Publications by authors named "Shihai Jia"

The vestibular maculae of the inner ear contain sensory receptor hair cells that detect linear acceleration and contribute to equilibrioception to coordinate posture and ambulatory movements. These hair cells are divided between two groups, separated by a line of polarity reversal (LPR), with oppositely oriented planar-polarized stereociliary bundles that detect motion in opposite directions. The transcription factor EMX2 is known to establish this planar polarized organization in mouse by regulating the distribution of the transmembrane receptor GPR156 at hair cell boundaries in one group of cells.

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Uncontrolled and sustained inflammation disrupts the wound-healing process and produces excessive reactive oxygen species, resulting in chronic or impaired wound closure. Natural antioxidants such as plant-based extracts and natural polysaccharides have a long history in wound care. However, they are hard to apply to wound beds due to high levels of exudate or anatomical sites to which securing a dressing is difficult.

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Oral cancer, constituted up to 90% by squamous cell carcinomas, is a significant health burden globally. Grape seed proanthocyanidins (PA) have been suggested as a potential chemopreventive agent for oral cancer. However, their efficacy can be restricted due to the low bioavailability and bioaccessibility.

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In these studies, we explored for the first time the molecular relationship between the paired-domain-containing transcription factor, , and the ectodysplasin () signaling pathway during mouse incisor formation. Mice that were deficient in both and were generated, and the status of dentition analyzed in all progeny using gross evaluation and histomorphometric means. When compared to wildtype controls, mice lack mandibular incisors.

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Introduction: The ability to resolve pulpal inflammation to achieve predictable regeneration of the dentin-pulp complex has remained elusive and presents a challenge for clinicians and researchers. Although the dentin-pulp complex can react naturally to injury by forming a bridge of reparative dentin that protects the pulp from further damage, this process is significantly impaired if inflammation persists. Because the secretion of inflammatory cytokines by injured pulpal cells causes significant pain and discomfort to patients, it is critical to resolve pulpal inflammation in a timely manner so as to create a microenvironment conducive for pulpal healing and reparative dentin formation.

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Clefts of the lip and/or palate are the most prevalent orofacial birth defects occurring in about 1:700 live human births worldwide. Early postnatal surgical interventions are extensive and staged to bring about optimal growth and fusion of palatal shelves. Severe cleft defects pose a challenge to correct with surgery alone, resulting in complications and sequelae requiring life-long, multidisciplinary care.

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Background: Despite the strides made in understanding the complex network of key regulatory genes and cellular processes that drive palate morphogenesis, patients suffering from these conditions face treatment options that are limited to complex surgeries and multidisciplinary care throughout life. Hence, a better understanding of how molecular interactions drive palatal growth and fusion is critical for the development of treatment and preventive strategies for cleft palates in humans. Our previous work demonstrated that Pax9-dependent Wnt signaling is critical for the growth and fusion of palatal shelves.

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Hydrogels are homogenous materials that are limited in their ability to form oriented multilayered architecture in three-dimensional (3D) tissue constructs. Current techniques have led to advancements in this area. Such techniques often require extra devices and/or involve complex processes that are inaccessible to many laboratories.

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Clefts of the palate and/or lip are among the most common human craniofacial malformations and involve multiple genetic and environmental factors. Defects can only be corrected surgically and require complex life-long treatments. Our studies utilized the well-characterized mouse model with a consistent cleft palate phenotype to test small-molecule Wnt agonist therapies.

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Mutations in MSX1 cause craniofacial developmental defects, including tooth agenesis, in humans and mice. Previous studies suggest that Msx1 activates Bmp4 expression in the developing tooth mesenchyme to drive early tooth organogenesis. Whereas Msx1 mice exhibit developmental arrest of all tooth germs at the bud stage, mice with neural crest-specific inactivation of Bmp4 (Bmp4), which lack Bmp4 expression in the developing tooth mesenchyme, showed developmental arrest of only mandibular molars.

