Hypothalamic neuronal outputs transmit sensorimotor signals at the onset of locomotor initiation.

The lateral hypothalamus (LH) plays a critical role in sensory integration to organize behavior responses. However, how projection-defined LH neuronal outputs dynamically transmit sensorimotor signals to major downstream targets to organize behavior is unknown. Here, using multi-fiber photometry, we show that three major LH neuronal outputs projecting to the dorsal raphe nucleus (DRN), ventral tegmental area (VTA), and lateral habenula (LHb) exhibit significant coherent activity in mice engaging sensory-evoked or self-initiated motor responses. Increased activity at LH axon terminals precedes movement initiation during active coping responses and the activity of serotonin neurons and dopamine neurons. The optogenetic activation of LH axon terminals in either of the DRN, VTA, or LHb was sufficient to increase motor initiation but had different effects on passive avoidance and sucrose consumption. Our findings support the complementary role of three projection-defined LH neuronal outputs in the transmission of sensorimotor signals to major downstream regions at movement onset.

Cardiac amyloidosis: a significant blind spot of the H2FPEF score.

BACKGROUND: Cardiac amyloidosis (CA) often mimics heart failure with preserved ejection fraction (HFpEF). Due to very different treatment strategies, an exact diagnosis and differentiation between pure HFpEF and CA-related heart failure (HF) is important. In the present study, we assessed the recently published H2FPEF score in patients with pure HFpEF, transthyretin (ATTR), as well as light chain (AL) amyloidosis-related HFpEF and tested whether it differentiates between these entities. METHODS: The H2FPEF scores consists of easy-to-assess clinical (Body Mass Index, number of hypertensive drugs, presence of atrial fibrillation, age) and echocardiographic (systolic pulmonary arterial pressure, E/E´) parameters. It can be computed in a categorical way resulting in scores between 0 and 9 points (0-1: HFpEF rule out, 2-5: further testing required, 6-9: HFpEF rule in), or in a continual way providing an exact percentage of a patient's HFpEF probability. Continuous and categorical variables were compared using the Kruskal-Wallis, Mann-Whitney-U, and χ2-tests. Diagnostic accuracy was computed from 2x2 tables. Survival analysis was performed with Kaplan-Meier curves. A P value of <0.05 was set as the level of significance. RESULTS: A total of 100 patients with pure HFpEF, 53 patients with ATTR, and 34 patients with AL CA were included in the present study. Median age (HFpEF: 71.5 years; ATTR CA: 77.0 years; AL CA: 60.0 years; P<0.001), gender distribution (HFpEF [female]: 73.0%, ATTR (female): 18.9%, AL [female]: 38.2%; P<0.001), and N-terminal prohormone of brain natriuretic peptide (HFpEF: 1045pg/mL; ATTR CA: 1927pg/mL; AL CA: 4308pg/mL; P<0.001) differed significantly between study cohorts. Median H2FPEF scores were highest among HFpEF (categorical: 5.0 points; continual: 95.1%), followed by ATTR (categorical: 4.0 points; continual: 89.0%), and AL CA (categorical: 3.0 points; continual: 31.2%). Respective P values were <0.001. Low H2FPEF scores (0-1 points) were found among patients in the AL CA cohort (29.4%), but not among HFpEF or ATTR CA patients (P<0.001). The majority of patients, irrespective of disease entity were in the intermediate score range (2-5 points, HFpEF: 80.0% ATTR CA: 94.3%, AL CA: 67.9%; P=0.006). High scores (6-9 points) were most often found among HFpEF patients (20.0%), followed by ATTR CA (5.7%) and AL CA (2.9%), (P=0.007). CONCLUSIONS: The H2FPEF score should be used with caution, as there is a significant overlap between HFpEF and CA-related HF.

Rheological Behavior of Pectin Gels Obtained from Araçá (Psidium cattleianum Sabine) Fruits: Influence of DM, Pectin and Calcium Concentrations.

