Temporal analysis of melanogenesis identifies fatty acid metabolism as key skin pigment regulator.

Therapeutic methods to modulate skin pigmentation has important implications for skin cancer prevention and for treating cutaneous hyperpigmentary conditions. Towards defining new potential targets, we followed temporal dynamics of melanogenesis using a cell-autonomous pigmentation model. Our study elucidates 3 dominant phases of synchronized metabolic and transcriptional reprogramming. The melanogenic trigger is associated with high MITF levels along with rapid uptake of glucose. The transition to pigmented state is accompanied by increased glucose channelisation to anabolic pathways that support melanosome biogenesis. SREBF1-mediated up-regulation of fatty acid synthesis results in a transient accumulation of lipid droplets and enhancement of fatty acids oxidation through mitochondrial respiration. While this heightened bioenergetic activity is important to sustain melanogenesis, it impairs mitochondria lately, shifting the metabolism towards glycolysis. This recovery phase is accompanied by activation of the NRF2 detoxication pathway. Finally, we show that inhibitors of lipid metabolism can resolve hyperpigmentary conditions in a guinea pig UV-tanning model. Our study reveals rewiring of the metabolic circuit during melanogenesis, and fatty acid metabolism as a potential therapeutic target in a variety of cutaneous diseases manifesting hyperpigmentary phenotype.

Biochemical and Molecular Basis of Chemically Induced Defense Activation in Maize against Banded Leaf and Sheath Blight Disease.

Maize is the third most vital global cereal, playing a key role in the world economy and plant genetics research. Despite its leadership in production, maize faces a severe threat from banded leaf and sheath blight, necessitating the urgent development of eco-friendly management strategies. This study aimed to understand the resistance mechanisms against banded leaf and sheath blight (BLSB) in maize hybrid "Vivek QPM-9". Seven fungicides at recommended doses (1000 and 500 ppm) and two plant defense inducers, salicylic acid (SA) and jasmonic acid (JA) at concentrations of 50 and 100 ppm, were applied. Fungicides, notably Azoxystrobin and Trifloxystrobin + Tebuconazole, demonstrated superior efficacy against BLSB, while Pencycuron showed limited effectiveness. Field-sprayed Azoxystrobin exhibited the lowest BLSB infection, correlating with heightened antioxidant enzyme activity (SOD, CAT, POX, ß-1,3-glucanase, PPO, PAL), similar to the Validamycin-treated plants. The expression of defense-related genes after seed priming with SA and JA was assessed via qRT-PCR. Lower SA concentrations down-regulated SOD, PPO, and APX genes but up-regulated CAT and ß-1,3-glucanase genes. JA at lower doses up-regulated CAT and APX genes, while higher doses up-regulated PPO and ß-1,3-glucanase genes; SOD gene expression was suppressed at both JA doses. This investigation elucidates the effectiveness of certain fungicides and plant defense inducers in mitigating BLSB in maize hybrids and sheds light on the intricate gene expression mechanisms governing defense responses against this pathogen.

Metabolomics-driven investigation of plant defense response against pest and pathogen attack.

The advancement of metabolomics has assisted in the identification of various bewildering characteristics of the biological system. Metabolomics is a standard approach, facilitating crucial aspects of system biology with absolute quantification of metabolites using minimum samples, based on liquid/gas chromatography, mass spectrometry and nuclear magnetic resonance. The metabolome profiling has narrowed the wide gaps of missing information and has enhanced the understanding of a wide spectrum of plant-environment interactions by highlighting the complex pathways regulating biochemical reactions and cellular physiology under a particular set of conditions. This high throughput technique also plays a prominent role in combined analyses of plant metabolomics and other omics datasets. Plant metabolomics has opened a wide paradigm of opportunities for developing stress-tolerant plants, ensuring better food quality and quantity. However, despite advantageous methods and databases, the technique has a few limitations, such as ineffective 3D capturing of metabolites, low comprehensiveness, and lack of cell-based sampling. In the future, an expansion of plant-pathogen and plant-pest response towards the metabolite architecture is necessary to understand the intricacies of plant defence against invaders, elucidation of metabolic pathway operational during defence and developing a direct correlation between metabolites and biotic stresses. Our aim is to provide an overview of metabolomics and its utilities for the identification of biomarkers or key metabolites associated with biotic stress, devising improved diagnostic methods to efficiently assess pest and pathogen attack and generating improved crop varieties with the help of combined application of analytical and molecular tools.

