Leishmania highjack host lipid body for its proliferation in macrophages by overexpressing host Rab18 and TRAPPC9 by downregulating miR-1914-3p expression.

Lipids stored in lipid-bodies (LBs) in host cells are potential sources of fatty acids for pathogens. However, the mechanism of recruitment of LBs from the host cells by pathogens to acquire fatty acids is not known. Here, we have found that Leishmania specifically upregulates the expression of host Rab18 and its GEF, TRAPPC9 by downregulating the expression of miR-1914-3p by reducing the level of Dicer in macrophages via their metalloprotease gp63. Our results also show that miR-1914-3p negatively regulates the expression of Rab18 and its GEF in cells. Subsequently, Leishmania containing parasitophorous vacuoles (Ld-PVs) recruit and retain host Rab18 and TRAPPC9. Leishmania infection also induces LB biogenesis in host cells and recruits LBs on Ld-PVs and acquires FLC12-labeled fatty acids from LBs. Moreover, overexpression of miR-1914-3p in macrophages significantly inhibits the recruitment of LBs and thereby suppresses the multiplication of parasites in macrophages as parasites are unable to acquire fatty acids. These results demonstrate a novel mechanism how Leishmania acquire fatty acids from LBs for their growth in macrophages.

Rab5 Isoforms Specifically Regulate Different Modes of Endocytosis in Leishmania.

Differential functions of Rab5 isoforms in endocytosis are not well characterized. Here, we cloned, expressed, and characterized Rab5a and Rab5b from Leishmania and found that both of them are localized in the early endosome. To understand the role of LdRab5 isoforms in different modes of endocytosis in Leishmania, we generated transgenic parasites overexpressing LdRab5a, LdRab5b, or their dominant-positive (LdRab5a:Q93L and LdRab5b:Q80L) or dominant-negative mutants (LdRab5a:N146I and LdRab5b:N133I). Using LdRab5a or its mutants overexpressing parasites, we found that LdRab5a specifically regulates the fluid-phase endocytosis of horseradish peroxidase and also specifically induced the transport of dextran-Texas Red to the lysosomes. In contrast, cells overexpressing LdRab5b or its mutants showed that LdRab5b explicitly controls receptor-mediated endocytosis of hemoglobin, and overexpression of LdRab5b:WT enhanced the transport of internalized Hb to the lysosomes in comparison with control cells. To unequivocally demonstrate the role of Rab5 isoforms in endocytosis in Leishmania, we tried to generate null-mutants of LdRab5a and LdRab5b parasites, but both were lethal indicating their essential functions in parasites. Therefore, we used heterozygous LdRab5a(+/-) and LdRab5b(+/-) cells. LdRab5a(+/-) Leishmania showed 50% inhibition of HRP uptake, but hemoglobin endocytosis was uninterrupted. In contrast, about 50% inhibition of Hb endocytosis was observed in LdRab5b(+/-) cells without any significant effect on HRP uptake. Finally, we tried to identify putative LdRab5a and LdRab5b effectors. We found that LdRab5b interacts with clathrin heavy chain and hemoglobin receptor. However, LdRab5a failed to interact with the clathrin heavy chain, and interaction with hemoglobin receptor was significantly less. Thus, our results showed that LdRab5a and LdRab5b differentially regulate fluid phase and receptor-mediated endocytosis in Leishmania.

Unconventional role of Rab4 in the secretory pathway in Leishmania.

