Heba M. Saad Eldien

Increased Levels of Type 1 Interferon in a Type 1 Diabetic Mouse Model Induce the Elimination of B Cells from the Periphery by Apoptosis and Increase their Retention in the Spleen

Background: The autoimmune disease type 1 diabetes mellitus (T1D) is associated with a defect in the immune response, which increases susceptibility to infection. We recently demonstrated that prolonged elevated levels of type 1 interferon (IFN) induce lymphocyte exhaustion during T1D. Aims: In the present study, we further investigated the effect of blocking the type I IFN receptor signaling pathway on diabetic dyslipidemia, in which an abnormal lipid profile leads to the exhaustion of B cells and alteration of their distribution and functions. Methods: T1D was induced in a mouse model by an intraperitoneal injection of a single dose (60 mg/kg) of streptozotocin (STZ). Three groups of mice were examined: a non-diabetic control group, a diabetic group and a diabetic group treated with an anti-IFN (alpha, beta and omega) receptor 1 (IFNAR1) blocking antibody to block type I IFN signaling. Results: We observed that induction of T1D was accompanied by a marked destruction of β cells and a reduction in the insulin levels in the diabetic group. Diabetic mice exhibited many changes, including alterations in their lipid profiles, expansion of splenic B cells, increased caspase-3, -8 and -9 activity, and apoptosis in peripheral B cells. Blocking type 1 IFN signaling in diabetic mice significantly returned the insulin and lipid profiles to normal levels, subsequently restored the B cell distribution, and rescued the peripheral B cells from apoptosis. Conclusion: Our data suggest the potential role of type I IFN in mediating diabetic dyslipidemia and an exhausted state of B cells during T1D.

Blocking Type I Interferon Signaling Rescues Lymphocytes from Oxidative Stress, Exhaustion, and Apoptosis in a Streptozotocin-Induced Mouse Model of Type I Diabetes

Elevated levels of type I interferon (IFN) during type 1 diabetes mellitus (T1D) are associated with a defective immune response. In the present study, we investigated whether blocking type I IFN signaling during streptozotocin- (STZ-) induced T1D in mice improves lymphocyte proliferation and escape from continuous apoptosis. Three groups of mice were examined: diabetic mice, type I IFN signaling-incompetent diabetic mice, and control nondiabetic mice. We first found that diabetes induction was accompanied by an elevation in the plasma levels of reactive oxygen species (ROS), hydroperoxide, malondialdehyde (MDN), and the proinflammatory cytokines IL-1α, IL-1β, IL-6, and CXCL10. Blocking type 1 IFN signaling in diabetic mice significantly decreased the levels of oxidative stress and proinflammatory cytokines. In addition, lymphocytes from diabetic mice exhibited a marked reduction in their proliferative capacity, increased apoptosis, upregulation of the exhaustion marker PD-1, and aberrant phosphorylation of STAT1, STAT2, AKT and IκB-α. Interestingly, following the blocking of type I IFN signaling in diabetic mice, the lymphocytes exhibited restored proliferative capacity, decreased apoptosis, normal expression of PD-1, and normal phosphorylation of STAT1, STAT2, AKT and IκB-α. Our data suggest that elevated levels of type I IFN during T1D trigger lymphocyte exhaustion and a defective lymphocyte-medicated immune response.

Blocking Type I Interferon (IFN) Signaling Impairs Antigen Responsiveness of Circulating Lymphocytes and Alters Their Homing to Lymphoid Organs: Protective Role of Type I IFN