Emerging trends in research and development on earth abundant materials for ammonia degradation coupled with H2 generation.

Ammonia, as an essential and economical fuel, is a key intermediate for the production of innumerable nitrogen-based compounds. Such compounds have found vast applications in the agricultural world, biological world (amino acids, proteins, and DNA), and various other chemical transformations. However, unlike other compounds, the decomposition of ammonia is widely recognized as an important step towards a safe and sustainable environment. Ammonia has been popularly recommended as a viable candidate for chemical storage because of its high hydrogen content. Although ruthenium (Ru) is considered an excellent catalyst for ammonia oxidation; however, its high cost and low abundance demand the utilization of cheaper, robust, and earth abundant catalyst. The present review article underlines the various ammonia decomposition methods with emphasis on the use of non-noble metals, such as iron, nickel, cobalt, molybdenum, and several other carbides as well as nitride species. In this review, we have highlighted various advances in ammonia decomposition catalysts. The major challenges that persist in designing such catalysts and the future developments in the production of efficient materials for ammonia decomposition are also discussed.

In this dynamic area, ammonia degradation to hydrogen fuel provides a valuable contribution in the carbon neutral economy. Ammonia has been used extensively in several industries and is considered an ideal candidate for hydrogen generation and storage due to its high hydrogen content. Consequently, the ammonia decomposition to yield green hydrogen has become a hot topic in research. Although numerous studies on ammonia decomposition have been conducted over the last few decades, still very few review articles on the most recent advances in this field of catalysis have been published. Through this review, systematic information on the types of decomposition catalysts including both noble (Ru) and non-noble earth abundant metals such as iron, nickel, cobalt, molybdenum, their carbides and nitrides, catalytic routes, as well as the reactivity and mechanism can be comprehended. The literature on newly discovered catalysts, specifically from the last five years, is well documented and explained in this review article. Furthermore, the effect of catalyst supports, their reaction kinetics and mechanistic insights have also been discussed. The challenges and opportunities associated with the decomposition catalysts are comprehensively explicated in the end.

Ammonia decomposition reaction (ADR) is a viable method for hydrogen storage in the form of chemical bonds.Catalysts composed of noble, non-noble metals, amides, imides, carbides, nitrides, and their combinations have been widely explored towards the ADR.Challenges and opportunities in the ammonia oxidation are pointed out.

Protective Role of Vitamin D Against Development of Active Tuberculosis in Close Household Contacts of Pulmonary Tuberculosis Patients: A Prospective Cohort Study.

Vitamin-D is known to promote innate immune responses by acting as a cofactor of VDR for induction of antimicrobial peptides like cathelicidin. Close household contacts of pulmonary tuberculosis patients are at high risk of active infection, Therefore, possible role of vitamin-D in TB prevention through cathelicidin production was studied in high-risk household contacts (HHCs) of pulmonary tuberculosis (PTB) patients. 20 HHCs of PTB patients were recruited and followed up for one year. Levels of vitamin-D (25(OH)D) and its associated molecules were evaluated at 3-months intervals for one year or until the development of active TB. 25(OH)D was measured using chemiluminescence method. Serum VDR and cathelicidin levels were measured by ELISA and VDR mRNA expression by qPCR. Throughout the study period mean range of serum 25(OH)D levels was 20.51 ± 5.12 ng/ml. VDR and cathelicidin levels however showed significant decline after six months suggesting decrease in bacterial exposure. None of the HHCs developed active infection even with high exposure to 2 + to 3 + AFB positive index cases. Mantoux positive household contacts had high levels of VDR and cathelicidin, suggestive of an early or latent phase of infection, did not develop active TB plausibly due to maintenance of adequate serum levels of vitamin-D. Optimal levels of 25(OH)D and its associated molecules during early stages of infection may serve as protective factor against development of active TB. Cohort of HHCs with severely deficient vitamin-D levels (10 ng/ml) could be followed up for a better risk assessment.