Leishmania donovani is an auxotroph for heme. Parasite acquires heme by clathrin-mediated endocytosis of hemoglobin by specific receptor. However, the regulation of receptor recycling pathway is not known in Leishmania. Here, we have cloned, expressed and characterized the Rab4 homologue from L. donovani. We have found that LdRab4 localizes in both early endosomes and Golgi in L. donovani. To understand the role of LdRab4 in L. donovani, we have generated transgenic parasites overexpressing GFP-LdRab4:WT, GFP-LdRab4:Q67L, and GFP-LdRab4:S22N. Our results have shown that overexpression of GFP-LdRab4:Q67L or GFP-LdRab4:S22N does not alter the cell surface localization of hemoglobin receptor in L. donovani. Surprisingly, we have found that overexpression of GFP-LdRab4:S22N significantly blocks the transport of Ldgp63 to the cell surface whereas the trafficking of Ldgp63 is induced to the cell surface in GFP-LdRab4:WT and GFP-LdRab4:Q67L overexpressing parasites. Consequently, we have found significant inhibition of gp63 secretion by GFP-LdRab4:S22N overexpressing parasites whereas secretion of Ldgp63 is enhanced in GFP-LdRab4:WT and GFP-LdRab4:Q67L overexpressing parasites in comparison to untransfected control parasites. Moreover, we have found that survival of transgenic parasites overexpressing GFP-LdRab4:S22N is severely compromised in macrophages in comparison to GFP-LdRab4:WT and GFP-LdRab4:Q67L expressing parasites. These results demonstrated that LdRab4 unconventionally regulates the secretory pathway in L. donovani.

Comparative Evaluation of Autogenous Bone Graft and Autologous Platelet-Rich Fibrin with and Without 1.2 mg in situ Rosuvastatin Gel in the Surgical Treatment of Intrabony Defect in Chronic Periodontitis Patients.

Context: Rosuvastatin (RSV) is a new synthetic, hydrophilic statin with potent anti-inflammatory and osseodifferentiation actions. Autogenous bone graft (ABG) is still considered the gold standard in reconstructive bone surgery. Addition of platelet-rich fibrin (PRF) to ABG provides sustained release of various growth factors and facilitates survival of the graft. Aims: The study aims to clinically and radiographically compare the effectiveness of ABG and PRF with and without 1.2 mg RSV gel in the surgical treatment of intrabony defect in chronic Periodontitis patient. Settings and Design: This was a randomized controlled clinical trial. Subjects and Methods: Thirty-nine patients (one site per participant) with chronic periodontitis were randomly divided into three groups: Group 1 (open flap debridement [OFD] + placebo), Group 2 (OFD + ABG + PRF), and Group 3 (OFD + ABG + PRF + 1.2 mg RSV). Relative attachment level (RAL) and probing pocket depth (PPD) were recorded at baseline, 3, 6, and 9 months. Radiographic measurements such as defect height (A and B) and defect width (C) were calculated at baseline and 9 months. Statistical Analysis Used: Intergroup comparison was done using Kruskal-Wallis ANOVA. An intragroup comparison was done using Friedman test and Wilcoxon signed-rank test. Results: The mean PPD reduction and mean RAL gain were highly significant in Group 3 and Group 2 than Group 1. For Group 3, a significant reduction of defect height and width and a significant amount of bone fill were achieved than Group 2 and Group 1. Conclusions: Addition of 1.2 mg RSV gel, PRF, and ABG has synergistic effects, explaining their role as a regenerative material in the treatment of intrabony defects.

Psychometric approach to evaluate periodontal disease using Revised Illness Perception Questionnaire.

INTRODUCTION: Illness perception is the cognitive representation of an illness, which determines how a person responds to it. The Revised Illness Perception Questionnaire (IPQ-R) assesses seven components of illness representation in various chronic diseases, but queries prevail about its factor structure. The study assesses the components of illness representation in patients with chronic periodontitis. MATERIALS AND METHODS: A total of 625 voluntary, consecutive dental patients with a clinical diagnosis of periodontitis were recruited into the study. The Hindi version of IPQ-R was used, consisting of three parts-identity scale, structured scale, and perceived causes of the patient's ailment. RESULTS: Of the 625 participants, 44.0% reported cyclical disease pattern, 30.4% said their disease was a mystery. Only 1.6% predicted it to remain throughout their life. A total of 44.0% of participants reported the disease to impact their day-to-day life severely. A significant difference was observed between males and females across seven components of IPQ-R. While 21.6% of participants attributed stress to be a major cause for their diseased state, 20.8% reported workload to be a major cause, but 42.4% attributed poor medical care in the past to be a major cause for their state. CONCLUSIONS: A sensible approach to treating a disease is to measure the patient's illness perception and target specific interventions accordingly. It would be cost-effective and break misconceptions about diseases in patients, ultimately providing them with better overall health and satisfaction.

