A Gland of Many Uses: a Diversity of Compounds in the Labial Glands of the Bumble Bee Bombus impatiens Suggests Multiple Signaling Functions.

Communication in social insect colonies depends on signals accurately reflecting the identity and physiological state of the individuals. Such information is coded by the products of multiple exocrine glands, and the resulting blends reflect the species, sex, caste, age, task, reproductive status, and health of an individual, and may also contain caste-specific pheromones regulating the behavior and physiology of other individuals. Here we examined the composition of labial gland secretions in females of the bumble bee Bombus impatiens, of different castes, social condition, age, mating status, and ovarian activation. We show that active queens, gynes, and workers each produce caste-specific compounds that may serve different communicative functions. The composition and amounts of wax esters, mostly octyl esters produced by active queens, differed significantly between castes, mating, and social conditions, suggesting a social signaling role. Farnesyl esters were predominant in gynes and peaked at optimal mating age (6-10 days), suggesting their possible roles as sex pheromone components. Reproductive status of females and age across castes was reflected by the ratio between short- and long-chain hydrocarbons, suggesting that these compounds may serve as fertility signals. Our findings overall suggest that the labial gland composition in B. impatiens reflects different facets of female physiology. While further bioassays are required to determine the functions of these compounds, they are likely to have important roles in communication between individuals.

Dysregulated interleukin 11 in primary Sjögren's syndrome contributes to apoptosis of glandular epithelial cells.

The purpose of this study was to explore the potential function of interleukin-11 (IL-11) in the pathogenesis of primary Sjögren's syndrome (pSS) patients. Real-time polymerase chain reaction was performed to examine IL-11 expression in the labial glands of 30 pSS patients and 30 healthy controls. Immunohistochemistry was conducted to assess the distribution of IL-ll-positive cells in labial glands. The human salivary gland (HSG) cell line was used to study the effects of IL-11 on gland epithelial cells in vitro. Cell viability and cell proliferation were examined by CCK-8 kit and EdU assay, respectively. The population of apoptotic cells was detected in flow cytometry followed by Annexin V/PI and Hoechst staining. We found that the expression levels of IL-11 were remarkably decreased in pSS labial glands and were positively correlated with C-reactive protein levels and negatively correlated with rheumatoid factor levels. Fewer numbers of glandular epithelial cells were observed to be positively stained with IL-11 antibody in labial glands from pSS patients than those in healthy control patients. After IL-11 treatment, the viability and proliferation of HSG cells were significantly higher than those in the control group. The total apoptotic and necrotic rates of HSG cells in the group after IL-11 treatment were significantly lower. In conclusion, the results indicated that IL-11 promoted viability and proliferation and inhibited apoptotic and necrotic rates of glandular epithelial cells. In pSS, downregulated IL-11 might contribute to the apoptosis of salivary gland epithelial cells. However, it might be a potential target to alleviate the pathological atrophy of glandular epithelial cells in pSS patients.

Spatial organization of the excretory ducts and sections of microcirculatory blood flow of the labial salivary glands in older adults.

OBJECTIVE: Introduction: Salivary glands have a significant impact on the state of the homeostasis of the human body, oral cavity in particular, sensitively responding to pathological processes. The reactivity of the salivary glands in response to pathological processes that are organically linked to morphology and functions of the organ's structures, and particularly the excretory ducts of the glands and their microcirculatory blood flow, is one of the problems which have not been solved to date. The aim of the paper was to elucidate the features of the stereomicroscopic structure of the excretory ducts and sectors of the microcirculatory blood flow in labial glands of older adults. PATIENTS AND METHODS: Materials and methods: The object of the study was the labial mucosa of the older adults, which was cut into 3х3 mm pieces and fixed in the buffered 4% glutaraldehyde solution with subsequent 2-hour fixation in osmium. Once the pieces were washed and dehydrated they were embedded into the Epon-812. The series of the semi-thin sections, made from the obtained epoxy blocks, were stained in phosphate buffered 0,1% toluidine blue solution. The serial semi-thin sections were subjected to histological and cytological studies and multilayered plastic reconstruction. RESULTS: Results and conclusions: The series of histological epoxy semi-thin sections, as well as graphic and plastic reconstruction of the sectors of microcirculatory blood flow and excretory ducts of the human labial glands have demonstrated a range of morphological facts that can be used to clarify the intertissue stereological relationships. They also determined the syntopic proximity of the capacitive sectors of microcirculatory blood flow to the excretory ducts of the gland. Such pattern is especially notable in the collecting venules and intralobular ducts. It has been shown that the biggest venule is the collecting venous vessel. Anastomoses between the intralobular arterioles and collecting venules have been found in the microcirculatory blood flow of the labial glands.