Chronic hyperglycemia drives alterations in macrophage effector function in pulmonary tuberculosis.

Diabetes mellitus (DM) alters immune responses and given the rising prevalence of DM in tuberculosis (TB) endemic countries; hyperglycemia can be a potential risk factor for active TB development. However, the impact of hyperglycemia on TB-specific innate immune response in terms of macrophage functions remains poorly addressed. We assessed macrophage effector functions in uncontrolled DM patients with or without TB infection (PTB+DM and DM), non-diabetic TB patients (PTB), and non-diabetic-uninfected controls. Phagocytic capacity against BCG and surface expression of different pattern recognition receptors (PRRs) (CD11b, CD14, CD206, MARCO, and TLR-2) were measured via flow cytometry. Effector molecules (ROS and NO) required for bacterial killing were assessed via DCFDA and Griess reaction respectively. A systematic dysregulation in phagocytic capacity with concurrent alterations in the expression pattern of key PRRs (CD11b, MARCO, and CD206) was observed in PTB+DM. These altered PRR expressions were associated with decreased phagocytic capacity of macrophages. Similarly, ROS was aberrantly higher while NO was lower in PTB+DM. These altered macrophage functions were positively correlated with increasing disease severity. Our results highlight several key patterns of immune dysregulation against TB infection under hyperglycemic conditions and highlight a negative impact of hyperglycemia with etiology and progression of TB.

DNA methylome analysis provides insights into gene regulatory mechanism for better performance of rice under fluctuating environmental conditions: epigenomics of adaptive plasticity.

MAIN CONCLUSION: Roots play an important role in adaptive plasticity of rice under dry/direct-sown conditions. However, hypomethylation of genes in leaves (resulting in up-regulated expression) complements the adaptive plasticity of Nagina-22 under DSR conditions. Rice is generally cultivated by transplanting which requires plenty of water for irrigation. Such a practice makes rice cultivation a challenging task under global climate change and reducing water availability. However, dry-seeded/direct-sown rice (DSR) has emerged as a resource-saving alternative to transplanted rice (TPR). Though some of the well-adapted local cultivars are used for DSR, only limited success has been achieved in developing DSR varieties mainly because of a limited knowledge of adaptability of rice under fluctuating environmental conditions. Based on better morpho-physiological and agronomic performance of Nagina-22 (N-22) under DSR conditions, N-22 and IR-64 were grown by transplanting and direct-sowing and used for whole genome methylome analysis to unravel the epigenetic basis of adaptive plasticity of rice. Comparative methylome and transcriptome analyses indicated a large number (4078) of genes regulated through DNA methylation/demethylation in N-22 under DSR conditions. Gene × environment interactions play important roles in adaptive plasticity of rice under direct-sown conditions. While genes for pectinesterase, LRK10, C2H2 zinc-finger protein, splicing factor, transposable elements, and some of the unannotated proteins were hypermethylated, the genes for regulation of transcription, protein phosphorylation, etc. were hypomethylated in CG context in the root of N-22, which played important roles in providing adaptive plasticity to N-22 under DSR conditions. Hypomethylation leading to up-regulation of gene expression in the leaf complements the adaptive plasticity of N-22 under DSR conditions. Moreover, differential post-translational modification of proteins and chromatin assembly/disassembly through DNA methylation in CHG context modulate adaptive plasticity of N-22. These findings would help developing DSR cultivars for increased water-productivity and ecological efficiency.

IGF-1 Microinjection in the Prefrontal Cortex Attenuates Fentanyl-Seeking Behavior in Mice.