In this work, purified pectins from Araçá fruits (Psidium cattleianum Sabine) were obtained and characterized after partial demethylation. On each prepared sample, the carboxylic yield was obtained by titration, the degree of methylation (DM) by 1H-NMR, and the molecular weight distribution by steric exclusion chromatography (SEC). Then, the gelation ability in the presence of calcium counterions was investigated and related to DM (59-0%); the pectin concentration (2-10 g L-1); and the CaCl2 concentration (0.1-1 mol L-1) used for dialysis. The critical pectin concentration for homogeneous gelation was above 2 g L-1 when formed against 1 mol L-1 CaCl2. The elastic modulus (G') increased with pectin concentration following the relationship G'~C2.8 in agreement with rigid physical gel network predictions. The purified samples APP and APP-A with DM ≥ 40% in the same conditions released heterogeneous systems formed of large aggregates. Gels formed against lower concentrations of CaCl2 down to 0.1 mol L-1 had a higher degree of swelling, indicating electrostatic repulsions between charged chains, thus, counterbalancing the Ca2+ cross-linkage. Compression/traction experiments demonstrated that an irreversible change in the gel structure occurred during small compression with an enhancement of the G' modulus.

A novel role for the lateral habenula in fear learning.

Fear is an extreme form of aversion that underlies pathological conditions such as panic or phobias. Fear conditioning (FC) is the best-understood model of fear learning. In FC the context and a cue are independently associated with a threatening unconditioned stimulus (US). The lateral habenula (LHb) is a general encoder of aversion. However, its role in fear learning remains poorly understood. Here we studied in rats the role of the LHb in FC using optogenetics and pharmacological tools. We found that inhibition or activation of the LHb during entire FC training impaired both cued and contextual FC. In contrast, optogenetic inhibition of the LHb restricted to cue and US presentation impaired cued but not contextual FC. In either case, simultaneous activation of contextual and cued components of FC, by the presentation of the cue in the training context, recovered the conditioned fear response. Our results support the notion that the LHb is required for the formation of independent contextual and cued fear memories, a previously uncharacterized function for this structure, that could be critical in fear generalization.

NPRL2 Inhibition of mTORC1 Controls Sodium Channel Expression and Brain Amino Acid Homeostasis.

Genetic mutations in nitrogen permease regulator-like 2 (NPRL2) are associated with a wide spectrum of familial focal epilepsies, autism, and sudden unexpected death of epileptics (SUDEP), but the mechanisms by which NPRL2 contributes to these effects are not well known. NPRL2 is a requisite subunit of the GAP activity toward Rags 1 (GATOR1) complex, which functions as a negative regulator of mammalian target of rapamycin complex 1 (mTORC1) kinase when intracellular amino acids are low. Here, we show that loss of NPRL2 expression in mouse excitatory glutamatergic neurons causes seizures before death, consistent with SUDEP in humans with epilepsy. Additionally, the absence of NPRL2 expression increases mTORC1-dependent signal transduction and significantly alters amino acid homeostasis in the brain. Loss of NPRL2 reduces dendritic branching and increases the strength of electrically stimulated action potentials (APs) in neurons. The increased AP strength is consistent with elevated expression of epilepsy-linked, voltage-gated sodium channels in the NPRL2-deficient brain. Targeted deletion of NPRL2 in primary neurons increases the expression of sodium channel Scn1A, whereas treatment with the pharmacological mTORC1 inhibitor called rapamycin prevents Scn1A upregulation. These studies demonstrate a novel role of NPRL2 and mTORC1 signaling in the regulation of sodium channels, which can contribute to seizures and early lethality.

Chronic Stress Induces Sex-Specific Functional and Morphological Alterations in Corticoaccumbal and Corticotegmental Pathways.

