ARNT

The underlying pathophysiology of nonhealing chronic wounds is poorly understood due to the changes occurring at the gene level and the complexity arising in their proteomic profile. Here, we elucidated the temporal and differential profile of the normal and diabetic wound-healing mediators along with their interactions and associated pathways. Skin tissues corresponding to normal and diabetic wounds were isolated at Days 0, 3, 6, and 9 representing different healing phases. Temporal gene expression was analyzed by quantitative real-time PCR. Concurrently, differential protein patterns in the wound tissues were identified by Nano LC-ESI-TOF mass spectrometry and later confirmed by Western blot analysis. Gene ontology annotation, protein-protein interaction, and protein pathway analysis were performed using DAVID, PANTHER, and STRING bioinformatics resources. Uniquely identified proteins (complement C3, amyloid beta precursor protein, and cytoplasmic linker associated protein 2) in the diabetic wound tissue implied that these proteins are involved in the pathogenesis of diabetic wound. They exhibit enhanced catalytic activity, trigger pathways linked with inflammation, and negatively regulate wound healing. However, in the normal wound tissue, axin 1, chondroitin sulfate proteoglycan 4, and sphingosine-1-phosphate receptor were identified, which are involved in proliferation, angiogenesis, and remodeling. Our findings demonstrate the correlation between elevated gene expression of tumor necrosis factor-α, interleukin (IL)-1β, and identified mediators: aryl hydrocarbon receptor nuclear translocator, 5'-aminolevulinate synthase 2, and CXC-family, that inflicted an inflammatory response by activating downstream MAPK, JAK-STAT, and NF-κB pathways. Similarly, in normal wound tissue, the upregulated IL-4 and hepatocyte growth factor levels in conjunction with the identified proteins, serine/threonine-protein kinase mTOR and peroxisome proliferator-activated receptor gamma, played a significant role in the cellular response to platelet-derived growth factor stimulus, dermal epithelialization, and cell proliferation, processes associated with the repair mechanism. Furthermore, Western blot analysis indicated elevated levels of inflammatory markers and reduced levels of proliferative and angiogenic factors in the diabetic wound.

Guizhou black goat is one of the indigenous black goat breeds in the southwest region of Guizhou, China, which is an ordinary goat for mutton production. They are characterized by moderate body size, black coat, favorite meat quality with tender meat and lower odor, and tolerance for cold and crude feed. However, little is known about the genetic characteristics or variations underlying their important economic traits.

Here, we resequenced the whole genome of Guizhou black goat from 30 unrelated individuals breeding in the five core farms. A total of 9,835,610 SNPs were detected, and 2,178,818 SNPs were identified specifically in this breed. The population structure analysis revealed that Guizhou black goat shared a common ancestry with Shaanbei white cashmere goat (0.146), Yunshang black goat (0.103), Iran indigenous goat (0.054), and Moroccan goat (0.002). However, Guizhou black goat showed relatively higher genetic diversity and a lower level of linkage disequilibrium than the other seven goat breeds by the analysis of the nucleotide diversity, linkage disequilibrium decay, and runs of homozygosity. Based on F_ST and θ_π values, we identified 645, 813, and 804 selected regions between Guizhou black goat and Yunshang black goat, Iran indigenous goat, and cashmere goats. Combined with the results of XP-EHH, there were 286, 322, and 359 candidate genes, respectively. Functional annotation analysis revealed that these genes are potentially responsible for the immune response (e.g., CD28, CD274, IL1A, TLR2, and SLC25A31), humility-cold resistance (e.g., HBEGF, SOSTDC1, ARNT, COL4A1/2, and EP300), meat quality traits (e.g., CHUK, GAB2, PLAAT3, and EP300), growth (e.g., GAB2, DPYD, and CSF1), fertility (e.g., METTL15 and MEI1), and visual function (e.g., PANK2 and NMNAT2) in Guizhou black goat.

Our results indicated that Guizhou black goat had a high level of genomic diversity and a low level of linkage disequilibrium in the whole genome. Selection signatures were detected in the genomic regions that were mainly related to growth and development, meat quality, reproduction, disease resistance, and humidity-cold resistance in Guizhou black goat. These results would provide a basis for further resource protection and breeding improvement of this very local breed.

Hypoxia-inducible factor-1 (HIF-1) is the key transcriptional mediator of the cellular response to hypoxia and is also involved in cancer progression. Regulation of its oxygen-sensitive HIF-1α subunit involves post-translational modifications that control its stability, subcellular localization, and activity. We have previously reported that phosphorylation of the HIF-1α C-terminal domain by ERK1/2 promotes HIF-1α nuclear accumulation and stimulates HIF-1 activity while lack of this modification triggers HIF-1α nuclear export and its association with mitochondria. On the other hand, modification of the N-terminal domain of HIF-1α by CK1δ impairs HIF-1 activity by obstructing the formation of a HIF-1α/ARNT heterodimer. Investigation of these two antagonistic events by expressing double phospho-site mutants in HIF1A^-/- cells under hypoxia revealed independent and additive phosphorylation effects that can create a gradient of HIF-1α subcellular localization and transcriptional activity. Furthermore, modification by CK1δ caused mitochondrial release of the non-nuclear HIF-1α form and binding to microtubules via its N-terminal domain. In agreement, endogenous HIF-1α could be shown to co-localize with mitotic spindle microtubules and interact with tubulin, both of which were inhibited by CK1δ silencing or inhibition. Moreover, CK1δ expression was necessary for equal partitioning of mother cell-produced HIF-1α to the daughter cell nuclei at the end of mitosis. Overall, our results suggest that phosphorylation by CK1δ stimulates the association of non-nuclear HIF-1α with microtubules, which may serve as a means to establish a symmetric distribution of HIF-1α during cell division under low oxygen conditions.