Changes in the chemical profile of cephalic salivary glands of Scaptotrigona postica (Hymenoptera, Meliponini) workers are phase related.

Most advanced eusocial bees recruit their nest mates to food resources. Recent studies in Meliponini species have revealed that the cephalic salivary (labial) glands (CSGs) are responsible for the production of scent trail pheromones. Studies on CSGs have shown that changes occur in worker glandular cell morphology from emergence from brood combs until forager phase, which may be correlated to changes in the composition of the CSG secretion. However, the composition of the CSG secretion and the chemical changes that occur in it according to the worker's life phase or tasks performed are unknown for many species, including Scaptotrigona postica. In this study, the chemical profile of CSG secretion in S. postica workers was studied. Glands were taken from specimens that were newly emerged (NE), working in the brood comb area (CA) and foraging (FO), and were analyzed by gas chromatography-mass spectrometry. The results showed that the glandular secretion consists of oxygenated compounds of middle volatility (acids, alcohols, aldehydes, ketones, esters and ether), and their quantity varies among the different life phases, increasing as the individual moves from intra- to extra-colonial activities. The NE phase contained the smallest variety and quantity of compounds. Because of the variability of compounds, the CA workers were separated into three subgroups according to the chemical constitution of their secretion. Forager workers showed the largest quantity and variety of chemical compounds. The major compounds in forager gland secretion were 7-hexadecen-1-yl acetate and 5-tetradecen-1-yl acetate. Statistical analysis indicates that the chemical composition of glandular secretion is phase related.

Defensive glands in Stylotermitidae (Blattodea, Isoptera).

The large abundance of termites is partially achieved by their defensive abilities. Stylotermitidae represented by a single extant genus, Stylotermes, is a member of a termite group Neoisoptera that encompasses 83% of termite species and 94% of termite genera and is characterized by the presence of the frontal gland. Within Neoisoptera, Stylotermitidae represents a species-poor sister lineage of all other groups. We studied the structure of the frontal, labral and labial glands in soldiers and workers of Stylotermes faveolus, and the composition of the frontal gland secretion in S. faveolus and Stylotermes halumicus. We show that the frontal gland is a small active secretory organ in soldiers and workers. It produces a cocktail of monoterpenes in soldiers, and some of these monoterpenes and unidentified proteins in workers. The labral and labial glands are developed similarly to other termite species and contribute to defensive activities (labral in both castes, labial in soldiers) or to the production of digestive enzymes (labial in workers). Our results support the importance of the frontal gland in the evolution of Neoisoptera. Toxic, irritating and detectable monoterpenes play defensive and pheromonal functions and are likely critical novelties contributing to the ecological success of these termites.

Reactivity of human labial glands in response to cevimeline treatment.

Among the pathologies affecting the salivary glands, the Sjögren's syndrome (SS), an autoimmune disease, causes progressive destruction of the glandular tissue. The effect of SS is particularly evident on the labial glands and the morphological analysis of these minor glands is considered useful for diagnosis. Cevimeline hydrochloride (SNI), a selective muscarinic agonist drug, is one of the elective treatments for the hyposalivation due to SS, acting not only on major salivary glands, but also on labial glands since their secretion is primarily under parasympathetic control. Aim of this study is to describe the morphology of human labial glands treated with SNI by light, transmission, and high-resolution scanning electron microscopy. Moreover, a morphometric analysis was applied to the light and transmission electron microscopy micrographs to obtain data that were then compared with analogous data collected on control and carbachol-treated labial glands. Following SNI administration, the mucous tubules exhibited enlarged lumina, which were filled with a dense mucous secretion. Occasionally, small broken debris of the cells were retrieved into the lumen. In the mucous secretory cells, some mucous droplets fused to form a large vacuole-like structure. Similarly, the seromucous acini showed both dilated lumina and canaliculi. These above reported signs of secretion were confirmed through morphometric analysis and a milder action of SNI than carbachol on labial parenchyma was observed. This study confirmed that SNI also evoked secretion on labial glands and that its effect is more physiologic than that of the pan-muscarinic agonists.

