-Dose Monthly Maternal Cholecalciferol Supplementation during Breastfeeding Affects Maternal and Infant Vitamin D Status at 5 Months Postpartum: A Randomized Controlled Trial.

BACKGROUND: Many countries recommend daily infant vitamin D supplementation during breastfeeding, but compliance is often poor. A monthly, high-dose maternal regimen may offer an alternative strategy, but its efficacy is unknown. OBJECTIVE: The objective of the study was to determine the effect of 2 different monthly maternal doses of cholecalciferol on maternal and infant 25-hydroxyvitamin D [25(OH)D] status during the first 5 mo of breastfeeding. METHODS: With the use of a randomized, double-blind, placebo-controlled design, women who were planning to exclusively breastfeed for 6 mo (n = 90; mean age: 32.1 y; 71% exclusively breastfeeding at week 20) were randomly assigned to receive either cholecalciferol (50,000 or 100,000 IU) or a placebo monthly from week 4 to week 20 postpartum. The treatment effects relative to placebo were estimated as changes in maternal and infant serum 25(OH)D from baseline to week 20 postpartum by using a linear fixed-effects regression model. Additional secondary analyses, adjusted for potential confounders such as season of birth, vitamin D-fortified formula intake, and infant or maternal skin color, were also conducted. RESULTS: After 16 wk of supplementation, changes in maternal serum 25(OH)D were significantly higher in the 50,000-IU/mo (12.8 nmol/L; 95% CI: 0.4, 25.2 nmol/L) and 100,000-IU/mo (21.5 nmol/L; 95% CI: 9.2, 33.8 nmol/L) groups than in the placebo group (P = 0.43 and P < 0.001, respectively). For infants, the unadjusted mean changes in serum 25(OH)D were 4.5 nmol/L (95% CI: -16.2, 25.0 nmol/L) for the 50,000-IU/mo group and 15.8 nmol/L (95% CI: -4.7, 36.4 nmol/L) for the 100,000-IU/mo group, but the changes did not differ from the placebo reference group. However, after adjustment for season of birth, vitamin D-fortified formula intake, and infant skin color, the mean change effect size for the 100,000-IU/mo group was 19.1 nmol/L (95% CI: 2.5, 35.6 nmol/L; P = 0.025) higher than that in the placebo group. CONCLUSIONS: Maternal cholecalciferol supplementation at a dose of 100,000 IU/mo during the first 5 mo of breastfeeding potentially benefits infant vitamin D status. Further studies are required to determine optimum dose and dosing frequency. This trial was registered at www.anzctr.org.au as ACTRN12611000108910.

Epigenetic regulation of miR-17~92 contributes to the pathogenesis of pulmonary fibrosis.

RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a disease of progressive lung fibrosis with a high mortality rate. In organ repair and remodeling, epigenetic events are important. MicroRNAs (miRNAs) regulate gene expression post-transcriptionally and can target epigenetic molecules important in DNA methylation. The miR-17~92 miRNA cluster is critical for lung development and lung epithelial cell homeostasis and is predicted to target fibrotic genes and DNA methyltransferase (DNMT)-1 expression. OBJECTIVES: We investigated the miR-17~92 cluster expression and its role in regulating DNA methylation events in IPF lung tissue. METHODS: Expression and DNA methylation patterns of miR-17~92 were determined in human IPF lung tissue and fibroblasts and fibrotic mouse lung tissue. The relationship between the miR-17~92 cluster and DNMT-1 expression was examined in vitro. Using a murine model of pulmonary fibrosis, we examined the therapeutic potential of the demethylating agent, 5'-aza-2'-deoxycytidine. MEASUREMENTS AND MAIN RESULTS: Compared with control samples, miR-17~92 expression was reduced in lung biopsies and lung fibroblasts from patients with IPF, whereas DNMT-1 expression and methylation of the miR-17~92 promoter was increased. Several miRNAs from the miR-17~92 cluster targeted DNMT-1 expression resulting in a negative feedback loop. Similarly, miR-17~92 expression was reduced in the lungs of bleomycin-treated mice. Treatment with 5'-aza-2'-deoxycytidine in a murine bleomycin-induced pulmonary fibrosis model reduced fibrotic gene and DNMT-1 expression, enhanced miR-17~92 cluster expression, and attenuated pulmonary fibrosis. CONCLUSIONS: This study provides insight into the pathobiology of IPF and identifies a novel epigenetic feedback loop between miR-17~92 and DNMT-1 in lung fibrosis.