BACKGROUND: Opioid use disorder (OUD) is a chronic relapsing psychiatric disorder with an enormous socioeconomic burden. Opioid overdose deaths have reached an epidemic level, especially for fentanyl. One of the biggest challenges to treat OUD is the relapse to drug seeking after prolonged abstinence. Abnormalities in insulin-like growth factor-1 (IGF-1) have been reported in various neurological and psychiatric disorders, including OUD. However, whether IGF-1 and its downstream signaling pathways are associated with relapse to fentanyl seeking remains unclear. METHODS: Mice were subjected to daily 2-hour fentanyl (10 µg/mL, 27 µL/infusion) oral self-administration training for 14 days, followed by 14-day fentanyl cessation. Expression levels of IGF-1/IGF-1 receptor and downstream signaling pathways in the dorsomedial prefrontal cortex (dmPFC) were detected. Then, IGF-1 was bilaterally microinjected into the dmPFC from fentanyl cessation day 9 to day 13. Fentanyl-seeking behavior and excitatory synaptic transmission of pyramidal neurons in PFC were evaluated. RESULTS: We found that 14-day cessation from fentanyl oral self-administration caused significant downregulation of IGF-1 and IGF-1 receptor phosphorylation in the dmPFC. These changes were accompanied by inhibition of the downstream Akt and S6 signaling pathway. In addition, local administration of IGF-1 in the dmPFC attenuated context-induced fentanyl-seeking behavior. Furthermore, electrophysiology and immunohistochemistry analyses showed that IGF-1 blocked fentanyl-induced reduction of a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and N-methyl-D-aspartate receptors-mediated excitatory synaptic transmission as well as synaptic expression of a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and N-methyl-D-aspartate receptor subunits. CONCLUSIONS: These results suggest that IGF-1 in the PFC plays a pivotal role in regulating fentanyl seeking after prolonged cessation from fentanyl oral self-administration.

Genome-wide profiling reveals pervasive transcriptional alterations in fibroblasts derived from lesional skin in vitiligo including a reduced potential to proliferate.

Fibroblasts interact with keratinocytes and melanocytes to maintain skin homeostasis. However, the impact of selective melanocyte loss on the transcriptome of fibroblasts is not fully understood. Thus, we sought to understand the genome-wide transcriptome of fibroblasts derived from non-lesional (NL) and lesional (L) dermis in patients with non-segmental vitiligo. Transcriptional profiling of NL and L fibroblasts was performed on three individuals with vitiligo using next-generation-sequencing. Functional protein-protein interaction (PPI) networks were constructed for the significantly upregulated and downregulated genes, as well as for a common set of genes that were downregulated in both fibroblasts and epidermis in L skin (identified previously). Proliferation potential of NL and L fibroblasts was assessed experimentally. Genome-wide transcriptome analysis revealed a total of 414 (282, downregulated; 132, upregulated) differentially expressed (DE)-transcripts in L as compared to NL fibroblasts. Unsupervised hierarchical clustering of DE-transcripts segregated L and NL fibroblasts into two distinct clades, despite the apparent heterogeneity in lesions of different vitiligo patients. Gene Ontology analysis of downregulated genes revealed enrichment of keratinocyte-specific biological processes such as cornification and keratinization. PPI networks constructed for the downregulated and upregulated genes revealed deregulation of several hub genes associated with cell cycle regulation and cAMP metabolism respectively. Similarly, the PPI networks constructed for 67 genes downregulated in both fibroblasts as well as epidermis of L skin revealed downregulation of hub genes including stratifin, PIK3CG and CDH1. Analysis of the in vitro proliferation potential of L fibroblasts revealed a decrease in the expression of proliferation markers Ki67, MCM6, pERK and pCDK2, a decreased S phase population and an increase in alpha-SMA and collagen expression, corroborating the downregulation of hub genes associated with proliferation identified by PPI network analysis. Our study revealed pervasive transcriptional alterations in L compared to NL fibroblasts in vitiligo. The PPI analysis suggested a reduced potential to proliferate in melanocyte-deprived lesional fibroblasts, which was validated experimentally as well.