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Four conserved signaling pathways, including the bone morphogenetic proteins (Bmp), fibroblast growth factors (Fgf), sonic hedgehog (Shh), and wingless-related (Wnt) pathways, are each repeatedly used throughout tooth development. Inactivation of any of these resulted in early tooth developmental arrest in mice. The mutations identified thus far in human patients with tooth agenesis also affect these pathways.

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Cleft palate is one of the most common birth defects in humans. Whereas gene knockout studies in mice have shown that both the Osr2 and Pax9 transcription factors are essential regulators of palatogenesis, little is known about the molecular mechanisms involving these transcription factors in palate development. We report here that Pax9 plays a crucial role in patterning the anterior-posterior axis and outgrowth of the developing palatal shelves.

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Previous studies have suggested that Bmp4 is a key Msx1-dependent mesenchymal odontogenic signal for driving tooth morphogenesis through the bud-to-cap transition. Whereas all tooth germs were arrested at the bud stage in Msx1(-/-) mice, we show that depleting functional Bmp4 mRNAs in the tooth mesenchyme, through neural crest-specific gene inactivation in Bmp4(f/f);Wnt1Cre mice, caused mandibular molar developmental arrest at the bud stage but allowed maxillary molars and incisors to develop to mineralized teeth. We found that expression of Osr2, which encodes a zinc finger protein that antagonizes Msx1-mediated activation of odontogenic mesenchyme, was significantly upregulated in the molar tooth mesenchyme in Bmp4(f/f);Wnt1Cre embryos.

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MicroRNAs (miRNAs) are endogenous non-coding genes that participate in post-transcription regulation by either degrading mRNA or blocking its translation. It is considered to be very important in regulating insect development and metamorphosis. We conducted a large-scale screening for miRNA genes in the silkworm Bombyx mori using sequence-by-synthesis (SBS) deep sequencing of mixed RNAs from egg, larval, pupal, and adult stages.

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Pair-rule genes (genes that are expressed only in alternate segments, odd or even) play an important role in translating the broad gradients of upstream genes into dual segment periodicity for body plan patterning in Drosophila. However, homologues of pair-rule genes show a remarkable diversity of expression patterns and functions in other insects. We cloned the homologue of runt in the silkworm Bombyx mori, an intermediate germband-type insect.

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The silk gland of the silkworm Bombyx mori undergoes programmed cell death (PCD) during pupal metamorphosis. On the basis of their morphological changes and the occurrence of a DNA ladder, the tissue cells were categorized into three groups: intact, committed, and dying. To identify the proteins involved in this process, we conducted a comparative proteomic analysis.

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Many genes act together during the complex process of insect larval and pupal development. 20-hydroxyecdysone interacts with juvenile hormone to control insect growth and development and then activates several transcription factors, i.e.

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We compared the bacterial communities in the larval midgut of field and laboratory populations of a polyphagous pest, the cotton bollworm (Helicoverpa armigera), using denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA sequences and 16S library sequence analysis. DGGE profiles and 16S rDNA library sequence analysis indicated similar patterns of midgut microbial community structure and diversity: specific bacterial types existed in both populations, and a more diverse microbial community was observed in caterpillars obtained from the field. The laboratory population harbored a rather simple gut microflora consisting mostly of phylotypes belonging to Enterococcus (84%).

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We established a genetic linkage map employing 518 simple sequence repeat (SSR, or microsatellite) markers for Bombyx mori (silkworm), the economically and culturally important lepidopteran insect, as part of an international genomics program. A survey of six representative silkworm strains using 2,500 (CA)n- and (CT)n-based SSR markers revealed 17-24% polymorphism, indicating a high degree of homozygosity resulting from a long history of inbreeding. Twenty-nine SSR linkage groups were established in well characterized Dazao and C108 strains based on genotyping of 189 backcross progeny derived from an F(1) male mated with a C108 female.

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We investigated the role of the salicylic acid (SA) signaling pathway in defense responses of tomato plants to the herbivore, cotton bollworm. After exposure to the cotton bollworm, tomato leaves rapidly accumulated a high level of SA. The transcription of PR1 and BGL2 genes, the marker genes of SA pathway, was up-regulated.

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