Molecular determinants and signaling effects of PKA RIα phase separation.

Spatiotemporal regulation of intracellular signaling molecules, such as the 3',5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA), ensures proper cellular function. Liquid-liquid phase separation (LLPS) of the ubiquitous PKA regulatory subunit RIα promotes cAMP compartmentation and signaling specificity. However, the molecular determinants of RIα LLPS remain unclear. Here, we reveal that two separate dimerization interfaces, combined with the cAMP-induced unleashing of the PKA catalytic subunit (PKA-C) from the pseudosubstrate inhibitory sequence, drive RIα condensate formation in the cytosol of mammalian cells, which is antagonized by docking to A-kinase anchoring proteins. Strikingly, we find that the RIα pseudosubstrate region is critically involved in forming a non-canonical R:C complex, which recruits active PKA-C to RIα condensates to maintain low basal PKA activity in the cytosol. Our results suggest that RIα LLPS not only facilitates cAMP compartmentation but also spatially restrains active PKA-C, thus highlighting the functional versatility of biomolecular condensates in driving signaling specificity.

Non-canonical ß-adrenergic activation of ERK at endosomes.

G-protein-coupled receptors (GPCRs), the largest family of signalling receptors, as well as important drug targets, are known to activate extracellular-signal-regulated kinase (ERK)-a master regulator of cell proliferation and survival1. However, the precise mechanisms that underlie GPCR-mediated ERK activation are not clearly understood2-4. Here we investigated how spatially organized ß2-adrenergic receptor (ß2AR) signalling controls ERK. Using subcellularly targeted ERK activity biosensors5, we show that ß2AR signalling induces ERK activity at endosomes, but not at the plasma membrane. This pool of ERK activity depends on active, endosome-localized Gαs and requires ligand-stimulated ß2AR endocytosis. We further identify an endosomally localized non-canonical signalling axis comprising Gαs, RAF and mitogen-activated protein kinase kinase, resulting in endosomal ERK activity that propagates into the nucleus. Selective inhibition of endosomal ß2AR and Gαs signalling blunted nuclear ERK activity, MYC gene expression and cell proliferation. These results reveal a non-canonical mechanism for the spatial regulation of ERK through GPCR signalling and identify a functionally important endosomal signalling axis.

Mortality after cardiac arrest in children less than 2 years: relevant factors.

BACKGROUND: There are only scant studies of predicting outcomes of pediatric resuscitation due to lack of population-based data. This study aimed to determine variable factors that may impact the survival of resuscitated children aged under 24 months. METHODS: This is a retrospective study of 66 children under 24 months. Cardiopulmonary resuscitation (CPR) with pediatric advanced life support guideline was performed uniformly for all children. Linear regression analysis with variable factors was conducted to determine impacts on mortality. RESULT: Factors with statistically significant increases in mortality were the number of administered epinephrine (p value < 0.001), total CPR duration (p value < 0.001), in-hospital CPR duration of out-hospital cardiac arrest (p value < 0.001), and changes in cardiac rhythm (p value < 0.040). However, there is no statistically significant association between patient outcomes and remaining factors such as age, sex, underlying disease, etiology, time between last normal to CPR, initial CPR location, initial cardiac rhythm, venous access time, or inotropic usage. CONCLUSION: More than 10 times of epinephrine administration and CPR duration longer than 30 minutes were associated with a higher mortality rate, while each epinephrine administration and prolonged CPR time increased mortality. IMPACT STATEMENT: This study analyzed various factors influencing mortality after cardiac arrest in patients under 24 months. Increased number of administered epinephrine and prolonged cardiopulmonary resuscitation duration do not increase survival rate in patients under 24 months. In patients with electrocardiogram rhythm changes during CPR, mortality increased when the rhythm changed into asystole in comparison to no changes occurring in the rhythm.

Clinical features of chronic fungal rhinosinusitis in Korean geriatric and non-geriatric patients.