Deciphering the role of miRNA in reprogramming plant responses to drought stress.

Drought is the most prevalent environmental stress that affects plants' growth, development, and crop productivity. However, plants have evolved adaptive mechanisms to respond to the harmful effects of drought. They reprogram their: transcriptome, proteome, and metabolome that alter their cellular and physiological processes and establish cellular homeostasis. One of the crucial regulatory processes that govern this reprogramming is post-transcriptional regulation by microRNAs (miRNAs). miRNAs are small non-coding RNAs, involved in the downregulation of the target mRNA via translation inhibition/mRNA degradation/miRNA-mediated mRNA decay/ribosome drop off/DNA methylation. Many drought-inducible miRNAs have been identified and characterized in plants. Their main targets are regulatory genes that influence growth, development, osmotic stress tolerance, antioxidant defense, phytohormone-mediated signaling, and delayed senescence during drought stress. Overexpression of drought-responsive miRNAs (Osa-miR535, miR160, miR408, Osa-miR393, Osa-miR319, and Gma-miR394) in certain plants has led to tolerance against drought stress indicating their vital role in stress mitigation. Similarly, knock down (miR166/miR398c) or deletion (miR169 and miR827) of miRNAs has also resulted in tolerance to drought stress. Likewise, engineered Arabidopsis plants with miR165, miR166 using short tandem target mimic strategy, exhibited drought tolerance. Since miRNAs regulate the expression of an array of drought-responsive genes, they can act as prospective targets for genetic manipulations to enhance drought tolerance in crops and achieve sustainable agriculture. Further investigations toward functional characterization of diverse miRNAs, and understanding stress-responses regulated by these miRNAs and their utilization in biotechnological applications is highly recommended.

PepAnalyzer: predicting peptide properties using its sequence.

Peptides are short linear molecules consisting of amino acids that play an essential role in most biological processes. They can treat diseases by working as a vaccine or antimicrobial agent and serves as a cancer molecule to deliver the drug to the target site for the treatment of cancer. They have the potential to solve the drawbacks of current medications and can be industrially produced in large quantities at low cost. However, poor chemical and physical stability, short circulating plasma half-life, and solubility are some issues that need solutions before they can be used as therapeutics. PepAnalyzer tool is a user-friendly tool that predicts 15 different properties such as binding potential, half-life, transmembrane patterns, test tube stability, charge, isoelectric point, molecular weights, and molar extinction coefficients only using the sequence. The tool is designed using BioPython utility and has even results with standard tools, such as Expasy, EBI, Genecorner, and Geneinfinity. The tool assists students, researchers, and the pharmaceutical sector. The PepAnalyzer tool's online platform is accessible at the link: http://www.iksmbrlabdu.in/peptool .

One-Step High-Temperature Electrodeposition of Fe-Based Films as Efficient Water Oxidation Catalysts.

Electrolysis of water to produce hydrogen requires an efficient catalyst preferably made of cheap and abundant metal ions for the improved water oxidation reaction. An Fe-based film has been deposited in a single step by electrochemical deposition at temperatures higher than the room temperature. Until now, the electrodeposition of iron oxide has been carried out at 298 K or at lower temperatures under a controlled atmosphere to prohibit atmospheric oxidation of Fe2+ of the iron precursor. A metal inorganic complex, ferrocene, and non-aqueous electrolyte medium propylene carbonate have been used to achieve electrodeposition of iron oxide without the need of any inert or controlled atmosphere. At 298 K, the amorphous film was formed, whereas at 313 K and at higher temperatures, the hematite film was grown, as confirmed by X-ray diffraction. The transformation of iron of the ferrocene into a higher oxidation state under the experimental conditions used was further confirmed by X-ray photoelectron spectroscopy, ultraviolet-visible, and electron paramagnetic resonance spectroscopic methods. The films deposited at 313 K showed the best performance for water oxidation with remarkable long-term electrocatalytic stability and an impressive turnover frequency of 0.028 s-1 which was 4.5 times higher than that of films deposited at 298 K (0.006 s-1). The observed overpotential to achieve a current density of 10 mA cm-2 was found to be 100 mV less for the film deposited at 313 K compared to room-temperature-derived films under similar experimental conditions. Furthermore, electrochemical impedance data revealed that films obtained at 313 K have the least charge transfer resistance (114 Ω) among all, supporting the most efficient electron transport in the film. To the best of our knowledge, this is the first-ever report where the crystalline iron-based film has been shown to be electrodeposited without any post-deposition additional treatment for alkaline oxygen evolution reaction application.

