Biomedical subjects

M Toyoda

Publications and source records attributed to M Toyoda.

At least 37 records · Page 2Linked to original sources

PubMed2001

Overexpression of hepatocyte growth factor/scatter factor promotes vascularization and granulation tissue formation in vivo.

The effect of hepatocyte growth factor/scatter factor (HGF/SF) during wound healing in the skin was investigated, using HGF/SF-overexpressing transgenic mouse model. Histological analysis of HGF/SF transgenic mouse excisional wound sites revealed increased granulation tissue with marked vascularization. Northern blot analysis demonstrated that, relative to control, vascular endothelial growth factor (VEGF) expression in transgenic skin was significantly higher at baseline and was robustly up-regulated during wound healing. Elevated levels of VEGF protein were detected immunohistochemically, predominantly in endothelial cells and fibroblasts within the granulation tissue of HGF/SF transgenic skin. Serum levels of VEGF were also elevated in HGF/SF transgenic mice. Thus, results from our study suggest that HGF/SF has a significant effect on vascularization and granulation tissue formation during wound healing in vivo, involving with induction of VEGF.

Animals↗

PubMed2001

Determination of aflatoxins B1, B2, G1 and G2 in spices using a multifunctional column clean-up.

A rapid and simple method using a multifunctional column, which contains lipophilic and charged active sites, was developed to analyse aflatoxins B1, B2, G1 and G2 in various spices, such as red pepper and nutmeg. After extraction by acetonitrile:water (9:1) and clean-up using MultiSep #228 column, the aflatoxins and aflatoxin-TFA derivatives are determined using LC with fluorescence detection. Recoveries of each aflatoxin B1, B2, G1 and G2 spiked to red pepper, white pepper, black pepper, nutmeg and tear grass at the level of 10 ng/g were over 80-85% in all instances. The minimum detectable concentration for aflatoxins in red pepper was 0.5 ng/g.

Aflatoxins↗

PubMed2001

Specific tissue distribution of megsin, a novel serpin, in the glomerulus and its up-regulation in IgA nephropathy.

Mesangial cells play critical roles in maintaining a structure and function of the glomerulus. We previously cloned a novel mesangium-predominant gene, megsin, a new serine protease inhibitor. To clarify localization and roles of megsin protein, we raised polyclonal antibodies to megsin. By immunohistochemistry, megsin protein was specifically identified in the mesangial area. The amount of megsin protein was increased in glomeruli of patients with IgA nephropathy than in those of normal individuals and of patients with minimal change nephrotic syndrome or membranous nephropathy, suggesting a pathophysiological role of megsin as a functional modulator of mesangial functions in situ.

Amino Acid Sequence↗

PubMed2001

Examination of oral sensitization with ovalbumin in Brown Norway rats and three strains of mice.

We studied the conditions needed to sensitize animals to the oral feeding of food allergens, without induction of tolerance, in order to investigate the allergenicity of orally ingested food proteins. Brown Norway (BN) rats were sensitized by daily OVA (ovalbumin)-gavage or by drinking OVA containing water ad libitum and the ASA (active systemic anaphylaxis) response, as the immediate hypersensitivity response to antigen stimulation after oral sensitization, was examined. The oral administration of OVA by gavage produced a higher OVA-specific IgE response and an increase in serum histamine after antigen challenge, as compared to those produced by drinking water. Next, we examined the effect of murine age, the oral feeding technique and the oral feeding dose on sensitization using BALB/c, B10A and ASK mice. Twenty-week-old mice showed the strongest OVA-specific IgE and IgG1 responses and ASA-associated serum histamine contents increased with gavage in the three different age groups of BALB/c mice. Administering 0.1 mg of OVA by gavage daily for 9 weeks appeared to induce a higher response than administering 1 mg of OVA, in terms of OVA-specific IgE and IgG1 antibody responses and ASA responses. Among the three strains of mice, B10A mice exhibited the highest response in terms of OVA-specific IgE and IgG1 antibody and ASA responses. These findings suggested BN rats and B10A mice were suitable models for oral sensitization with antigen protein and that oral sensitization in mice requires low dose, intermittent antigen intakes.