Comparative evaluation of implant stability with and without autologous platelet-rich fibrin prior to prosthetic loading - A split-mouth randomized clinical trial.

Context: Status of bone-implant interface or osseointegration can be assessed by using resonance frequency analysis (RFA), which measures implant stability. A modified implant surface can significantly enhance osseointegration and reduce healing period. Platelet-rich fibrin (PRF) consists of fibrin mesh with entrapped platelets and leukocytes that release a huge number of growth factors which contribute to wound healing and tissue regeneration. Aims: The present study aims to evaluate the effect of PRF on osseointegration in terms of implant stability. Settings and Design: This was a split-mouth randomized clinical trial. Materials and Methods: Sixty surgical sites were divided randomly into two groups. In Group 1 (thirty sites), PRF was placed in osteotomy sites before implant placement whereas no PRF was placed in Group 2 (thirty sites). Stability was measured using RFA in terms of implant stability quotient (ISQ) at baseline, 1 week, 1 month, and 3 months. Statistical Analysis: Intergroup comparison was done using Mann-Whitney U-test. Intragroup comparison was done using Friedman's test followed by pairwise comparison using Wilcoxon signed-rank test. Results: On intergroup comparison, Group 1 showed higher values for ISQ which were statistically significant (P < 0.05) at 1 week and 1 month. No significant difference (P > 0.05) was found at baseline and 3 months. Intragroup comparison and further pairwise comparison revealed a highly significant difference for values between all pairs of time intervals (P < 0.01) with higher values at 3 months. Conclusions: PRF has a significant effect on osseointegration of dental implants during the early healing period prior to loading.

Role of adjunct use of omega 3 fatty acids in periodontal therapy of periodontitis. A systematic review and meta-analysis.

BACKGROUND: Host modulation therapy has emerged as a new concept for the treatment of periodontal disease. Recently, a lot of research is being done in product containing docosahexaenoic acid (DHA) and eicosapentanoic acid (EPA). Omega-3 PUFA have therapeutic, anti-inflammatory and protective properties. This systematic review analysed the adjunctive use of omega-3 fatty acids in periodontal therapy of periodontitis patients. METHODS: PICO question (patient, intervention, comparison, and outcome) was formed. Keywords were generated and were fed in databases. The databases were Pubmed, Cochrane library and LIVIVO. Studies selected are Randomized clinical trial, clinical studies, and longitudinal studies. Meta -analysis were performed for Pocket depth (PD), Clinical attachment level (CAL), Gingival index (GI) and Plaque Index (PI). Risk of bias was also assessed. RESULTS: On analysis of all the 8 studies at 3 months showed significant effect of omega -3 fatty acid on clinical attachment level (CAL), Pocket depth (PD). There was significant effect of omega-3 fatty acids in 4 studies at 6 months. CONCLUSION: Within the limitation of the review, omega- 3 polyunsaturated fatty acids seems to have a positive effect on periodontal healing following periodontal therapy. Chronic periodontitis patient should be counselled to incorporate omega -3 fatty acid in their diet along with standard periodontal therapy.

Rab5b function is essential to acquire heme from hemoglobin endocytosis for survival of Leishmania.