Comparative transcriptome analysis of Zea mays upon mechanical wounding.

BACKGROUND: Mechanical wounding (MW) is mainly caused due to high wind, sand, heavy rains and insect infestation, leading to damage to crop plants and an increase in the incidences of pathogen infection. Plants respond to MW by altering expression of genes, proteins, and metabolites that help them to cope up with the stress. METHODS AND RESULTS: In order to characterize maize transcriptome in response to mechanical wounding, a microarray analysis was executed. The study revealed 407 differentially expressed genes (DEGs) (134 upregulated and 273 downregulated). The upregulated genes were engaged in protein synthesis, transcription regulation, phytohormone signaling-mediated by salicylic acid, auxin, jasmonates, biotic and abiotic stress including bacterial, insect, salt and endoplasmic reticulum stress, cellular transport, on the other hand downregulated genes were involved in primary metabolism, developmental processes, protein modification, catalytic activity, DNA repair pathways, and cell cycle. CONCLUSION: The transcriptome data present here can be further utilized for understanding inducible transcriptional response during mechanical injury and their purpose in biotic and abiotic stress tolerance. Furthermore, future study concentrating on the functional characterization of the selected key genes (Bowman Bird trypsin inhibitor, NBS-LRR-like protein, Receptor-like protein kinase-like, probable LRR receptor-like ser/thr-protein kinase, Cytochrome P450 84A1, leucoanthocyanidin dioxygenase, jasmonate O-methyltransferase) and utilizing them for genetic engineering for crop improvement is strongly recommended.

An aphid RNA transcript migrates systemically within plants and is a virulence factor.

Aphids are sap-feeding insects that colonize a broad range of plant species and often cause feeding damage and transmit plant pathogens, including bacteria, viruses, and viroids. These insects feed from the plant vascular tissue, predominantly the phloem. However, it remains largely unknown how aphids, and other sap-feeding insects, establish intimate long-term interactions with plants. To identify aphid virulence factors, we took advantage of the ability of the green peach aphid Myzus persicae to colonize divergent plant species. We found that a M. persicae clone of near-identical females established stable colonies on nine plant species of five representative plant eudicot and monocot families that span the angiosperm phylogeny. Members of the novel aphid gene family Ya are differentially expressed in aphids on the nine plant species and are coregulated and organized as tandem repeats in aphid genomes. Aphids translocate Ya transcripts into plants, and some transcripts migrate to distal leaves within several plant species. RNAi-mediated knockdown of Ya genes reduces M. persicae fecundity, and M. persicae produces more progeny on transgenic plants that heterologously produce one of the systemically migrating Ya transcripts as a long noncoding (lnc) RNA. Taken together, our findings show that beyond a range of pathogens, M. persicae aphids translocate their own transcripts into plants, including a Ya lncRNA that migrates to distal locations within plants, promotes aphid fecundity, and is a member of a previously undescribed host-responsive aphid gene family that operate as virulence factors.

Silicon nanoparticles: Synthesis, uptake and their role in mitigation of biotic stress.