Administration, Oral↗

PubMed2001

Expression of survivin correlates with apoptosis, proliferation, and angiogenesis during human colorectal tumorigenesis.

BACKGROUND: To identify the role of survivin, a novel inhibitor of apoptosis (IAP) in colorectal tumorigenesis, the authors investigated tissue expression of survivin in human colorectal tumors including 43 hyperplastic polyps, 171 adenomas with low dysplasia, 42 adenomas with high dysplasia, and 60 carcinomas in adenoma, and examined whether the expression of survivin correlated with tumor cell apoptosis, proliferation, and angiogenesis, which is known to initiate the imbalance between cell proliferation and apoptosis. METHODS: Immunohistochemical staining for the paraffin sections by using the monoclonal antibodies, survivin, p53, bcl-2, Ki-67, and CD34, was performed by the standard avidin-biotin-peroxidase technique. The apoptotic cells were detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method, using an Apop Tag in situ detection kit. RESULTS: The immunoreactivity of survivin significantly increased in the transition from adenoma with low dysplasia to high dysplasia/carcinoma (P < 0.001). Similar changes in protein expression were observed for p53 but not for bcl-2, which was expressed throughout the colorectal tumorigenesis. This transition was associated with a significant decrease in the apoptotic index (AI) and significant increases in the Ki-67 labeling index (LI) and microvessel density (MVD; P < 0.001 for both). The expression of survivin inversely correlated with AI and was positively correlated with Ki-67 LI and MVD (P < 0.001 for both). CONCLUSIONS: These results suggest that, like p53, survivin plays an important role in transition from adenoma with low dysplasia to high dysplasia during human colorectal tumorigenesis.

Adenoma↗

PubMed2001

Prolongation of allograft survival with viral IL-10 transfection in a highly histoincompatible model of rat heart allograft rejection.

BACKGROUND: The ability to express genes with potential immunoregulatory capacity could reduce the immunogenicity of allografts and result in long-term graft survival. In this study, we examine the feasibility of transferring viral interleukin-10 (vIL-10) gene into rat hearts using adenovirus by intracoronary administration. The subsequent effects of delivered vIL-10 alone or with subtherapeutic doses of cyclosporine A (CsA) on parameters of allograft rejection (AR) were also examined. METHODS: Recombinant adenovirus vectors containing vIL-10 (Ad-vIL-10) or beta-galactosidase (Ad-beta-gal) were derived from adenovirus type 5. vIL-10 expression in supernatants of transfected COS7 cell cultures and in transfected heart allografts were examined by enzyme immunoassay (EIA) and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. Rat heart transplants (LEWS->ACI) were performed in five groups [group 1: no treatment, group 2: Ad-beta-gal, group 3: AdvIL-10, group 4: CsA (10 mg/kg), and group 5: Ad-vIL10+CsA (10 mg/kg)]. Allograft survival was determined by palpating heartbeats. Allograft tissues were also submitted for histological study. RESULTS: vIL-10 expression was shown in both transfected COS7 cells and heart isografts. Animals transfected with vIL-10 showed prolongation of graft survival (19.6 vs. 12 days, P<0.001) when compared to beta-gal transfected controls. Animals treated with a single low dose injection of CsA showed no significant prolongation of graft survival compared to controls (11.7 vs. 10.5 days). Animals treated with both vIL-10 and CsA demonstrated a synergistic prolongation of allograft survival compared with controls and with animals treated with CsA or vIL-10 treatment alone (36.7 days vs. 11.7, P<0.001 or 36.7 vs.19.6, P<0.001, respectively). Histological study showed that allografts from untreated controls exhibited extensive AR with loss of graft architecture by day 7 posttransplant while those from the vIL-10 group showed less AR. The best pathological scores were seen in vIL-10 + CsA-treated animals. CONCLUSIONS: 1) Delivering Ad-vIL-10 into donor hearts by intracoronary perfusion results in overexpression of vIL-10 and significantly prolongs cardiac allograft survival in a highly histoincompatible rat model. 2) Subtherapeutic doses of CsA do not prolong allograft survival, but act synergistically with vIL-10 to significantly prolong graft survival beyond that achieved with either agent alone.