High frequency ultrasound assessment of labial glands simulating small nodules or granulomas after lip augmentation.

AIM OF THE STUDY: The aim of this study is to evaluate the utility of high-frequency ultrasound in the assessment of the nature and differentiation of lumps occurring in the labial mucosa after lip filling procedures. MATERIAL AND METHODS: The study sample included 5 women aged from 28 to 43 years (mean age: 37.4 years) who previously underwent a lip augmentation or rejuvenation procedure. Photographic documentation was taken and high-frequency ultrasound assessment was performed in all the patients. The presence of deposits, foreign body granulomas, fibrosis and labial glands was mainly investigated taking into account the shape of the abnormalities, their margins, surface area, location and echogenicity. In order to confirm the diagnosis, histopathological examination was performed. RESULTS: The examinations performed made it possible to differentiate between granulomas and persistent deposit nodules and to demonstrate the presence of massive fibrosis and of labial glands pushed out by these abnormalities with the glands presenting as hypoechoic oval areas. Histopathological examination confirmed the morphology of labial glands reported by the patients as uncomfortable lumps felt from the side of the mucosa, which clinically simulate persistent deposit nodules or granulomas. CONCLUSIONS: High-frequency ultrasound is a method that is essential for the correct differentiation between complications of tissue filler procedures. This, in turn, makes it possible to apply the right treatment. In this study, it was demonstrated for the first time that the lumps reported by patients who have had a lip filling procedure may be the result of labial glands being pushed out by deposits, granulomas or massive fibrosis, which are complications of such procedures.

Cabbage looper (Trichoplusia ni Hübner) labial glands contain unique bacterial flora in contrast with their alimentary canal, mandibular glands, and Malpighian tubules.

In recent years, several studies have examined the gut microbiome of lepidopteran larvae and how factors such as host plant affect it, and in turn, how gut bacteria affect host plant responses to herbivory. In addition, other studies have detailed how secretions of the labial (salivary) glands can alter host plant defense responses. We examined the gut microbiome of the cabbage looper (Trichoplusia ni) feeding on collards (Brassica oleracea) and separately analyzed the microbiomes of various organs that open directly into the alimentary canal, including the labial glands, mandibular glands, and the Malpighian tubules. In this study, the gut microbiome of T. ni was found to be generally consistent with those of other lepidopteran larvae in prior studies. The greatest diversity of bacteria appeared in the Firmicutes, Actinobacteria, Proteobacteria, and Bacteriodetes. Well-represented genera included Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas, Diaphorobacter, Methylobacterium, Flavobacterium, and Cloacibacterium. Across all organs, two amplicon sequence variants (ASVs) associated with the genera Diaphorobacter and Cloacibacterium appeared to be most abundant. In terms of the most prevalent ASVs, the alimentary canal, Malpighian tubules, and mandibular glands appeared to have similar complements of bacteria, with relatively few significant differences evident. However, aside from the Diaphorobacter and Cloacibacterium ASVs common to all the organs, the labial glands appeared to possess a distinctive complement of bacteria which was absent or poorly represented in the other organs. Among these were representatives of the Pseudomonas, Flavobacterium, Caulobacterium, Anaerococcus, and Methylobacterium. These results suggest that the labial glands present bacteria with different selective pressures than those occurring in the mandibular gland, Malpighian tubules and the alimentary canal. Given the documented effects that labial gland secretions and the gut microbiome can exert on host plant defenses, the effects exerted by the bacteria inhabiting the labial glands themselves deserve further study.