In the current scenario of global warming and climate change, plants face many biotic stresses, which restrain growth, development and productivity. Nanotechnology is gaining precedence over other means to deal with biotic and abiotic constraints for sustainable agriculture. One of nature's most beneficial metalloids, silicon (Si) shows ameliorative effect against environmental challenges. Silicon/Silica nanoparticles (Si/SiO2NPs) have gained special attention due to their significant chemical and optoelectronic capabilities. Its mesoporous nature, easy availability and least biological toxicity has made it very attractive to researchers. Si/SiO2NPs can be synthesised by chemical, physical and biological methods and supplied to plants by foliar, soil, or seed priming. Upon uptake and translocation, Si/SiO2NPs reach their destined cells and cause optimum growth, development and tolerance against environmental stresses as well as pest attack and pathogen infection. Using Si/SiO2NPs as a supplement can be an eco-friendly and cost-effective option for sustainable agriculture as they facilitate the delivery of nutrients, assist plants to mitigate biotic stress and enhances plant resistance. This review aims to present an overview of the methods of formulation of Si/SiO2NPs, their application, uptake, translocation and emphasize the role of Si/SiO2NPs in boosting growth and development of plants as well as their conventional advantage as fertilizers with special consideration on their mitigating effects towards biotic stress.

Lingual Artery as the Recipient Vessel of Choice in Patients Requiring a Second or Third Free Flap in Recurrent Oral Cancers and Vessel-Depleted Neck: A 5-Year Experience in a Single Institute.

Introduction Reconstruction with free flaps becomes a challenge in recurrent cases having previously treated necks, in patients who have received prior radiation therapy or chemotherapy or both, and where the patient has already undergone free flap reconstruction in a prior surgery. Depleted cervical recipient vessels can increase the complexity of reconstruction in achieving successful free flap prefusion and thereby increasing flap thrombosis and eventually failure. Materials and Methods Over a period of 5 years from January 2018 to February 2023, we encountered a total of 22 cases of recurrent or second primary oral cancer with bilateral necks operated, postadjuvant chemo-radiotherapy, and requiring a second or third free flap reconstruction. In most of the cases we resorted to the lingual artery as the recipient artery of choice. Results No flap loss was reported. No cases were reexplored either for hematoma or for congestion. All patients recovered uneventfully. Conclusion To the best of our knowledge, there has been no paper yet that focuses on the lingual artery to be the recipient vessel of choice in recurrent oral cancers. We find the lingual artery to be a reliable and safe option and advocate its usage as recipient vessel of choice in recurrent oral cancers requiring more than one free flap reconstruction.

Differential regulation of miR-21-5p delays wound healing of melanocyte-deprived vitiligo skin by modulating the expression of tumor-suppressors PDCD4 and Maspin.

The loss of melanocytes in vitiligo is associated with architectural, transcriptional, and cellular perturbations of keratinocytes and manifests as a reduced proliferation potential in vitro and delayed re-epithelialization in vivo. To understand the molecular mechanisms underlying this delay, microRNA (miRNA) profiling was performed on split skin biopsies collected on Day 1 (basal level) and Day 14 (wound re-epithelialization) from nonlesional (NL) and lesional (L) skin of five subjects with stable nonsegmental vitiligo and 129 miRNAs were found to be differentially regulated between the NL and L healed epidermis. miR-21-5p, expressed at comparable levels on NL and L Day 1 samples, demonstrated significant upregulation during re-epithelialization. However, the extent of its upregulation was relatively lower in L (10 times compared to Day 1) as compared to NL skin (17 times compared to Day 1). The overexpression of miR-21 in keratinocytes led to a significant increase in the expression of proliferation markers (Ki67 and MCM6 messenger RNA, Ki67 positivity), along with an increase in keratinocyte migration. Using a small interfering RNA mediated knockdown approach, we further demonstrated that miR-21-5p mediates its effects by suppressing the expression of programmed cell death 4 (PDCD4) and mammary serine protease inhibitor (Maspin), both tumor-suppressor genes. Investigation of clinical samples corroborated the lower miR-21 levels and a higher expression of PDCD4 and Maspin in L Day 14 compared to the NL Day 14 epidermis. In conclusion, this study revealed that a relatively lower upregulation of miR-21-5p in L skin leads to significantly higher levels of PDCD4 and Maspin, delaying wound re-epithelialization by reducing the proliferation and migration of keratinocytes.

pH-controlled histone acetylation amplifies melanocyte differentiation downstream of MITF.