PURPOSE: Worldwide, the incidence of chronic fungal rhinosinusitis (CFRS) has increased. Although ageing leads to weakening of the immune system, which increases susceptibility to CFRS, the CFRS characteristics in geriatric patients are unclear. Therefore, we comparatively analysed the clinical characteristics of CFRS in geriatric and non-geriatric patients. METHODS: This retrospective analysis compared the demographics, rhinologic symptoms, multiple allergen simultaneous tests, olfactory function tests, paranasal sinus computed tomography findings, and outcomes of 131 patients with CFRS who underwent functional endoscopic sinus surgery and 131 enrolled patients were divided in geriatric (> 65 years) and non-geriatric (≤ 65 years) groups. RESULTS: Among the geriatric and non-geriatric participants (n = 65, 49.6% and n = 66, 50.4%, respectively), hypertension and diabetes mellitus were more common in the geriatric group. Demographics, including symptoms, showed no significant intergroup differences. Normosmia and hyposmia were significantly less prevalent, whereas phantosmia and parosmia were more prevalent in the geriatric group than in the non-geriatric group (p = 0.03 and p = 0.01, respectively). Sphenoidal sinus involvement was significantly higher in geriatric patients than in non-geriatric patients (p = 0.02). CONCLUSION: Based on greater sphenoidal sinus involvement, a deeper anatomical area is more vulnerable to fungal infection in the geriatric group than in the non-geriatric group. Increasing clinicians' awareness of CFRS in geriatric patients with olfactory dysfunction, including phantosmia and parosmia, is important for early intervention.

CMOS Detector Staggered Array Module for Sub-Terahertz Imaging on Conveyor Belt System.

A complementary metal-oxide-semiconductor (CMOS) detector array is proposed to improve the sub-terahertz imaging resolution for objects in the conveyor belt system. The image resolution is limited to the implemented configuration, such as the wide spacing in the detector array, the high conveyor belt speed, and the slow response of the signal conditioning block. The proposed array can improve the image resolution in the direction perpendicular to the movement of the belt, which is determined by the size and interval of the detector pixel, by configuring the array into two replaceable columns located at the misaligned horizontal positions. Replaceable detector unit pixels are individually attached to the motherboard after measuring and evaluating the detection performance to construct the proposed array. The intensities of 32 detector pixels placed under the conveyor belt with a width of 160 mm were initially calibrated in every image, including the beam pattern of 0.2 THz signals generated from the gyrotron. The image resolution of the perpendicular direction obtained from the proposed array was measured to be approximately 5 mm at a conveyor belt speed of 16 mm/s, demonstrating a 200% improvement in resolution compared to the conventional linear array under the same conditions.

Concurrent-Mode CMOS Detector IC for Sub-Terahertz Imaging System.

A CMOS detector with a concurrent mode for high-quality images in the sub-terahertz region has been proposed. The detector improves output-signal coupling characteristics at the output node. A cross-coupling capacitor is added to isolate the DC bias between the drain and gate. The detector is designed to combine a 180° phase shift based on common source operation and an in-phase output signal based on the drain input. The circuit layout and phase shift occurring in the cross-coupled capacitor during phase coupling are verified using an EM simulation. The detector is fabricated using the TSMC 0.25-µm mixed-signal 1-poly 5-metal layer CMOS process, where the size, including the pad, is 1.13 mm × 0.74 mm. The detector IC comprises a folded dipole antenna, the proposed detector, a preamplifier, and a voltage buffer. Measurement results using a 200-GHz gyrotron source demonstrate that the proposed detector voltage responsivity is 14.13 MV/W with a noise-equivalent power of 34.42 pW/√Hz. The high detection performance helps resolve the 2-mm line width. The proposed detector exhibits a signal-to-noise ratio of 49 dB with regard to the THz imaging performance, which is 9 dB higher than that of the previous CMOS detector core circuits with gate-drain capacitors.

Development of a novel denture care agent with highly active enzyme, arazyme.