Aberrant expression of the innate restriction factor bone marrow stromal antigen-2 in primary Sjögren's syndrome.

OBJECTIVE: The objective of this study was to analyze bone marrow stromal antigen-2 (BST-2) levels in labial glands, total peripheral blood mononuclear cells (PBMCs) and PBMC subpopulations from primary Sjögren's syndrome (pSS) patients and determine the correlation between BST-2 expression and clinical characteristics. MATERIALS AND METHODS: PBMC subsets were positively separated using magnetic microbeads. BST-2 mRNA levels in labial glands, total PBMCs and PBMC subsets of 30 pSS and 30 healthy control (HC) subjects were investigated using real-time polymerase chain reaction (RT-PCR). Distribution of BST-2-positive cells in the labial glands was assessed by immunohistochemistry. RESULTS: BST-2 was significantly increased in pSS labial glands and was positively correlated with the VAS value for parotid gland swelling and rheumatoid factor and ß2-microglobulin serum levels. BST-2 levels were statistically different between pSS patients with positive and negative expression of anti-SSA antibody. Positive focal infiltrating lymphocytes and adjacent ductal epithelial cells were observed in labial glands from pSS patients, while there were a few scattered positive ductal epithelial cells in controls. BST-2 was also up-regulated in CD19+ B cells and the remaining CD4-CD8-CD19- PBMCs. CONCLUSION: BST-2 was aberrantly expressed in pSS patients, and expression in labial glands was positively correlated with important clinical characteristics; thus, it may be a potential biomarker of pSS activity.

Characteristics of Labial Gland Mesenchymal Stem Cells of Healthy Individuals and Patients with Sjögren's Syndrome: A Preliminary Study.

Sjögren's syndrome (SS) is a systemic autoimmune disease that is characterized by focal lymphocytic infiltration into exocrine organs such as salivary and lacrimal glands, resulting in dry mouth and eyes, and other systemic injuries. There is no curative clinical therapy for SS, and stem cell therapy has shown great potential in this area. The mesenchymal stem cells (MSCs) in the salivary glands of healthy individuals and in patients with SS have not been extensively studied. The aim of this study was to elucidate the characteristics of MSCs from the labial glands of healthy controls and of those from patients with SS to elucidate the related pathogenesis and to uncover potential avenues for novel clinical interventions. Labial glands from patients with SS and healthy subjects were obtained, and MSCs were isolated and cultured by using the tissue adherent method. The MSC characteristics of the cultured cells were confirmed by using morphology, proliferation, colony forming-unit (CFU) efficiency, and multipotentiality, including osteogenic, adipogenic, and salivary gland differentiation. The MSCs from the healthy controls and SS patients expressed characteristic MSC markers, including CD29, CD44, CD73, CD90, and CD105; they were negative for CD34, CD45, and CD106, and also negative for the salivary gland epithelium markers (CD49f and CD117). Labial gland MSCs from both groups were capable of osteogenic and adipogenic differentiation. The CFU efficiency and adipogenic differentiation potential of MSCs were significantly lower in the SS group compared with the healthy controls. Cells from both groups could also be induced into salivary gland-like cells. Real-time polymerase chain reaction and immunofluorescence staining showed that the gene and protein expression of AMY1, AQP5, and ZO-1 in cells from the SS group was lower than that in cells from the healthy group. Thus, MSCs from the labial glands in patients with SS could lack certain characteristics and functions, especially related to salivary secretion. These preliminary data provided insights that could lead to the development of novel therapeutic strategies for the treatment of SS.

Age-dependent changes in ultrastructure of the defensive glands of Neocapritermes taracua workers (Isoptera, Termitidae).