Tanning response and melanocyte differentiation are mediated by the central transcription factor MITF. This involves the rapid and selective induction of melanocyte maturation genes, while concomitantly the expression of other effector genes is maintained. In this study, using cell-based and zebrafish model systems, we report on a pH-mediated feed-forward mechanism of epigenetic regulation that enables selective amplification of the melanocyte maturation program. We demonstrate that MITF activation directly elevates the expression of the enzyme carbonic anhydrase 14 (CA14). Nuclear localization of CA14 leads to an increase of the intracellular pH, resulting in the activation of the histone acetyl transferase p300/CBP. In turn, enhanced H3K27 histone acetylation at selected differentiation genes facilitates their amplified expression via MITF. CRISPR-mediated targeted missense mutation of CA14 in zebrafish results in the formation of immature acidic melanocytes with decreased pigmentation, establishing a central role for this mechanism during melanocyte differentiation in vivo. Thus, we describe an epigenetic control system via pH modulation that reinforces cell fate determination by altering chromatin dynamics.

Mechanistic insights into non-coding Y RNA processing.

Y RNAs (84-112 nt) are non-coding RNAs transcribed by RNA polymerase III and are characterized by a distinctive secondary structure. Human Y RNAs interact with the autoimmune proteins SSB and RO60 that together form a ribonucleoprotein (RNP) complex termed RoRNP and Y RNAs also perform regulatory roles in DNA and RNA replication and stability, which has major implications for diseases including cancer. During cellular stress and apoptosis, Y RNAs are cleaved into 3' and 5' end fragments termed Y RNA-derived small RNAs (ysRNAs). Although some ysRNA functions in stress, apoptosis and cancer have been reported, their fundamental biogenesis has not been described. Here we report that 3' end RNY5 cleavage is structure dependent. In high throughput mutagenesis experiments, cleavage occurred between the 2nd and 3rd nt above a double stranded stem comprising high GC content. We demonstrate that an internal loop above stem S3 is critical for producing 3' end ysRNAs (31 nt) with mutants resulting in longer or no ysRNAs. We show a UGGGU sequence motif at position 22 of RNY5 is critical for producing 5' end ysRNAs (22-25 nt). We show that intact RO60 is critical for ysRNA biogenesis. We conclude that ribonuclease L (RNASEL) contributes to Y RNA cleavage in mouse embryonic fibroblasts but is not the only endoribonuclease important in human cells.

Molecular insights into an ancient form of Paget's disease of bone.

Paget's disease of bone (PDB) is a chronic skeletal disorder that can affect one or several bones in individuals older than 55 y of age. PDB-like changes have been reported in archaeological remains as old as Roman, although accurate diagnosis and natural history of the disease is lacking. Six skeletons from a collection of 130 excavated at Norton Priory in the North West of England, which dates to medieval times, show atypical and extensive pathological changes resembling contemporary PDB affecting as many as 75% of individual skeletons. Disease prevalence in the remaining collection is high, at least 16% of adults, with age at death estimations as low as 35 y. Despite these atypical features, paleoproteomic analysis identified sequestosome 1 (SQSTM1) or p62, a protein central to the pathological milieu of PDB, as one of the few noncollagenous human sequences preserved in skeletal samples. Targeted proteomic analysis detected >60% of the ancient p62 primary sequence, with Western blotting indicating p62 abnormalities, including in dentition. Direct sequencing of ancient DNA excluded contemporary PDB-associated SQSTM1 mutations. Our observations indicate that the ancient p62 protein is likely modified within its C-terminal ubiquitin-associated domain. Ancient miRNAs were remarkably preserved in an osteosarcoma from a skeleton with extensive disease, with miR-16 expression consistent with that reported in contemporary PDB-associated bone tumors. Our work displays the use of proteomics to inform diagnosis of ancient diseases such as atypical PDB, which has unusual features presumably potentiated by yet-unidentified environmental or genetic factors.