BACKGROUND: The importance of efficient denture deposit removal and oral hygiene has been further underscored by the continuous increase of denture wearers. Denture hygiene management has also become an important aspect associated with denture-induced stomatitis. This study aims to evaluate the denture cleaning effect of arazyme, the metalloprotease produced from the Serratia proteamaculans HY-3. We performed growth inhibition tests against oral opportunistic pathogens to be used as a potential oral health care agent. METHODS: The proteolytic activities of arazyme was evaluated over broad ranges of temperature, pH, and denture components compared to those of subtilisin in commercially available denture cleansers. The washing effects of arazyme were also measured by using homogeneously soiled EMPA 105 cottons. To investigate the denture cleaning capability of arazyme, artificially contaminated dentures were treated with arazyme, subtilisin (Everlase 6.0T), and Polident®, respectively. The growth kinetics of Candida albicans, Enterococcus faecalis, Staphylococcus epidermis, and Streptococcus mutans were evaluated in the presence of different concentrations of arazyme to estimate the prevention effects of arazyme against major oral opportunistic pathogens. RESULTS: Arazyme showed strong proteolytic activities over wide temperature and pH ranges compared with the serine protease of the subtilisin family. Arazyme demonstrated efficient removal and decomposition of artificially contaminated dentures and showed explicit washing effects against soiled cottons. Moreover arazyme inhibited the growth of oral opportunistic pathogens, including C. albicans, E. faecalis, S. epidermis, and S. mutans, with more than 80% inhibition against C. albicans, the major cause of denture stomatitis, with 250 mg/mL arazyme. CONCLUSIONS: Arazyme shows promise as a biological oral health care agent with effective cleaning and antimicrobial activities and is a potential source for developing novel denture care agents.

Similarities in Clinical and Psychosocial Characteristics of Functional Diarrhea and Irritable Bowel Syndrome With Diarrhea.

BACKGROUND & AIMS: There have been few published studies of clinical and psychological characteristics of patients with functional diarrhea (FDr). We studied the clinical and psychological characteristics of patients with FDr presenting to a tertiary care clinic, and compared symptom profiles of FDr with those of IBS-diarrhea (IBS-D). METHODS: Consecutive patients with a diagnosis of FDr (n = 48) or IBS-D (n = 49), per Rome IV criteria, completed a detailed symptom survey from October 2017 through July 2018. Abdominal pain and diarrhea severity were assessed using patient-reported outcomes measurement information system (PROMIS) questionnaires. Patients with anxiety, depression, or sleep disturbances were identified based on PROMIS T-score of 60 or more. Mean and proportions were compared using the Student t test and chi-square analyses, respectively. RESULTS: A significantly lower proportion of patients with FDr reported abdominal pain (77.1%) than patients with IBS-D (100%, P < .001). The proportion of patients reporting abdominal bloating and level of severity did not differ significantly between groups. Proportions of bowel movements with diarrhea did not differ significantly between groups (P = .54), but the mean diarrhea PROMIS T-score was significantly higher among patients with IBS-D (P = .03). This difference resulted from the significantly higher levels of fecal urgency-related distress reported by patients with IBS-D (P = .007). Proportions of patients with anxiety, depression, or sleep disturbance, and their severities, did not differ significantly between groups. CONCLUSIONS: In an analysis of about 100 patients with FDr or IBS-D, we found overlap in gastrointestinal and psychosomatic symptoms. These 2 entities appear to be a continuum.

Chronic Diarrhea and Constipation Are More Common in Depressed Individuals.