Adenoviridae↗

PubMed2001

Comparative evaluation of surgical stress of laparoscopic and open surgeries for colorectal carcinoma.

PURPOSE: To objectively evaluate the benefits of laparoscopic procedures for colorectal carcinoma, a prospective study to measure the stress response to laparoscopic surgery (n = 15) compared with open surgery (n = 12) was undertaken. In addition, to compare the various parameters relevant to surgical stress, the major surgery group (transthoracic esophagectomy for esophageal carcinoma, n = 4; and left upper abdominal evisceration for gastric carcinoma, n = 3) was assigned. METHODS: Peripheral blood samples were obtained to measure serum interleukin-6, C-reactive protein, peripheral leukocytes, and lymphocyte counts. Additionally, the level of lymphocyte apoptosis was quantified using flow cytometry. RESULTS: The interleukin-6 and C-reactive protein levels were significantly greater in the open group than in the laparoscopy group one day (P < 0.05) and two days (P < 0.05) after surgery, respectively. In the laparoscopy group, lymphocyte counts were significantly higher than in the open group two days after surgery. The laparoscopy and open groups did not differ significantly in their lymphocyte apoptotic index. In the major surgery group, the apoptotic index was significantly higher than in either the laparoscopy group or the open group in the early postoperative period. CONCLUSION: Changes in the various parameters pertinent to surgical stress evaluated in this study suggest that laparoscopic surgery for colorectal carcinoma leads to less postoperative stress than conventional open surgery.

Aged↗

PubMed2001

Identification of a new point mutation in the human xanthine dehydrogenase gene responsible for a case of classical type I xanthinuria.

A 60-year-old Japanese man was diagnosed as having hypouricemia at an annual health check-up. The routine laboratory data was not remarkable except that the patient's hypouricemia and plasma levels of xanthine and hypoxanthine were much higher than those of normal subjects. Furthermore, the patient's daily urinary excretion of xanthine and hypoxanthine was markedly increased compared with reference values. The xanthine dehyrogenase activity of the duodenal mucosa was below the limits of detection. Nevertheless, allopurinol was metabolized to oxypurinol in vivo. Based on these findings, a subtype of classical xanthinuria (type I) was diagnosed. The xanthine dehyrogenase protein was detected by Western blotting analysis. Sequencing of the cDNA of the xanthine dehyrogenase obtained from the duodenal mucosa revealed that a point mutation of C to T had occurred in nucleotide 445. This changed codon 149 from CGC (Arg) to TGC (Cys), a finding that has not been previously reported in patients with classical xanthinuria type I.

Allopurinol↗

PubMed2001

Regression of lymph node metastases by immunotherapy using autologous breast tumor-lysate pulsed dendritic cells: report of a case.

A 50-year-old woman was diagnosed as having stage IV breast cancer with bilateral supraclavicular lymph node metastasis resistant to CAF therapy. She received immunotherapy using autologous tumor lysate-pulsed dendritic cells (DCs). Four cycles of DC injection into the right supraclavicular lymph nodes resulted in regression of bilateral supraclavicular lymphogenous metastasis. Histological studies revealed an accumulation of CD45+ T lymphcytes in the regressive lymph nodes. This case suggests that immunotherapy with DCs may be a safe and promising approach for the treatment of advanced breast cancer.

Adjuvants, Immunologic↗

PubMed2001

Pathogenesis of acne.