Protection against predators and competitors is one of the main concerns of termite colonies, which developed a specialised defensive caste, the soldiers. However, soldiers are rare or even missing in several lineages of termites, while workers often develop new defence strategies especially in soil-feeding species. Here, we describe the morphology and ultrastructure of the autothysis-associated glands of Neocapritermes taracua workers and report their age-related changes in structure. The defensive glands of N. taracua workers consist of a pair of labial and a pair of crystal glands, whose secretions mix together through autothysis. Autothysis always occurs at the line of weakness connecting the anterior parts of the crystal-bearing pouches. The crystal glands consist of groups of bicellular secretory units (secretory and corresponding canal cells) which secrete the blue crystal material into external pouches. Their secretory activity is maximal in the middle of worker life, and is considerably lower in very young and old workers. The labial glands are composed of two types of secretory cells: the central and the parietal cells. While the central cells are developed similarly to other termites and secrete proteinaceous secretion into labial gland ducts, the parietal cells develop proteinaceous granules which may eventually bud off the cells. The secretory function of parietal cells is so far unique to N. taracua and differs from other termite species in which they are only responsible of water uptake by acini. The defensive device of N. taracua is truly exceptional as it involves a new gland and a previously undescribed function for parietal cells, being a remarkable example of evolution of morphological innovation.

Royal jelly-like protein localization reveals differences in hypopharyngeal glands buildup and conserved expression pattern in brains of bumblebees and honeybees.

Royal jelly proteins (MRJPs) of the honeybee bear several open questions. One of them is their expression in tissues other than the hypopharyngeal glands (HGs), the site of royal jelly production. The sole MRJP-like gene of the bumblebee, Bombus terrestris (BtRJPL), represents a pre-diversification stage of the MRJP gene evolution in bees. Here we investigate the expression of BtRJPL in the HGs and the brain of bumblebees. Comparison of the HGs of bumblebees and honeybees revealed striking differences in their morphology with respect to sex- and caste-specific appearance, number of cells per acinus, and filamentous actin (F-actin) rings. At the cellular level, we found a temporary F-actin-covered meshwork in the secretory cells, which suggests a role for actin in the biogenesis of the end apparatus in HGs. Using immunohistochemical localization, we show that BtRJPL is expressed in the bumblebee brain, predominantly in the Kenyon cells of the mushroom bodies, the site of sensory integration in insects, and in the optic lobes. Our data suggest that a dual gland-brain function preceded the multiplication of MRJPs in the honeybee lineage. In the course of the honeybee evolution, HGs dramatically changed their morphology in order to serve a food-producing function.

Correlation of serum level of TNF-α and TGF-β1 with infiltration degree of lymphocytes in labial glands and interstitial lung disease in patients with primary Sjogren's syndrome / 重庆医学

Objective To investigate the correlation between peripheral serum TNF-α and TGF-β1 expression levels with the infiltration degree of lymphocytes in labial glands and interstitial lung disease(ILD) in the patients with primary Sjogren's syndrome (pSS).Methods Serum level of TNF-α and TGF-β1 in 116 patients with pSS and 20 persons undergoing physical examination were measured by ELISA.Meanwhile the labial gland samples in pSS patients were performed the pathological examination.The patients were grouped according to the lesion stage of ILD and pathology grade of labial glands.The serum TNF-α and TGF-β1 levels were statistically analyzed.Results Serum levels of TNF-α and TGF-β1 in the pSS-ILD group were significantly higher than those in the simple pSS group and control group(P＜0.01).The levels of serum TNF-α and TGF-β1 in the simple pSS group were significantly higher than those in the control group(P＜0.01).The levels of serum TNF-α and TGF-β1 in the labial glands lymphocytes infiltration group were significantly higher than those in the labial glands lymphocytes non-infiltration group and control group(P＜0.01),while the levels of serum TNF-α and TGF-β1 in the labial glands lymphocytes non-infiltration group were significantly higher than those in the control group(P＜0.01).The TNF-α and TGF-β1 expression was positively correlated with lymphocytes infiltration lesion grade(r=0.867,0.613,P=0.000);the expression of TNF-α and TGF-β1 was positively correlated with the lesion grade of ILD(r=0.814,0.864,P =0.000);the level of TNF-α was positively correlated with the TGF-β1 relative expression amount(r=0.857,P=0.000).Conclusion TNF-α and TGF-β1 are involved in the lymphocytes infiltration of labial glands and ILD occurrence and develvp ment,and their expression increase may be the cause of labial glands structure destruction and complicating ILD.