BACKGROUND AND AIMS: Depression is a major health issue in the United States and is highly comorbid with gastrointestinal conditions. We collected data from the National Health and Nutrition Examination Survey (NHANES), a representative sample of the US population, to study the relationship between depression and bowel habits. METHODS: Using data from the NHANES (2009-2010), we identified 495 depressed and 4709 non-depressed adults who filled out the Bowel Health Questionnaire. Depression was defined according to a validated questionnaire. We used multivariable analysis, controlling for clinical and demographic variables, to evaluate the relationship between mood and bowel habits. RESULTS: In our weighed sample, 24.6% of depressed individuals and 12.6% of non-depressed individuals reported disordered bowel habits. Chronic diarrhea was significantly more prevalent in depressed individuals (15.53%; 95% CI, 11.34%-20.90%) than non-depressed individuals (6.05%; 95% CI, 5.24%-6.98%; P = .0001). Chronic constipation was also more common in depressed individuals (9.10%; 95% CI, 7.02%-11.69%) than non-depressed individuals (6.55%; 95% CI, 5.55%-7.70% CI; P = .003). Mean depression scores in patients with chronic diarrhea (4.9 ± 5.8) and with chronic constipation (4.4 ± 4.93) were significantly higher than mean depression scores for individuals with normal bowel habits (3.2 ± 4.6) (P < .001). Moderate and severe depression were significantly associated with chronic diarrhea but not chronic constipation. Only mild depression was significantly associated with chronic constipation. CONCLUSIONS: In an analysis of the NHANES database, we found a higher proportion of depressed individuals to have chronic diarrhea and constipation than non-depressed individuals; chronic diarrhea was more strongly associated with depression. Our findings provide support for the relationship between mood and specific bowel habits, accounting for multiple co-variables in a large sample of the general US population.

Effects of Irritable Bowel Syndrome on Daily Activities Vary Among Subtypes Based on Results From the IBS in America Survey.

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is associated with significant disease burden and decreased quality of life (QOL). We investigated the effects of IBS on different areas of daily function and compared these among disease subtypes. METHODS: The Life with IBS survey was conducted by Gfk Public Affairs & Corporate Communications from September through October 2015. Respondents met Rome III criteria for constipation-predominant or diarrhea-predominant IBS (IBS-C and IBS-D, respectively). Data were collected from 3254 individuals (mean age, 47 years; 81% female; and 90% Caucasian) who met IBS criteria. RESULTS: Respondents who were employed or in school (n = 1885) reported that IBS symptoms affected their productivity an average of 8.0 days out of the month and they missed approximately 1.5 days of work/school per month because of IBS. More than half the individuals reported that their symptoms were very bothersome. Individuals with IBS-C were more likely than with IBS-D to report avoiding sex, difficulty concentrating, and feeling self-conscious. Individuals with IBS-D reported more avoidance of places without bathrooms, difficulty making plans, avoiding leaving the house, and reluctance to travel. These differences remained when controlling for symptom bothersomeness, age, sex, and employment status. In exchange for 1 month of relief from IBS, more than half of the sample reported they would be willing to give up caffeine or alcohol, 40% would give up sex, 24.5% would give up cell phones, and 21.5% would give up the internet for 1 month. CONCLUSIONS: Although the perceived effects of IBS symptoms on productivity are similar among its subtypes, patients with IBS-C and IBS-D report differences in specific areas of daily function.

RECK isoforms differentially regulate fibroblast migration by modulating tubulin post-translational modifications.

Cell migration is essential for proper development and the defense against pathogens. Our previous work detailed a pathway of REversion-inducing-Cysteine-rich protein with Kazal motifs (RECK) isoform-mediated invasion in which a shorter RECK protein competes with MMP9 for interaction with the canonical RECK protein on the cell surface. Here we demonstrate that the mechanism through which RECK isoforms affect cell migration is mediated through changes in the levels of post-translational modifications (PTM) of α-tubulin. We show that both the canonical and short RECK isoforms modulate levels of tubulin acetylation and detyrosination. We demonstrate that these changes are sufficient to modulate the rate of fibroblast migration. If these tubulin PTMs are not altered, the effects of the canonical RECK isoform on cell migration are reversed. In defining the molecular pathway linking RECK and tubulin PTMs, we found that MMP9 and integrin activity both act as upstream regulators of tubulin acetylation and detyrosination. Overall, we propose a mechanism in which RECK isoforms on the cell surface have opposing effects on cell migration through MMP9-modulated changes to integrin-extracellular matrix (ECM) interactions that, in turn, affect microtubule PTMs.