BACKGROUND: The medial prefrontal cortex (mPFC) is part of a complex circuit controlling stress responses by sending projections to different limbic structures including the nucleus accumbens (NAc) and ventral tegmental area (VTA). However, the impact of chronic stress on NAc- and VTA-projecting mPFC neurons is still unknown, and the distinct contribution of these pathways to stress responses in males and females is unclear. METHODS: Behavioral stress responses were induced by 21 days of chronic variable stress in male and female C57BL/6NCrl mice. An intersectional viral approach was used to label both pathways and assess the functional, morphological, and transcriptional adaptations in NAc- and VTA-projecting mPFC neurons in stressed males and females. Using chemogenetic approaches, we modified neuronal activity of NAc-projecting mPFC neurons to decipher their contribution to stress phenotypes. RESULTS: Chronic variable stress induced depressive-like behaviors in males and females. NAc- and VTA-projecting mPFC neurons exhibited sex-specific functional, morphological, and transcriptional alterations. The functional changes were more severe in females in NAc-projecting mPFC neurons, while males exhibited more drastic reductions in dendritic complexity in VTA-projecting mPFC neurons after chronic variable stress. Finally, chemogenetic overactivation of the corticoaccumbal pathway triggered anxiety and behavioral despair in both sexes, while its inhibition rescued the phenotype only in females. CONCLUSIONS: Our results suggest that stress responses in males and females result from pathway-specific changes in the activity of transcriptional programs controlling the morphological and synaptic properties of corticoaccumbal and corticotegmental pathways in a sex-specific fashion.

Identification of HIF-dependent alternative splicing in gastrointestinal cancers and characterization of a long, coding isoform of SLC35A3.

Intra-tumor hypoxia is a common feature in many solid cancers. Although transcriptional targets of hypoxia-inducible factors (HIFs) have been well characterized, alternative splicing or processing of pre-mRNA transcripts which occurs during hypoxia and subsequent HIF stabilization is much less understood. Here, we identify many HIF-dependent alternative splicing events after whole transcriptome sequencing in pancreatic cancer cells exposed to hypoxia with and without downregulation of the aryl hydrocarbon receptor nuclear translocator (ARNT), a protein required for HIFs to form a transcriptionally active dimer. We correlate the discovered hypoxia-driven events with available sequencing data from pan-cancer TCGA patient cohorts to select a narrow set of putative biologically relevant splice events for experimental validation. We validate a small set of candidate HIF-dependent alternative splicing events in multiple human gastrointestinal cancer cell lines as well as patient-derived human pancreatic cancer organoids. Lastly, we report the discovery of a HIF-dependent mechanism to produce a hypoxia-dependent, long and coding isoform of the UDP-N-acetylglucosamine transporter SLC35A3.

Combined PARP and ATR inhibition potentiates genome instability and cell death in ATM-deficient cancer cells.

The poly (ADP-ribose) polymerase (PARP) inhibitor olaparib is FDA approved for the treatment of BRCA-mutated breast, ovarian and pancreatic cancers. Olaparib inhibits PARP1/2 enzymatic activity and traps PARP1 on DNA at single-strand breaks, leading to replication-induced DNA damage that requires BRCA1/2-dependent homologous recombination repair. Moreover, DNA damage response pathways mediated by the ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia mutated and Rad3-related (ATR) kinases are hypothesised to be important survival pathways in response to PARP-inhibitor treatment. Here, we show that olaparib combines synergistically with the ATR-inhibitor AZD6738 (ceralasertib), in vitro, leading to selective cell death in ATM-deficient cells. We observe that 24 h olaparib treatment causes cells to accumulate in G2-M of the cell cycle, however, co-administration with AZD6738 releases the olaparib-treated cells from G2 arrest. Selectively in ATM-knockout cells, we show that combined olaparib/AZD6738 treatment induces more chromosomal aberrations and achieves this at lower concentrations and earlier treatment time-points than either monotherapy. Furthermore, single-agent olaparib efficacy in vitro requires PARP inhibition throughout multiple rounds of replication. Here, we demonstrate in several ATM-deficient cell lines that the olaparib and AZD6738 combination induces cell death within 1-2 cell divisions, suggesting that combined treatment could circumvent the need for prolonged drug exposure. Finally, we demonstrate in vivo combination activity of olaparib and AZD6738 in xenograft and PDX mouse models with complete ATM loss. Collectively, these data provide a mechanistic understanding of combined PARP and ATR inhibition in ATM-deficient models, and support the clinical development of AZD6738 in combination with olaparib.