Acne vulgaris is a skin disorder of the sebaceous follicles that commonly occurs in adolescence and in young adulthood. The major pathogenic factors involved are hyperkeratinization, obstruction of sebaceous follicles resulting from abnormal keratinization of the infundibular epithelium, stimulation of sebaceous gland secretion by androgens, and microbial colonization of pilosebaceous units by Propionibacterium acnes, which promotes perifollicular inflammation. The clinical presentation of acne can range from a mild comedonal form to severe inflammatory cystic acne of the face, chest, and back. At the ultrastructural level, follicular keratinocytes in comedones can be seen to possess increased numbers of desmosomes and tonofilaments, which result in ductal hypercornification. The increased activity of sebaceous glands elicited by androgen causes proliferation of P. acnes, an anaerobe present within the retained sebum in the pilosebaceous ducts. The organism possesses a ribosome-rich cytoplasm and a relatively thick cell wall, and produces several biologically active mediators that may contribute to inflammation, for instance, by promoting leukocyte migration and follicular rupture. In inflamed lesions, numerous neutrophils and macrophages infiltrate around hair follicles and sometimes phagocytose P. acnes. To examine the participation of neurogenic factors in the pathogenesis of acne, we quantitatively assessed the effects of neuropeptides on the morphology of sebaceous glands in vitro using electron microscopy. Substance P, which can be elicited by stress, promoted the development of cytoplasmic organelles in sebaceous cells, stimulated sebaceous germinative cells, and induced significant increases in the area of sebaceous glands. It also increased the size of individual sebaceous cells and the number of sebum vacuoles for each differentiated sebaceous cell, all of which suggests that substance P promotes both the proliferation and the differentiation of sebaceous glands. In this review, we introduce the general concept of pathogenic factors involved in acne, including typical electron microscopic findings and recent evidence of stress-induced exacerbation of acne from a neurological point of view. An improved understanding of the pathogenesis of acne should lead to a rational therapy to successfully treat this skin disease.

Acne Vulgaris↗

PubMed2001

Ultrastructural characteristics of trichilemmal cysts: report of two cases.

Two trichilemmal cysts (TC) on the scalps of two Japanese women were examined at the electron microscopic level. The ultrastructural characteristics of the TC included an abrupt transition from nucleate to anucleate cells, a few oval, small, keratohyaline granules mixed with increasing numbers of tonofibrils from the peripheral layer towards the center, spherical particles with lipid droplets, desmosomal structures in keratinized cells, and the interdigitation of keratin in the uppermost keratinizing cells. The keratinization pattern of the TC was unique in that typical soft or hard keratinization processes did not occur. Trichilemmal keratinization is observed in the trichilemmal sacs that surround the lower ends of catagen or telogen hairs, as well as in the outer root sheaths in the follicular isthmus of anagen hairs. Comparison of the ultrastructure of these two known types of trichilemmal keratinization with the keratinization pattern of the TC in our patients indicates that TC may differentiate into, or originate from, the proliferation of the outer root sheath in the follicular isthmus of anagen hairs.

Adult↗

PubMed2001

Update of daily intake of PCDDs, PCDFs, and dioxin-like PCBs from food in Japan.