Previously, we showed that Rab5a and Rab5b differentially regulate fluid-phase and receptor-mediated endocytosis in Leishmania, respectively. To unequivocally demonstrate the role of Rab5b in hemoglobin endocytosis in Leishmania, we generated null-mutants of Rab5b parasites by sequentially replacing both copies of LdRab5b with the hygromycin and neomycin resistance gene cassettes. LdRab5b-/- null-mutant parasite was confirmed by qPCR analysis of genomic DNA using LdRab5b specific primers. LdRab5b-/- cells showed severe growth defect indicating essential function of LdRab5b in parasite. To characterize the role of Rab5b in Hb endocytosis in parasites, LdRab5b-/- cells were rescued by exogenous addition of hemin in growth medium. Our results showed that LdRab5b-/- cells are relatively smaller in size. Ultrastructural analysis revealed the presence of relatively enlarged flagellar pocket and bigger intracellular vesicles in these cells in comparison to control cells. Both promastigotes and amastigotes of Rab5b null-mutant parasites were unable to internalize Hb but fluid phase endocytosis of different markers was not affected. However, complementation of LdRab5b:WT in LdRab5b-/- cells (LdRab5b-/-:pRab5b:WT) rescued Hb internalization in these cells. Interestingly, LdRab5b-/- cells showed significantly less Hb-receptor on cell surface in comparison to control cells indicating a block in HbR trafficking. Finally, we showed that LdRab5b-/- parasites can infect the macrophages but are unable to survive after 96 h of infection in comparison to control cells. However, supplementation of hemin in the growth medium significantly rescued LdRab5b-/-Leishmania survival in macrophage indicating that LdRab5b function is essential for the acquisition of heme from internalized Hb for the survival of Leishmania.

Identification and characterization of the hemoglobin-binding domain of hemoglobin receptor in Leishmania.

Leishmania internalize hemoglobin (Hb) via a specific receptor (HbR) for their survival. To identify the Hb-binding domain of HbR, we cloned and expressed several truncated proteins of HbR and determined their ability to bind Hb. Our findings reveal that 90% of Hb-binding activity is retained in HbR41-80 in comparison with HbR1-471 . We synthesized a 40 amino acid peptide (SSEKMKQLTMYMIHEMVEGLEGRPSTVRMLPSFVYTSDPA) corresponding to HbR41-80 and found that it specifically binds Hb. Subsequently, we found that the HbR41-80 peptide completely blocks Hb uptake in both promastigote and amastigote forms of Leishmania and, thereby, inhibits the growth of the parasite. These results demonstrate that HbR41-80 is the Hb-binding domain of HbR, which might be used as a potential therapeutic agent to inhibit the growth of Leishmania.

Melanotic neuroectodermal tumor of infancy in oral cavity at unusual age.

The melanotic neuroectodermal tumor of infancy is an extremely rare, fast-growing but benign lesion, commonly occurring in the maxilla of children within the first year of life. Only about 380 cases of this particular tumor have been documented in the medical literature and very few of them have been reported to have occurred in late childhood. We describe here a relatively uncommon presentation of melanotic neuroectodermal tumor of infancy of maxilla arising from palatal gingiva of a 10 year-old female, its course and management by surgical excision with safe margins.

Langerhans' Cell Histiocytosis Diagnosed through Periodontal Lesion in a 15-year-old Child: A Case Report.

Langerhans' cell histiocytosis (LCH) is a rare disease of the reticuloendothelial system in which there are abnormal proliferation and accumulation of histiocytes, abnormal cells deriving from bone marrow that can migrate from the skin to the lymph nodes. Langerhans' cell histiocytosis has three variants: unifocal (eosinophilic granuloma), multifocal unisystem (Hand-Schuller-Christian triad), and multifocal multisystem (Letterer-Siwe disease). We present a case of oral lesions associated with LCH in a young male aged 15 years. The history, radiological appearance, histopathology, and treatment options of the patient are discussed. How to cite this article: Soangra R, Kapoor A, Meena D, et al. Langerhans' Cell Histiocytosis Diagnosed through Periodontal Lesion in a 15-year-old Child: A Case Report. Int J Clin Pediatr Dent 2020;13(S-1):S115-S118.

Effect of commercially available nano-hydroxy apatite containing desensitizing mouthwash on dentinal tubular occlusion: an in vitro FESEM analysis.