Multi-Fiber Photometry to Record Neural Activity in Freely-Moving Animals.

Recording the activity of a group of neurons in a freely-moving animal is a challenging undertaking. Moreover, as the brain is dissected into smaller and smaller functional subgroups, it becomes paramount to record from projections and/or genetically-defined subpopulations of neurons. Fiber photometry is an accessible and powerful approach that can overcome these challenges. By combining optical and genetic methodologies, neural activity can be measured in deep brain structures by expressing genetically-encoded calcium indicators, which translate neural activity into an optical signal that can be easily measured. The current protocol details the components of a multi-fiber photometry system, how to access deep brain structures to deliver and collect light, a method to account for motion artifacts, and how to process and analyze fluorescent signals. The protocol details experimental considerations when performing single and dual color imaging, from either single or multiple implanted optic fibers.

Chromatin-sensitive cryptic promoters putatively drive expression of alternative protein isoforms in yeast.

Cryptic transcription is widespread and generates a heterogeneous group of RNA molecules of unknown function. To improve our understanding of cryptic transcription, we investigated their transcription start site (TSS) usage, chromatin organization, and posttranscriptional consequences in Saccharomyces cerevisiae We show that TSSs of chromatin-sensitive internal cryptic transcripts retain comparable features of canonical TSSs in terms of DNA sequence, directionality, and chromatin accessibility. We define the 5' and 3' boundaries of cryptic transcripts and show that, contrary to RNA degradation-sensitive ones, they often overlap with the end of the gene, thereby using the canonical polyadenylation site, and associate to polyribosomes. We show that chromatin-sensitive cryptic transcripts can be recognized by ribosomes and may produce truncated polypeptides from downstream, in-frame start codons. Finally, we confirm the presence of the predicted polypeptides by reanalyzing N-terminal proteomic data sets. Our work suggests that a fraction of chromatin-sensitive internal cryptic promoters initiates the transcription of alternative truncated mRNA isoforms. The expression of these chromatin-sensitive isoforms is conserved from yeast to human, expanding the functional consequences of cryptic transcription and proteome complexity.

A Fatty Acid Oxidation-dependent Metabolic Shift Regulates the Adaptation of BRAF-mutated Melanoma to MAPK Inhibitors.

PURPOSE: Treatment of BRAFV600E -mutant melanomas with MAPK inhibitors (MAPKi) results in significant tumor regression, but acquired resistance is pervasive. To understand nonmutational mechanisms underlying the adaptation to MAPKi and to identify novel vulnerabilities of melanomas treated with MAPKi, we focused on the initial response phase during treatment with MAPKi. EXPERIMENTAL DESIGN: By screening proteins expressed on the cell surface of melanoma cells, we identified the fatty acid transporter CD36 as the most consistently upregulated protein upon short-term treatment with MAPKi. We further investigated the effects of MAPKi on fatty acid metabolism using in vitro and in vivo models and analyzing patients' pre- and on-treatment tumor specimens. RESULTS: Melanoma cells treated with MAPKi displayed increased levels of CD36 and of PPARα-mediated and carnitine palmitoyltransferase 1A (CPT1A)-dependent fatty acid oxidation (FAO). While CD36 is a useful marker of melanoma cells during adaptation and drug-tolerant phases, the upregulation of CD36 is not functionally involved in FAO changes that characterize MAPKi-treated cells. Increased FAO is required for BRAFV600E -mutant melanoma cells to survive under the MAPKi-induced metabolic stress prior to acquiring drug resistance. The upfront and concomitant inhibition of FAO, glycolysis, and MAPK synergistically inhibits tumor cell growth in vitro and in vivo. CONCLUSIONS: Thus, we identified a clinically relevant therapeutic approach that has the potential to improve initial responses and to delay acquired drug resistance of BRAFV600E -mutant melanoma.