Total diet study (TDS) samples of 14 food groups from 16 locations in Japan, collected in 1999 and 2000, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) to estimate the update of daily intake of these contaminants from food. The mean daily intake of toxic equivalency (TEQ) for an adult weighing 50 kg, calculated at non-detected isomer concentrations equal to zero (ND = 0), was estimated to be 2.25 pg TEQ/kg b.w./day. When non-detected isomer concentrations are assumed to be equal to half of the limits of detection (ND = 1/2 LOD), the mean daily intake was estimated to be 3.22 pg TEQ/kg b.w./day. These values were below the tolerable daily intake (TDI) of 4 pg TEQ/kg b.w. for PCDD/Fs and dioxin-like PCBs set in Japan. In both the estimates, the mean daily intakes were highest from fish and shellfish (76.9% at ND = 0 and 53.9% at ND = 1/2 LOD of the total TEQs), followed by those from meat and eggs (15.5% at ND = 0 and 11.7% at ND = 1/2 LOD of the total TEQs). Congener specific data revealed that these total TEQ levels were dominated by 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB in each case (71.7% at ND = 0 and 63.1% at ND = 1/2 LOD of the total TEQs). The dioxin-like PCBs (non-ortho and mono-ortho PCBs) accounted for about 50% of these total TEQs. These data will be very useful in the risk assessment of PCDD/Fs and dioxin-like PCBs from food in Japan.

Adult↗

PubMed2001

Ultrastructural characterization of microvasculature in photoaging.

The cutaneous microvasculature was examined by electron microscopy in order to compare its characteristics in photodamaged preauricular skin and in sun-protected postauricular sites of 15 Japanese women aged 58-81 years. The characteristic ultrastructural features of the microvasculature in photodamaged skin compared with those in sun-protected skin included dilated vessels embedded in elastin which depressed endothelial cells, vessels surrounded by a thick amorphous material composed of multiple laminations of a basement membrane-like material, and activated endothelial cells which had increased numbers of cytoplasmic organelles and pinocytotic vesicles. A novel finding of this study in photodamaged vessels was an increased formation of new vessels (angiogenesis) via two distinct pathways. In severe elastosis, activated endothelial cells with densely packed intracytoplasmic microfilaments extended large pseudopods into the elastotic material. In contrast, isolated mesenchymal cells, which possessed immature Weibel-Palade bodies, were scattered around pre-existing vessels within the Grenz zone. In some cases, many mesenchymal cells with electron-lucent cytoplasms aggregated and interconnected by cytoplasmic processes, which was followed by the formation of vascular structures. These results suggest that there are significant ultrastructural differences in vessels between photoaged and intrinsically aged facial skin and that the photodamaged microvascular system is characterized by the co-existence of regressive changes and angiogenesis.

Aged↗

PubMed2001

Antithrombin III inhibits lymphocyte proliferation, immunoglobulin production and mRNA expression of lymphocyte growth factors (IL-2, gamma-IFN and IL-4) in vitro.

BACKGROUND: Antithrombin III (AT-III) is a physiological inhibitor of thrombin and other serine proteases, and has antiinflammatory properties. Thrombin is known to enhance T lymphocyte activation in vitro and serine proteases can act as costimulators for lymphocyte proliferation and cytokine production. We have previously shown that AT-III significantly inhibited allograft rejection in a highly histoincompatible model of rat lung transplantation and in vitro cell proliferation in ConA-stimulated rat spleen cells. In this study, we examined the involvement of cytokine gene expression in the above inhibitory effect of AT-III. We also examined the effect of AT-III on several in vitro immune reactions in human peripheral blood mononuclear cells (PBMCs). METHODS: mRNA expression of cytokines/cytokine receptor important in lymphocyte activation was examined. Rat spleen cells were stimulated with Con-A with/without AT-III and submitted for reverse transcriptase-polymerase chain reaction (RT-PCR). To assess the effect of AT-III on human PBMCs, we examined the effects of AT-III on cell proliferation of human PBMCs stimulated in mixed lymphocyte reaction (MLR) (allogeneic stimulation), with OKT3 (T cell receptor activation) and with PHA (mitogenic stimulation). The effect of AT-III on PWM-stimulated immunoglobulin (Ig) production by human PBMCs was also examined. All experiments for cell proliferation were performed in 10% serum and in serum-free (SF) media to determine whether AT-III exerted its effects through its interaction with thrombin in serum. RESULTS: mRNA expression of IL-2, gamma-IFN and IL-4 in ConA-stimulated rat spleen cells was nearly completely inhibited by AT-III at 15 IU/ml. mRNA levels for IL-6, IL-2R and TGF-beta1 were not significantly affected by AT-III. AT-III showed a dose-dependent inhibition of cell proliferation in human PBMCs. At 15 IU/ml, cell proliferation was inhibited by approximately 86%, approximately 81% and approximately 56% in the MLR-, OKT3- and PHA-stimulated PBMCs, respectively in both serum and SF media. AT-III inhibited PWM-stimulated Ig production in a dose-dependent manner. IgG, IgM and IgA production was reduced by approximately 60%, 80% and 70%, respectively in cultures incubated with 15 IU/ml AT-III. CONCLUSIONS: (1) Inhibition of IL-2, gamma-IFN and IL-4 mRNA expression might be responsible for inhibition of cell proliferation by AT-III in ConA-stimulated rat spleen cells, (2) AT-III inhibits cell proliferation in the MLR-, OKT3- and PHA-stimulated human PBMCs, and Ig production in PWM-stimulated human PBMCs, (3) The immune regulatory effects of AT-III are independent of its interaction with thrombin since similar levels of suppression were seen in SF media, and (4) These results suggest that AT-III has potent inhibitory effects on lymphocyte activation and cytokine production and may have potential applications as an immunomodulatory agent.