Emergency Department Burden of Gastroparesis in the United States, 2006 to 2013.

BACKGROUND AND AIMS: Gastroparesis, a chronic gastrointestinal disorder defined by delayed stomach emptying in the absence of obstruction, is often associated with frequent and costly visits to the emergency department (ED). The aim of this study was to analyze trends in gastroparesis-related ED visits from 2006 to 2013. MATERIALS AND METHODS: Patients with a primary diagnosis of gastroparesis were identified from the Nationwide Emergency Department Sample (NEDS), the largest publicly available ED all-payer representative database in the United States. ED visits, admission rates, duration of hospitalizations, and charges were compiled. Patients with a secondary diagnosis of diabetes mellitus were analyzed as a subgroup. RESULTS: The number of ED visits for gastroparesis as a primary diagnosis in the United States increased from 15,459 in 2006 to 36,820 in 2013, an increase from 12.9 to 27.3 per 100,000 ED visits. The total charges associated with these ED visits and subsequent admissions increased from $286 million to $592 million. In contrast, admission rates through the ED decreased by 22%, procedure rates decreased by 6.2%, and the mean length of stay was shortened by 0.6 days. ED visits for patients with diabetic gastroparesis increased from 5696 to 14,114, an increase from 4.7 to 10.5 per 100,000 ED visits, with an increase in total associated charges for ED visits and subsequent admissions from $84 million to $182 million. CONCLUSIONS: The number of ED visits and associated charges for a primary diagnosis of gastroparesis with or without a secondary diagnosis of diabetes mellitus rose significantly from 2006 to 2013.

Nonviral Genome Editing Based on a Polymer-Derivatized CRISPR Nanocomplex for Targeting Bacterial Pathogens and Antibiotic Resistance.

The overuse of antibiotics plays a major role in the emergence and spread of multidrug-resistant bacteria. A molecularly targeted, specific treatment method for bacterial pathogens can prevent this problem by reducing the selective pressure during microbial growth. Herein, we introduce a nonviral treatment strategy delivering genome editing material for targeting antibacterial resistance. We apply the CRISPR-Cas9 system, which has been recognized as an innovative tool for highly specific and efficient genome engineering in different organisms, as the delivery cargo. We utilize polymer-derivatized Cas9, by direct covalent modification of the protein with cationic polymer, for subsequent complexation with single-guide RNA targeting antibiotic resistance. We show that nanosized CRISPR complexes (= Cr-Nanocomplex) were successfully formed, while maintaining the functional activity of Cas9 endonuclease to induce double-strand DNA cleavage. We also demonstrate that the Cr-Nanocomplex designed to target mecA-the major gene involved in methicillin resistance-can be efficiently delivered into Methicillin-resistant Staphylococcus aureus (MRSA), and allow the editing of the bacterial genome with much higher efficiency compared to using native Cas9 complexes or conventional lipid-based formulations. The present study shows for the first time that a covalently modified CRISPR system allows nonviral, therapeutic genome editing, and can be potentially applied as a target specific antimicrobial.

Calcium-Triggered Pulsatile Delivery of Parathyroid Hormone from Microbeads for Osteoporosis Treatment.

Recombinant human parathyroid hormone 1-34 (rhPTH 1-34) is the most potent anabolic drug recommended for patients with osteoporosis who do not respond to conventional treatment. However, subcutaneous intermittent injection is the only effective regimen due to its unusual action of mechanism. This regimen is inconvenient and is a big hurdle in clinical applications. In this study, we designed polyelectrolyte microbeads that can deliver rhPTH 1-34 in response to Ca2+ concentration, which indicates the osteoporotic status. Dextran photopolymer was synthesized, mixed with anionic monoacrylate, and photopolymerized by passing through capillary microfluidics to obtain the microbeads. The anionic property of microbeads was confirmed by toluidine blue staining. One microbead, loaded with a 1 day dose of rhPTH 1-34 (23.4 ± 0.9 µg), released rhPTH 1-34 in a triggered manner following the addition of Ca2+ ion. In vitro cell study demonstrated that rhPTH 1-34 released in a pulsatile manner from the microbeads induced osteogenic markers (ALP, RUNX2, and OPN) and precipitated mineral disposition more effectively.