Intracanal Optic Nerve Cavernous Hemangioma: A Case Report and Review of the Literature.

BACKGROUND: Cerebral cavernous malformations of the intracanalicular optic nerve are extremely rare lesions. Only a few case reports and 1 case series have been published. We report an additional case with atypical imaging and review the existing literature with attention to time to surgery and imaging characteristics. CASE DESCRIPTION: In a 38-year-old man with progressive visual field deficit, a lesion compressing the left optic nerve in the optic canal was diagnosed. On magnetic resonance imaging, this lesion had a homogeneous signal and was tentatively diagnosed as a meningioma. A left frontolateral craniotomy with extradural skull base approach with neuronavigation was performed for resection and definitive diagnosis of the lesion. Pathologic examination showed a lesion most consistent with a cavernous hemangioma. Follow-up magnetic resonance imaging at 6 months showed no remaining tissue or recurrence. Clinically, there was subjective and objective improvement of sight. CONCLUSIONS: A cerebral cavernous malformation should always be in the differential diagnosis of a lesion causing an optic neuropathy with visual acuity loss and visual field defect. Clinical presentation of an optic neuropathy requires medical imaging; magnetic resonance imaging is the modality of choice in the diagnosis of these lesions. The treatment of cerebral cavernous malformation is gross total resection.

Synthetically modified methoxsalen for enhanced cytotoxicity in light and dark reactions.

Linear furocoumarins, also known as psoralens, are clinically useful photo-activated pharmaceuticals employed to address hyperproliferative skin diseases. Seven diverse cytotoxic pharmacophores have been synthetically attached to 8-methoxypsoralen via a 5-amino functionality. The resulting unique set of compounds was evaluated for dark and light toxicity against PAM212 keratinocytes in culture.

A Wireless Fiber Photometry System Based on a High-Precision CMOS Biosensor With Embedded Continuous-Time Modulation.

Fluorescence biophotometry measurements require wide dynamic range (DR) and high-sensitivity laboratory apparatus. Indeed, it is often very challenging to accurately resolve the small fluorescence variations in presence of noise and high-background tissue autofluorescence. There is a great need for smaller detectors combining high linearity, high sensitivity, and high-energy efficiency. This paper presents a new biophotometry sensor merging two individual building blocks, namely a low-noise sensing front-end and a order continuous-time modulator (CTSDM), into a single module for enabling high-sensitivity and high energy-efficiency photo-sensing. In particular, a differential CMOS photodetector associated with a differential capacitive transimpedance amplifier-based sensing front-end is merged with an incremental order 1-bit CTSDM to achieve a large DR, low hardware complexity, and high-energy efficiency. The sensor leverages a hardware sharing strategy to simplify the implementation and reduce power consumption. The proposed CMOS biosensor is integrated within a miniature wireless head mountable prototype for enabling biophotometry with a single implantable fiber in the brain of live mice. The proposed biophotometry sensor is implemented in a 0.18- CMOS technology, consuming from a 1.8- supply voltage, while achieving a peak dynamic range of over a 50- input bandwidth, a sensitivity of 24 mV/nW, and a minimum detectable current of 2.46- at a 20- sampling rate.

Bipolar Dislocation of the Arm (Shoulder And Elbow): About One Case in an African Teaching Hospital.