Animals↗

PubMed2001

Effect of alpha-tocopherol on hepatocarcinogenesis in transforming growth factor-alpha (TGF-alpha) transgenic mice treated with diethylnitrosamine.

To examine the potentially chemopreventive effects of alpha-tocopherol on hepatocarcinogenesis, we fed the transgenic mice line MT42, which overexpresses transforming growth factor-alpha (TGF-alpha) and which has been established as having a high incidence of liver tumor, with different concentrations of alpha-tocopherol and examined the hepatic tumorigenesis of these mice. At 3 weeks of age, MT42 male mice received a single intraperitoneal injection of diethylnitrosamine (DEN), 5 mg/kg body weight, to initiate the formation of liver tumors. The mice were divided into three groups: group A, control diet (20 mg/kg of alpha-tocopherylacetate); group B, deficient diet (less than 1 mg/kg); group C, supplemented diet (500 mg/kg). Neoplastic change was determined at 40 weeks of age. The incidence of adenomas (p < 0.05), the maximum tumor size (p < 0.01), the mean relative liver weight (p < 0.01), and the proliferating cell nuclear antigen (PCNA) labeling indices of the non-tumor sites (p < 0.01) of group B were significantly higher than those of group C. No toxic effects of alpha-tocopherol were found. Alpha-tocopherol-deficient diet accelerated the hepatocarcinogenesis of TGF-alpha transgenic mice treated with DEN. At best, these data demonstrate that alpha-tocopherol-deficiency is not beneficial for prevention of hepatocarcinogenesis in this model. Alpha-tocopherol may be useful for the chemoprevention for liver cancer.

Alkylating Agents↗

PubMed2001

Immunohistochemical expression of cyclooxygenase-2 in skin cancers.

BACKGROUND: Cyclooxygenase (COX), also known as prostaglandin endoperoxide synthase, catalyses the conversion of arachidonic acid to prostanoids. There are two different isoforms of COX, referred to as COX-1 and COX-2. Overexpression of COX-2 has been demonstrated in various neoplasms, such as experimentally promoted tumors, gastrointestinal cancers and breast tumors. METHODS: In this study, we used immunohistochemistry to investigate COX-2 expression in a series of basal cell epitheliomas (BCE), Bowen's disease, squamous cell carcinomas (SCC) and metastatic tumors of the skin. RESULTS: Four of 16 BCE showed a positive reaction for COX-2 and the adenoid type of BCE was the most strongly positive. In Bowen's disease, the extent of positive staining for COX-2 was even higher than that in BCE. Eleven of 15 SCC showed a positive reaction for COX-2 and the pattern of staining was heterogeneous with more intense staining in the center of the tumor nests. In metastatic tumors, the percentage of COX-2-positive tumor cells and the intensity of their staining was low compared with Bowen's disease and SCC. CONCLUSIONS: These results indicate that the intensity of COX-2 staining and its heterogeneous distribution are related to the degree of cellular differentiation and the various phenotypes of tumor cells, but the extent of COX-2 staining did not correlate with the degree of malignancy.