Effects of early adolescent environmental enrichment on cognitive dysfunction, prefrontal cortex development, and inflammatory cytokines after early life stress.

Early postnatal stress such as maternal separation causes cognitive dysfunction later in life, including working memory deficits that are largely mediated by the prefrontal cortex. Maternal separation in male rats also yields a loss of parvalbumin-containing prefrontal cortex interneurons in adolescence, which may occur via inflammatory or oxidative stress mechanisms. Environmental enrichment can prevent several effects of maternal separation; however, effects of enrichment on prefrontal cortex development are not well understood. Here, we report that enrichment prevented cognitive dysfunction in maternally separated males and females, and prevented elevated circulating pro-inflammatory cytokines that was evident in maternally separated males, but not females. However, enrichment did not prevent parvalbumin loss or adolescent measures of oxidative stress. Significant correlations indicated that adolescents with higher oxidative damage and less prefrontal cortex parvalbumin in adolescence committed more errors on the win-shift task; therefore, maternal separation may affect cognitive dysfunction via aberrant interneuron development. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 482-491, 2016.

Dysport and Botox at a ratio of 2.5:1 units in cervical dystonia: a double-blind, randomized study.

We aimed to compare Dysport (abobotulinumtoxinA, Ipsen Biopharm, Slough, UK) and Botox (onabotulinumtoxinA, Allergan, Irvine, CA, USA) at a 2.5:1 ratio in the treatment of cervical dystonia (CD). A Dysport/Botox ratio of lower than 3:1 was suggested as a more appropriate conversion ratio, considering its higher efficacy and more frequent incidence of adverse effects not only in the treatment of CD but also in other focal movement disorders. A randomized, double-blind, multicenter, non-inferiority, two-period crossover study was done in CD, with a duration of at least 18 months. Patients were randomly assigned to treatment for the first period with Dysport or Botox, and they were followed up for 16 weeks after the injection. After a 4-week washout period, they were switched to the other formulation and then followed up for 16 weeks. The primary outcome was the changes in the Tsui scale between the baseline value and that at 1 month after each injection. A total of 103 patients were enrolled, and 94 completed the study. Mean changes in the Tsui scale between baseline and 4 weeks after each injection tended to favor Botox; however, this was not statistically significant (4.0 ± 3.9 points for the Dysport treatment vs. 4.8 ± 4.1 points for Botox; 95% confidence interval, -0.1-1.7; P = 0.091). The mean change of the Toronto western spasmodic torticollis rating scale score, the proportion of improvement in clinical global impression and patient global impression, and the incidences of adverse events were not significantly different between the two treatments. With regard to safety and efficacy, Dysport was not inferior to Botox in patients with CD at a conversion factor of 2.5:1. [clinicaltrial.gov: NCT00950664]

Opposing regulation of PROX1 by interleukin-3 receptor and NOTCH directs differential host cell fate reprogramming by Kaposi sarcoma herpes virus.

Lymphatic endothelial cells (LECs) are differentiated from blood vascular endothelial cells (BECs) during embryogenesis and this physiological cell fate specification is controlled by PROX1, the master regulator for lymphatic development. When Kaposi sarcoma herpes virus (KSHV) infects host cells, it activates the otherwise silenced embryonic endothelial differentiation program and reprograms their cell fates. Interestingly, previous studies demonstrated that KSHV drives BECs to acquire a partial lymphatic phenotype by upregulating PROX1 (forward reprogramming), but stimulates LECs to regain some BEC-signature genes by downregulating PROX1 (reverse reprogramming). Despite the significance of this KSHV-induced bidirectional cell fate reprogramming in KS pathogenesis, its underlying molecular mechanism remains undefined. Here, we report that IL3 receptor alpha (IL3Rα) and NOTCH play integral roles in the host cell type-specific regulation of PROX1 by KSHV. In BECs, KSHV upregulates IL3Rα and phosphorylates STAT5, which binds and activates the PROX1 promoter. In LECs, however, PROX1 was rather downregulated by KSHV-induced NOTCH signal via HEY1, which binds and represses the PROX1 promoter. Moreover, PROX1 was found to be required to maintain HEY1 expression in LECs, establishing a reciprocal regulation between PROX1 and HEY1. Upon co-activation of IL3Rα and NOTCH, PROX1 was upregulated in BECs, but downregulated in LECs. Together, our study provides the molecular mechanism underlying the cell type-specific endothelial fate reprogramming by KSHV.