Background: We recently demonstrated that type I Interferon (IFN) rescues in vitro, human B-lymphocytes from apoptosis via PI3Kδ/Akt, Rho-A, NFĸB and Bcl-2/BclXL. In the present study we extended our work to clarify, in vivo, the role of type I IFN signalling on the circulating and lymphoid organs homing lymphocytes. Methodology: Two groups of mice 13 in each were set: type I IFN signalling blocked mice injected with anti-IFNAR1 antagonist antibody (10 mg/kg body weight) once/day for up to 20 days, and control group were injected with vehicle alone. Results: Flow cytometry analysis to monitor the blood lymphocyte phenotype and proliferation have shown a significant decrease in CD45R/CD220+ B cells, CD4+ and CD8+ T cells in treated animals. Furthermore, the proliferative capacities of these lymphocyte subsets were significantly decreased in treated animals compared to those of control mice. Marked reduction in the plasma levels of IL-2 and IL-7 (cytokines important for the development of T and B cells) but not of IL-6 or IL-10 was observed in treated mice and this may a cause for emergence decrease in B and T cell numbers. Immunohistochemical studies have further shown a marked reduction in the numbers of CD20+ B cells in spleen and Peyer’s patches and CD3+ T cells in thymus of treated animals. Moreover, electron microscopy examinations have revealed a loss of lymphocytes with characteristic features of apoptosis. Conclusion: Our data confirmed that the in vivo inhibition of type I IFN signaling induce decrease in the numbers and defective functions of circulating and lymphoid organs homing lymphocytes providing a strong evidence for the protective effects of type 1 IFNs (IFN-α/ β) on B and T lymphocytes.

Time-dependent Morphological and Biochemical Changes following Cutaneous Thermal Burn Injury and Their Modulation by Copper Nicotinate Complex: An Animal Model

Background: Thermal tissue injury is partly mediated by reactive oxygen metabolites. Oxygen free radicals are contributory to local tissue damage following thermal injury and accordingly an interventional therapy using antioxidants may be beneficial. Copper nicotinate complex can scavenge reactive oxygen species (i.e., has antioxidant activity). Objectives: To examine time-related morphological and biochemical changes following skin thermal injury and their modulation by copper nicotinate complex. Materials and Methods: An animal model composed of 80 albino rats was established. Ten rats (nonburn group) served as a control group. Seventy rats (burn group) were anesthetized, given a 10% total body surface area, full-thickness burn. Ten rats (from the postburn group) were sacrificed after 24 h (without treatment, i.e., untreated-burn group). The remaining rats were divided into three subgroups (20 rats, each) and were treated topically either with soft paraffin, moist exposed burn ointment (MEBO, a standard therapeutic treatment for burns), or copper nicotinate complex. Five animals from each subgroup were sacrificed every week over a period of 4 weeks. The morphological and biochemical changes were evaluated and compared among the different groups. Results: High levels of the plasma and skin nitiric oxide (marker of oxidative stress) were observed in the untreated-burn group. These levels were significantly low following the application of copper nicotinate complex. Low levels of plasma and skin superoxide dismutase (marker of oxidative stress) and plasma ceruloplasmin were observed in the untreated-burn group. These levels were significantly high following copper nicotinate complex treatment. The total and differential leukocyte counts were low following the onset of the thermal injury. They gradually returned to normal levels over a 4-week period following the application of MEBO or copper nicotinate complex. Compared to untreated-burn group, postburn-healing changes (resolution of the inflammatory reaction, reepithelization of the epidermis, angiogenesis, deposition of collagen fibers, and recovery of the subcellualr organelles) were significantly accelerated following the application of either MEBO or copper nicotinate complex. Conclusions: Application of copper nicotinate complex was associated with improved healing of the thermal burns of the skin. The underlying molecular changes underlying these effects await further investigations.

Sensory innervation of the female human umbilical skin: morphological studies.

Background: Sensory stimuli are conducted by several cutaneous sensory nerves and tactile corpuscles. The latter are specialized sensory organs that represent the starting point of many afferent sensory pathways. To date, our knowledge about the distribution of the sensory innervation in the umbilical skin of females is incomplete. Aim of the study: To elucidate the morphology of the cutaneous innervation of the normal female umbilical skin. Materials and methods: Biopsies of normal umbilical skin were obtained from female patients undergoing umbilical hernial repair. The specimens were processed for both immunohistological (antibodies against PGP9.5, pan-neuronal marker, and S-100 protein, marker of Schwann cells) and ultrastructural (transmission electron microscopy) examinations. Results: The authors found abundant genital end-bulb-like structures, numerous epidermal and dermal Merkel cells, Meissner and Ruffini corpuscles, intraepidermal nerve terminals, and multiple free nerve endings surrounding the ducts and acini of the sweat glands. Conclusions: The umbilical skin of females has abundant sensory innervation similar to that of the glans penis.