Fijación del material protésico en la hernioplastia inguinal abierta: sutura vs. cola sintética / Prosthetic material fixation in open inguinal hernioplasty: suture vs. synthetic glue

Introducción: El empleo de colas sintéticas se ha convertido en práctica habitual en varios campos quirúrgicos. El objetivo de este estudio es comparar los resultados del pegamento y de la sutura convencional a corto y a medio plazo en la fijación de las prótesis en la hernioplastia inguinal abierta con técnica de tapón y parche. Materiales y métodos Estudio prospectivo comparativo incluyendo 198 pacientes con diagnóstico de hernia inguinal no recidivada intervenidos a cielo abierto y asignados de manera aleatoria a fijación de las mallas con pegamento de cianoacrilato (n=101) o con sutura (n=98). Se analizaron las características demográficas, las complicaciones a corto plazo, la estancia postoperatoria, la baja laboral, la recidiva herniaria y la neuralgia inguinal crónica. Resultados La morbilidad global ha sido del 13,9% en el grupo del pegamento y del 30,9% en el grupo de sutura. No observamos reacciones inflamatorias ni casos de migración de la prótesis. La estancia postoperatoria ha sido de 14,7h en el caso de fijación con pegamento y de 19,1h en el caso de suturas (p<0,0001). No encontramos diferencia entre los 2 grupos en cuanto a días de baja laboral. La morbilidad a corto plazo fue superior en el caso de fijación con sutura (19,6 vs. 10,9%). Al año, se observó una recidiva en el grupo de sutura (1%) y ninguna en el grupo del pegamento. No obstante, la tasa de neuralgia crónica de intensidad moderada/severa fue de 2,9% en el grupo de pegamento y de 10,3% en el grupo de sutura (p=0,03) (AU)

Introduction: The use of synthetic glues has become normal practice in several surgicalfields. The objective of this study is to compare the short and medium term results of glue and conventional suture in the fixation of the prosthesis in open inguinal hernia repair with a plug and patch technique. Materials and methods: A comparative prospective study was conducted on 198 patients with a diagnosis of a non-recurrent inguinal hernia subjected to open surgery and randomly assigned to mesh fixation with cyanoacrylate glue (n = 101) or with suture (n = 98). The demographic characteristics, short-term complications, hospital stay, time off work, herniarecurrence, and chronic inguinal neuralgia, were analysed. Results: The overall morbidity was 13.9% in the glue group, and 30.9% in the suture group. No undue inflammatory reactions ormeshmigration were observed in the group. The postoperative stay was 14.7 h for the glue group, and 19.1 h in the suture group (P < .0001). No differences were found regarding days off work. The short-term morbidity was higher in the suture group (19.6% vs. 10.9%). After one year, there was one recurrence in the suture group (1%), and none in the glue group. However, the incidence of moderate/severe intensity chronic neuralgia was 2.9% in the glue group, and 10.3% in the suture group(P = .03).Conclusion: The use of cyanoacrylate is safe and effective in open inguinal hernia repair, with good results in the short and medium term (AU)

[Prosthetic material fixation in open inguinal hernioplasty: suture vs. synthetic glue]. / Fijación del material protésico en la hernioplastia inguinal abierta: sutura vs. cola sintética.

INTRODUCTION: The use of synthetic glues has become normal practice in several surgical fields. The objective of this study is to compare the short and medium term results of glue and conventional suture in the fixation of the prosthesis in open inguinal hernia repair with a plug and patch technique. MATERIALS AND METHODS: A comparative prospective study was conducted on 198 patients with a diagnosis of a non-recurrent inguinal hernia subjected to open surgery and randomly assigned to mesh fixation with cyanoacrylate glue (n=101) or with suture (n=98). The demographic characteristics, short-term complications, hospital stay, time off work, hernia recurrence, and chronic inguinal neuralgia, were analysed. RESULTS: The overall morbidity was 13.9% in the glue group, and 30.9% in the suture group. No undue inflammatory reactions or mesh migration were observed in the group. The post-operative stay was 14.7h for the glue group, and 19.1h in the suture group (P<.0001). No differences were found regarding days off work. The short-term morbidity was higher in the suture group (19.6% vs. 10.9%). After one year, there was one recurrence in the suture group (1%), and none in the glue group. However, the incidence of moderate/severe intensity chronic neuralgia was 2.9% in the glue group, and 10.3% in the suture group (P=.03). CONCLUSION: The use of cyanoacrylate is safe and effective in open inguinal hernia repair, with good results in the short and medium term.

Somatostatinoma pancreático de comportamiento inusual / Atypical pancreatic somatostatinoma

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