We report an exceptional clinical case of an ipsilateral dislocation fracture of the shoulder and right elbow, realizing a "swinging arm". Following a violent road accident, patient S.I, a 43-year-old left-handed sports educator, presented with an antero-medial shoulder dislocation fracture and a posterolateral ipsilateral elbow fracture-dislocation. The reduction in urgency, followed by the orthopedic compression by Mayo Clinic and functional rehabilitation, allowed obtaining a good result after seven months. The ipsilateral bipolar dislocation of the shoulder and elbow is an exceptional lesional entity. Its adequate care in emergency makes it possible to obtain good anatomical and functional results.

A neural pathway controlling motivation to exert effort.

The neural mechanisms conferring reduced motivation, as observed in depressed individuals, is poorly understood. Here, we examine in rodents if reduced motivation to exert effort is controlled by transmission from the lateral habenula (LHb), a nucleus overactive in depressed-like states, to the rostromedial tegmental nucleus (RMTg), a nucleus that inhibits dopaminergic neurons. In an aversive test wherein immobility indicates loss of effort, LHb→RMTg transmission increased during transitions into immobility, driving LHb→RMTg increased immobility, and inhibiting LHb→RMTg produced the opposite effects. In an appetitive test, driving LHb→RMTg reduced the effort exerted to receive a reward, without affecting the reward's hedonic property. Notably, LHb→RMTg stimulation only affected specific aspects of these motor tasks, did not affect all motor tasks, and promoted avoidance, indicating that LHb→RMTg activity does not generally reduce movement but appears to carry a negative valence that reduces effort. These results indicate that LHb→RMTg activity controls the motivation to exert effort and may contribute to the reduced motivation in depression.

Identification of a Pyranocoumarin Photosensitizer that is a Potent Inhibitor of Keratinocyte Growth.

Photosensitizers are used in the treatment of epidermal proliferation and differentiation disorders such as psoriasis and vitiligo. In these studies, a ring-expanded carbon homolog of the linear psoralen (furo[3,2-g]benzopyran-7-one) class of photosensitizers, 4,10-dimethyl-2H,8H-benzo[1,2-b:5,4-b']dipyran-2-one (NDH2476), was synthesized and analyzed for biological activity. Following activation by ultraviolet light (UVA, 320-400 nm), NDH2476 was found to be a potent inhibitor of keratinocyte growth (IC50  = 9 nm). Similar derivatives methylated in the pyran ring, or containing a saturated pyran ring structure, were markedly less active or inactive as photosensitizers. NDH2476 was found to intercalate and damage DNA following UVA light treatment as determined by plasmid DNA unwinding and nicking experiments. Taken together, these data demonstrate that an intact furan ring in psoralen photosensitizers is not required for keratinocyte growth inhibition or DNA damage. Our findings that low nanomolar concentrations of a benzopyranone derivative were active as a photosensitizer indicates that this or a structurally related compound may be useful in the treatment of skin diseases involving aberrant epidermal cell growth and differentiation.

Correction of gene model annotations improves isoform abundance estimates: the example of ketohexokinase ( Khk).

Next generation sequencing protocols such as RNA-seq have made the genome wide characterization of the transcriptome a crucial part of many research projects in biology. Analyses of the resulting data provide key information on gene expression and in certain cases on exon or isoform usage. The emergence of transcript quantification software such as Salmon has enabled researchers to efficiently estimate isoform and gene expressions across the genome while tremendously reducing the necessary computational power. Although overall gene expression estimations were shown to be accurate, isoform expression quantifications appear to be a more challenging task. Low expression levels and uneven or insufficient coverage were reported as potential explanations for inconsistent estimates. Here, through the example of the ketohexokinase ( Khk) gene in mouse, we demonstrate that the use of an incorrect gene annotation can also result in erroneous isoform quantification results. Manual correction of the input Khk gene model provided a much more accurate estimation of relative Khk isoform expression when compared to quantitative PCR (qPCR measurements). In particular, removal of an unexpressed retained intron and a proper adjustment of the 5' and 3' untranslated regions both had a strong impact on the correction of erroneous estimates. Finally, we observed a better concordance in isoform quantification between datasets and sequencing strategies when relying on the newly generated Khk annotations. These results highlight the importance of accurate gene models and annotations for correct isoform quantification and reassert the need for orthogonal methods of estimation of isoform expression to confirm important findings.