BACKGROUND AND AIM: Dentinal hypersensitivity is a significant clinical problem encountered in daily dental practice. The management of this condition requires a good understanding of the complexity of the problem, as well as the variety of treatments currently available. The treatment approaches can be either home care products or professionally applied desensitizing agents. The present in-vitro study was designed to investigate the dentinal tubule occluding ability of commercially available nano HA containing mouthwash using FESEM analysis. METHODS: In the present in vitro study, 15 human premolars and canines were taken and sectioned mesiodistally. A total of 30 dentinal samples were obtained. All the dentinal discs were etched with 6% citric acid for 2 minutes. The treated samples were washed thoroughly with distilled water for 30 seconds. Samples were divided in two groups of 15 each. The specimens in Group I were shaken vigorously in the Vitis Sensitive mouthwash for 2 min twice daily for 14 days. After this intervention samples were placed in distilled water. Group II specimens were immersed in distilled water. Samples were subjected to FESEM to analyze for tubular occlusion. RESULTS: In group I nearly complete dentinal surface occlusion was present on the 7th and 14th day and precipitates were seen covering a large part of the dentinal surface. In group II no dentinal tubular occlusion was observed. CONCLUSION: The results of the present study support the ability of nHA containing Vitis sensitive mouthwash to occlude the dentinal tubules and thus it may demonstrate a significant reduction in dentinal hypersensitivity when used clinically.

Clinical efficacy of amino bisphosphonate on periodontal disease status in postmenopausal women: Randomized double-blind placebo-controlled trial.

OBJECTIVES: Osteoporosis is a common skeletal disorder affecting postmenopausal women. Data suggest that postmenopausal women are at increased risk of periodontal diseases. Amino bisphosphonates are potent inhibitors of bone resorption and effectively used in the treatment of osteoporosis. Preliminary data indicate that there is a potential role for bisphosphonates in the management of periodontitis. Hence, this randomized placebo-controlled trial was designed to investigate the clinical efficacy of amino bisphosphonate on periodontal disease status among postmenopausal women. MATERIALS AND METHODS: Thirty patients were randomly allocated to two treatment groups: Group A, which received scaling and root debridement and 70 mg weekly single oral dose of alendronate drug, and Group B, which received scaling and root debridement and placebo drug for 6 months. Clinical periodontal measurements were carried out for all patients at the baseline and 6 months later. Mandibular bone mineral density (BMD) was measured using a dual energy X-ray absorptiometer at the beginning of the study and the end of 6 months. RESULTS: A weekly single oral dose of 70 mg alendronate was well-tolerated. The intragroup comparison showed significant improvement in periodontal parameters in both groups. The intergroup comparison showed a significant increase in BMD after 6 months in Group A when compared with Group B (P = 0.0179). CONCLUSION: Single oral dose of 70 mg alendronate per week is well-tolerable, gastro-intestinally safe, and improves the clinical outcome of nonsurgical periodontal therapy.

Efficacy of Locally Administered 1.2% Rosuvastatin Gel in Patients with Periodontitis: A Randomized Placebo Controlled Clinical Trial.

OBJECTIVE: Periodontitis initiation and progression are a result of host immune inflammatory response to oral pathogens. Several pharmacological agents are being delivered locally, to improve periodontal health. Hence, the present randomized placebo controlled clinical trial is designed to check the clinical and antimicrobial efficacy of locally delivered 1.2% rosuvastatin (RSV) in intrabony defects (IBD) in periodontitis patients. MATERIALS AND METHODS: One-hundred patients were randomly allotted into two treatment groups: group A received 1. 2% RSV gel, scaling and root debridement and group B received placebo gel, scaling and root debridement. Clinical parameters, including modified sulcus bleeding index (mSBI), probing depth (PD), clinical attachment level (CAL), and plaque index (PI), were recorded at baseline before phase 1 and after 6 months. Radiographic assessment of IBD was done by cone beam computed tomography at baseline and after 6 months. Anaerobic colony count was done at baseline and after 180 days. RESULTS: On intragroup comparison, there is a significant improvement in periodontal parameters in both the groups. On intergroup comparison, there is significant gain in CAL in group A than group B (p = 0.04). There is significant decrease in PD in group A, compared to group B. There is significant bone fill in group A (p = 0.034), compared to group B. With respect to mSBI, PI, and anaerobic colony count, there is no significant difference between the two groups after 6 months. No adverse effect was noticed in any subjects. CONCLUSION: The author concludes that 1.2% RSV gel when delivered locally into IBD improved periodontal clinical parameters such as PD and CAL and showed significant bone fill.