9-cis retinoic acid promotes lymphangiogenesis and enhances lymphatic vessel regeneration: therapeutic implications of 9-cis retinoic acid for secondary lymphedema.

BACKGROUND: The lymphatic system plays a key role in tissue fluid homeostasis and lymphatic dysfunction caused by genetic defects, or lymphatic vessel obstruction can cause lymphedema, disfiguring tissue swelling often associated with fibrosis and recurrent infections with no available cures to date. In this study, retinoic acids (RAs) were determined to be a potent therapeutic agent that is immediately applicable to reduce secondary lymphedema. METHODS AND RESULTS: We report that RAs promote proliferation, migration, and tube formation of cultured lymphatic endothelial cells by activating fibroblast growth factor receptor signaling. Moreover, RAs control the expression of cell-cycle checkpoint regulators such as p27(Kip1), p57(Kip2), and the aurora kinases through both an Akt-mediated nongenomic action and a transcription-dependent genomic action that is mediated by Prox1, a master regulator of lymphatic development. Moreover, 9-cisRA was found to activate in vivo lymphangiogenesis in animals in mouse trachea, Matrigel plug, and cornea pocket assays. Finally, we demonstrate that 9-cisRA can provide a strong therapeutic efficacy in ameliorating experimental mouse tail lymphedema by enhancing lymphatic vessel regeneration. CONCLUSION: These in vitro and animal studies demonstrate that 9-cisRA potently activates lymphangiogenesis and promotes lymphatic regeneration in an experimental lymphedema model, presenting it as a promising novel therapeutic agent to treat human lymphedema patients.

Interleukin-8 reduces post-surgical lymphedema formation by promoting lymphatic vessel regeneration.

Lymphedema is mainly caused by lymphatic obstruction and manifested as tissue swelling, often in the arms and legs. Lymphedema is one of the most common post-surgical complications in breast cancer patients and presents a painful and disfiguring chronic illness that has few treatment options. Here, we evaluated the therapeutic potential of interleukin (IL)-8 in lymphatic regeneration independent of its pro-inflammatory activity. We found that IL-8 promoted proliferation, tube formation, and migration of lymphatic endothelial cells (LECs) without activating the VEGF signaling. Additionally, IL-8 suppressed the major cell cycle inhibitor CDKN1C/p57(KIP2) by downregulating its positive regulator PROX1, which is known as the master regulator of LEC-differentiation. Animal-based studies such as matrigel plug and cornea micropocket assays demonstrated potent efficacy of IL-8 in activating lymphangiogenesis in vivo. Moreover, we have generated a novel transgenic mouse model (K14-hIL8) that expresses human IL-8 in the skin and then crossed with lymphatic-specific fluorescent (Prox1-GFP) mouse. The resulting double transgenic mice showed that a stable expression of IL-8 could promote embryonic lymphangiogenesis. Moreover, an immunodeficient IL-8-expressing mouse line that was established by crossing K14-hIL8 mice with athymic nude mice displayed an enhanced tumor-associated lymphangiogenesis. Finally, when experimental lymphedema was introduced, K14-hIL8 mice showed an improved amelioration of lymphedema with an increased lymphatic regeneration. Together, we report that IL-8 can activate lymphangiogenesis in vitro and in vivo with a therapeutic efficacy in post-surgical lymphedema.