SYNTHESIS AND EVALUATION OF WATER-SOLUBLE DIMETHYLAMINOETHYL ETHERS OF METHOXSALEN FOR PROLIFERATIVE SKIN DISORDERS.

The natural product 8-methoxypsoralen (methoxsalen or 8-MOP) in combination with long wavelength ultraviolet light (UVA, 320-400 nm), also referred to as PUVA therapy, is used for the treatment of cutaneous proliferative disorders including psoriasis, vitiligo and mycosis fungoides. The use of 8-MOP (3) is limited by its poor water solubility and there remains a need to develop more water-soluble psoralens to enhance bioavailability following oral administration of the drug. In the present studies a water-soluble dimethylaminoethyl ether analog of 8-MOP was synthesized and analyzed for biological activity. This analog, (8-[2-(N,N-dimethylamino)ethoxy]-psoralen hydrochloride (1) [or CAS name: 9-[2-(dimethylamino)ethoxy]-7H-furo[3,2-g][1]benzopyran-7-one, hydrochloride], was found to be significantly more active than 3 in keratinocyte growth inhibition assays (IC50 = 12 nM and 130 nM for 1 and 3, respectively). The partially reduced dihydro derivative of 1, 8-[2-(N,N-dimethylamino)ethoxy]-4',5'-dihydropsoralen hydrochloride (2) [or CAS name: 9-[2-(dimethylamino)ethoxy]-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one, hydrochloride] and the partially reduced 4',5'-dihydro-8-methoxypsoralen (4) lacking the water-solubilizing side-chain were significantly less active. As inhibitors of keratinocyte growth they ranked as IC50 = 13,000 nM and 70,000 nM for 2 and 4, respectively, indicating that an unsaturated furan ring in the psoralen was required for maximal activity. Compound (1) was found to readily intercalate and damage DNA following UVA light treatment as determined by plasmid DNA nicking and unwinding experiments in neutral and alkaline agarose gels. Taken together, these data demonstrate that a water-soluble dimethylaminoethyl ether psoralen targets DNA, is highly active as a photosensitizer, and may be useful in the treatment of skin diseases involving abnormal keratinocyte proliferation.

Sulfur mustard induced mast cell degranulation in mouse skin is inhibited by a novel anti-inflammatory and anticholinergic bifunctional prodrug.

Sulfur mustard (SM, bis(2-chloroethyl sulfide) is a potent vesicating agent known to cause skin inflammation, necrosis and blistering. Evidence suggests that inflammatory cells and mediators that they generate are important in the pathogenic responses to SM. In the present studies we investigated the role of mast cells in SM-induced skin injury using a murine vapor cup exposure model. Mast cells, identified by toluidine blue staining, were localized in the dermis, adjacent to dermal appendages and at the dermal/epidermal junction. In control mice, 48-61% of mast cells were degranulated. SM exposure (1.4g/m3 in air for 6min) resulted in increased numbers of degranulated mast cells 1-14days post-exposure. Treatment of mice topically with an indomethacin choline bioisostere containing prodrug linked by an aromatic ester-carbonate that targets cyclooxygenases (COX) enzymes and acetylcholinesterase (1% in an ointment) 1-14days after SM reduced skin inflammation and injury and enhanced tissue repair. This was associated with a decrease in mast cell degranulation from 90% to 49% 1-3days post SM, and from 84% to 44% 7-14days post SM. These data suggest that reduced inflammation and injury in response to the bifunctional indomethacin prodrug may be due, at least in part, to abrogating mast cell degranulation. The use of inhibitors of mast cell degranulation may be an effective strategy for mitigating skin injury induced by SM.