Beta 2 Adrenergic Receptor Genetic Polymorphisms in Bronchial Asthma: Relationship to Disease Risk, Severity, and Treatment Response

BackgroundThe β2-adrenergic receptor gene is one of the most extensively studied genes with respect to asthma prevalence and severity. The Arg16Gly and Gln27Glu polymorphisms in the β2-adrenergic receptor gene cause changes in the amino acids sequence of the receptor which may cause alteration in response to bronchodilators and the risk of asthma.ObjectiveThe purpose of the study was to determine the association between β2-adrenergic receptor gene polymorphisms and asthma risk, severity and response to therapy.Subjects and Methods58 asthmatic patients and 38 healthy subjects were included. The β2-adrenergic receptor polymorphisms genotyping was done using Real-Time polymerase chain reaction.ResultsThe allelic frequencies for the Arg16Gly polymorphism were 15.5%, 48.3%, and 36.2% for the homozygous A wild, heterozygous, and homozygous G mutant alleles in asthmatics (P < 0.01) and 5.3%, 47.4%, and 47.4% in healthy subjects (P < 0.01). For the Gln27Glu polymorphism, the allelic frequencies for the homozygous C wild, heterozygous and homozygous G mutant alleles were 51.7%, 41.4%, and 6.9% in asthmatics (P < 0.01) and 44.7%, 39.5%, and 15.8% in healthy subjects (P < 0.01). The heterozygous Arg16Gly and Gln27Glu were found in most of severe asthma cases (7/13, 53.8% each). While homozygous wild and mutant seemed to be protective and associated with mild disease in both alleles. Finally, 75% of Arg16Gly heterozygous group were good responders (P < 0.01), 81% of homozygous G mutant were bad responders. For Gln27Glu polymorphism, 60% of C wild group were good responders and 75% of G mutant group were bad responders.ConclusionsThe findings suggest that the Arg16Gly and Gln27Glu polymorphisms in the β2-AR gene are associated with asthma severity and response to therapy and might be used in personalized treatment for these patients in the future. This work is registered in ClinicalTrial.gov with ID: NCT03118869.

The possible protective and therapeutic roles of fucoidan in cyclosporine-induced histological changes in the bone marrow and spleen in rats

Background Cyclosporine A (CsA), a potent immunosuppressive agent, has several adverse effects. Mild myelotoxicity and splenic toxicity has been reported after the administration of CsA. Fucoidan (FU) is a sulfated polysaccharide extracted from marine algae, and it has numerous biological activities, acting as an antioxidant and immune-modulator. The aims of the study were therefore to evaluate whether CsA toxicity in the bone marrow and spleen are dose and duration dependent and also to study the possible protective and therapeutic role of FU in these tissues. Materials and methods Rats were divided into six equal groups. Group C1 and group C2 were used as controls. Group CAI was treated with a small dose of CsA, group CAI+FUI was treated with CsA concomitant with FU, group CAII was treated with a high dose of CsA and allowed to recover for another 10 days, and group CAII+FUII was treated with CsA, followed by with FU for another 10 days. Result After a small dose of CsA was administered, the bone marrow showed numerous plasma cells, with variable degrees of degenerative changes, and macrophages. After FU treatment, immature and healthy cells were increased. After a large dose of CsA was administered, marked degenerative changes were observed, the changes that occurred later were ameliorated after FU treatment. Moreover, reductions in CD3+, major histocompatibility complex II+ expression in the spleen as well as interleukin-2 levels in the plasma were observed after CsA; these changes were ameliorated to varying degrees after FU treatment. Conclusion CsA exerted dose-dependent and duration-dependent toxicity in the bone marrow and spleen. FU treatment exerted immune-modulator and antioxidant effects against CsA-induced changes in the bone marrow and spleen.