Salmonella SipA mimics a cognate SNARE for host Syntaxin8 to promote fusion with early endosomes.

SipA is a major effector of Salmonella, which causes gastroenteritis and enteric fever. Caspase-3 cleaves SipA into two domains: the C-terminal domain regulates actin polymerization, whereas the function of the N terminus is unknown. We show that the cleaved SipA N terminus binds and recruits host Syntaxin8 (Syn8) to Salmonella-containing vacuoles (SCVs). The SipA N terminus contains a SNARE motif with a conserved arginine residue like mammalian R-SNAREs. SipAR204Q and SipA1-435R204Q do not bind Syn8, demonstrating that SipA mimics a cognate R-SNARE for Syn8. Consequently, Salmonella lacking SipA or that express the SipA1-435R204Q SNARE mutant are unable to recruit Syn8 to SCVs. Finally, we show that SipA mimicking an R-SNARE recruits Syn8, Syn13, and Syn7 to the SCV and promotes its fusion with early endosomes to potentially arrest its maturation. Our results reveal that SipA functionally substitutes endogenous SNAREs in order to hijack the host trafficking pathway and promote Salmonella survival.

Functional characterisation of a WRKY transcription factor of wheat and its expression analysis during leaf rust pathogenesis.

WRKY proteins are a large family of plant-specific transcription factors associated with regulation of biotic and abiotic stress responses, but how they respond to cereal rust pathogens has never been explored at the molecular level. Full-length cDNA of TaWRKY1B was obtained from a wheat cultivar HD2329 derivative containing leaf rust resistance gene Lr28 based on domain characteristics. The unique feature of this WRKY transcription factor gene was the close proximity of the DNA-binding domain and consensus DNA element W-Box within the open reading frame. Infection with a virulent race of leaf rust fungus resulted in 146-fold induction of the gene in resistant plants, but only 12-fold in the susceptible plants as compared with mock-inoculated controls. Docking models of 74 amino acids DNA-binding domain and 26bp W-Box element showed that the WRKY domain, located on the ß1 strand, only interacts with the W-Box at positions corresponding to W125, R126, K127 and Y128 amino acids. A truncated recombinant protein of 9.0 kD, encompassing the DNA-binding domain also showed binding specificity to the 32bp W-Box element in electrophoretic mobility shift assays. The protein-DNA ensemble was also characterised using high-resolution atomic force microscopic imaging. The results contribute to an understanding of the molecular structure and function of a previously uncharacterised WRKY transcription factor in wheat that can be manipulated to improve biotic stress tolerance.

Management of Phenytoin-Induced Gingival Enlargement: A Case Report.

Gingival enlargement is frequently observed in patients taking certain drugs such as anticonvulsants, immune suppressants, and calcium channel blockers. The effects of these drugs are not only directed at the primary target tissues, but also on secondary target tissues, such as gingival connective tissue, causing clinical, and histopathological aberrations. These aberrations can adversely affect speech, mastication, tooth eruption, and esthetics. Disfiguring gingival overgrowth triggered by these medications often impairs the nutrition and provides access to oral infection, caries, and periodontal disease. The present case report describes the treatment of a patient with a phenytoin induced gingival enlargement.

Papilla Reconstruction: A Case Report.

Smile plays an important role in improving esthetics and radiates health and self-confidence. The perfect smile requires an optimal relationship between the teeth, surrounding oral tissues, and periodontal complex. When a disharmony exists between any of these components, the result is a smile that is likely to be perceived as unaesthetic. Similar is the case with interdental bone loss resulting in increased embrasure spaces, with unaesthetic appearance especially in the anterior maxillary regions. Periodontal papilla reconstruction has proved to be a successful technique and a boon to the patient in such a case to return an esthetic and healthy smile to the patient. We report here a similar case of papilla reconstruction with pre-treatment and post-treatment differences depicted in the esthetics.