Adenocarcinoma↗

PubMed2001

Immunohistochemical study of inducible nitric oxide synthase in skin cancers.

BACKGROUND: Nitric oxide (NO) is synthesized from the amino acid L-arginine by NO synthase (NOS). Experimental evidence suggests that increased express of inducible NOS (iNOS), which is an NOS isoform and calcium independent, is related to various pathological processes, such as inflammation and cancer. METHODS: In this study, we used immunohistochemistry to investigate iNOS expression in a series of basal cell carcinomas (BCC), Bowen's disease, squamous cell carcinomas (SCC), extramammary Paget's disease (EPD) and metastatic tumors of the skin. RESULTS: Only 1 of 16 BCC cases was positive for iNOS and the intensity of staining was weak. In most of the 10 cases of Bowen's disease, iNOS was weakly expressed and there was a wide range in the percentage of positive tumor cells. Twelve of the 16 cases of SCC were positive for iNOS and the extent of positivity was greater than in Bowen's disease. Two of the 7 cases of EPD were positive for iNOS, and 12 of the 15 cases of metastatic cancer were positive. Well-differentiated adenocarcinomas were diffusely positive, whereas poorly-differentiated ones showed strong and heterogeneous staining. CONCLUSIONS: These results indicated that the expression of iNOS may reflect the proliferation of tumor cells and that a heterogeneous distribution of iNOS may correlate with a wide variety of biological behavior of tumor cells.

Adenocarcinoma↗

PubMed2001

Expression of neuropeptide-degrading enzymes in alopecia areata: an immunohistochemical study.

BACKGROUND: Much clinical evidence suggests that the nervous system, including psychological factors, can influence the course of alopecia areata (AA). However, there has been little substantial evidence of specific participation of cutaneous neurogenic factors in the disease process. OBJECTIVES: As previous studies have demonstrated that stress elicits the release of the neuropeptide substance P (SP) from peripheral nerves and that some patients with AA show prominent SP expression in nerves surrounding their hair follicles, we aimed to evaluate the role of SP in AA. METHODS: We used immunohistochemistry to examine the expression of SP and SP-degrading enzymes in scalp biopsies from patients with AA and from healthy controls. RESULTS: Affected hair follicles in the centre of the areas of hair loss of patients with AA were richly innervated by SP-staining nerve fibres. Strong expression of the SP-degrading enzyme, neutral endopeptidase (NEP), was observed in hair follicles not only in the acute progressive phase of AA but also in the chronic stable phase. Expression of NEP in hair follicles from the margins of areas of hair loss was stronger than in normal controls, but was weaker than in the centre of the areas of hair loss. In addition, endothelial immunoreactivity for angiotensin-converting enzyme (also capable of degrading SP) was not observed in the centre of the areas of hair loss, which was in significant contrast to normal controls as well as to the margins of areas of hair loss where it was expressed. Further, intense expression of endothelial leucocyte adhesion molecule-1 on vessels and many degranulating mast cells was observed adjacent to affected hair follicles in AA, in admixture with dense lymphocytic inflammation. CONCLUSIONS: These findings suggest that SP is endogenously released by dermal nerve fibres around hair follicles and that it may play an important part in epithelial-mesenchymal-neuroectodermal interactions in AA. This study reveals that SP and its degrading enzymes are involved in the pathogenesis of AA, which in turn might explain the pathological significance of neurogenic and psychogenic aspects in the disease process.

Adult↗